HomeMy WebLinkAbout1993-01-19 Public hearing
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NOTICE OF PUBLIC HEARING
NOlicols hereby givon Ihat a public hearing will bo held by
tho City Council of Iowa City, Iowa, at 7:30 P.M, on the 19th
day of January 1993, In Ihe Civic Canter Council Chambers,
Iowa Chy, Iowa; al which hearing Iho Council will consider the
following hem:
1. Adopting the 1991 Edhion of Ihe Unllorm Plumbing
Codo as amended,
Copies of the proposod ordinance are on file for public
oxamination In the office ollhe Chy Clerk, Civic Center, Iowa
City, Iowa, Persons wishing 10 make their vlows known for
Council consldoralion are encouraged 10 appoar allho ebove.
mentioned lime and place,
MARIAN K, KARR, CITY CLERK
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City of Iowa City
MEMORANDUM
Date: January 13, 1993
To: Honorable Mayor Darrel G, Courtney and Members of the City Council
From: Bernard Osvald, Building Inspection
Re: 1991 Uniform Plumbing Code
Following Is a summary of the major changes from the previous plumbing code:
1. Sections 401 (a) and 503(a) limit plastic DWV (drain, waste and vent) Installation to
structures having three or fewer stories. The previous limitation to the Installation of
plastic pipe was to combustible construction (four stories).
2, Section 1003A - provisions for cross connection control and containment. This section
Is being enacted to comply with Iowa Stale regulations which mandate that cllles of
15,000 population or greater shall enact a backflow prevention program with containment
by January 1, 1996, These regulations are being Instituted to ensure that the public water
system Is not contaminated by a customer's water system,
I will be In attendance at your work session to answer any questions you may have regarding the
updated plumbing code.
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XC slow to enforce
fouled-water law,
state officials say
I
iIlustJates what can go wrong ,
when backfiow check valves' ;
malfunction. ,The devkes keep I':
rontaminantsfrom' backing up
, into drinking water supplies.
Contaminanls backflow or
siphon into the water supply when
water pressure goes down and
water flow reverses, Water pres-
One autumn day four years ago. sure went down al the school
students and faculty at the Joe because the water supply had b~n
Herndon Area Vocational T echni. shut off wbile' a water line was
caJ ~d1001 bad to 'have their, being inslalled nearby. " , '
stomachs ~aned out. ' ,.' Raytown learned its lesson I
Sometbmg had gone ~rong wltli wben'two backtlow valves at the ,
. I the plumbing; and toxk anti-rust Herndon, ctlltef, 'got ',~i~y and ]
i ) ~i:a~ froiJ:l..lbe boiler ~ped jamm~. Nobody, ~Ild, t.ested. tb~;' :
: .. lOW :..the ' watcr~ supply, ~I' the, valves'ln years, -saId Jim :Games,, '
.' RaYlowliscbooi.c,. ': ' :"~"'j ,," diiectoroftbeschDDI:,~t:i :~':;, :"
i! Evcryon~ who tooi'-ii'.tirlnk hail' Officiais fear. tbar even biw:r
j; to gO to the hospital for hearing, problems,:. ,await. Ka_, City.
,. blood aDd urine 'tests. They also Whileotberc:iticsin the,stme~
~: bad to drink a gooey; pink syrup an dJicienl backflow prevention
thut made them lbrow up. In large program, KanSas City's is slow
~ i doses, tbe atlti.niSt., chemical ,and inconsistent, they'said;!; .\
,: \ could have ~used hearing 11m, "Its wbDle altitude is that il will
- 'and kidney and liver damage. wllit'imtil sometJiing big happens.
~ The incident, ~t' ,the', school' '", -' Sea Crrv;B-IfCoI.1,
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~ty is suppos-:d ~o
" ensure use of devices..
i that prevent backfl~w.
By AMRITA KANG
S\I" Writer
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8-6
Tuesdal', Dcc~mber f, 1~2
The ~Cill' S\8r
Metropolitan
City is slow to prevent waterbackflow, offi
ofbad:nollld~iccs. businesses on Ihe cill"s Ii&! of lIlld dan'l Bi\(
TIllII )'lm", Kansas Citl"s Wllter 23/)1)0 putcntialt)' hwro.ous "Custom.,.lhould ba ioJlallatioo.
and lbCll it will do somelhil\8." and PoUulilln Conllnl De9an- commmiaJ Cll5lomers, ICI slone aware of the problems that MCuSlomclS
said Micbael Loptan, envjron. ment Ilgmd 10 comply with the luivelbede\it~in!laI~. comaupwhend&vicesare the problem I
mental engineer 31 Ihe Miii1lllTi slale provision and adOPled a Logston sald Ibe city's list put into p1aoo." ckvim are
Nlltul3t&W1!ICCSDtpJlrtIllCDI. backllow prevention program im:ludC50J11ycommercialClliWm- T3lJI1ey51lid.
KaIl5llS 01)' is tolJrtillg a Wnilarloll1cslale's, CIS, Tn.. (is! deem'l deal wilb - BiJ/TarpJey Many cities
IaI\'Suil if d~dl)' conlaUJill2llls Aaording to Mi~llri !.all" polmliaJ hnMds in fm: SIIPllrtS' Miml\lri, incl
SfC)I inlo iu wateUIlPpll', LOililon watcr SlIpplicrs - 5Ill:n as tne sian systems aT meotW lawll J'mi;, Springli
saiL1, cily's tIIlIler dCjlmmcnl - mull sprinkler /i)\'lcms. he said. Dr 11Jll', city donn'l nlllif)' all of ilS pClIdence, SI.
That is not ill\PDWb\c, Cllcmi. lccp records or 1111 cu5lOmcr C\'t'll bOltlCGWJlelS milS! lit 110- hiBh-hazard CilSlomm at one LoI1is, arc II
cali from tloilClS, monuarics, bac1floll/l)'.IIClW. They also mu~ lilillll. liRlt,asS'llltc8llidelincsSl/Wll bae~flow pre
b81te1y lllalluflt:llll'ClSlInd KIVagt notifl' CUJ100nrn wilh poICfItill Jolin E. B1lll15, OWIIcr and Cunomrn often dDII't compll' l.Qpton said. St
,; u-eatmenl p\Ilnls el\1U tne water huanls Ihat lhe proper batlcnaw rraiocr at Comct F11lW, a back. with blllldIlI\\' regulaliDII, Logi!on pqmm ind
'I sfSImI'Cvery day. And b1ck/low devices mll5l be: iJmaIlcd, IInd DIWI JIltl'Clllion traioill1\ btJimm Sllid, becall5e Olbm in ibcir SIalc'sror2S
Q dt~ices arc lim:ly ilW2llt'd or nolify CIlSlOJ1\l:lS earn year thDl in S;Jrill8lield, 5CBlllICllCr to the indllStries mren'l notiflCd amI Pm'atc utiliti
- checked. devja:~ mUil be Inled aud rcIlnill Kansas City water depanmCDI in arm'lin tOllI]llill1la:. bave implemen
:; K!ma1 Cil)' water lk:paJ\Jntn1 aflerfIVC)'Wl. Aujusl, l1IJli!l& il 10 improve ils HiglJ./Iazard ClIS1OD1Illi intlude pmgtIl/IIlIlmD\l.!
- officials declined to fl:Jpcmd to Tlu:lawsaysili.slbecalnomcr.;' pr~m. auto and melal induslrics, 10D said. St. I
::; LogitoD's COlI1IIICntI. A dcpal1~ mpcmsibility to inSlalI and main. BoD~' kiter said lhal only arwahes, sewage IrcIlmelll approach.
r ment 5lIoltcsmao said Ibe eit)' lllin tbcir ,ysuru IlId bave lhcm aboul 700 of Kmw Cily's tIIlIlcr p!mu, IlmjJitab lIld clinics, . Th~ a pIiVll
-lllloulildiKutstbcsiluatiDII~9 clJcdcdbyceniiit'dtcslcn. C:UPODIcnhavebac1dlOWJY.itms. aU10JlJY rooms ami monuatics, n ~ W
-: 81 a hearing bef~ tbe Cil)' KansasCilyl1lJCIIfon:cdaaodc If ibe clly bad romp1ie4 wilh itl Bullbme affected b)' tht: law also pcl'SOlI In dI1i
:: Co1lllcil's Opemions and Avia. lb.alrtquimbatldlowsystellllin pl'OB/1ImthewayitKtOllltodoin inrlBde hOOleO\\1lm wilb Iawn,1b~pllI1OlIm
I liDIIOlmmitUe, ncw IlOJIttmaion, losilOD said, 1987, il would ha..-e had 40,00!I SjIIiuklersyUcna de~1CU Ind 3m
, Bullllc cily ha n01 ~tliwdy CllStOlllC!3in comp!iaoccby nDW. BiRTarpleJ',lIlliningdim:lorll! CUilODlCl\.'
j Codes and customers implemtnted a JlI1lu.IIm for CJliU. &01$ C5timaltd in the ItllCr Ihc P1l1mbcrs& Pipeliltm Train- St Joseph. QI
-- T"c ]R74 fed....] Safe Dlinkin. ill1\SJ'lems,hesaid. , lhalloo,oOO back/low d~iceun: ing Center in Katwls CiIY, saKI noI compIywlth I
U T wa.... needed in the K1111'IBs Cily 5CJVice ,L ' y' -Ii' I lire lem BJIlIthcr
-r" Waitt Att requires s!alel aud IAlplon al~ criliciz<d KaulaS .111m we ell S noo 112110n CIlm -. 120 da)'$
-::1 waler ..-liers to JlIOICCl d,ink. ut), for il5 siD\\' l1otilicWon lI41ea they 10 0111 _ lack M1tial l:I~n .
- -- informalion. thci""llel'I5 ~u
.... ing SUwTlCS from blCkOo\\' coo. JIIOllC'i. In May I "2, the city 1arpley, wIIo also works lYith WalC' ~ntneL
T' tamiml5, lqIn ~dinJl Icnm tD JSO L 'I.. Cd dJine f"-. 1INlI.
":"1 A 1987 Mis$cnui IlIw 'cq~i~ commercial customers euh mar. () eo . the Mc:tbanical ConllllClm'l MID- Lu.IIIJ' ~s ,__
- w"ICi JIIpjJlim to protel:l &pinu mOIItb. ' Logston al10 crilicized ~nsas cilltio.n, said !be leum don't lawn spnnlder,
contamination witl1 B prevemion At lbal mlc.lopIon said, it wm Citl' fur the mndOlJJ 'YJ)' II ha~ CJlplllln thaI ,ba~lctlov.' sy&lCms Gnmr,
:T~ progQlllthat indudcsannlJllltell.! tal<<: mort tban 10 yurs to notify nOlirled bUJillWtl. lie uid Ib~ mllS\ be remltll Brier five )'all ~lJCr.
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ent waterbacldlow, officials say
llJllI dmn't give a deadline for Whim the Jobnson Counly
iullallation. diilriCl began us baddlow prmn-
uCunom~1S shOllld be aware of tion progl'ilffi, itlaunthed a public
the problemi that come up whl.-n ednt3tion campaign to inform ils
devices ate pm into plm," cullomm about wiult backflow is
1arpleysaid. and tbe lwardsit can cawe,
Many clues in Kansas mnd 1m wmllaigo CUCO~ lar-
Mimlllri, includill~ Overland gMelIle volnnlar)' complianc:e.
Park, Spril1gficld, JDjIlin. Inde- Grover said, Mon: than 2.90D
city dDWI'1 nDlif)' all Dr il5 ptnl!cmce, 51, Jmcph and 51. cuslomm wilb lawn sprinkler
high-llazard cullCmletS al on~ Lollis, an: opcllltiog tffiti~t sYJilcmsOOlllPlied,heSJIid.
limr,8liSllllesmddinesw,wsL bal1RO\l' prevt:lltion programs, In R1}'1own, the eilY's waler
CoS1Oll1m often dllD't compll' U1v1oll said. St. Louil. has had a 5Upp1~ aad th~ Raytown SdloM
witt. blIckf1l1W regulaliOll. LogiIon program indCjlllDiIcJIl or Ihe DiuriCl have s1~ up pm,wre
wil, bctal\!e olbm in their 5IlIt~'5for2S}'Wl.be&llid, Oll9d!llO!stoprevelltatcidtl11S.
indllS1ries weren't nolirtcd and Pm'ate utilities in UIIIIC cities "We Bit the walefl.mlle," 5IIid
llrCII'linL'OlllJllilmcc. bave imp\enu:ntell a backnoll' Bud Fillll\lllcr, diSlrii:lll1llllll8cral
liigh-hazard CUilOlllIlB incl~dc pItl{!l1llIl ,1mDS! ovcrnight, Log~ Public Water Supply Dj~lriel~ !'lo.
auIo and metal induslric~. 10D said. St, JOStPh 10Ilk lhlll 2 in Ravtown. '
...J. "We' don'l ha' ve ., hr" a
C8rw,uhes. sewage tleatmtlll 'PII'O""", ow ....
plmU, ~l~ and clinie<;, . Th~, a prlvat~ Ulilil)', Mmou- problem as KmIw CiIY, bul WI:
au10lIsy room~ muI mmtuatlei, n AmCflCl1l Water Co., has GlIC 11ft re5JlIlllUblc for hawds,!' he
BuIIbDIIC lIlTllCIed bf the law also pcrsoD in clt&Q:I:. of b.I,clcnllW. said. "We lire lhe: lilSl mod larI
include hllll\COll1lCll with laM!' lbll)pmoDmntslOijlCdUIMOlI linc."
5lfIiuklcr~yJICJ1U. deVICG and smds letterS D'~t to 1\1I)', BllII, ~ lIlDIlIIDI BII SiID4o,p .
Bin Tacple}'. traininJldirCl:loral CUItolllm..' 'IUI), Star QuIIItDd AU. To ~,..
the Plumbm& Pipdilltn lnUn- St, Joseph. CU9lo~~~ who do &Cb1lJa'~II~-Adl-.
i~ Cenw in KallSllS CiIY, $lid nolClOlltlllYwllntllelllnlllln:qnciI
the cily's nDliflwion Icum _ a~ iClIl anotha' leUer ~d lbell
IWIcn lbey ~ 0111 _ lack C'Mial El~n rID ~!)'$ to compIl before
informauon. theirwaleru~loll'.
L..~1. of deadline Tarplcy, "mo aim walks wilb Watel !,>nlRtl N!l- I ofJ.~
'...... the Mctbanical ColltraclOTl AnD- COUOl)' !I regulatuJg re5!Dmrial
loptou alsn crilitiml Kallllll cilltion, said tlrc Jenm dOll'! tal'lll SjlnllldCl' If~, SIIid OlIn
Cill' for the mndOlll 'VllY il hili explain lhal bacld1ov.' 1iY&\Cms Gl'O\'tr, troI6--OQnncdlO/\ wnuol
MImed bUlinesm, He said Ib~ mUSl be rchllilt nrler live yelll matllJCr.
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businesses on lIle cill"s list of
23.'100 putentiall)' bl\1llrdous
commercial tllSlomers, It I alone
hllve lbedevU:~inllaned,
Logston said lbc cily's list
inclllda 0JI1r ClImmertial ClIIWm-
CIS, Tile lisl dOCiR'1 deal witb
poItnli!l baurds in fll'C SIIpprCi'
stun ~s or mcntiallawR
spJinlderiY'ltDli. he said_ 0,.111\I',
e\'Cll bDl1lCGWllm mull ~ Jll)-
liffed.
Jolin E. BolllS, OWIltl 3lld
lfaiuer III Comel Flow, a back-
fIl)W pltl'Cltlion traini~ buiio~
in S;lriRBlield, scal ~ leller 10 the
KIlII511S City water dtplnro~1 in
Aujusl. ~1Il: il to illljlll)\lc ils
progam. '
BoDU' h:ucr said tlllll only
aIJoul 700 of t;,nw; City's WI1~
t\lnoJIIcn have batkIJow JYltemS.
If lIle city bad romplWl with itt
pl'lijnlmlhewayit sel OUI to do in
1987. il WlI1IId bal'C had 40.000
CIl1itOlllm in COlOp\iaqCC by now.
Boots erlil1l!tfd in the lener
that 100,000 bac:KIIow dC\'icci JlIt
IIfCIIcd in the KlIllBS City scJVil.'t
JlIea
"CustommllMnlkl be
lIWare 01 the problems that
come up when d8Vices are
pul inlo place,"
- BiJ1TarpJey
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"The Complete Concept
in Cross Connection Contror
I,' , The Watts devices U1ustratcd below give you tho widest choice 01
products to meet 011 degrees of hazards for protecting the potoble
water supply distribution system. Write lor Catalog C.BPD.
::::::..-....... Y 1''r.'
ComplieswithA.S,S.E,Standardl011 B ' " '. . '
No. NF8,
For frost-proof hydrants. NF8:;,~ .
.
No. 90
BackflowPreventer
with Intermediate Atmospheric Vent
Sizes1/2",3M"
Complies with A.5,S.E. Standard 1012
7 Series
Dual Check Backflow Preventer
for Residential Supply Service
or Indillldual Outlets.
Meets A,S,S,E, Standard 1024
(=:
No. NLF9 . N9
Double Check Valllo Type with Atmospheric Vent
Specially mildo for laboratory faucets but can be
furnlshad with 1/4" or 3/8" pipe sizes,
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288A Series
Antl-5iphon Vacuum Breakers
Slzos 1/4" Ihrough 3"
Complies with A,S.S,E, Standard 1001
No. N3BB Series Sizes 1/4", 3/e"
800 Series
Antl-Siphon Pressure Type Vacuum Breaker
Sizes 1/2" Ihrouoh 2"
Complies wl'h A,S,S,E, Standard 1020
No,BOOM2 SilOS '12". 1"
No, BOOM Series 'h", '14"
709/007 Series
Ooublo Chock Volvo Assombly
709 Sizes W', 10/007 \\", 2"
Compllos wllh A,S,S.E,
Slandard 1015
NO.70900C/909RPOA
Double Detector Check Vallie
Assembly with water meter
and double chock In by-pass
line, SilOS 3" through 10",
Complies with A,S,S,E,
Standard 1016
909/009 Series
Reduced Pressuro Zone
BackllewPrcvenlor ~'\I.
909 Sizes 'A", 10" ''<(10
009 Sizes 'n",3"
Complios with A,S,S,E,
Stand>rd 1013 and fCCCHR 01 USC
F.BPG.7
Prlnlod In U,S,A,
World Clm V.I,os F,BPG- 7
~IWATrS.
. REGULATOR
_Sfncel874
BACKFLOW
PREVENTION
GU!DE
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--,,'...,.. 'd.',"" or .protectlOno",..,
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i;:if,;IH ECPOT ABLFWATER3SUp'pLv.:
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This "guide" is offered to simplify the
selection of back flow preventive devices and
to ensure that the most suitable device is
applied to protect cross connections based
on the degree of hazard and the comparative
cost.
Degree of hazard is determined by whether
the substance in the non,potable system is
"toxic" (treated boiler water etc,1 or "non.
toxic" (sugar, soda pop etc,). Since this
"degree of hazard" subject is often a matter
of code interpretation, we offer this data
as a helpful guide and suggest you consult
your code authoritv, However, it is based
on a consensus of plumbing and health
codes surveved throughout the country, and
we hope it will be useful as a condensation
of this very broad subject.
Watts has the most extensive choice of pro.
ducts to provide you with alternate choices
to meet a specific condition, Wo also have
conveniently located sales engineering offices
throughout the country, who are available
to assist you in cross connection control
programs and educational meetings, Thus
you can depend on both the Watts line
and the Watts organization,
'"Yf!1I! North Andov,r,MA 01845 U,S,A,
()~tllII5 *llVlJ ~/1ladtllJ/'tjJ Stilet /!14
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INSTALLATION
INSTALLATION
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'W!.~/.',t_\:,:",.,'"..,\:.:;..
'mOM,MENDED
0',: pDofiU'Cis' 'i
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Air Compressors , , , , , . , . _ ,
. Air Conditioning , , , , , . , . _ ,
. Air Conditioned Chillwater . _ , _
. Air Conditioned Condenser Water
. Air Conditioned Cooling Towers,
Air Washers , , , , , , , , , , . _ ,
Aspirator, Medical , , , . , . , , "
Aspirator, Weedicide and Root "
Feeders , , , , , , , , , , , _ , ':
Autoclave & Sterilizer, , , , , , " '
Autopsy Tables, , , , , _ , , , , , '
Baptismal Fount . , , , , , _ , , ,
Bathtub Below Rim Filler , , , ,
tBedpan Washer, Flushing Rim ".'
Beverage Dispensing Machines , , '
Bidet, , , , , , , , , , , , , , , , . '.,
Boiler, Industrial Feed Line ",:.
Boiler, Residential Feed Line, , ,:
Brine Tank, , , , . , , - , , , , , 'i
tBottle Washer , , , , , , , , , , , , ,
Carbonated Beverage ; ,
Vending Machine , , , , , , , ," 9BD
. Chemical Feeder Tanks , , , , " 909, 009;
Chiller Tanks , , , , , , , , , , " 9D '
Chlorinator, , , , . , , , , , , , , . 9D
Coffee Urn """",,'., 288A, N388
Cooking Kettles, , , , . , , , , " 288A. 11388
Condensate Tank, , , , , , , , " Air Gap
Cuspidor, Dental , , , , , , , , , .' . '288A, .N388
t Dairy Equipment , , , , , , , , , "., 2BBAorBOO.
. Degreasing Equipment, , , , , , ';, 909, 009 '
tDetergent Dispenser "",." :2BBA or BOO
t' Developing Tanks, Photo , , , , " 2BBA or BOO
Digesters, Hospital , , , , . , , , , 909, 009' .
tDishwasher, , , , , " , , , , , ,.: 2BBAorBOO,
Drinking Fountain , , , , , , . '-: Air Gap
. Dye Vats & Tanks, , , , , , , , ,:. 909, 009 '
Etching Tanks, , , , , , , , , , , " 909,009.
Fountain, Livestock Drinking, , '. 9D
Fountain Ornamental" , , , , , '; 709, 007
Garbage Cnn Washer , , , , , , , ,', '9D
Garbnge Disposers " , , . , , , .; ;2BBA,,'
Hose Fnucets , , , , , , , , , , , " B orNFB
,
Humidifier Tank & Boxes , , , , " 2BBA
Hydro,Thernpy Baths, . , , , , , .; . 288A"N388'
Air Gap ,....,
909,.009
909, 009
909, 009
909, 009
. Air Gap
288A, N388
i ~, .. ' . ", ': ;
tlrrigation System, , , , , , , , . , 1'909,BOO,009:
Janitor Closets '""."". r B" . .
Laundry Machine, Hospital. , , , i 909,009,,'
Lavatory. , , , , . , , . , , , . , , : Air Gap ,..,',. ,
t Lawn Sprinkler , , , , , , , , , , , .2BB~,709,~00/1
Lawn Sprinkler, Chemical Injection : 909,009 '.':' ",(
Main Line , . , , , , , , , , , , , . ! 909, 009 .,' ,: i
Make-up Tank, , , , , , , , , , , _ !9D:
Marina, Boat Connections, . , , , i: B,7:3/8:: ,
Mobile Homes . . . . . . . . . . . . :'" 7 . ""
Pipette Washer , , , , , , , , , , . :,2BBA,:
Phoio Lab Sinks , . , , , , , , , , : 2BBA ';"
Potato Peeler, , , . , , , , , , , ,IAir,Gap
'Processing Tanks, , , . , , , . , , (909, 009"
Pump, Prime Lines. , , , . , , , , !9D
Pump, Water Oper Eject. , , , , , ,9D ,
\. .,'.:' "'.
. Re,circulated Water, , , , , , , , , '909,009
Residential Supplv Service , . , , , 1:,7.,
Reclaim Pit , , , , , , , , . . , , , :2BBA
Serrated Faucets , . , . , , , , , , ::NLf.9'
Sewer Flushing Manhole, , , . , ,2BBA, ,
Shampoo Basin Hose Rinse. , , , : 2BBA orN~
Sinks, Wash-up , , " . , , , , . _ (,Air Gap'
Sitz Bath, . _ , , , . , , , , , , , , : 2BBA '
Sizing Vats & Boxes, , , , , , , , :~09, 007 . ,.'
Soap Mixing Tank ,_ , , , , , , . '2.BBA .
'Solution Tanks, , , , , , , , , , , ;909,009,;:.
Sprinkler System, Fire Protection, :7090DC/909AP.DA)
Starch Tanks, , , '. , , , , , , , !'709,007 '.
Steam Cleaner Connection , , , _ ::S
Steam Table, , , , , , . , . , , , , ; 288A, N388
tStills , , , , , , , . , , , , , , , , , ; 2BBA or BOO
Swimming, Pool, Commercial, , , '709, 007
Telephone, Showers , , , , . , , ,ss '.
Trap Primer , , , . , , , . , , , . , :, 9D .'
Ultrasonic Cleaner , , , , , , . , , ;, 2BBA
Urinal, Trough """,.". ; 9D
Wall Hydrants, , . , , . , . , , . , : B or NFB ,
Wall Hydrants, Frost Free " , , : NFB
Water Treatment Tanks , , , , , , : 709, 007
Water Well Secondary System ., 909,009
'Seleclion is besed on equipment using
loxic ch,micels, If chemlc,lls non'loxic,
seleclion could b, 0, C, V, Assembly,
t 800 S,ries Pressur, Vacuum Bre,k,r 10
b, used wher, continuous pressure is
encountered,
BSeries\.
2BSA
, 2BSA
9D
9D "
'2BBA or BOO.
9BD "
, 288A, N388 '"
909,009' '.
9D,911, '.'..'
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Cross'Co~nection .4;.
Questions,
Answers,
a Illustrations
Relating To
Backflow Prevention Products
and
Protection of
Safe Drinking Water Supply
Prepared by
World Class V./,os
_Slneo 1874
~WATrS@
REGULATOR
DACKFLOW pnEVENTlON DIVISION
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1 What Is back-siphonage?
Back-siphonage Is the reversal of normal flow In a system ('I
caused by a negallve pressure (vacuum or partial vacuum) In ,
the supply piping, ,
I
2 What factors can cause back.slphonage?
Back-siphonage can be created when there Is stoppage of the
water supply due to nearby flre-flghllng, repairs or breaks In
city main, elc, The effect Is similar to the sipping of an Ice
cream soda by Inhaling through a straw, which Induces a flow
In the opposite dlrectl(,n,
3 What Is backpressure backflow?
Backpressure backflow Is the reversal of normal flow In a
system due to an Increase In the downstream pressure
above that of the supply pressure,
4 What factors can cause a back pressure.backflow condlllon? SUPPlY FEEDVA.lVE
Y
Back pressure-backllow Is created whenever the downstream - c::J
pressure exceeds the supply pressure which Is possible In (~'"
Installallons such as heating systems, elevated tanks, and l "
pressure-producing systems, An example would be a hot water ...~~~
space-healing boiler operallng under 15-20 Ibs, pressure flETUIlN- BOilER
coincidental with a reducllon of the city water supply below
such pressure (or higher In most commercial boilers), As water
tends to flow In the dlrecllon of least resistance, a back-
I pressure-backflow condition would be created and the
contaminated boiler water would flow Into the potable water
supply,
5 What Is a cross connecllon? ~
A cross connection Is a direct arrangement of a piping line
which allows the potable water supply to be connected to a
line which contains a contaminant. An example Is the common
garden hose attached to a sill cock with the end of the hose
lying In a cesspool. Other examples are a garden hose
attached to a service sink with the end of the hose submerged
In a tub full of detergent, supply lines connected to bottom-fed
tanks, supply lines to boilers,
6 What Is the most common form of a cross connecllon?
Ironically, the ordinary garden hose Is the most common
offender as It can be easily connected to the potable water
supply and used for a variety of potentially dangerous
appllcallons,
2 17~
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7 What Is potentially dangerous about an unprotected sill cock?
The purpose of a sill cock Is to permit easy attachment of a
hose for outside watering purposes, However, a garden hose
can be extremely hazardous because they are left submerged
In swimming pools, lay In elevated locations (above the sill
cock) watering shrubs, chemical sprayers are attached to
hoses for weed-killing, etc,; and hoses are often left laying on
the ground which may be contaminated with ferllllzer, cess-
pools, and garden chemicals,
: ,
8 What protecllon Is required for sill cocks?
A hose bibb vacuum breaker should be Installed on every sill
cock to isolate garden hose appllcallons thus protecllng the
potable water supply from contamlnallon,
"
to:
,
9 Should a hose bibb vacuum breaker be used on frost-free
hydrants?
Definitely, providing the device Is equipped with means to
permit the line to drain after the hydrant is shut-off. A "remov-
able" type hose bibb vacuum breaker could allow the hydrant
to be drained, but the possibility exists that users might fall to
remove It for draining purposes, thus defeallng the benefit of
the frost-proof hydrant feature, lithe device Is of the
"Non-Removable" type, be sure It Is equipped with means to
drain the line to prevent winter freezing,
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1 0 Can an atmospheric type, an II-siphon vacuum breaker be
Installed on a hose bibb?
Theorellcally yes, but pracllcally no, An anll-slphon vacuum
breaker must be elevated above the sill cock to operate
properly, This would require elevated piping up to the vacuum
breaker and down to the sill cock and Is normally not a feasible
Installallon, On the other hand, a hose bibb vacuum breaker
can be attached dlreclly to the sill cock, without plumbing
Changes and at minor cost.
11
What Is an atmospheric type vacuum breaker?
The most commonly used atmospheric type anti-siphon
vacuum breakers Incorporate an atmospheric vent In
comblnallon wllh a check valve, lis operallon depends on a
supply of potable water to seal off the atmospheric vent,
admitting the water to downstream equipment. If a negallve
pressure develops In the supply line, the loss of pressure
permits the check valve to drop sealing the orifice while at the
same lime the vent opens admltllng air to the system to break
the vacuum,
-0 ./
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HOSE BIBB VACUUM BREAKER
No,S
1_.'
HOSE BIBB VACUUM BREAKER
FOR FROST-PROOF HYORANTS
No, NFB
ATMOSPHERIC VACUUM BREAKER
No,2SBA
3
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12 Will an antl.slphon vacuum breaker protect against a backpressure
backllow condition?
Absolutely not! If there Is an Increase In the downstream
pressure over that of the supply pressure, the check valve
would tend to "modulate" thus permlltlng the backflow of
Contaminated water to pass through the oritlce Into the
potable water supply line,
13 Can an atmospheric type vacuum breaker be used on lawn-
sprinkler systems?
Yes, If these are properly Installed, they will protect the
potable water supply, The device shall be Installed 6"
above the highest sprinkler head and shall have no
control valves located downstream from the device,
14 Can an atmospheric type vacuum breaker be used under
continuous pressure?
No! Codes do not permit this as the device could become
"frozen", and not function under an emergency condition,
15
Can a pressure vacuum breaker be used on a multi.
zone lawn sprinkler system?
Yes, This type of vacuum breaker can be used under
continuous pressure, Therefore, it properly Installed,
It will proteclthe potable water supply, The device
shatl be Installed 12" above the highest sprinkler head,
I
1 6 What Is continuous pressure?
This Is a term applied to an Installation In which the pressure
Is being supplied continuously to a backflow preventive device
for pPrlods over 12 hours at a time, Laboratory faucet equip-
ment, for example, Is entirely suitable for a non-pressure,
atmospheric type anti-siphon vacuum breaker because the
supply Is periodically being turned on and shut off. A vacuum
breaker should never be subjected to continuous pressure
unless it Is of the continuous pressure type and clearly Identl.
fled for this service.
1 7 Are check valves approved lor use on boiler feed lines?
Most Jurisdictions require backllow protection on all boiler
feed lines, Some will ellow a backflow preventer with
Intermediate vent as minimum protection for residential
boilers, A reduced pressure backllow preventer is generally
required on commercial and compound boilers,
4
('~r;,l
SINGLE ZONE SYSTEM
,
DripValvoallowPoinl
inSYSlom
PlOssure vacuum broakor (Ell
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.... Sprinkler head!
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Dnp O"O!j",-",
OllowOSIPoinl
ZonoShUl-oIlVafvo- \
ZonoConlrolValvo
MUL TI.ZONE SYSTEM
SUPPLY
NO 90
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w/:C::\,WJ,iL' ~2q;:': ,'I~l:'/:;: : ~~D ,..'~ .'; :':::, ,: ,::'-',>; \::":';, ,{:\:::
,~ However, low cost, continuous pressure backflow preventers
are now available which will perform with maximum
protection; thus check valves are not recommended.
'.
i
!
18 What Is the difference between potlutlon and contamination?
Pollution of the water supply does not constitute an actual
health hazard, although the quality of the water Is Impaired
with respect to taste, odor or utility, Contamination of the
water supply, however, does constitute an actual health
hazard; the consumer being SUbjected to potentially lethal
water borne disease or Illness,
,
,
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1 9 What recent case would reflect users being exposed to
"pollution" of the water supply?
Pollution can sometimes beamusing, In December of 1970 in a
winery In Cincinnati, Ohio the water supply valve was
Inadvertently left open after lIushlng out wine-distilling tanks,
The result was that during a subsequent fermenting process,
sparkling Burgundy back flowed from the vats Into the city
main and out of the kitchen faucets of nearby homeowners,
This typical reversal of flow in water supply piping caused by
the distilling tanks operating at a pressure higher than the city
water supply did Impair the condition of the water but did not
make It dangerous, Indeed, many thought It was the best water
they ever tasted,
2 0 Whet recenl case would reflect users being exposed to
"contamination" of the water supply?
In May 19691n a Pennsylvania college, the air conditioning
system which contains dangerous chromates became blocked
preventing circulation of the coolant In an attempt to unblock
the pipe line, a maintenance man Inserted a hose In the pipe
and attempted to dislodge the blockage by water pressure, A
reversal of flow developed, allowing the chemicals in the air
conditioning line to backflow through the hose and into the
potable water supply, Unknowing students in other parts of
the building subsequently drank what was thought to be
potable water, resulting In Illness to 23 persons,
21
Are there any other records of recent cases Involving unpro-
tected cross connections?
The startling fact Is that cross connections are increasing at
the estimated rate of 100,000 per day and there are frequently
documented cases Involving reverse flow,
22 What recently reported cases occurred In a plant?
\J In addition to the case described In "No, 19", there are addi-
tional reports but because of the possibility of litigation for
these pending cases, Information Is difficult to obtain. However,
fEAlAENTlNG'~NK
SPARl<llNOWINE
ATIOOPSIPAESSURE
I!ACK PRESSURE BACKFlOW
;PAEVINTERREOUIRED
IN THIS LINE
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a3 0 WATERSUPP\.Y
YALVH7 VALVE 18 I zltNETOmTERS
IFQflWASHINGt
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In 1972 In San Francisco, an Industrial plant had a
submerged water Inlet supplying a lye vat. Immediately
adjacent to this Installation was the employee's shower room,
Officials fortunately discovered the cross connection, but were
alarmed that employees could potentially be bathing In water
contaminated with lye from the vats,
2 3 What recent case IVas reported Involving a school?
Most people are familiar with the details of the Holy Cross
Football Teams' "hepatitis" Incident, which was later
determined to be caused by a backllow of contaminated water,
II took close to nine months for officials to determine that a
severe fire In nearby Worcester lowered the pressure In the
football field area to the pOint where a back pressure backflow
condition was created allOWing contaminants from a sunken
hose bibb pit to back flow Into the field house drinking bubbler,
24 What recent case was reported Involving a commercial bldg,?
Much to the surprise of the customers of a bank In Atlanta,
Georgia they saw yellow water flowing from drinking fountains
and green Ice roiling out of cafeteria dispensing machines,
It was later reported that a pump, used for the air conditioning
system, burned out; and a maintenance man, unaware of the
danger, connected the system to another pump used for
potable water. The result caused large doses of bichromate
of soda to be forced Into the potable water supply, caUSing
the dramatic appearance of yellow waler and colored
Ice cubes,
2 5 Are there any cases Involving outside processing activities?
Yes, In 1972 a case occurred In a gravel pit operation In illinois,
A pump was used In the processing operation supplying 100 <Y,,~;;~:
Ibs, pressure, Contaminated water was forced back through an SERv~
unprotected "prime line" overcoming the city water pressure of
451bs, The contaminated water entered the city main and was
channeled Into a nearby bottling plant. This probably would
have gone undetected except that personnel In the bottling
plant noticed that the water was not only dirty but was warm,
City officials were Immediately called which led to the discov-
ery of the reverse flow from the gravel pit operation,
26
What other typical cases have been reported recently?
In 1972 an Automatic Car Wash Injected gallons of a strong
detergent solution Into the clly supply, The reverse flowing
detergent was discovered In nearby homes more than a block
away and was officially classified as being caused by an un-
protected cross connection In the plumbing line,
6
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In 1970 In Utah a Doctor reported two gold fish flowing Into his
bath tub, Earlier In the day he had been filling his gold fish
pool with a garden hose when a back-siphonage condition de-
veloped resulting in the late emergence of the gold fish Into
the bath tub,
What is more significant, however, is the number of recent
cases that have not been reported, With the number of un-
protected cross connections in existence today, these are
potential disasters which can occur any time unless adequate
protective devices are installed,
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2 7 What Is meant by "Degree of Hazard"?
The degree of hazard is a commonly used phrase utilized in
cross connection programs and is simply a determination on
whether the substance In the non-potable system is toxic or
non-toxic, Referencing No, 19 and No, 20, the winery would be
a low hazard, while the air conditioning system would be a
high hazard Installation,
2 8 Whalls the difference between a toxic and a non-toxic
substance?
Toxic substance is any liquid, solid or gas, which, when intro-
duced into the water supply, creates, or may create, a danger
to health and well-being of the consumer, An example is
treated boiler water, A non-toxic substance is any substance
that may create a moderate hazard, is a nuisance or is aesthe-
tically objectionable, For example, food stuff, such as sugar,
soda pop etc, Therefore, you must select the proper device
according to the type of connection and degree of hazard,
There are five basic devices that can be used to correct cross
connection,
.,,,:~:'~\
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2 9 What are the five basic devices used for protection of cross
connections?
The five basic devices are:
1. Air Gap
2, Atmospheric Vacuum Breakers - Which also
Includes hose connection vacuum breakers,
3, Pressure Type Vacuum Breakers - which also
Includes Backflow Preventer with Intermediate
Atmospheric Vent for 1/2" and 3/4" lines,
4, Double Check Valve Assembly
5, Reduced Pressure PrinCiple Backflow Preventers,
d 0 What Is an Air Gap?
, / Air Gap Is the physical separallon 01 the potable and non-
potable system by an air space. The vertical distance between
Cc U
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the supply pipe and the tlood level rim should be two times the
diameter of the supply pipe, but never less than 1 ", The air gap
can be used on a direct or Inlet connection and tor all toxic
substances,
31
Where Is an Atmospheric Type Vacuum Breaker used?
Atmospheric Vacuum Breakers may be used only on
connections to a non-potable system where the vacuum
breaker Is never subJected to back-pressure and Is Installed on
the discharge side of the last control valve, It must be Installed
above the usage point. It cannot be used under continuous
pressure, (Also see No, 11)
3 2 Where Is a Hose Bibb Vacuum Breaker used?
Hose Bibb Vacuum Breakers are small Inexpensive devices
with hose connections which are simply attached to sill cocks,
and threaded faucets or wherever there Is a possibility of a
hose being attached which could be Introduced to a
contaminant. However, like the Atmospheric Type Vacuum
Breaker they should not be used under continuous pressure,
3 3 Where Is a Pressure Type Vacuum Breaker used?
Pressure Type Vacuum Breakers may be used as protection for
connections to all types ot non-potable systems where the
vacuum breakers are not subject to back-pressure, These units
may be used under continuous supply pressure, They must be
Installed above the usage point.
3 4 Where Is a Backflow Preventer with Intermediate Atmospheric
Vent used?
These devices are made for 1/2" and 3/4" lines and may be
used as an alternate equal tor pressure type vacuum breakers.
In addition, however, they provide the added advantage of
providing protection against back-pressure,
35
Where Is'a Double Check Valve Assembly used?
A double check valve assembly may be used as protection of
all direct connections through which torelgn material might
entsr the potable system In concentration which would consti-
tute a nuisance or be aesthetically objectionable, such as air,
steam, food, or other material which does not constitute a
health hazard,
B
r
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1';3 6 Where Is a Reduced Pressure Principle Backflow Preventer used?
Reduced Pressure Zone Devices may be used on all direct con-
nections which may be subject to back-pressure or
back-siphonage, and where there is the possibility of
contamination by the material that does constitute a potential
health hazard,
3 7 What are typical applications for an Air Gap?
Because today's complex plumbing systems normally require
continuous pressure, air gap applications are actually in the
minority, It should be remembered, however, that whenever a
piping terminates a suitable distance above a contaminant,
this Itsellis actually an air gap, Air Gaps are frequently used
on industrial proceSSing application, but care should be taken
that subsequent alterations are not made to the piping which
would result In a direct connection,
!
SUIl't.YVALV[
bj.
',II.:.
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'1~IUIlEOIl
APPlIAlICE
38 What are typical applications for Atmospheric Type Vacuum
Breakers? coco
Atmospheric Type Vacuum Breakers can be used on most inlet
(""') type water connections which are not SUbject to back-pressure OISIlWASlfER
'...."... such as low Inlet feeds to receptacles containing toxic and
non-toxic substances, valve outlet or fixture with hose
attachments, lawn-sprinkler systems and commercial
dishwashers,
i
I ,
,
, 39 What are typical applications for Hose Bibb Vacuum Breakers? I
,
i ,
I
1 Hose Bibb Vacuum Breakers are popularly used on sill cocks, I
,
service sinks and any threaded pipe to which a hose may I
! potentially be attached,
,
I
I
,
40 What are typical applications for Pressure Type Vacuum Breakers? !
These applications should be similar to the Atmospheric Type
Vacuum Breaker with the exception that these may be used
under continuous pressure, However, they should not be
subject to back-pressure,
OACKFLOW WAlinliA,~I~'[IlS'IOCK AllfllSI[R
PREVENTEn ...-
41 What are typical applications of Backflow Preventer with Inter. "
mediate Vent?
U~ Sffl(A.~' DflAI'l
For 1/2" and 3/4" lines these devices are popularly used on COIl!(l('lVAlV{
boiler feed water supply lines, cattle drinking fountains, trailer ~W"'"",'''''''''
/ park water supply connections and other similar low-flow ap-
plications, They will protect against both back-siphonage and
back-pressure and can be used under continuous pressure,
11~
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, '.
4 2 What are typical appllcallons for Double Check Valve
Assemblies?
Briefly, Double Check Valve Assemblies may be used where
the degree of hazard Is low, meaning that the non-potable
source is polluted rather than contaminated, The degree of
hazard is oftentimes determined by locallnspeclion Depart-
ments and, therefore, such departments should be questioned
in order to comply with local regulations,
4 3 What are typical applications for Reduced Pressure PrinCiple
Backflow Preventers?
This type shouid be used whenever the non-potable source Is
more of a contaminant than a pollutant. Basically, they are
applied as main line protection to protect the munlclpai water
supply, but should also be used on branch line applications
where non-potable fiuld would constitute a heallh hazard,
such as boiler feed lines, commercial garbage disposal
systems, Industrial boiiers, etc,
4 4 Are there any regulations In OSHA regarding cross
connections?
Yes, OSHA requires that no cross connection be allowed In an
Installation unless It Is properly protected with an approved
backflow prevention device, These requirements are also
covered In B,O,C,A" Southern Std, Building Code, Uniform
Plumbing Code and City, State and Federal Regulations,
~ WATTSN.,'"
STAAINEA { AlA GAP
(.1
BOilER FILL
I VALVE
4 5 What Standards are available governing the manufacture of A'TUAN
backllow prevention devices? "-
Table A on Page 12 provides a summary of the various
'standards available relating to specific types of backflow pre-
vention devices,
46
What Is the benefit of a strainer preceding a backllow
preventer?
A strainer will protect the check valves of a backflow preventer
from fouling due to foreign matter and debris which may be
flowing through the line, This not only protects the device but
eliminates nuisance fouling and subsequent maintenance
and shutdown, The use of a strainer with a water pressure
reducing valve has been an accepted practice for years, The
amount of pressure drop attributed to the strainer Is negligible
and Is far outweighed by the advantages provided by the
strainer.
10
I;.' ~..'
CROSS
cmmfCllmJ
COD[5&
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l~ 7 What would cause a reduced pressure principle back flow pre.
I \It venter to leak?
Leakage from a backflow preventer Is normally attributed to
foreign matter lodging on the seating area of either the first or
second check valve, Most times this can be corrected by
simply flushing the device which will dislodge any loose
particles, It is, therefore, most important on new installations
that the piping be thoroughly flushed before installing the
unit. It should be remembered, however, that spillage does
provide a "warning signal" that the device is in need of main-
tenance,
4 8 Is periodic tesflng required for reduced pressure principle
backflow preventers?
Yes, and this is to ensure that the device is working properly
and is a requirement of many states and cross connection
control programs, Test cocks are provided on the device for
this purpose and manufacturers are required to furnish field
testing information,
4 9 Should a backllow preventer be Installed In the water supply
line to each residence?
! ':) Because of the growing number of serious residential backflow
cases, many water purveyors are now requiring the installalion of
approved dual check valve backflow preventers at residenlial water
meters, They are also educaling the public concerning cross
connections and the danger of backflow Into the local water
supply, Since water purveyors cennot possibly be responsible for
or monitor the use of water within a residence, the requirements
for these cross conneclion control programs are increasing
throughout the country,
ULlTlPl
1I11VAlVU
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5 0 What is a cross connection control program?
This is a combined cooperative effort between plumbing and
health officials, water works companies, properly owners and (T:;\ .
certified testers to establish and administer guidelines for \ c'"') "
controlling cross connections and Implementing means to!- '
""
ensure their enforcement so that the public potable water
supply will be protected both in the city main and within
buildings, The elements of a program deffne the type of pro- \
tectlon required and responsibility for the administration and
enforcement. Other elements ensure continuing education
programs,
,~./
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Watts complete line of Backflow Prevention Devices.
The Complete Concept in Cross.Connection Control and Containment
REFERENCES:
ASS:: . American Society 01 Sanitary EnginccOIing
AWWA . American Walm Works Associalion
FCCCHA 01 use . Universi~ 01 Soulhern Calilomia, Foundation lor Cross
CannatHan Conlrol Reseorch
NSF. National Sanitation Foundalion
OTHER BACKFLOW PREVENTION DEVICES:
I/o, 709mODCDA . doubl, cheek d,leelor ""mbl,,,
I/o, 909RPDA . ICduced pICSS",O d'leelor ""mbly
No. 28BA, N388 . atmospheric vacuum breaker
No. 911 combination backOow plcvanlor and he1 waler boilCl rill valvo.
1/0,1/9 similar 10 I/lF9 v,;lh I,ma'o inl,J.
No, 9BD backllow pl8vonlor 10/ vending machinas.
No. FHV flost-proal wall hvdfllnls with vacuum brooke/.
For Easy seUer rClrofil adaplor wjl~ dual c~ock backnow provcnlcr, No. WES2-7
World Class Valves Wall' R'gulator Companv
~IWlm@IDDTRS:815CIICSlnUISI'"AndOV"'MAOI8-lS
MAll: Ilo. 628 L.l.llcncc, MA 018,12 hln: sn.l60
, . TeLI50elftB8-1811 FU:I~08Im.1B48
-(i, Inl,,""loOlISubsld,..ltI'\'I.ullllc,ul,lIo<0ICJnJl',1llil
REGUL A"OR 101 1-116, 5s1 A\91 1.,. 14161 BII 878B
HI 1'I,ltlsncqul,ltnr(UCllrrl,lMlbv 'clc. 6.U35J5~
_Since 1874 DACKFLOW pnEVENTION DIVISION
Series 8 . Backflow Preventers for
Hose Bibb Installations
For 'A" H, T sill cocks and threaded
faucets where a portable hose cOllld be
allached, Tesled and approved under
A,S,S,E, Std, lOll, and CSA Sid, 864,2,
ANSI A112,1.3
No, 8,8C,8A,8AC,88,8P,S8,S8C, and I/F8,
No, 8A,8AC,8,8P,S8C,NF8 and NF8C are
lislod by 'APMO,
~
@@
No, 90 . Backflow Preventer
with Intermediate
atmospheric vent
Suitable for conllnuous
pressure, Sizes v,", 'A" NPT,
Meets AS,S,E, Std, 1012
and CSA Sid, 864,3,
TABLE A
STANOAROS AND TESTING LABORATORIES
FOR 8ACKFLOW PREVENTER PERFORMANCE
TEST ANO CONSTRUCTION
PRODUCT
Atmospheric type
vacuumbreakan
Hose connection
vacuum break en
Backflowprevenler
with intermediate
atmosp~ericvenl
Reducedpreuure
princlplebackllow
prevenler
CURRENT STANDARDS
ANSU FCCCI/R WATTS
ASSE CSA 01 USC SERIES
10DI B64,\,1 Soclion 1 D 288A,N388
1011 B64,2 8
lDI2 B84,3 9D
909,
lDI3 B84.4 Seclion 10 009
Oouble check valve '
tvpebackpreuure
backflowpreventer
Vacuumbreaken,
prnsure type
Oual check valve
backflowpreventer
labo/Btorylaucet
vacuum bleaker
1015
B84,5
Seclion 10
709,
OD7
lD20 B84,1.2 Seclion ID
800
1024
864,6
B64,7
1D35
NLF9
F,50 9227
No, NLF9 - Laboratory FBucet
Vacuum Breaker
Double check valve with almospheric vent,
Especially made lor use on laboratory
faucels with gooseneck spollL
Size '/a" NPT, Male inleL
Certified under ANSI/ASSE Sid, 1035,
"Laboratory Faucet Vacuum Breakers",
Listed by I.AP,M,O,
~t
- ::: -.
r
~
Series 7 - Dual Check
Backflow Preventer
Dual check backflow preuenler
for residential waler supply service
or individual oullets, Sizes y,", I V4 ",
ANSIfAS,S,E, SId, 1024,and CSA Sid, B64,6,
I/o, 7e size ~- chrom, finish, No, 78@" -"\ ~
size :Y. compacl design. Series A7 angle ~" J I ,,' ~(!
dual check. ", ~.
@"."
~
,.,1..,
No, BOOQT, BOOM2QT, 800M3QT Pressure
TYP8 Vacuum Bre8ker
Anti,siphon pressure type vacuum
breakers for continuous pressure
piping systems, AS,S,E. No, 1020,
and 864,1.2, @~
FCCHR of use, ~P.s
Sizes '12". 2",
OOUBLE CHECK VALVE
8ACKFLOW PREVENTERS
Series 007 'I, ". 3"
Series 709mO 4". 10"
REDUCED PRESSURE ZONE
OACKFLOW PREVENTERS
Series 009 'h ". 3"
Series 909 'I, ". 10"
For additional Information,
sand for C,BPD cala/og,
'-,
Printed in U,S,A,
17~
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TYPICAL CASES FOR BACKFLOW PREVENTION
F-SBN.2
STOP
BACKFLOW
~acB(fl@w
prevention
programs
are reqMiredl I@
protect safe
drin.(ing water
World Class Valves
"1. i'~~WAns
't ,~ REGULATOR
DACKFLOW PIlEVENTlON DIVISION
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BACKFLOW CAN BE HAZARDOUS
Consumers turn their faucels on and what they believe
to be "safe drinking water" is Immediately available, pure
and plenlilul, They assume the waler is sale simply
because no one has warned them otherwise,
"Safe drinking waler" is Federaily.mandaled end
regulated by the Environmental Protection Agency. As a
prolesslonal body. and under these mandates, the water
utility is responsible lor ensuring overall proteclion of sale
drinking water under all foreseeable circumstances.
However. dospite lhese slrlct regulatIons. extremely
dangerous slluatlons continue to occur when backllow 01
contaminants are inadvertantly allowod to onter our salo
drinking waler supptiosl
The purposo 01 this booklet is to provide an understand.
Ing 01 how far-roachIng and crilical backllow contamina-
i10n probloms aro and 10 urgo Iho dovolopmonl 011110
l1ighost backilow provonlion programs poosiblo, To
iIIustrato this, we have compilod a numbor 01 case hislories
- true accounts of hazardous. ovon latal, situations wilh
Inollecilve backilow provonilon lochniquos. Additionaily,
on Page 50, you willlind an ovorview 01 the rundamentals
Involved in and the rationale bohind Walls backllow
prevention programs.
Backflow prevontlon Is a long.term investment with
ongoing requiromonts and all Industry professIonals are
110ld 10 1110 highor slandnrds ond lovols of rosponslbilily
nocessary to protect that Investment.
Wo ora conildonl Il1al whon planning or updailng a
backilow pravonilon program, Il1ls pubilcation and 1110
Walls PAC Progroms will servo flS a remlndor of tho
professional commitment and rosponslblllly to provido the
public with sale drinking water,
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May 1973
Bacldlow Case . insecticide chlordane
This one happened in New Jersey and was reported in the
New Jersey AWWA publication. PIPELINE,
A breakdown in a 24" water distributiunll1ain on May 16.
1973, triggered an cventwhich endangered residents nf the
Morganville and Wickatunk section of Marlboro Township who
receive water service from the Marlboro Township Municipal
Utilities Authority,
An exterminating contractor created an illegal cross,
connection by diluting a quantity of Ihe highly toxic insecti,
clde, C1JLORDANE, by means of a submerged garden hose
into a drum of this material.. The main break, which occurred
during this operation, caused a negative pressure in Ihe diSlri,
bution system resulting in the syphonage uf the entire cun'
tents of the drum, throogh the house service cunneetion and
into the distribution system,
Althuugh extensive flushiug of the main was affected on
the ordClS uf the Bureau of Potable Water, the velucity pro,
vided by the standard hydrant ports was insumcienl to prop'
erly flush out the chlordane from the 20" main, The required
velucity was achieved by attaching a fire pumper to a 4" port
on the hydrant, Subsequently, additional samples taken by Mr,
Wiseman of the Bureau of Potable Water demonstrated the
success of this prucedure,
This incident exemplifles the danger of illegal cross.
connections, Ihe need for public awareness or their dangers,
and indicates the need for the provisiun of check valves or
vacuum breakers on all outside hose bibs,
I CHLORD,t.,NE
','
Hose
Vacuum
Breaker
should
have been
~ln5lalled
horo
nCllrmlcd Itom:
AQUARIUS
February 1974
Poultry Farm Cross Connections. virus vaccine
The following arc delnils regarding an article which appeared in the February, 1074 issue of
"Ponltry Digest" regarding cross connections in the Poultry Indnstry,
The fCt~ling of live virlll vnccine into potable water to Immnnlze ponltry agnimt dlsense is n popnlar
practice, hnt one that erentes a serions cross connection, Significantly, the food nnd Drng Administra.
tinn pnbllshed nlist of twenty-two live virus vaccines used to Immnnize callie, swine, and ponltry;
nnd most of these aro pathogenic to mnn,
There nre over 57,000 poultry fnrms in the United States, Lnst year n cross connection snrvey
WILl eondneted at twenty-six [urms hJCnted in five eonnties of n sonthern stote, , ,rlllnlting in the discovery
of 13,000 cross eonnectlonsl
Therefore, in order to prevent the possibility of the virns flowing back into the drinking water
snpply, It Is IlIsential that baekflow prevention devices be installed,
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December 1974
Backflow Case Fast Food Chain Restaurant. boiler water chemical
Q1 ~ 7, 1974, in a rroderate size city in North Carolina, a wajor fast fcxxl
chain resturant received canplaints of a bitter taste in the soft drinks they \\ere selling.
0Jer 300 people \\ere served soft drinks during the pericxl in question.
Syrups \\ere changed several tilres but to no avail. ~ n>anager, realizing that the
principal ingredient was water, drew a glass of water fran the nearby tap. It was found
to be discolored with a strong chanical taste. The local water departJrent was notified
and an investigation was inmedi.ately started.
~ local water department traced the problem to a chanical in the water and
detennined this particular cl'emi.cal was used to treat boiler water in a fertilizer plant,
locq.ted Ole-half mile away fran the restaurant. Investigation at the fertilizer plant
revealed that a check valve 01 the supply line to the boiler was leaking and all<::lned the
chemicals in the boiler to backflw into the street wain supplying the restaurant.
This represents an excellent example of I-Ihy "contai.nrrent" of a building, at the rebar,
is important for protection of the public water supply...and also the necessity of
"isolating" individual equiprent for protection of enployees within the plant. It is
ironic to consider that even if the restaurant in this case was fully protected, the SaJre
result IDlld have occured because it was ~lied with contaminated water fran another
water user. A chain is only as strong as lts \\eakest link, and backflw cases will
continue to occur lUlless programs are irnplerented to ensure canplete protection of
potable water sUWly lines against accidental backflw.
Canplaints of children becaning ill as a result of drinking the beverages at the
restaurant have been received with threats of lawsuits. ~refore, this particular case
again supports the statarent that "backflw.. . often costs nore than tie protection."
PRESSURIZED
BOILER
fAST fOOD REST AURANT
Rmiving Conllmlnlud Water
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June 1974
Backflow Case. Hynes Auditorium. Boston. MA . chromium from
chilled water system.
Tuesday morning, June 18, 1974, was typical of the ever changing Boston weather,
A hot, humid day followed two days of periodic rain, ilnd it was tlJIcomfortable for tile
thousands of registralll\ who thronged Boston's Hynes Memorial Auditorium for the 94th
Annual A WW A Conference and Exposition,
Murmurs of "turn up the nir conditioning" were soon followed by "check the nir
conditioning" ns thousands of people noticed a yellow hue to the drinking water, What
happened thnt dny is described ns follows from the Boston Globe edition of June 21,
1974, Chromium WllS added to the chilled water system by menns of a manually
operated shut off valve. It WllS Inter determined that this shut off WllS inadvertently left
opened. A reverse flow condition occurred and resulted in the "yellow water" being
distributed to drinking bubblers, soda fountains and coffee makers in the Auditorium.
Tuesday night, handles were removed from the drinking fountnins and water using in
the cafeteria wns close down,
The problem WllS later corrected with the installation of a Watts Reduced
Pressure Principle Backflow Preventer on the supply to the chemical treatment plant.
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October 1974
Backflow Case in Automative Coating Plant. cleaning solvent
(Xl Octoter 25, 1973, a backflow case was reported in a autarobile
coating shop located in an industrial mall in a city in (Xltario, Canada.
This typJ of business is fairly pcpular in Canada where cars are
driven into the shq:> for the purposes of \U1dercoating and preventive coating in
trunks. \U1der hocxls, door panels, etc., to preserve tre car metal. The rnall
was only partially filled with tenants, the \U1dercoating plant located in Unit
No. 11, and the next occupied \U1it J:eing No. 21, leaving ten \U1occupied areas
in J:e~.
In tre pre-cleaning q:eration, hot and cold water was fed to a punp
operating at approximately 75 lbs. with the discharge side of the punp con-
nected to a gun type spray nozzle. A hose was tren connected fran the plm'p
into a solvent tank which supplied tre solvent to the spray gun. (Xl OctoJ:er 25,
1973, the punp was .left on J:e~n cycles, and the plm'p pressure of 75 lbs.
werCiUlle the city su[:ply pressure of 50 lbs. causing the cleaning solvent to
backflow fran the coating shop and into the su[:ply rrain. A tenant in Unit
No. 21, which was the rext "occupied" \U1it within the rnall, reported a bad
taste in the water which eventually lead to the discovery of the backflow
condition.
To correct the problan, it was recam-ended that Watts No. 9D
Backflow Preventer with Intenrediate Atmospheric Vent J:e instslled on both
the hot and cold supply lines to tre plm'p and a' Peduced Pressure
Principle Backflow preventer J:e instslled at the meter; also, a Watts No.8
was attached to the hose billl fauret.
J\dditionally, in order to clear the supply lines of the contaminant
'0'-.,/' in tre unoccupied building lines, it was neressary to drain the lines, after which
trey \\\')re steam cleaned to ranove tre chanicals. This is an exrellent exanple
in suFPOrt of tre statanent that "backflow certainly costs rrore than the prevention."
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September 1974
BackfJow Case. New York City Office Building. chromates from
air conditioning
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It is universally reeognized that people have the utmost confidence in the water they drink, We open
a faucet and drink what comes out. , . even if it tastes different, , , and even if it is discolored!
That is what happened in an office huilding in New York City on Septemher 23, 1974 when twenty
city employees hecame ill aCler drinking contaminated water, The cause was a cross connection hetween
the potahle water supply and the air conditioning system, A hackpressure hackflow condition forced
chromates into drinking water lines ultimately causing illness to twenty persons, This case is similar, in
effect, to the Hynes Auditorium, Boston, hack flow case, reported to you in our August Stop Backflow
Mailing, where the same "yellow water" was distrihuted to fixtures, It is more similar to the St. Joseph's
College, Pa, case reported in August, 1970 when a maintenance man hooked a hose from a service sink to
dislodge a blockage in the air conditioning system,
This case involved a 32.story office building which has the air conditioning system located on the top
floor, This serves the entire building, except, the 5th and 6th floors which has its own independent air
conditioning system. On Saturday, Septemher 21st, trouble developed with the 5th, 6th floors' system
apparently caused by a compressor breakdown, The servicing company temporarily hooked this system
into the entire building's air conditioning system, The compressor was corrected on Sunday, September
third, and in order to get the system going, an unidentified maintenance man from the servicing company
connected a hose from a threaded faucet on the 5th, 6th floor to the 5th _ 6th floors' air conditioning
system to admit make,up water. However, the huilding's air conditioning was still hooked into the
5th, 6th floors' system, The supply pressure on the 5th, 6th floors was lower then the pressure created
hy the building's air conditioning system resulting in chromates backflowing through the hose and into
the 5th. 6th floors' potable water supply,
This case, as in all backflow cases, emphasizes the importance of periodic inspecting of distribution
lines to discover actual or potential cross connections and correct them accordingly, Many officials are
concerned solely with protecting city distribution lines hy requiring a hackflow prevention device at the
meter, However, this reported case points out the importance of protecting all cross connections within
a building because it is only through the protection of these individual fixtures that employees within
that building will be assured of consuming safe water,
The threaded faucet in this particular case, for example, was not an actual cross connection, , . it
was a potential cross connection! It became a hazard when the hose was attached to admit make.up
water, This is a typical exumple of how a potential hazard was converted to an actual hazard by means
of human error, Ironically, if an inexpensive Hose Bibb Vacuum Breaker had been installed on the
threaded faucet, this case never would have occured!
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October 1978
Backf/ow Case. U.S. Naval Ship. photographic developer
Another documented case of backflow, occurring on a U. S. Naval Ship, was
reported recently in the Morbidity and Mortality Weekly Report, Volume 27, No. 28,
issued by the Center for Disease Control of the U, S. Department of Health and
Welfare. The case concerned itself with a "makeshift" cross connection consisting
of a rubber hose which led from a 40-gallon tank used to mix photo developer
(hydroquinone) to the ship's potable water system. 544 crewmen aboard this large
Naval vessel developed a gastrointestinal disease as a result of this cross connection.
Details are quoted as follows:
"Between July 21-31. 1977, 544 crewmen aboard a large U. S. Naval
vessel developed gastrointestinal disease. The illness was charac-
terized by the acute onset of nausea. vomiting, abdominal cramps,
and diarrhea generally resolving within 12-36 hours, On the morning
of July 28, when reporting for their required morning roll call, 301
men from 4 units with high attack rates were interviewed, Fifty-five
of these individuals met the definition of a case (vomiting during the last
7 days), leaving 246 controls. Interview responses indicated that
cases were significantly more likely to have drunk water while the
ship was at sea. implicating the ship's water system.
J,
CHILLED WATER
TO
MIXING TANK V';""~i:\
~ J,.."..,.....
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40 O^,LON ~..,.'-;-- ' """:""':_, , ~~
"h' ...".<,. MIXINO TANK FOR>". -;:-::-',:7 ;1 C"rct~O'WAT.,Il.~ ""',
'''":.-",\, PHOT~ OEVELOP.ER I_i'j', >- . -,"; ." " I.'!"'-' <l!l:;U.J.-1.oI....r
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fI =iJ I Hose Vacuum Breaker should
--===r have been Installed here,
PHOTO DEVELOPER
SUPPLY
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OEVELOPING MACtllNES
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October 1979
Another Pesticide Back-siphonage Case - pesticide
Approximately three gallons of chlordane, a highly toxic insecticide, was
sucked (back- siphonage) into the water system of a residential area of a good size
eastern city in October 1979. Residents complained that the "water looked milky,
felt greasy, foamed and smelled, as one woman described it, "like a combination
of kerosene and Black Flag pesticide. "
The problem developed October 12 while water department personneL were
repairing a water line. An exterminator, meanwhile, was treating a nearby home
with chlordane for termites. The workmen for the exterminating company left one
end of a hose com\ected to a water tap and left the other end in a' barrel of diluted
pesticide. During the water service interruption, the solution was siphoned into
the pipes from the barrel. This back. siphonage "accident" has followed precisely
the same pattern as other such cases documented during the past few years.
,
The water department undertook an extensive program of flushing the mains
and the possib~ity exists that some of the mains, the service lines, hot water
heaters and appliances, will have to be re[iaced.
A water department employee said that the homes in the affect,ed area, be-
cause of hilly terrain, are particularly susceptive to siphoning in the water lines
and were built 17 to 20 year s ago before the city building code required vacuum
breakers or backflo'M valves in new construction.
This is another case where even though the back- siphonage condition existed
in the street water mains, the reverse flow of the pesticide through the garden hose
and resultant contamination of an entire neighborhood could have readily been pre-
vented with the use of a Residential Dual Check Backflow Preventer or a Hose
Connection Vacuum Breaker.
Hose Vacuum Breaker
y should havn bee" I""alled here
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October 1979
Meat Contamination at Pacldng Plant. sewage water
A case of contamination of large quantities of meat occurred reo
cently at the Swift & Company packing plant in Marshalltown, Iowa. The pre.
cise cause of the contamination is still under investigation; however, it is
known that a great deal of pork was contaminated by waste water at this large
packing plant. Several U. S, Department of Agricultural officials have com.
mented that the impoundment of pork from this plant is one of the largest im-
poundments that they can recall.
As reported by the Times Republican, "because the wrong pipe
was hooked up to a newly drilled wel! at the Swift and Company plant here,
some $2,000,000 worth of pork has been contaminated by the waste water. "
The meat became contaminated when plant employees unwittingly sprayed
contaminated water on hog carcasses and cuttings during the normal cleaning
process, As reported in the April 30th issue of Food Chemical News, "food I
safety and quality service officials have concluded that there was a cross
connection of water lines between potable and non-potable water, causing
sewage water from the kill floor and water used to deodorize rendering opera-
tions ,to get into the potable water line. It
The seriousness of the situation was such that once detected, the
plant was shut down for an extended period of time while federal officials
attempted to determine the exact cause of the contamination, monitor de-
contamination and sterilization procedures, and determine what specifically
will be done with the $2, ODD, 000 of pork in process in the plant at the time
of the occurrence.
Swift and Company has reportedly spent over $3, ODD, 000 already
as a result of the problem, in addition to the fact that 200 people were unem-
ployed for extended periods of time while the situation was cleaned up.
The cost of effective cross connection control cannot be over.
emphasized in light of this significant occurrence, The expense entailed
in installing, testing and maintaining backflow hardware becomes insignifi-
cant when compared to the magnitude of the economic loss in situations
such as this.
The bottom line is protection of potable water lines through effec-
tive use of cross connection control devices.
9
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February 1979
Backpressure Backflow Incident. Seattle. Washington Car Wash
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THE INCIDENT
Monday, February 12, 1979, was typical of city bolidays, with skeleton office and laboratory staff, and
field crews sufficient for emergency response, At approximately 9;00 a,m" the Seattle Water Quality Labora-
tory received a call from a resident of a mobile home park reporting that the water coming from the tap was
grey,green in color and felt "slippery", Almost immediately, another party from the same park reported the
water as appearing "muddy", The problem was assumed to be a local condition within the park, since no
other complaints from this serviee area had been received that morning, and "dirty water" complaints usually
involve more than one customer's service, Both customers were advised to flush their cold water taps and call
back if the condition persisted,
An hour later, the first caller came into the laboratory with a sample of his tap water, confirming the physi,
cal appearance reported earlier, Preliminary laboratory tests indicated eontamination with what appeared to
be a detergent solution, While the laboratory tests were being conducted, additional "soapy water" calls began
coming in, this time from outside the mobile home park, One caller remarked that the water was black ami had
the odor of garbage,
The Department's Assistunt director of Water Quality, when advised of these developments, immediately
contacted the operations dispatcher with instructions for the emergency field crew to initiate flushing of specifie
hydrants in the affectcd area, although at this point neither the scope nor the source of the problem had been
determined, He also left for the area in a radio,equipped car to investigate the source of the problem and direct
the progress of the flushing erews, The fact of the soapy water immediately signaled car wash or laundry, and
upon arrival io the area, the source was readily identified as a large car wash located on Auront Avenue North,
The proprietor of the car wash Wa, extremely cooperative in first admittiog to. nnd then explnining, the cir-
cumstances which caused the baekflow coodition, tllll.' saving valuable time in tryiog to loente the source and
identify the contaminant. Once the source was located, it was a relatively straightforward matter to track the
path of the contaminated slug by the location of customers' complaint" request additional flushing crews, and
direct the flushing to intercept nnd limit the scope of the contaminntiou,
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Once the "soapy water problem" wns determined to be more widespread thnn initially thought, considera_
tion was given to public notification, The State and City Health Departmeuts were first apprised of the situa-
tion, and theu a statement for release to the news media was drafted, Approval for the stntemeut was given by
the Superintendent of Water, nnd a total of six radio and television statioas were contacted, with one television
station interviewing the Water Qnality Engineer and another filming the flushing crew,
The flushing crews worked well into the evening hours until strong chlorine residuals at each hydrant flushed
indicated the problem had been abated.
THE CROSS CONNECTION
The eireumstances leading up to the incident just described is an object lesson for ail water utilities, Briefly,
the following occurred:
- On Saturday, February 10, 1979, about 2:00 p,m" a pump broke down at the car wash, This is a high
preg,ure pump which takes its suction from the tank containing the reelaimed wash and rinse water and pumps
(recycles) it into the initial (scrubber) cycle of the car wash, This cycle is not normally connected to the sta.
tiun's potahle waler supply,
- Mter the pnmp broke down, the piping,in the rinse cycle (which operates with city waler pressnre) was
cuunected 10 the scruhher cycle piping by means of a two,inch hose, This arrangement allowed the car wash
to remain in OPer<ition,
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-On Mondn)', Februar)' 12, 1979, at 8:00 a,m" the owner came into the station and examined the pump,
The pump WILl repaiwd almost immedilltcl)' Ilnd turned on, The two,ineh hose (ernss connection) between the
scrubber and rinse e)'c1e plumbing WllI still connected, Howel'er, the emplo)'cc., at the car wash did not realize
that a quantit)' of the redaimed 'l'IL,h/rinse water had been forced into the twcll'e,inch water main in Aurora
Al'enue North through the cross connection and the stations's two-inch serl'ice connection whcn the pump was
turned back on,
-Sometime iatcr (thc owner said 8,30 a,m,), an emplo)'ee went into the stations's restroom and noticcd
brown soap)' water in the toilct bowlaftcr it WIlS flushed, The cross counection WllI immediatclo)' realized and
the two,ineh hose remol'ed,
THE OUTCOME
VariDlLI samples for laborator)' a",:I)'5is were taken during the course of the incident. In addition to the previous,
I)' mentioned tests which characterized the problem as a dctergent, bacteriological samples were anal)'zed for
total coliform and Standard Plate Count. All were within normal limits, Special samples collected following the
incident for organic anal)'sis were submillt-d the U,S, Enl'ironmental Proteetinn Agenc)' laborator)' in Seattle.
These laborator)' results also were within normal limits, Two customers in the eontaminoted area reported ill.
nesses after drinking thewnter, but inl'estigations b)' the Seatile,King Count)' Health Department epidemiologist
were unable to authenticate either oecurreuce, Within twent)'.four hours of the incident, the owner of the car
wush hnd installed atwo,inch rt~Iueed pressure baekOow prel'ention del'iee on Hs water serl'ice, and within one
week, all car washes using a wash watcr rcclaim s)'stem were notified of the State requirement for bnckOow
protection,
SCHEMATIC PIPING INSTALLATION OF CAR WASH
SHOWING CROSS CONNECTION
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March 1980
Backpressure Backflow Incident. rust inhibitors. antioxident chemicals
On Saturday, March I, 1980,a large fire occurred two
blocks awny from n seven story office buildiug in downtown
Mnnchester, N,H, On Sundny, March 2, the maintenance
crew of the office bnilding arrived to perfonn 1he weckly
c!enning, nnd after drinking Ihe wnter from the drinking
fountains nnd sampling the cnffee fromlhe cuffee mnchines,
they noticed that Ihe water ~nelled rubbery nnd hnd n
strong biller taste,
THE CROSS CONNECTION
The neighborhood distribution system grid plans were
examined and buildings most likely to have questionable
or possible contaminants were checked first. A nearby
radiator shop was found to have 200 gallons of antifreeze,
soldering flux and related liquids contained within the
building, together with many cross connections, Samples
of water found in this building were not similar to the
contaminant samples taken from the ,seven stnry building,
however, the internal plumbing in this radiator repair
shop was immediately required to be upgraded and back,
flow preventers added, Other potentially hazardous sitos
on the grid system were protected by hack flow prevention
devices at their service entrances,
The seven story office building housed one of the
latest solor heating systems in the northeastern area of
the United States and accompanying it was a very complex
plumbing and piping system, This presented a great chal.
lenge in attempting to determine if a cross connection was
preseat. Knowing the type of contaminant was helpful
in attempting to determine the source of the cross eonnec.
tion, Water pH levels of the building water and water pH
samples taken at the water treatment plant were com.
pared. This indicated that an injection of chemicals had
taken place in the water system and in all probability it
had occurred within the seven story building,
The Cro~~ Connection Control [nspeetors traced each
potable water line iaside the .roven story huilding in an
attempt to determine the source of the potential ero~~
connection, They were very fortunate in being able 10
locate a potable supply line that fed the make.up water
to a 10,000 gallon hot water storuge tank that was used
for heat storage in the solar heating system, It did not
have any baekflow protection. As this storage tank pres.
sure increased above the supply pressure due to thermal
expansion, the potential for backpressure backflow was
present. Normally this would not occur because a boost
pump in the main supply line would keep the supply
pressure to the storage tank always greater than highest
tank pressures, The addition of rust inhibiting ehemiea~
to this storage tank greatly increased the degree of hazard
of the liquid, Unfortunately, at the time that the fire
took place on Saturday, the pressure in the mains was
depleted to an unusually dangerously low point and
low pressure eut-off switches simultaneously shut off
the booster pumps in the building. This combination
gave the boiler water, together with its chemical contam.
inants, the time to travel into the potable drinking water
supply within the building, When pressure was reestab,
lished in the mains and the booster pumps kicked in,
contaminated water was delivered throughout the entire
building,
THE OUTCOME
Backflow prevention devices were required to correct
the internal dericiencies on the make,up supply and back,
flow units were also required at the service entrance to
comply with the Manchester Water Works Cross Connec.
tion Control containment regulation, The Manchester
Plumbing Inspector and the head of the Manchester
Health Department were contacted and shown the prob.
lems in an attempt to help others recognize the importance
of the cross connection control problems as it pertains
to internal piping systems within buildings,
This incident again emphnsizes the importance of
providing back flow protection to boiler feed supply
lines, make,up feeds, nnd hnzardous storage tanks, The
contnminnnt encouutered in this Manchester cross connec.
tion control incident was a result of rust inhibitors, nnti.
oxidant chemicals and deroamants being injected into
the heat storage tanks, The mixture consisted or a 30%
solution of sodiulll nitrate, 20% defoamant, 50% NABT
and 20% sodiulll bOlilte, Surely the addition of these
chemicals 10 water creates a toxic ,ubstnnce thnt, if
IIlIowed to flow back into the potable waler supply,
creales a serious health hazard,
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January 1981
Backflow Case Fast Food Restaurant. sea water
On Thursday morning, January 29, 1981, a nationally renowned fast
food restaurant located in Norfolk, Virginia, complained to the Water Depart-
ment that all their drinks were being rejected by customers as tasting "salty".
This included soda fountain beverages, coffee, orange juice, etc.
The Senior Water Quality Specialist promptly arrived at the restau-
rant to investigate the complaint, He found that the cold water used in making
the drinks was chilled by passing through refrigeration coils and was then auto-
matically blended with other ingredients to make the drinks, The chilled water
system as well as all potable water supply lines on the premises were inspected
for cross connections, however, none were found.
A check was then made with adjacent water customers which revealed
that an additional salty water complaint had occurred simultaneously at a water-
front ship repair facility, Both the restaurant and the shipyard were being served
from the same water main lateral which, in turn, came off the main distribution
line, A cross connection control inspection of ~le ship repair facility was prompt-
ly conducted and revealed the following:
I) The backflow preventer that had been installed on the service
line to the shipyard had frozen and burst earlier in the winter.
It had been removed and was replaced by a sic eve in order to
maintain the watel' supply to the shipyard. All protection
against backflow was thereby eliminated!
2) The shipyard fire protection system consisted of high pressure
sea water maintained by both electric and diesel driven pumps,
3) The pwnps were primed through the use of a city water line
which was directly connected to the high pressure fire system.
\ViOl the priming line left open and the first service pumps maintain-
ing high pressure in the fire service lines, raw salt water was being pwnped
under positive backpressure through the sleeve into the public water distribu-
tion system, '
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To correct the problem, the city water prime line to the pumps
was removed and a new backfiow preventer promptly installed at the service
line in place of the sleeve. Heat tape was wrapped around the backflow pre-
venter to prevent future freeze-ups,
This is another example of how several seemingly innocuous events
can simultaneously occur in a vast public water supply distribution system and
lead to a potentially extremely hazardous situation, The cross connection con-
sisted of utilizing an IUlprotected potable water prime at the high pressure sea
water pumps. In combination with the removal of the backfiow prevention de-
vice at the service line, the contamination problem occurred, Fortunately,
no illness resulted,
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SALTWATER
l"On FIRE PROTECTION
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July 1981
Contaminated Water Supply in Allegheny County. insecticide chlordane
and heptachlor
The Allegheny County Housing Authority spent approximately $300, 000.
to replace the plumbing piping, both inside and outside, of a large Allegheny County
Housing Authority development in Robinson Township. Groveton Village is a neigh-
borhood consisting of twenty-three buildings, each consisting of four apartments,
owned and operated by the Allegheny County Housing Authority. The piping was
made unserviceable as a result of chemical contamination of the drinking water as
a direct result of insecticide getting into the potable water supply, Chemical tests
of the water showed that the chemicals, chlordane and heptachlor, which are toxic
and which have been banned since 1976 for agricultural use, entered the potable
water supply as a result of a cross connection. ,-'
The insecticide entered the water supply system while an exterminat-
ing company was applying it as a preventative measure against termites. A pesti-
cide contractor was mixing the chemicals, chlordane and heptachlor, in a tank
tl'uck with water from a garden hose from one of the apartments. The end of the
hose was submerged in the chemicals, at the same time the water to the area was
being shut off and the lines were being drained. A plumber cut into a six inch
main line to put in a gate valve. When he cut the pipe and the water started to
drain, this set up a back-siphonage condition. The drainage point was downstream
of the tank truck. Consequently, the chemicals were siphoned out of the truck and
fed into the system. It is not known what quantity was involved.
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The services to seventy five apartments housing about three hundred
people were contaminated. Repeated efforts to clean and flush the lines were
not satisfactory and it was finally decided to replace the water line and all of the
plumbing that was affected. There are no reports of illness, however, residents
of the Housing Authority were told not to use any tap water for any purpose and
they were given water that was trucked into the area by volunteer fire department
personnel, They were without water for 27 days.
The township contacted the Pennsylvania State Heprescntatives from
Allegheny and Washington Counties cencel'lling thc introduction of legislation to
prevent this problem horn happening again.
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November 1981
Backflow of Heating System Anti-Freeze into Potable Water
When the price of home heating oil started to soar three or four years ago, many homeowners,
seeking relief from the rapidly rising prices, turned to less expensive means to heat their homes,
The abundant forests in the northeastern part of the U. S. provided harried homeowners with
an easy answer: wood burning stoves,
Unfortunately, using wood (or coal) burning stoves can present the homeowner with
another problem, If the central heating system is a hydronic system (hot water space heating),
then the homeowner faces the real possibility of frozen pipes when the central heating system
is not being used (which, hopefully, is most of the time). Recognizing the possibility of frozen
pipes in their heating system, some homeowners, unaware of the hazard of backflow, have
added anti-freeze to the hot water boiler,
The news article which appeared in the November 12, 1981 edition of the Bangor News
Daily relates a backflow incident concerning anti.freeze In hot water system
The make,up line to a hot water heating boiler is always a cross connection and should be
protected with an appropriate backflow preventer (local codes prevail). However, when
chemicals such as ethylene glycol anti.freeze are added to the boiler, the hazards are increased
manifold and a backflow incident could be lethal to the homeowner and to his neighbors by
contamination of the city potable water supply.
When you think of the number of people who are heating with wood stoves and who may
have added anti.freeze to their boiler to prevent frozen pipes, the potential for a serious
backflow incident Is alarming,
The solution. First, the homeowner must be educated and made aware of the dangers to
his health from the backflow of chemicals added to a heating system boiler. Second, appropriate
backflow prevention devices must be installed to protect the cross connection between a hot
water boilcr and thc potablc water supply.
Thercforc, cross connection control inspcctors and administrators in the "colder climatcs"
have another high hazard cross connection to rcckon with if they haven't donc so already,
18
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Sunday Eagle-Tribune Lawrence, Mass.
July 1982
-
--........
Water in plant now drinkable
Western Electric assures employees
-
-
By Chris Woodward
Eagle-Tribune Writer
NORTH ANDOVER - Western Electric
Co.'s 9,000 cmployees return from a wcek's
vacation tomorrow with assurances that drink-
ing water contaminated while they wcrc away
has bcen cleaned up.
"We ran ovcr 500 tests and found no traces
of any substance," John Connors, spokesman
for the company, said Friday, Further tests
were to be made yesterday,
On Tuesday hexavalent chromium was found
in the drinking water of the plant. Traces of the
toxic metal were discovered in four bathrooms
and two bubblers in the rear of the plant.
Hexavalent chromium is used in rccirculated
water as an anti-corrosive and bacteria fighter,
Officials said that bccause the plant was not in
use, pressure in the recirculating water system
buiit up, eventually backing up into the potable
water system,
John Keating, sanitary engincer for the state
Department of Environmental Qnality Engin.
cering, said Western Elcctric actcd illegally in
not having a back-flow preventer where the
pressnre build.up oceured, but praised the com-
pany for reacting to thc problem in an effective
manner,
Quantities of 50 paris per million of hexaval-
ent chromium were found in the drinking water,
enough to cause severe vomiting, diarrhea and
intestinal sickness, said Keating, who inspected
the plant.
j
-
Coincidentally, a summer intestinal flu bug
has been spreading in Greater Lawrence, but is
not related to the contamination,
According to state toxicologist Halina
Brown, the metal docs not have long.term ef.
fects unless taken in large quantities over a pro-
longed period of time. The body has ways of
cleaning out a one-time ingestion, she said, ad.
ding that it can be fatal if taken in large enough
quantities,
Connors said the skeleton crew working last
week was warned by signs and lowdspeaker not
to use the water.
Western officials said there were no reports
of illness from the contamination, Keating said
the company called area hospitals and employ-
ecs who reported in sick to see if anyone was
eontaminatcd,
"It looks like they got on top of the situation
pretty quickly," said Keating, "They're going
to opcn the plant Monday and they shonld be
all set, There should be no problem."
In addition to correcting the back flow pro-
blem, Keating said plant officials thoroughly
flushed the potable water system and ran multi-
ple tests.
He said there would be no attempts to pro.
secute the company for violations beeanse of
the way company officials reacted to correct the
problem,
"it was very serious, what happened," said
Keating. "But the way they handled the situation
I think is very good."
The sanitary engineer said he plans to con-
tinue inspections at the plant this snmmer,
(see pllge 20.21)
19
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July 1982
Backpressure Backflow Incident. North Andover. MA
A maintenance mechanic, in attempting to cor,
rect a fogging lens in an overcoolcd laser machinc,
installed a tempering vah'c, This inndvertently set
the stage for a backpressure backflow incident that
resulted in a toxic substance contaminating drink-
ingwater, The water affected was at the Western
Electric Company in North Andover,
Massachusetts. a large electronic manufacturing
firm employing 9000 employees, Quantities of 50
parts per million of hexavalent cllromium were
found in the drinkiug water which is sufficient to
cause severe vomiting, diarrhea, and intestinal
sickness, Maintenance crews working during tl",
plant shutdown were able to eliminate the cross
connection and thoroughly flush the potable water
system, thereby preventing a serious health hazard
from occurring,
A large refrigeration chiller within the plant
to primarily circulate chilled water for air condi,
tioning purposes supplied a portion of the wnter
to a laser machine in order to kecp its lenses cool-
cd during uperation, The water used in the chiller
system was treated with hexavalent chromium, a
chemical additive used as an anti,eorrosive agent
and as an algicide to combat the buildup of
bacteria in the closed loop, recirculated water
system, This chilled water presented a toxic, non
potable substance unsuituble for human cOlllllmp'
tion but very acceptnble for industrinl \,roecss
water, Nn hazard to hcnlth wns presentns ong HI
the piping wns well idcntified, kcpt separate from
drinking wnter lines and not cross connectcd to the
potnble wnter supply,
A maintennnce mechnnie, seeing thntthe lelllcs
of the Illm mnchine were becoming fogged ns a
result of being excessively cooled by the chilled
wnter supply, decidcd to correct tho situation hy
instnlling a tempering valve in the chilled lvoter
pipeline lending to the laser machine, By so doing,
he reasoned that he could warm up the chilled
wnter supply to the laser und ellminllte the fogg.
ing lenses. J-lis theory WIIS correct, since the
tempering vlllve mixed the chilled wllter with hot
water from a hot water hellter IInd the r~\lllting
warmer wnter solved the fngging lens situatinn,
The problem with the instnllation nf the temller-
ing vnlve WIIS thnt a direct cross connection lIul
heen made inadvertently hetween the tuxie chill,
cd wnter nnd the putnble wnter supply line,
During normal plant operation, the pressure
balance at the tempering valve was such, that the
pressure coming from the plant chiller circulating
pumps was approximately equal to the pressure in
the line coming out of the hot water heater, With
equnl pressure inputs to the tempering valve, no
over'pressure oecurred at the cross connection that
re,ultcd In any backprclSure bias, The systcm per-
formed satisfnctorily with no fogging of the laser
lellles and no noticeable contaminntion of the
potable water supply. However the stnge had been
set, for n cr~is in the event of a pressure imbalance,
The chiller pumping sl'stem required repairs
which were put off until the summer shutdown,
To facilitate the use of the chiller during the rc-
quired downtime, an altcrnate pnmp was tem-
porarily installed, The temporary pump had the
ability to build pressure np to 150 PSI. This pro.
mptly established an imbalance at the tempering
valve, overpressuring the 60 PSI potnble supply
Backpressure baekflow resulted and pushed the
toxic chilled water into the water heater and then
into the plant potablesuply. Yellowish-green water
started pouring out of the drinking fonntains and
into the washroom outlets,
Immediate action of maintenance personnel
detected the elluse of the problem, A hack flow
preventer was instnlled, nnd the lines thoroughly
fh~hed. Over 500 tests were mnde of the potable
water until uo traces of the hexavalent chromium
were fonnd nnd the potnble wnter declnred snfe,
The 9000 employees returned to work from vnen,
tion shutdown ll~,ured thnt the drinking wnter,
contaminated II'hile they were nll'ny, had been
c1enned up,
This entire incidenl eonld hnve easily been
prevented if n hac kiloII' preventer hnd beenillltnll-
cd in the hol II'nler SLIPI'll' line to the tempering
valve nt the same time the tempering valve was
added, Bncklloll' ens~, like thi,l nre being recogniz-
ed on n dnily hnsis; while only n fell' years ngo,
II'nter contnmination lI'ould be hnshed up, Todny,
ineideuts arc no longer heing ignored or
enmouflnged; they IIrc pnhlished in local
newspnpers and mnny gnin nationnl attention,
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1, To stop bnekflow, ullllze qunllty
bnekllow preventcrs enrrying one or more nn.
llonnl orgunlznllonnl seuls of npprovnl, such
ns A WW A, USC, ASSE und CSA.
2. Employ trulncd mcchnnles, plumbers,
plpeflllers nnd ull'ehnnlcnl eontrnctors, Don't
be nfrnld to lllk to sce thclr IIccnse to prne.
lice, If you employ In, house mnlnlenunee
personnel, hnve they rccelvcd conllnulng
eduenllon fromloenl community colleges or
voeallonnl schools?
3. Rcview)'oor loenl stnte nod federnl code,
Codes nre deslgucd for the protcellon of life
nnd property,
4. If, nfter nil this, you nre not eertnin thnt
)'our piping system Is propcrly protected, nsk
your snfety committee to Inspect It. They
should solicit ns.llstnnee from the plumbing
Inspcetor, henlth depnrtment or wnter
purveyor,
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21
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August 1982
Backflow into the City Water Supply. propane gas
Hundreds of people were evaeuated from their homes and businesses on an August afternoon in a
New England town, Fires were reported in two homes as a result of propane entering the city water supply,
A work crew purging propane from a large propane tank that was in need of repair never checked the
pressure ),1 the propane tank which was greater than the pressure in the water line that fed it. As a result,
propane vapor entered the water lines througll backpressure forcing 500 people from their homes and
contaminating the town water supply,
One five room residence was gutted by a blaze resulting from propane gas "bubbling and hissing" from
a bathroom toilet. In another home a wasldng machine explosion blew a woman against a wall, Residents
throughout the area reported hissing, bUbbling noises coming from washing machines, sinks and toilets.
Faucets sputtered out small streams of water mixed with gas and residents in the area were asked to
evacuate their homes by local firemen and other officials, Prompt action by police, gas company workers
and water works personnel resulted in first sealing off the affected area, followed by individual house
checks and the flushing of individual home plumbing systems, fire hydrant flushing and gas monitoring,
Following lab testing of the water to determine that no gas was in the system, workers restored household
water utility service. The temporary use of bottled water was discontinued, A thorough investigation by
utility company representatives and state and local officials was launched to detennine the exact cause
of the problem, Revised propane purging procedures were promptly instituted,
How could a near disaster of this nature occur and what could be done to prevent reoccurence?
A propane plant in the area that consists of twenty,six sub,surface 30,000 gallon capacity liquid propane
storage tanks, Town water provides both fire and domestic water service to the gas company facility thrOUgh
an 8 inch combination service, It supplies two private hydrants and downstream of the last hydrant it
reduees to ~3 inch domestic line which further reduces to a I inch domestic line servicing two bUildings
located on the site,
The procedure in progress, at the time of the accident, was a "purging" of one propane tank using water
from one of the private hydrants located on the gas company property, There arc two common methods
or procedures for purging liquid propane tanks, i.e, using an inert gas such as carbon dioxide or the use of
water, which is the preferred method since it is more positive and will float out any sludge as well as gas vapors
In this case, water was used from one of the private hydrants on the property to the gas tank, The problem
with this procedure was that the tank pressure was 85 to 90 psi and the water pressure was only 65 to 70 psi,
The result was backpressure backflow of the propane gas into the water main, It was estimated that the gas
flowed into the water mains for about twenty minutes and that about 2,000 cubic feet of gas was involved,
This was approximately enough gas to fill one mile of an 8 Inch water main,
22
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The inci~ent graphically illustrates tho nee~ for cross,connection control programs, to incln~e:
I. Provisions for the installation of backfiow preventers on private industrial fire protection systems-
a frequently overlooke~ item in a cross'connection control survey,
2, E~ucation of personnel associate~ with maintenance operations, stressing the problems involve~
when any potable watet source is cross'connecte~ to a potential higher pressure source or any
source that coul~ contaminate the public water supply,
CONCLUSION:
I, Nothing shoul~ ~iscourage local enforce~ cross,connection control measures, A comprehensive
containment program for the protection of public water supply as well as internal isolation of known
hazards per local plumbing codes.
2, Use of private fire hy~rants for purposes other than fire protection is prohibite~,
3, Consult your local Watts representative for cross,connection control products an~ literature,
4, An approve~ backfiow preventer shoul~ be installe~ where the town supply enters the property,
Subject to local an~/or state approval, a Double Check Valve Assembly woul~ be one means of
protection with the proviso that the ~evice be teste~ at least twice a year,
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September 1982
Dia!ysls Machine Contamination. anti.freeze solution
In spite of a progrc.lSive baekflow program, cross connections and problems associated with cross coanee-
tions can occur in a community that are totally unexpected and unanticipated, Where the pablie health
is concerned, constant vigilance is the key in preventing unforseen cross connectioas that can lead to very
serious consequences, The following case bighlights this problem,
In a large midwest city a coroner's jury recently ruled that renal dinlysis machines that were ac.
cidently contaminated by nnti.frecze solutions in a large medical center were found to be a "significant
condition" in the denths of two patients, On the olher hand, this same I'ury stated that" After listening
to several doctors aad pnthologists, the jury unnnimously agrees that tIC ethelyne glycol contnminnnt
did not eoutribute to the death of either man", In spite of this confusion, the fnet is that the deceased
Ilersons werc two of six pntients who underwent dinlysis at the medical in thc fall of 1082, One died the
allowing day and the other died 10 days later,
What is known is that ethelyne glycol entered the dialysis equipment through a seres of events trig-
gcred by n manually operated valve being left slightly open, Tbe open valve permitted water to flow
into a holding tunk thut was used to replenish n mix of glycol and wuter to tbe air eoaditioning system,
Tbe glycol is customarily utilized in air conditioning wuter to kecp the water from freezing in cold weather,
With the valve partially open, wuter continunlly flowed slowly into the glycol/wnter mixture holding
tnnk until it filled to the point wherc the pr~\Sure in the e10sed tnnk equnlled the pressure in the wnter
supply system, At this point, the stnge was set for disaster.
As long as the SU11ply pres.llIfC in the line with the vnlve purtinlly open did not decrease, no bnekpr~\Sure
flow would oecur, I , however, the sup/Ill' pressure dropped for nny rea,on, the potnble supply lines in
the hos/lilal would bc contuminated wit I the glycol/water mix as the direct result of the cross connection
at the IOlding tank combined with baekpres.llIfC baekflow,
It is thcorized that somcone in the medical center flushed a toilet or turned on a faucet which, ia
turn, dropped the pressure in the water pip~' and allowed the glycol/water mixture to drain out of the
holding tank and into the medical center water pip~', In so doing, the contaminated water catered the
dialysis filtration s)'stem that is used to purify the water for the dialysis muehines, This filtration system .
takes out traec chemicals, such a, those l~ed at the city water treatment plant; however, the system couldn't
handle the henvy 10lld of ehemienls to which it WIl' suddenly subjected,
The effect on the dialysis patieats WIIS drnmatie; Plltients became drowsy and confused, Some fell
unconscious, All were moved promptly to intensive care wherc blood sampl~, werc taken, Thc blood
sample., revealed a buildup of acid and the medical director stated that, "Somcthing has happened in
dialysis:' Dialysis was repeatcd on thc patients a second aad third time, In thc meaatime, detective work
was initiated to determine the cause of the problem,
Te.,t of the water supply to the filtration system determined the pm,ence Df "an undesireable chemical
in the water purification system:' The defective valve that had permitted water eoataining glycol to drain
from the air cOlldllloaing holding tank Into the diulysls filtration system and frum there into the dialysis
machines wa, discovered,
If the water supply to the glycol tank had been air-gapped or pruteeted with a Rednced Pre.lSure
Priaciple DaekIlow Preventer, tho iacident would not hllve oecurred. This highlights the need for hydraulic
containment of other hazardous area, pm,entin all hospitals and medical ceaters. Mortuarl' rooms, autopsy
rooms, lauadry rooms, boiler rooms, air conditioning units, pharmacy rooms shonldal be isolated and
contained with the uso of baekflow preventers on their potable supply Iiaes,
Internal cross connection control and containment wnuld have prevented this dialysis aecideat.
24
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June 1983
Backflow Case. herbicide paraquat
When a town has no backflow prevention program
for its town water system, the system is out of control.
An emergency intrusion of a foreign substance causes
confusion and fear which is followed by tremendous
unnecessary expense.
Members of the Woodsboro, Maryland Fire Company
went door.to.door warning citizens of the danger of using
town water which may have been contaminated with
lethal pesticides. An ominous lighted sign, posted at the
Woodsboro Inn, greeted people entering town with the
words "Welcome to Woodsboro, don't drink the water",
"Yellow gushy stuff" had poured from some of the
faucets in town and the State of Maryland had placed
a ban from drinking the Woodsboro water supply, Residents were warned not to use the water
for cooking, bathing, drinking or any other purpose except for flushing toilets,
The incident drew widespread attention and made the local newspapers in addition to being
the lead story on the ABC news affiliate in Washington, DC and virtually all the Washington!
Baltimore newspapers that evening, The news media contended that lethal pesticides may
have contaminated the water supply and among the contaminants was paraquat, a powerful
agricultural herbicide,
Workers who had originally detected the prohlem notified the county health department,
who in turn notified the state water snpply division, who were promptly dispatched to take
water samples for analysis, The Woodsboro water system was extensively flushed and a
concurrent investigation undertalwn to determine the source of the problem.
The investigation disclosed that the water pressure in the town water mains was temporarily
reduced due to a water pump failure in the town water supply pumping system. Coincidentally
a gate valve between a herbicide chemical holding tank and the town water supply piping had
been left open. A lethal cross.connection had been created that permittcd the herbicide to
flow into the potable water supply system. Upon restoration of water pressure, the herbicide
flowed into the many faucets and outlets on the town water distribution system.
This cross.connection created a needless and costly event that fortunately did not result
in serious illness or loss of life, Door.to.door publie notification, extensive flnshing, water
sample analysis, emergency arrangements to provide temporary potable water from tanker
trucks, all contributed to an expensive and unnecessary town burden,
An effective town cross-connection control procram could have simply and effectively
averted the entire problem through enforcement of stringent containment control. The
installation of a reduced pressure principle back flow preventer on the incoming potable
supply feeding the herbicide holding tank would have effectively and inexpensively resolved
the potential problem, A Walts 909 would have been a simple and cost effective solution,
versus the alternative of obtaining a separate source of water by drilling a private well.
26
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"Out of Control vs. Cross Connection Control"
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Out of control water supply cross connections create needless hazards and
emergencies. The cost to temporarily supply potable water is often not even
considered as a factor, Properly installed Backflow Preventers are the only
answer to eliminating such costly emergencies, An ounce of prevention is
often equal to a pound of cure, To control out of control water supply
cross connections install back flow prevention devices at all cross connections
in potable water distribution systems in accordance with the degree of hazard
in each case.
~,;
HERBICIDE
/'
Herbicide diluted with water was held in Mixing Sink(B). With Gate
Valve (A) left open and town water supply pressure reduced due to
water pump failure. Backflow of Herbicide containment flowed into
town water main,
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HOLDING TANK
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PROPER LOCATION
WATTS REDUCED PRESSURE ZONE
BACKFLOW PREVENTER
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27
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July 1983
Shipyard Backflow Contamination. raw river water
Water fountains at an east coast shipyard were posted "NO DRINKING" as workers flushed
the water lines to eliminate raw river water that had entered the shipyard following contam.
ination from incorrectly connected water lines between ships at the pier and the yard. A
third shift workman paused at a fonntain for a drink shortly after reporting to work and reo
marked, "Yon conldn't believe what it tasted like." Some third shift employees drank the
water before the pollution was discovered and later complained of stomach cramps and diarrhea,
F,
I
"
Upon notification, the shipyard trucked in potable water and had trncks stationed through.
out the shipyard so that employees could obtain drinking water, Warning signs were posted
at drinking fountains and flushing of the mains was started together with beefing up of the
chlorine content to disinfect the system, Fortunately, the contamination was confined just
to the areas of the shipyard complex and not the adjacent city water supply system, This /',
was confirmed by water tests conducted by the shipyard laborntory and state officials.
The cause of the problem was a direct cross connection between the on board salt water
fire protection water system and the fresh water connected to one of the ships at the dock,
While the shipyard had been aware of the need for backflow protection devices at the dock.
side tie up area, the devices had not been delivered and installed prior to the time of the
incident. As a result, the on board salt water fire protection system, being at a greater pres.
sure than the potable supply, forced the salt water through backpressure, into the shipyard
potable supply.
Fortunately, a small demand for potable water at the time of the incident, prevented
widespread pollution in the shipyard and the surrounding areas.
Investigation by shipyard personnel into the cause of the incident disclosed that it was stan.
dard operating procedure to reqnire the hookup of a potable supply line to a dockside back.
flow preventer with subsequent connection to shipboard service. The lack of a backflow
prevention device at the dock resulted in a direct connection between the potable supply at
the dock and the ship, Reduced pressnre principle baekflow prevention devices have been
subsequently installed at dockside and the shipynrd potable supply from the town has been
protected with the installation of large bacl<flow prevention devices.
Had the bacl<f1ow devices been in plnce and utilized according to established proccdures,
the entire incident would not havc occurrcd. Educntion and thc firm commitmcnt to estab.
Iishcd procedures is all important in thc protcction of ('ross cOllncctions for pnhlic health.
28
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SHIPBOARD RAW WATER PUMPING
SYSTEM FOR FIRE PROTECTION
AT PRESSURE PI
WHEN THE PRESSURE PI IS GREATER THAN THE WATER MAIN
NORMAL PRESSURE P2, BACKFLOW OCCURS,
SHIPYARD POTAbLE SUppl Y HOSE
*REOUCEO PRESSURE PRINCIPLE
BACKFLOW PREVENTERS
SHOULD HAVE BEEN INSTALLED
AT DOCKSIDE OUTlETS ANO
OTHER LOCATIONS
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DAilyliMES
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June 1984
Backflow Case Farmington. New Mexico. High School. chromium
sodium dichromate
Farmington High School was closed for several days, when it was noticed by a home econo.
mics teacher, that the water was yellow. City chemists determined that samples taken contained
levels of chromium as high as 700 parts per million, "astronomically higher than the accepted levels
of .05 part per million." Gary Lee, head chemist with the city of Farmington, said it was miracu.
lous that no one was seriously injured or killed by the high levels of chromium. No one knew
how much of the chrominm had run through the water system at the school before the situation
was noticed and samples taken. The chemical was identified as sodium dichromate, a toxic form
of chromium. It was agreed, that a person could get very sick or possibly could die, if the water
had been consumed.
\
No students or faculty were known to have consumed any of the water; however, area phy.
sicians and hospitals were advised, that if anyone had taken iu those high levels of chromium,
the symptoms would be nausea, diarrhea, and burning of the month and throat. Fortnnately, the
home economics teacher, who first saw the discolored water before school started, immediately
covered all water fountains with towels so that no one would drink the water.
Investigation disclosed, that chromium used in the heating systems hailers to inhibit corrosion
of the metal parts, entered the potable water supply system of the school, as a result of backflow
through leaky check valves on the boiler feed lines.
The check valves were replaced with Watl~ series 909, reduced pressure principle backflow
preventers.
'rhe high hazards associated with commercial boilers cannot be overemphasized: Toxic rust
inhibitors and defoamants that are routinely added to these boilers are an ever threatening toxic
potential to the potable water supply, The superior pressure in the boilers, together with the
toxic nature of boiler water, arc an ever present menace to industrial, commercial, hospital,
schools, colleges and university water systems. The use of reduced pressure principle hack flow
preventers on all of these hailer feed lines, and make.up lines, is an essential ingredient of all
effective eross.connection control programs along with federal and state regnlations. Effective
cross.connection control also includes Ccrtified Backflow Testers and semi annual testing program.
For superior protection, use the Walts 909 Series, reduccd pressure principle backflow
preventers. They are available for cold and hot water installations configurations and incorporate
the unique "air.in.waler.out" principlc, that provides advanced state of.lhe.art protection.
30
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FARMINGTON HIGH SCHOOL
WATER COOLER
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1>"''-:'1 BACKPRESSURE ROUTE
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h~i::'fl POTABLE WATER SUPPLY SYSTEM
31
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November 1984
Backflow of creosote into potable water in Macon. Georgia
\
Creosote entered the water distribution system of the Macon,Bibb Connty Water Authority in Macon, Georgia,
ns it result of it cross.connection between n J~" hose being llsed as:1 priming line between a fire service connection
and the suction side of a creosote pnmp. The hose cnntinually supplied water to the pump to ensure the pump
was primed at all times. However, while repairs were being made to a private fire hydrant, the creosote baeksiphoned
into the water mains and contaminated a section of the water distribution system.
The sequence of events occured as follows:
A company utilized creosote under pressure to produce railroad tics and telephone poles. On November 17,
1984 at9 A.M" the company called the distribution department of the Macon,llibb County Water Aothority in
Macon, Georgia amI requested that their water service be turned off so that repairs could be made to one of their
private fire hydrants. The company IVas supplied nonmetered water from two six,inch mains located at opposite
sides of their property, The company had the capability to s!mt off their water supply to only one of the two ser.
vice lines. The Macon water company was needed to shut 'down the other six.inch service line.
At3 P.M. the same day, the company called the water department and reported that the repairs had been made,
and requested that their water service be restored. This was done by 4 P,M.
At6 P,M" customer complaints began coming in to the water department relative to bad tasting water. Prompt
response resulted in the flushing of adjacent fire hydrants and the collection of samples for analysis. Samples did
detect creosote and both valves supplying the wood preservative company were immediately closed,
Water and Sewage Authority crews began opening fire hydrants located within a tight radius of the wnod preser.
vative company in an effort to cause a reversal of wa:er ffow in the distribution system. This wonld allow the
contamination to be brought back to the source, as opposed tn further dispersion into the far reaches of the water
, distribution system. 'All local radio stations were notified, as well as Civil Defense, EPA, the Fire Department,
and the Police Depamnenl. Hospitals and clinics were notified and briefed on the possible chemical constituents
of the contaminants. Persons on life.support systems and those who suspected they had consumed some of the
contaminated water were given instructions on what to do and whom to call.
Flushing continued and a complete reversal of the water flow was achieved by 7:30 P.M. Until midnight, crews
traveled from fire hydrant.to,fire hydntnt 'lnd house. to' house, taking water samples. At 3:00 P.M. on November
18, 1984, laboratory analysis ind cated that the system was free of contamination. Residents IVere notified that
tlley should flush their plumbing for thirty minutes, and that their water bills would be adjusted accordingly.
Following flushing of the wood preservative company's system for twenty.four hours, it was discovered that
creosote had reached, and still remained in, the far areas of their fire system. Ilackflow preventers were installed
and all lines on the property completely flushed prior to restoring service. Detailed investigation into the cause
of the incident disclosed that the wood preservative company, as part of thier operation, pumped creosote from
collective pits to other parts of their operation, The pump autnmatically shuts off when the creosote in the pit
is lowered to a predetermined level. After the creosote level returns to a higher level, the pumr restans. This
pump, however, quite often would lose it's prime prior to the f,it refilling, To prevent the loss 0 the f,rime, the
woodrreservative company connected a hose from a '11" hose 1ibb located on the fire service line to t e suction
side 0 the pump, The hose bibb remaincd open continuously in an effort to keep the pump primed at all times,
It was necessary to remove the damaged hydrant in order to make repairs, and since it was nt a Significantly
Inwer level than the creosote pit, the crcosote hacksiphoned through the W' pump priming hose connecting the
creosote pit to the fire service line,
After the repairs were made to the hydrant, and the water service restored, the creosote now in the fire lines
was flushed out into the main water distrihution system,
This case history presents several lessons and considerations nn the suhject of haeldlow prevent inn as it per.
tains to degree of hazard .md device selection:
I. Had WallS 909 rednced pressure znne hackflow preventcrs heen installed on hnth six.inch service emntnce lines
prior tn the incident, the crensote enntamination would have heen contained within thc confines of the wnod
preservative plantlthe enntainment approach to haekflnw preventionl, and nnt sp,ead to the adiaeent homes,
2, The actual crnss'connection cre'lled hy the W' hnse, hooked op hetween the lire line service and the sn~tion
side nf the crenSOle pnmp, represented an extremely high haz,trd, Considenttion shnuld have heen given tn insr'lll.
in~;l -WI permanent water pipe as a priming line amllltilizin~ a Watts Y/I 909 reduced pressure zonc hackflow
preventer in this line,
.1. Since the wood preservative enmpany lIlilized a mete,ed domestic water line, hranchcd off the fire Iioe service,
a Watts 909 reduced pressure principlc baekflow preventcr should have heen installed at the meter to prevent
potential contamination of thc intcrnal potahle water supply from crcosote.
32
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FOR POTABLE
SUPPLY
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1""'1 NORMAL WATER FLOW
33
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April 1986
Backtlow of Pesticide into the Potable Water
28
THE FAYETTEVILLE TIMES, Thursday, April 24, 1986
Hope Mills Says Pesticide Found In Water
By JEFFRY COUCH
01 Tho TlmllS Slafl
HOPE MILLS - A pelticide
contaminated what appeared to
be u "small" part of the Hope
Mills water sl'stem lasl week,
prompting the town to warn
residents of about 23 households
not to driuk their water, officials
said Wednesdal',
The warnings, which affect
two to three blocks iu the North
Muin Street area, will remain in
erfeet until officiuls determine
that the eontumination has heeu
nushed nut of the system and is
not in the pipel of indil'idual
residences, ueeording tn state and
local officials,
Residences along Phillips Street
und Fountain Lalle were sent
wurnings, aeeordiog tn Hope
Mills Ioterim Tuwn ~Ianuger
John Beasley,
Besidents in the affected urea
are heing.supplied wuter from u
tunk parked in the parking Intut
the Lnkel'iew Office Building,
Beuslel' said,
Snnie residents had reported
smelling nn odor in their water
hut there hUl'e heen no repnrts of
illness frnm ingelting the wuter,
enntnminnted with n I'estieide
eontnlniug the ehClnicn s chi or.
dnne und hepluehlnr,
Astute toxiClllogist snid the t1Jn.
luminutiun is lIut "dangerous to
unyhody right now ,"
"We think it's prohnhly nush.
cd ollt," Beusley suid,
The state Depurtmellt of
Agriellltnre is inl'e,stigatiug hnw
"
lhe contamination occurred, ac-
cording to Wall I' Venriek,
regional eugineer (or the state
Division of Health Services Water
Suppll' Branch,
AutllOrities heliel'e the prohlem
Decllrred lust week whell a
war. rline hroke along Nnrth Main
Street.
Workers frnm the Eennnmy
Pest Control Serl'iee al the
Lakel'iew Office Bllilding on
North Main Street were filling one
of the peslicide truck tanks with
water when the hreak neeurred
and pre-'llIrc in the wuterline was
reduced, cntlsing material from
inside the tank 10 be sucked into
the huilding's waterline,
authorities said,
The pcsticide is used 10 kill "Ier.
miles aod hug,I," ueeordiug to
Frank ~Iorris, a-'Iistanl reginual
engineer for the Water Supply
Brnueh,
Contacted at his home
Wednesday night, Ted Taylor,
the state toxicologist said there "is
no immiuent health huzard,"
The highest eoutamination
lel'e1 was detected April 17 iathe
Lakel'iew Office Building, Mor.
ris said, He said tcsts showed there
were 5,5 parts per hillina of hep.
taehlor in the water,
On Friday afternonn, ,07 I,arts
per billion of ehlnrdaue mll ,0,1
parts I'er billion of heptachlor
were ( eteeted in water sampled
from oue fire hydrunt near the
huilding, he said, At two other
hydrants, eontaminatiou was nnt
detected, according to Morris,
34
On Wednesday, the Water
Supply Branch took additionul
samplcl from three homes and a
drive in restaurant and a bait and
tackle shol' on North Main Strcet.
OHieia s said the restaurant
owner e1nsed his bnsincss on his
own Wednc.lday, while there has
alsn heen a repnrt that ahout
J ,000 minnows died at the hait
and tackle shop after the water
was ehnnged in the tank. But oi.
ficials said they dn not know if the
contumination has an}1hing to do
with the minnow's deaths,
A private company look sam.
\'lings frnm the Phillips Streetund
~ollntllin Lane residences and
from snme businesles along North
Main Street Tnesday to determine
if the water is eontalninated, ae.
cording tn Beasley.
Fire hydrnuts are being nnsh.
cd and residents have heen urged
to drnintheir lines and hot wuter
heaters, Beasley said,
After the incident, the
Lakel'iew building's water supply
was cut off fromlhe town system
to try to prevent enntaminatinn,
officials said,
The first written notice, from
tnwn officials warned people not
to IIse the water fnr "hllman eon.
sUIllJlUon nr bathing" if they
detected and odnr like gasoline nr
petroleulll,
The TlIl~day notices juslwarn.
cd them nnt tn use wuter for
drinking or cooking,
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June 1986
PENOBSCOT NEWS ARTICLE. Bangor. Maine. residential containment
. --~
Most towns, cities and countics in the U,S, have hcard about the residential backflow preventer,
Everyday there is a new water company putting forth an effort to protect the primary water
system from backflow con tamination,
The protection programs consist of:
(A) Plumbillg code requirements: solulion of the potenlial hazard or inlemal protection (consi.
dercd the first /ine of defense)
Plumbing codes are very specific here, They generally require backflow protection as follows:
L Air gaps to be built into sink, tub and basin faucets.
2. Antisiphon.type ballcocks are required on water closets (toilets),
3. Backflow preventers or vaeuum breakers on lawn sprinklers.
4. Vacuum breakers on hose bibbs and sill cocks.
5, Backflow preventers on supply lines to boilers or other equipment containing non.potable
fluids and cross.connected to the potable water system.
Because some local authorities modify existing national codes, certain areas require backflow
protection on the following as well:
L Residential swimming pools, hot tubs and spas.
2. Residential sdlar heating systems.
3, Private wells and other auxiliary water supplies.
(B) \Vater utility requirements: contaillment ora bachflow preventerat every meter (collsidered
the secoI,d /ine of defense)
Sincc most watcr purvcyors lire conccrncd that the plumbing code enforcementmllY not be adc.
quatc cnough to guarautce primary systcm backflow protcction thcy are rcquiring a sccond line
of dcfcnse, An IIrtidc from the "Pcnobscot" Slit. . Snn. June 21.22, 1986 indiclltc.~ what was donc
by thc Bangor Water Dislrictto cstablish a "sccond line of defcnse", They utilizcd a dual ehcck
at every rcsidcnllalwater mctcr,
This is based upon the same common scnse that we find in the excerpt from the A WW A policy
statement as shown below,
"If, in the opinion of the utility, effective measures consistent with the deb'l'ec of hazard have
not been taken by the regulatory agency, the water purveyor should take such mensures as he
may deem necessary to ensure that the primary distribution system is protected from contllll1i.
nation, Such action wonld include the installation of a backflow prevention device, consistent
with the degree of hazard, at the service connection (dual check at evcry metcr) or discontin.
uWlce of the service",
35
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March 1985 and April 1987
Ethylene Glycol In Air Conditioning Cooling System and Heating System
Contaminates Water Systems
The Center for Disease Control, in their Weekly Morbidity and Mortality Report, reported in
their September 18, 1987 issue IVol. 36/No, 361, that two instances of contamination of the potable
water supply systems had been encountered due to ethylene glycol baekflowing into the potable
water supply. The first incident occured in New York in 1985, and the second, in North Dakota,
in 1987.
~"N.V^W("MY"~V#AV.~VWVNA,~~~V~^VNM
In March 1985, a hospitalized women in New York died one day after being exposed to
ethylene glycol while undergoing hemodialysis treatment. A review of the accident disclosed
that the hospital's water system, which was the source of water used to prepare the dialysis fluid, had
become inadvertently contaminated when the air conditioning system was flushed with a commercial
solution that consisted of 95% ethylene glycol together with a market dye,
A direct connection between the potable water supply and the chilled water circuit of the air
conditioning system was open for flushing of the chilled water circuit when the chilled water pump
was activated. A check valve in the potable water supply system failed to prevent backflow from the
pressurized circuit into the potable water system. While the contamination was detected in other areas
of the hospital, it went unrecognized in the dialysis unit!
The patient suffered a coma, metabolic acidosis, and irreversible shock 12 hours later,
One hospital worker had taken a sip of the contaminated water but had not swallowed it because
of its taste and obvious discoloration,
The cross.connection of the potable water supply to the chilled water circuit of the air conditioning
system, was inadequately proteeted with a simple plumbing check valve! The high degree of hazard
inherent in this type of potable water supply make.up system requires the installation of reduced pressure
principle backflow preventcrs to insure positive protection to the potable water supply system, Simple
plumbing check valvcs are totally inadequate for use on high hazard installations as this tragic
case documents,
Air Condlllonlng Sysl,m
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o NORMAL FLOW
o REVERSE FLOW
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Watts Roduced PreslU" Zona
BackflnwP"v"ler
Q DI,lyslsEqulpmonl
36
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In April 1987, two children, ages 4 and 7, were admitted to a rural North Dakota hospital
because of acute drowsiness, vomiting, and loss of muscle coordination. Following transfer to a
Fargo hospital, toxicological studies revealed the presence of ethylene glycoL
On the day of the illness, both children had been at a picnic attented by approximately 400 persons
at a firehall in rural North Dakota. Extensive investigation of all persons attending the picnic revealed
that one food item, a non.carbonated soft drink, was strongly associated with the illness of 28 people.
The water used to prepare the powdered beverage had been drawn from a spigot nearest the firehall's
heating system. The heating system used a mixture of water and anti.freeze and was cross,connected
to the potable water supply to make up feed water. The feed water was regulated by a single hand
shut,off valve. A water sample taken at the spigot the evening of the picnic had an ethylene glycol
concentration of 9%!
The cross.connection between the potable water supply feed to the heating system that
utilized ethylene glycol was totally unprotected. Again, the high degree of hazard requires the use of
reduced pressure principle backflow preventers on the potable water feed to the heating system.
Center lor Disease Control Editorial Note: "Ethylene.glycol.based" heating systems, which have been
increasingly popular in North Dakota in the last few years, are usually designed to circulate
a heated mixture 01 ethylene glycol and water through the pipes imbedded in concrete floors.
These systems are most often found in farmer's workshops and auto repair shops,"
These two documented cases strongly support the need for the installation of approved backflow
prevention devices on potable water feeds to air conditioning cooling systems and commercial
heating systems. Only through aggressive educational programs, and constant awareness on
behalf of plumbers, plumbing inspectors, town officials, water department personnel, and the public,
can situations like these be eliminated and the salety 01 the public health be assured.
" I
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Flrohall
Hoallng
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POlablo Food "Fluid" usod lor
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In H~ollng 81slom
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PROPER LOCATION
W't1sR,ducod Pre"u" Zon,
BockflowPrevontcr
o NORMAL FLOW
o REVERSE FLOW
37
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October 1986
Burned In the Shower . sodium hydroxide
A resident of Lacey's Chapel, Alabama, jumped in the shower at 5 a.m. one morning in October,
1986, and when he got out of the shower his body was covered with tiny red blisters. "The more I
rubbed it, the worse it got", the 60 year old resident said. hIt looked like somcooe took a blow torch
and singed me."
He and severnl other Lacey's Chapel residents received medical treatment at the emergency room
of the local hospital after the water system was contaminated with sodium hydroxide, a strong
caustic solution.
Other residents claimed that "It (thc water) bubbled up and looked like Alka.Seltzer. I stuck my
hand under the faucet and some blisters came up." One neighbor's head was covered with blisters
aIter she washed her hair and others complained of burned throats or mouths after drinking the
water.
The incident hegan after an 8 inch water main broke that fed the town of Lacey's Chapel from
the Bessemer Water Service. While repairing the water main, one workman suffered leg burns from a
chemical in the water and required medical treatment. Measurements of the ph of the water were as
high as 13 in some sections of the pipe.
Investigation of the problem led to a possihle source of the contamination from a nearby
chemical company which distributes chemicals such lIS sodium hydroxide, The sodium hydroxide
is brought to the plant in liquid form in bulk tanker trucks and is transferred to a holding tank and then
pumped into 55 gallon drums. When the water maiu broke, a truck driver was adding water to a
tanker truck that had carried sodium hydroxide, Unfortunately, the driver was adding the water from
the bottom of the tank truck instead of from the top. As a result, the sodium hydroxide back.siphoned
into the water supply s)'stem.
The seriousness of this back-siphonage incident, and its impact on the entire community of Lacey's
Chapel, is obvious. Had the truck driver added the water from the top of the tank truck, through a
normal air gap, the sodium hydroxide contents could not have baek.siphoned through the hose and
into the potable water system. Even if the truck driver utili~ed the top fill of the tank truck, it is
possible that he could have pushed the hose deep into the tank which would have compromised an
air gap, and the sodium hydroxide still could have baek.siphoned up through the hose, and entered
the potable water supply system,
Thc incident emphasizcs the need for education of all concerned in the haadling and transfer of
bulk hazardous liquid" Awareness of possihle ero".eonneetions with the potable water supply system
when diluting or washing out a haznrdous chemical coutained in any tank or reservoir with a hose
connected to a potable supply is the key to fluid transfer safety,
Had an inexpensive Watts No, 8 hose bibb vacuum breaker been installed on the hose hihh to
which the hose WILl attached that led to the tank truck, the baek.siphonage incident would never
have occurred.
Backflow prevention programs are important!
The water company authority in Lneey's Chapel is respousihle for supplying drinking water and,
along with it, the implied warrantee that the water is safe to drink, even to the hLlt tap, Without a
baekflow prevention program which Involves the water user, this is needlc-Isly ILmuming the total legal
Iiahility for safe drinking water. Backflow prevention programs that require the end user to maintaiu
Plumhing Code compliance for his snfet)' and containment eoutrol for ndditional protection, benefits
the community water supply as wellns the water user, For the water supplier to operate without a
formal au-going hnekflow preventinn program placc-, him and the community at risk of financial
disaster from Inw suits, and the consumer at jeopardy from haekflow danger in the form of injury or
denth. What Is the point of not having a Baekflow Prevention Progrnm1It's a uo win situntlon
for the water supplier, water user and the local eomlllunity where baekflow danger surcly lurks,
Today the wuter systems arc more complicated thuu ever before in the history of water, The op.
portunity for an aecldeutlnvolvlng the pollutlou or eoutamlnutlon of the water Is alarm lug and more
likely thau ever, Hecently it wus discovered thatlusurnuce com panic-, arc uot protectlug subseribcrs in
Cases nf pollution or eontamlnatlou sluee they feel that pollution aud eontumlnatiuu have alreudy
enntrlbutred too much to the lusuruuee crisis In America today,
38
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Water utilities that provide watcr and practice back flow prevention, as wcll as owners of facilities
under the jurisdiction of cross. connection control programs as spccificd in the plumbing codal, all
control water piping systems, They allow pcoplc to unrestrictivcly utilize the water and they have
major responsibilities such as:
(I) Comply with latest safety prceautions, (Random sample and water talting)
(2) Survey the system to identify actual or potential problem areas.
(3) Install, test, and maintain approved backflow prevention devices.
(4) Keep records.
(5) Develop a contingency plan to prevent any unnecessary injury or possible damage resulting in
deaths, when an incident is discovered, ie., STOP PEOPLE FROM DRINKING THE WATER. All
states are required to have such a plan. It would be beneficial for water purveyors to review same.
PROPER LOCATION
WATTS NO. a
I HOSE CONNECTION
VACUUM BREAKER
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June 1987
Pesticides Contaminate 63 Homes. 21 Million Dollar Lawsuit Follows
Sixty.three homes were without wnter in n northern New Jersey munieipnlity beenuse n pesticide
used for termlle eontrol WllS found in the wnter supply, The pesticide, primarily consisting of Dllrsbun,
WllS fOllnd in the potable water sllpply tn these homes and WllS discovered after workers repaired a
water mnin brenk, Several hOllrs nfter the water mnin brenk WllS repaired, a customer cnlled the
water department to complain that the water WILl milky and smelled had, "I put the water on aud it
eame out white like milk nnd had an odor," the customer snid.
Officials immediately cut off the water supply to the 63 afft'Cted customers and notified them
orally and in writing not to drink the water or use it to cook, hathe, or wllSh clothes, Officinls
arranged for a tank truck with potablo water to be pllrked at II restaurant in the middle of the
affected block, IInd shower facilities were opened up and mllde available te the public at the public high
school and middle school. Affected water pipes were fImhed and then super.chlorinated,
The contllminlltion occurred lit the time that II water main WllS being repaired thllt had been
broken inadvertently while a construction creW WIIS widening a hridge. In the two hours that it took
to repllir the break, four pesticides used to killtcrmites, ticks, and other pests, entered the water main
through back.siphonllge from the !leSticide company. The pesticides consisted primarily of Durshun,
with chlorodanel heptachlor, and indune. In smull diluted doses these chemicals ure not harmful, but
ingestion of mouerate doses cnmes vomiting. Large doses cause breathing difficulties and may be
lifc.threatening,
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PESTICIDE COMPANY
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PROPER LOCATION
Walll No. 9B9
Baclllo. Provenle,
IColllelnmonlVelvel
~ Flow of Pesticide During Back.siphDnage
lit Flow of Pesticide Following Repair of Water Main
40
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Thc cause of the contamination was determincd to havc been brought about by a combination of
slmultancous events. A siphoning action occurred in the water pipes resulting from the water main
break, Concurrently, a tcrmite control company employee was rinsing a tank that contained a weak
solution of heptachlor and chlorodane. The hose that he was using had Dursban on it and approx-
imately one to three gallons of the pesticide chemicals were sucked into the potable water supply
system.
The pest control company was ordered to cease and desist operations immediately following thc in-
cident when it was learned that they did not have a backflow prevention device in place, Following
the installation of a backflow prevcnter, thcy were allowed to resume operations.
Becanse the contaminants would "cling" to the potable water supply piping, the plumbing in many
of the homes was being considercd for total replacement;the cost of which was alleged to be the
responsibility of the pest control company. Cost estimates for plumbing replacement were being
assessed together with the financial liability involved for replacement of a length of water main, new .
valves, and new service lines to the houses, Additional potential expenses accumulated as a resnlt of
the incident included the water supplied by the tanker trucks, water coolers proVided to nine loca.
tions, overtime charges for employees, cost of materials to flush the lines with chlorine, and water
testing charges, In addition, the pest control company could be liable for fines of up to $3,000 per
day for not having the backflow preventer in place.
Fortunately, there were no injuriesl However, had a backflow preventer been initially installed on
the main service line to the pest control company (a containment valve), the incident would not have
occnrred. The backflow preventer wonld have prevented the contaminants from back-siphoning into
the main distribution system of the public water snpply system and would havc prevented the con-
tamination of 63 adjacent homcs.
A 21 million dollar law snit has been filed in federal court against thc pesticide company by 21
homeowners. They claim that the pesticide company, who was held responsible for contamination,
irreparably damaged plnmblng fixtures, and the residents eonlinue to suffer physical injnry and have
been snbJected to mental distress, inconvenience, and loss of propcrty.
^~~~~~'-~'-~~~~~'''''~~;~-1ftt
This incident ngain emphnsizes the need for pnblie wnter snpply eompnnies to insist upon isolalion of
high hnznrd instnllations through the lISe of back flow prevenlion dcviee,s. Hnd the tcrmitc control com-
pnny inslnlled n rednced pre,ssure principle device nlthe wnler meter (a contuinntent device) lhe pesticide
wonld not have back.siphnncd into the waler main nnd eonlnntiunted 03 hnmes, The use of fixlure onllcl
proteclion back flow prcvenlion dcvices on the hoscs, spigots nnd hnse bibbs withio the lcrmitc control
compnny bnildlng would hnve protecled their own inlernnl plumbing and nssnrcd lhc pcrsonnl snfety
of thcir own cmployccs,
41
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October 1982
Copper Sulfate Poisoning. Soft Drink Dispenser
Copper tubing
suspected in
galne cro\vd
. 0
pOisonIng
~
Rescue workers rush victim of copper sulfate poisoning into
ambulance at Monterey Park. Calif.
MONTEnEY PAnK,Calif.. (UP!)
Nausea aud dizzinc." that struck
200 people who drunk sort drinks
at a high sehnol foot hall game were
tentatively blamed ou poisouous
copper sulfnte from pip'" at a con.
cession stund.
Jack Williams, a Los.Angeb
County health official said Satur.
day Ihat food and drink from the
staud were Iwing tc.sted to deter.
mine exactly what eansed the out-
hreak nf Illness Friday night.
Eight hospitals trealed seo"'-s of
patients for vomiting, dizziness,
nnmboess aud chills. Threc wcrc
ho,spltalized ovcrnlghl,
Police said there appeared to I",
no relatloaship with re<:ent produl'l
poisouing ca,ses.
"Prclimlnnry indications nre
copper sulfate pnisoning, which
means it eomc.s from the sort drink
and is definitely accidental," Police
Chief Jon Elder said.
Police said the sulfate most like.
Iy came from copper tuhing con.
necting the soft.drink syrup
canister to carhonated wnter and
the drink dispcnser.
Esther Hcntcriu, a spokt'Swomun
for Emt Los Angclt~ Collcge,
wherc the game WI'" playcd, said
those affected "nil had Coca.Cola
frol1l II particular concession
stand," The pre,ssurizcd contuiner
of cola syrnp "Wll' prc.scalcd ntthe
factory." she said, adding. "There's
no way you can putanylhing in
il."
Elder snid ahout 00 of tl", most
serionsly illwcrc taken from the
sladium by ambulance. The
stricken were allending a game bel.
42
ween Franklin and Garfield High
schools,
As the first victims became ill,
the crowd WItS warned over the
puhlie addrc.ss system not to drink
cola sold at concession stanck
"Apparently they had the drinks
at halftime hecause it slarted right
after the half," said a newspaper
phntngrupher. "A Int of kids were
panicking aad eryiag, trying tn
console their friends,"
Leticia Heyes, 15, of the Gar.
field High Sehoolllaod, who was
treated at COImty.USC ~fedieal
Center, said: "Justarter halrtime,
some of the penple on the dri"
team just s!llrted fainting. Tlu\,..
were heiug carried down by
teachers, theuthe place was teem.
ing with ambnlanec.s and trucks. A
couple of them hud hreathing ap.
parutus on them,"
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July 29, 1986
At approximately 10 a.m, on JUly 29,
1986, an adult woman and two daughters, who
were part of a Girl Scout Troop performing at
a local fair in southwest Missouri, came to
the first aid station presenting symptoms of
vomiting and abdominal distress. After
vomiting, the two girls' symptoms resolved
almost immediately. Investigation by the
Environmental Health team of the Springfield-
Greene County Health Department which was at
the first aid station, determined that
abdominal distress occurred within minutes of
partially consuming a soft drink.
I
,
)
,
It was determined that the soft drink
was fountain-dispensed. The food stand where
the 50ft drink was purchased was temporarily
closed. The owner agreed to a detailed
examination of the dispensing machine.
Based upon the symptomology presented,
it was suspected that a heavy metal poison
was the primary cause. The possibility
existed that a backflow preventer had failed
somewhere within the system of mixing and
dispensing lines, With the failing of the
backflow preventer, the possibility existed
that either cleanser or carbonated beverage
"""",had stayed in contact with metal surfaces the
previous night, eroding metal ions that were
_,1incorporated into the drinks. Samples were
drawn for atomic absorption analysis at the
environmental health laboratory in
Springfield,
!
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,
.\
An inspection of the equipment revealed
a check valve in the carbonation line that
prevents carbonated water from reverse flow
into a copper tubing line which carries
potable tap which is then mixed with the
syrup for finished product dispensing,
Laboratory analyses, which were received at
2:30 p.m., revealed the "tap" potable water
before entering the system had a copper level
of ,15 ppm, zinc of ,7 ppm and chromium
nondetectable. The suspected finished product
tested 2. 7 ppm copper, zinc 2,2 ppm, and
chromium nondetectable,
Another flavor finished product tested
6.4 ppm copper, 3.8 ppm zinc, and chromium
nondetectable. The suspected soft drink line,
according to the manager, had been flushed
prior to taking samples. However, the other
Une had not been flushed and was determined
to be used only during peak periods of trade.
Examination of the check-valve which allowed
carbonated water to back into the copper line
revealed a stuck spring, allowing for
backflow slphonage,
Repair and flushing of the system was
completed by 3,30 p,m. Laboratory analysis of
the finished product after repair, comploted
._/by 4: 30 p.m., revealed acceptable results for
copper, The stand was reMopcned for business
at 5, p.m. The patients were strongly advised
to seck medical evaluation but reported they
were feeling "O.K." and proceeded to their
next performance.
February, 1988
Letter To Major
Soft Drink Vendors
From Division Of
Environmental Health
State Of Minnesota
Letter reads as follows:
We are writing to inform you of a
current public health problem, and to request
your cooperation and assistance in efforts to
resolve the problem.
The Minnesota Department of Health has
received numerous reports of illness
associated with the ingestion of beverages
from post-mix-type carbonated beverage
dispensing machines. These illnesses have
been demonstrated to be a result of carbon
dioxide causing the leaching of copper from
copper tubing, with resulting high
concentrations of copper being ingested.
Copper can be very toxic, with acute illness
potential ranging from gastrointestinal tract
irritations and vomiting to death,
A major factor contributing to the
current problem is that carbonated beverage
machines are normally supplied and installed
only with a check valve or double check valve
at the carbonator. For such machines, a check
valve or double check is not adequate. To
comply with the Minnesota Plumbing Code, an
approved backflow preventer must be installed
preceding the carbonator. The appropriate
backflow preventer for this use is a double
check valve type backflow preventer with
intermediate atmospheric vent, It should be
installed between the pump and the
carbonator, and a unit which is specifically
designed for installation on carbonated
beverage machines is highly recommended to
promote proper functioning and greater
lifespan of the device, In addition, there
should be no copper tubing in the system down
line of the backflow preventer,
The Department is asking the
manufacturers and distrl butors of carbonated
beverage dispensing machines to supply them
only with approved backflow preventer., and
that the beverage companies inform their
field personnel that all installations must
1 be verlfled to have an approved back flow
preventer, whether suppled wi th the equipment
or added in the field,
Your cooperation in resolving this
problem is greatly appreciated, If you have
any questione, feel free to call Mr, Milton
nellin at 612/623-5517.
Sincerely yours,
Raymond W, Thron, Ph.D., P.E.
Director, Division of
Environmental Health
4S
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.
Ga,land Daily News
by Ken Turetzky
Daily News Staff
(Dallas, Texas)
t"l
January 7, 1989
Theater Manager Averts Poisoning Tragedy
A dozen children who attend a
pair of Garland day-care centers
suffered copper poisoning after
drinking water and Cokes while
attending a special show Dec. 31 at
the Walnut Twin Theatre, investigators
at the Garland Environmental
Management Department said recently.
However, the officials said, all
of the children recovered quickly. The
quick work of theater manager Betty
Christenson prevented more children
from becoming ill, the officials
added,
The children attend Treehouse
Pre-school at 602 Castle Glen and
'l'reehouse North, 3317 Buckingham, both
owned by Louis and Carol Coates of
Garland, The incident has not
disrupted either school, Ms. Coates
said. "All of our kids are just fine,"
she said. "There's no problem."
The environmental department shut
the theater down about 11 a,m. Dec. 31
and allowed it to reopen at 8 a,m.
Jan. 2, Investigators said a
malfunctioning soft drink mixer sent
carbonated water into the theater's
water lines and created the problem.
Cbildren from four area day-care
centers attended the show,
environmental investigators said.
However, 161 children from the
Treehouse schools arrived first. Eight
children from Treehouse Pre-school and
four from Treehouse North suffered
severe vomiting and stomach cramps,
Environmental Management Department
Sanitarian Chuck Henry said.
"When I arrived about 10:50
a.m.," he said, "the water department
had already flushed the lines and
(Garland Fire Department) paramedics
were treating the children."
Henry was able to obtain a water
sample, although the lines had been
flushed.
"They (Water Department crew
members) responded very quickly,"
Henry said. "They were just doing what
~_.. ....~~_... ._..,..... . _.. _._ ' ~ _.u.~ __~~_....
they were supposed to do." Technicians
at the Dallas County Forensic
Laboratory later confirmed the
children suffered from copper
poisoning.
"The amount of copper was
one-third higher than the normal
amount found in Coca-Cola,"
Environmental Management Director Pat
Fowler said.
Technical Services Coordinator
John Teel of the environmental
department explained a backflow
preventer on a mixing head attached to
a soft drink tank had malfunctioned
about 9 p ,m, Dec. 30. Employees shu t
the soft drink tap off when the
malfunction occurred, Teel said, but
they did not realize the nature of the
accident and began using the machine
again the next day.
,r
i
'....,
With the backflow preventer
disabled. Teel added, carbonated water
had settled overnight in the theater's
water line and "leeched" copper from
the line.
"Copper salts were carried in the
lines to the drinking fountain about
15 feet away and to the Isoft drink
dispenser," Teel said. The first
children to drink copper-laced water
suffered the most severe cramps,
Teel said.
But theater manager Betty
Christenson acted quickly when
children became ill, he .aid.
"When she saw the number of
children vomiting, she refused to
allow any other children to have
anything to drink," he said.
"She physically removed the
remaining soft drink containers from
all of the other children," Fowler
added. "It could have been a very bad' )
situation." \""
"If (Ms. Christenson I hadn't been
so calm," Teed said, "We would have
been in trouble."
44
17~
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Story as related to Walls Regulator Co. by
Mr. AI Hermsen, Consullant to the Water Industry
Topeka. Kansas . T et (913) 235.9994
,~
Jarbonated Beverage Incidents. Topelca, Kansas
I.,'
There were a cnuple ef rclatcd incidents that eccurrcd
herc in Topeka that really point up the need for a careful
assessment of every watcr outlet for cross.connection,
About two months ago, thcrc was ,a complaint from
a convenien9c store that they werc cxperiencing air in
their water. Thc cemplaint was that thc air was messing
up thc coffec maehinc, call ling too strong a brew, because
not enough water was being metered Into each batch.
An Investigation revealed that, Indced, there was air
In the water. Other outlets in the restrooms, etc., did have
the usual blast of pre.~lure from air In the system.
However, no other stores In the same shopping center had
reported similar conditions, Subsequent chccks of the
re.ltrooms In those facilities did not revcal any air in thc
watcr.
So, back to the drawing board. Obviously the source
of the air had to bc from within the convcnienec store
Itself. The onl.y conncetion that could cause a gas to enter
the water wns a fountain drink machine, the type that
has a water connection.
If the gll' that was entering the water was carbon diox.
ide, the Ph would have to be low. A grab sample was
taken to thc watcr lab. Our normal Ph III the water leaves
~')e plant is around 8.4 Thc sample camc in at O.S, eb.
',_--, ously proving thc CO, Will getting Into thc water.
The supplier was called and replaced the lillle check
valve that Is supposed to prevent this from happening.
In my oplnien, the small check valve in the earbonator
Is not sullieient protection to prcl'ent CO, from migrating
back Into the copper plumbing. Without a baekllow
prel'enter that can be tested on a regular hillis, there is
no way to predict its rcliabillty. The small cost of a device
on each drink machlue at the point just downstream from
the connection to copper would be alow cost insurance
to protect the public health.
To continue wiJhout more baekflow protection au
fountain drink machines would be courting dlslllter. An
approved dual check valve, te.lted annually, should give
the protection needed at a very small cosl.
Not too bad an incident, right? No one really hurt, just
some bad coffee. Read on. This one was jnst plain luekyl
Some cight weekl or so later, the Hcalth Department
got a call rcporting that a coaple wiJh a young daughter
had stopped for rcfreshmcnts at an Ice crcam store. The
man had caten an Ice crcam dish and thc \ oman and
girl both had a cola drink. Shortly aftcr drinking the cola,
both suffered SC\'ere stomach cramps and nausea. Since
this Will the only thing eiJher had ingested, they were ecr-
tain the cola had caused the symptoms.
Thc health olliccr suspected hcavy mctal poisoning
from the symptoms and called me te check for a possible
cross.connection. From thc previous experience, I im.
mediately suspected the fountain drink machine.
I again took a water sample to the water lab, This time
the Ph was dowuto S.S, so there was apparently a larger
umount of CO, getting into the water, Also, an atomic
ahsorption test revealed a large amoant of copper in the
sample.
Further discassions with the operators of the ice cream
store revealed that the young man who opened the store
at 10:00 a.m. had servcd himself a drink out of the
machine at aboatlO:30, Apparentl)' this was made from
watcr that had spent the night In the plastic piping that
form cd the lalt foar feet or so of the plumbing, because
he didn't suffer any discomfort. Then, this drink must
have becn made with water that had become acid from
CO, leaking back into the copper plumbing. This acidic
l\'fiter was nggressive enough to cause enough copper to
go Into solutina tn become toxic.
Stop Backflow In Carbonated Beverage Equipment
No. 9BD
Code ollicials:
Protect safc drinking water hy inspecting all Installations of cnrhonatcd bcveragc dispcnsing maehine.1
and cquipmcnt, Install a Walls Nn. ODD hackllow 1,,"ventcr for vending machine water supply line.1
In accordance with mannfaeturcrs installation instrnctions.
This Inost stringcnt protcction of the safe drinking water is necc"mry to protcetugulnst buck.pressurc
buckllow to prevcnt copper sulfute poisoning, '
Dc SlIre tn follow ull instullutionlnstructions und never ullow u CO. tunk and e'luipmentto he instull.
ed In u closed vuulllnon i'en(iluted cnelosure.
Slzo:
,,\' F,C.T,
I \ W NPTM
\,...1 II' NPTM
for further lnformlllloll .~{'nd fur S.OnD,
45
17~
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'.
February 1990
Antifreeze Taints Water At School
1");.)
,
THE DENVER PoST
Februill'/ 1, 1990
Antifreeze
taints water
at school
Drinking fountains
poison eight students
By Jim Kirksey
Denver Pasl SlallWriler
\
Eight Brighton middle.sehool
students were sent to the hospital
yesterday after drinking antifreeze
that had seeped into the water in the
school's drinking fountains,
Overland Trail Middle School was
closed after II a.m, yesterday, and it
will remain closed today while
authorities seek the souree of the
pollution.
The school's nurse, Becky Green,
described the water coming from the
school'l drinking fountains ns
"murky blue.green. It was really ugly
and smelly."
Five of the youngslers from
Overlaud Trail were sent to the Platte
Vnlley Medical Center in Brighton
from sehool. Three more studel1ls
were brought into the medical center
later. All eight were sent home from
the medical center after being trealed
for ethylene glycol poisouing.
Blood tests failed to deteet any of
the substanee in auy of the students'
\f1ice a/the Rocky MOlllllllill Empire
bloodstreams,
Other students - 450 children
aged 10 to 14 are enrolled - may
have been taken to other area hos.
pitals or to private doctors, but
school officials couldn't confirm that
last night.
Rodger Quist, principal of the
6.year.o!d school, said the ethylene
glycol substance is used in the
building's hot.water heating system,
which isn't supposed to be connected
to the drinking water system at
Overland Trail.
"It's supposed to be self-con.
tained," he explained. "But, for
some reason, it (the antifreeze mix.
ture) got pushed into our water
supply." He added, "We're guessing
at this point, it's probably a valve
that let water through there."
He said the sehool will be closed
today and possibly ionger, while
engineers try to figure out how the
two systems gal crossed, eorrect the
problem aud flush the system.
Quisl said a school cook noticed
the discolored waler about 9:45 a.m.,
uotified the head clIStodian, who eon-
taeled the assistaul priucipal. He said
an announcement was made im-
mediately advising studenls not to
driuk the water, bul five youngsters
who said they had druuk from the
founlains complained of headnehes
and stomach cramps, and Ihcy were
taken 10 Platte Valley.
Samples of the polluted water were
sent 10 three different laboratories for
testing.
The principal said Ihe students
46
Final Edition / 25ccnts
were kept in class until the district's
buses could be returned to the school;
then they were sent home.
The youngsters were treated with
a charcoal substance, washed down
with 7.Up, to help flush out their
systems, said hospital spokesman
Daryl Meyers. Charcoal is highly ab.
sorbent and can be consumed to
remove toxic subtances from the
digestive tract.
"The doctor said he doubts th~""~,
they ingested very much," Mey~
said, "The charcoal gets into thC''''
digestive tract and helps to get out
some of that poison. It also wili cause
diarrhea, so . . . they get flushed
ouL"
He said none of Ihe ehildren
seemed to have acute problems,
"This was a great time for them
today, at least for most of them that
came over here," Meyers said. "One
was feeling a little stronger ,stomach
aehe, but for the others this was
much better than studying "in
school."
Nurse Green said the children had
flu.like symptoms of nausea,
vomiting, abdominal pains and
headaches. One of their biggest com.
plaints, however, was the chareoal
they had to drink.
"One of the kids said, 'It's totally
gross,' II
i~)
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January 1990
Fouled Water Closes School In Brighton
All too often the things we learn come about because
of some dangerous occurrence. This latest boiler anti.freeze
backfiow incident took place in a middle school in
Brighton, Colorado,
In 1983, our Walls representative in Colorado put on
several seminars on cross connection control for school
maintenance personnel in several sehool districts, including
the Brighton Sehool District. According to AI Hudson,
"boiler anti.freeze was a point covered in depth." At the
time, it was indicated that while the problem was recog.
nized, not very much could be done because of budget
limitalions.
On Tuesday, January 30, 1990, according to the Rocky
Mountain News, "authorities closed a Brighton middle
school. . . after an anti. freeze like chemical was found
to have leaked into the school's water!' Nine Overland
Middle School students were treated in an area medical
center complaining of fiu.like symptoms including
vomiting, abdominal pain, and headache. They were
released from the medical center after being treated for
ethylene glycol poisoning. The school was closed for an
additional day so that workers could repair the heating
,.....!jstem leak that led to the apparent contamination, and
I fiush the water pipes in the building,
"~".'?
The contamination from backfiow occurred because a
valve designed to prevent anti.freeze in the heating system
from mixing with the school's drinking water was not
installed, Another valve that would have stopped the
backfiow of anti.freeze was Icrt open.
According to the school principal, "Nobody spoiled it
for the six years that (the buildiug) hns been in existence."
The school nurse described the water from thc drinking
fountains as "murky blue.grcen, It was really ugly and
smelly."
The district finance director, Scoll Murphy, indicatcd
that the diversion\vas corrected by late afternoon of the
incidcnt.
According to the Denver Post, thc Colorado Departmcnt
of Health inspected the building and verified the water
testing, The dcpartment will send "a Icller of non.
compliance" to the school district nnd thc City of Brighton.
However, no one is 10 be cited in the easc, snid Glenn
Bodnar, public health engineer.
J
Note: The scene above can be prcvcnted from recurring
in other schools in othcr cilies. Thc steps to bc taken consist
of:
A, Education of the in.house staff
B. Survey of the system
C. Remedial action
D. Adoption of a backfiow prevention program,
including records keeping on.going Annual re.
certification for watcr system safcty and protection
of the safe drinking water
Walls Regulator Company offcrs a Plumbing Code
compliance program for the PROTECTION AND CON.
SERVATlON OF SAFE DRINKING WATER for in.
dustrial, commercial, and institutionai complexes, known
as the PAC II Program. The first step in implementing the
PAC II Program for Schools is to call your local Walls
represenlative.
L
..
..
n
~
J
I
I,l~~:~'l
PROPER LOCATION
WallllRoducodPllWUfOZono
OaekflowProvontOI
o REVERSE FLOW
47
17'J.
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Health Hazards In School Systems Are Cases Of Plumbing Code Non-Compliance
f""'\
: f
. 1977 Twenty seven children were rushed to Ralcigh,
North Carolina hospitals suffering from severe
stomach cramps, headaches, and nausea. All wcre
treated and released within a few hours. Upon
investigation, it was found that the drinking waler
had been contaminated from an unknown source,
The children were affected after drinking from the
water fountains. THE GREENVILLE NEWS,
October 20, 1977
. 1982 Students at Palm Harbor Elemenlary School were
told not to drink the water when alert school
maintenance personnel detceted a strange odor and
found residue in the school drinkiug water. In.
vestigation by the combined efforts of the water
department, city health department, and Ihe
mainlcnance personnel showed Ihat contaminatcd
waler from the air conditioning system entered Ihe
safe drinking water supply. Decause of the quick
action taken by aUlltorities none of the students
were adversely affccted. AIR CONDITIONING,
HEATING, & REFRIGERATION NEWS,
Novcmber IS, 1982
. 1982 A hot water heater explosion at an elementary
school in Spencer, Oklahoma kills scvcn. In.
vestigators determincd that thc tempcrature.sensing
element had been removed, leaving the T&P relief
valve with no temperature relief capability, They
further discovered that thc relief valve had becn im.
properly installed, using a 45' elbow filling which
would have made it impossible to install in place
and properly projecting into the upper six inches
of watcr iu the heater, FIRE JOURNAL,
September, 1982
. 1984 Sodium dichromate, that was used in hcating
system boilers to inhibit corrosion of metal parts,
backflowed into the safe drinking water system in
Farmington, New Mexico high school. FARM.
INGTON DAILY TIMES, June I, 1984
. 1990 I.Iuman error and a faulty water system allowed
ethylene glycol, an anti.freeze used in the heating
system, to back flow into the drinking watcr systcm
of a Brighton, Colomdo middle school. Nine chil.
drcn wcre taken 10 an urca mcdical ccntcr
complaining of vomiting, abdominal pain, and
hcadachc. ROCKY MOUNTAIN NEWS, Jan. 31,
1990; DENVER POST, Feb. I, 1990
Thc incidcnts dcscribcd above occurrcd in schools, Whilc
no onc Iikcs to think of schools as potcntially dangcrons
sitcs, thcy, in fact, can bc if propcr plumbing codc practiccs
arc not followcd withinlhc school complcxes. Tampcring
with proper installation methods and the existence of
un.protecled cross conneclions are dangerous and are
prohibiled by all Plumbing Codes.
It is generally conceded that many school districts operate
on controlled budgets. As in the case of Brighton, Colorado,
the problem of cross connections in school buildings was
presented Ihrough seminars given by Walls representatives
in 1983. However, due to budget constraints, Iillle was done
to correct Ihe cross connections existing in the school system.
Much publicity has been given when back flow incidents
occur within the public safe waler distribution system or
within industrial/commercial complexes. Schools and school
districts are not immune from pOlentially dangerous in.
cidents taking place wilhin their drinking water systems if
cross connections within the school buildings arc not
protected.
School district officials should be aware of their respon.
sibility to protect safe drinking water that flows within their
system. The American mind.set is such that parents believe
that schools are "safe places" for their children to be during
school hours, r'
If a back flow incident docs occur within the schot
district's jurisdiction, the officials must be able to prove that"
"reasonable care" was expended to protect the children
while under the care of the school district. Otherwise the
school district will be liable for expensive lawsuits from
angry parents who assumed the school was a safe place for
their children.
Arc these scare tactics to use in order to get organiza.
tions to adopt good plumbing practices? Some might
interpret it as such, Let us remind those in authority,
however, that federal laws and mandates exist to protect
the general welfare. The Safe Drinking Water Aet- Public
Law 93.523 (1974) and the Environmental Protection
Agency CROSS CONNECTION CONTROL MANUAL,
June 1989. In addition, state health departments prohibit
unprotected cross connections IImt pose as potential health
hazards. Also, the Uaiform Plumbing Code, Section 1003
is representative of all plumbing codes and good plumb.
ing praeliee.
"No person shall install any water operated equipment
or mechanism, or use any water treating chemical or
substance, if it is found that such equipment may
cause polhllion of the domestic water supply, Such
equipment or mechanism may be permilled only when
cquipped with an approved back flow prevention
asscmbly." .'
School district officials arc responsible for eSlablishint~)
on. going safety and code compliance programs within and
npon Ihe campus for the PROTECTION AND
CONSERVATION OF SAFE DRINKING WATER.
48
I'~
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An effective Watts PAC (Protection and
Conservation of safe drinking water)
Program ~ Fundamentals & Rationale
1.
2.
3m
"
Adopt operating rules or an ordinance to begin
implementing your backflow prevention program:
Program objectives must be clearly defined and all written material
must be reviewed by legal counsel, Protection of safe water begins
at the point of treatment and continues to the point of use;
therefore, the utility must inform the consumer of their shared
responsibility to uphold expected program standards, The con.
sumer's plumbing system will be periodically examined and
evaluated to ensure that program rules, regulatiuns and operating
procedures continue to be met,
Backflow Prevention Program regulations must
include a mandatory safety evaluation of the con-
sumer's system
A thorough water system survey must be conducted on the con.
sumer's premises to asssure piumbing code compliance, Backrlow
prevention devices shall be installed, as required by the plumb.
ing code, at all cross.connections . . both actual and potential.
. that are not protected by an air gap separation, A backrlow
preventer shall be installed at the main water supply connection
(usually at the meter),
The back flow prevention program administrator
shall oversee compliance with all requirements of
the program. maintain all program records and
review the following:
I , New service applications,
2, Change of ownership proceedings,
3, Inspection and reinspection of consumer premises,
All records pertainIng to consumers must contain:
a, Name of the qualified survey agent (either plumber, pro.
fesslonal engineer, owner or other!,
b, Description of types of water uses on the consumer's
premises,
(, Classlrication of individual's system. . i.e, "residential" or
"commercial",
d, location of all air gaps and mechanical backrlow preven.
tlon devices, including containment and cross connection.
control devices and any other safety valves, Certified test
result records must also be maintained,
e, Statement of compliance of the consumer's system (Le,
"system Is presentiy In compliance with plumbing code"!,
50
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BACKFLOW PREVENTION
ASSEMBl~ES
709/007 SERIES
009QT ~
~~ ~ ~W9
I~ 112':' 3" V ;t!f
3/4'.2"
REOUCEO PRESSURE ZONE BACKFLOW PREVENTER
For high hazard cross conneclions and continuous pressure applications.
DOUBLE CHECK VALVE ASSEMBLY
For low hazard cross connections and continuous pressure applications.
709DCDA1909RPDA SERIES
7B9DCOA
3".10"
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7 SERlESIW@;E I(S;';~~
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7Serfes 'I . . ......
3/B'.1.114' . .~~.
DUAL CHECK VALVE BACK FLOW PREVENTER
For low haulId applicalions. Resldenlial syslem conlalnmenl,
WES2.7IWES2.H.7 Water metcr easy.setter retrofit adapter
with No.7.
Forlowhawdapolicalions
FOIhlghhUllrdappliCalrOrI5
DOUBLE OETECTOR CHECK VALVE ASSEMBLY
For lire protection system supply mains.
, .. JD, 980, N9, NLF9 Vi ~~;9~L 1/4~~/B" JllM'J
g' 1111'/''''''1 III titl
. 9BD 1 !l E~fr~~ l1i1 (.
3/B"FCf ~., :!':'--
90112".314" 1/4",3/B"NPTM'fJ I "U O[ ~
SPECIALTY BACKFLOW PREVENTERS WITH INTERMEOIATE
ATMOSPHERIC VENT
For low hazard cross connections fn small pipe sizes.
Continuous pressure applications.
288A1N388/188A SERIES
~'I m
2BBA (F'- N3BB
114'.3" .. 1I4".3/B" 1(11'
18BA Irrlgalion "
1/4".3" ATMOSPHERIC VACUUM BREAKERS
For high hal1lrd cross conneclions not subjeet 10
continuous pressure. 6" above flood lIm.
800/800M SERIES '~
BOOOT ~r~1
1f2".2"~i'-,
890M2
1/2".1"
8/8A/88/NF8/8P/S8
B'MB ~31'~'- fJ fdI'l
"" r: S1f2Bg I ..._",,~,.,.:=II
3/4"HT "~i= 3/~f~T -~ll, .._"
HOSE CONNECTION VACUUM BREAKERS
For res/denl/al and indus/rial hose supply oul/els
not sublect to continuous pressure.
BBBMC.QT nl-,II~' @"'-'~
1I2"'314"r
PRESSURE TYPE VACUUM BREAKERS
For high hBl1lrd cross conneel/ons,
Conl/nuous pressure eppl/cal/ons. 12" above I/ood rim,
. " Used In con/uncI/on with ""'"
BDckl/ow Proventcrs, Llml/s system ,~\" '_
pressure III/hcevent of/hermal expansion. \\~ i, "
"Walls@Governor80" ~"
BALL COCK and RELIEF VALVE II
I. Anlfslphon ba~f/ow ptovenlor used lopro/eel walol supply
III wO/Orcloso/or/olle/Illnhcorlnf1Clloll.
2. Con/rots ,helmlll expansion. Govcms /lnd Ilmils Iho SlIlIIc
P'a$SUIO In Ihodomcsllc walel system 10 a ptaSel OOpS/liS
rcqulrodbyptumblngcodes.
3.Suporlorlillvaliflllssombly,
,;l!
I,~
,,,
~4'M10'1~14~
.. ~J!J.U_' ..-
FROST.PROOF AUTOMATIC ORAINING WALL HYORANTS
WITH BACK FLOW PREVENTERS
FHV'11nlel (Dual Conneclion) 112" copper x 112' male I.P.S.
mV'2lnlet (Dllal Conneetion)314" male I.P.S. x 112" female I,P'S,
FHV SERIES
AllVALVESCEATlfIEOWltEAEAPPlICAnL[
forlddillonltlntormlllon.undIQrC,nPD.
07F SERIES/No, 07S
No. B7S 1" I~O_r,:';J:l
~_!.i
Dual ChecklSlnole Check lor Fire SpllaklBr Systems
Series 07F detecter check ler aulomatic 'lfe sp,in~er syslcllls
Ne, B7S dlfat check backllow prevenler ler resldcnllatlilC sp,inkler sysllll
~ @">,"I'" @~ @
: 'lJ. . ~p.
""\-'" ' . .
. ..... 8U &~
h""'.I, ,~II .'..1\
B7F
4".10"
A.S,S.E,.AWWA.
fCCCltnOfUSC.IAPMO.
(UPC~S.O.C.C.I..CSA.
ANSI.U.LJEM.
~.
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~ " , ' . i;'. . ., . \ . . "'," . , ,." . .' - . , l ~ \, t <, ,
':'::., \~ ,;:' ":~ ;\~;!:' . ~~'~',,' I . ~ l ~.:,' . "" :"':,,,^',,: ,t' .:,,:~~,
"
For technical assistance, call your authorized Watts agent.
T.I.ph,ne , Fax'
Trayco Salf:~, Inc. P,O, Box B53, Lynnlield, MA BI94B 617334,607B B17334.2859 ~~
W,P, HaneyC,,, Inc, 51 Norl,lk Ave" SOUlh Easlon, MA 02375 5OB238,2B3O 5OB238.6353
E. W,Leenard,lne, Ray Palmer Rd" P,O, Box 371, Moodus, CT 06469.0011 2OJB73,6891 20J 873,6893
WMSSales,lnc, 95BB Counly Rd" Cla"nce Cenler, NY 14032 71B741,9575 716632.0633
WMSSales,lnc, 7437 Meadowbrook Or" Baldwinsville, NY 13B27 315622,0763 315622,0764
WMSSales,lnc, 4 McMillen Place, Delmar, NY 12654 51B475,1B17
Edwards, Plall & Deely, Inc, 1 Slone Place, Bronxville, NY 1B7BB 0Ilice:212671,6400 914337,5069
IWa"house: 263 R'yal Ave" Hawthorne, NJ B7506) BOB 433,315B
Warehouse: N,Y,914 337'5511
Vernon Bilzer Associates, Inc. 138 Railroad Dr" NMbhamplon Ind, Pk" Ivyland, PA 18974 215953.1400 215953,1250
Bruce Parroll, N,E, Reg, Mgr, B15 Cheslnut St" Norlh Andover, MA B1B45 5OB666.1Bl1 5OB794'IB4B
RMI Glenlield Bus, Ctr" 2535 Mechanicsville Tpk" Richmond, VA 23223 B0464J.7355 804643,7380
Smith & Stevenson 4935 Chastain Ava" Chall,lIe, NC 2B21B 7B4525,338B 704525,6749
Central Sales C,mpany 2700 MUlt"esbor' Rd" Anlioch, TN 37B13 615361,4244 B15366,1175
Central SalesC'mpany 217B York Ave" Memphis, TN 3B104 90127B'2251 901272.1614
Sptllswood Associates 6700 Best Friend Rd" Nor"oss, IAtlanla) GA30071,2919 404447,1227 4B4263,6B99
Dislributor Sales of Florida 652B 351h St North, Pinellas Park, Fl33565 B13527,6B51 B13S28.1IIi02
Eall L GrillinCo, 2776 B,M. MontgomelY St" Birmingham, AL 35209 205B79,3469 20587B.5027
Earl L Grillin Co, 6517 Buggy Whip Court, Mobile,AL36695 205661-1199
Billingsley & Associates, Inc. 5609.0 Salmen SI" Harahan, lA 70123 504733,7624 504733,6904
Billingsley & Associales, Inc, 478 Cheyenne lane, MadISon, MS 39110 601 B58,7565 601B58,6390
JlM & Assoc" Ine, 1447 Amenco Miranda Caparra Terrace, Rio Piedras, PR B9922 8B97B2,4244 6Og7B1.7970
The Joyce Agency, Inc, \B520 Warv.;ckAve" Fairla<, VA 2203B 703591,2BOB 703591,6826
(Wa"house: 7313 Boudinot Dr" Springlield, VA)
J, B, O'Connor C,mpany, Inc, 12B Union St" BlidgeVllle, PA 15017 412221,5300 412221.451B
Hugh M, Cunningham, Inc, 4369 N, Beltwood Pkwy" Dallas, TX 75244,3294' 214661,0222 214490.6678
Hugh M, Cunningham, Inc, 1999 K,lIahl, Hous"n, TX 77023 713923,2311 713923.6357
Hugh M, Cunningham, Inc, 5130 SeNice Cenler, San Anleni" TX 7B21B 512661,4161 512661,6954
Bill J,hnson, S,E. Reg. Director P,O, Box 14B153, Orland" Fl32B14,B153 407B95,34B1 4B7695,3462
Mid,Conlinenl Malkeling SelVices LId, 1724 Armilage CI" Addison, Il6B\B1 7BB953'1211 708953,1067
Mid,Conlinent Malkeling SeNicas LId. 101B9 Appl' Spice 01" Indianap,lis, IN 4623B 317B23,1532 317B23'1663
Advance Industlial Malkeling LId, 923 SOUlh Bird SI., Sun Prairie, WI 5359B 608B37.5005 6OB637.2368
Dave Watson Associales 1325Wesl Beecher, Adlian, MI49221 517263,B968 517263'232B
Th' Harris,Billings C" P,O, Box 41304, 1920 Annap,lis Lana Norlh, Plymoulh, MN 55441 612559,9400 B12559,B239
Mack McClain & Associates, Inc, 1537 Ohi, St.. Das M,lnas, IA 50314 515268.B1B4 51528B'5049 C)
Mack McClain & Associalas.lnc, 1569BWastI16IhSI"OIalh',KS66062 913339,6677 913339,951B
Mack McClain & Associales, Ine, 16037 "N" Circle, Omaha, NE 68135 402B96'68D4 4B2696.6807
R, R,lverso~F"nceC" 8168 E, 441h S\., Tulsa, OK 74145 9IB664'0423 918664,6069
J, W, SUllivanC,mpany 79B1 MancheslBl Ave" Stlouis, MO 63143 314644,5454 314644,5527
Disney.Mclane, Inc. 2704 Celerain Avo" Cincinnali, 011 45225 513541.16B2 513541,0073
Madsen,Bayer & Associates, Ine, 251B Englewood Or" Columbus, 01143219 61447B,lB33 614476.1B46
Madsen.BaYBl & Associates, Inc. 464B WalnC/ Rd" Garfield Heights, DH 44125 21B641.5B68 216B41'5546
\ GalY S, Gilpin Sales C" 4468 Emberson Avo" leulsvill', KY 4B2B9 502367.217B 502367.90BB
Oon Sinsabaugh, MidWest Reg, Sales Mgl. 42W, 597 Steeple Chase, S\. Challes, Il60175 7BB377.3871 706513,5063
R, C, Hallnell & Associales 3OB52 Hunlw"d Ave" HaVW"d, CA 94544 415471,7200 415471-4441
H,lIabaugh BrelhBls& Associales 1260 61h Avo, Soulh, Se3ltl" WA9BI34,1368 2OB467'0346 2OB467'6368
H,"abaugh Brelhers & Associatas 302B S,E, 171h Avo" Portland, OR 97202 503238,0313 503235'2B24
R, E, Fillpalrick Salas, Ine, 16 East 81h Ave" Midvale, UT B4047 601566,7158 601568,4979
Hudson and lening Salas C" 2596W, BarbC/1Y Place, DonvC/, CO BB204 303B23'11B6 303B23.6876
OenisekAssoclales 2267 Valas Ave" Los Angelas, CA 9004B 2136B5'9900 2136B5'3164
R, 0, WagC/ C,mpany, 2012Wes141hSI" Temp',AZB52Bl 602968.B5B6 602B29,76B2
RockyMounlainM"keling 33110 Princeton N,E" N,27, AlbuquC/quc, NM B71B7 505B6J.4405 505891.37B7
ClOwn Salas 380 Mokau" St" Hon,lulu, III 96B19 8OBB45,7BBI 606B41-4504 ,
Jim Eng"d, WeslReg,SalesMgl. 749 Renal' Way, Paso R'bles, CA93446 605239,6652 605239,6859 )
,
I
HOBTRS, Walls Regulat" Co,/EXPORT 815 Chaslnlll St, N, AndovC/, MA B1B45 T.I..: 94,7460 5OB6BB.1B11 5OB794'IB4B
506794,1674
WallsRegulalor,ICanadaUd, 44111anlan Rd" W"dbridg', Dnlalio l4L3T1, Canada 41BB51,B591 41B651,B7BB
Walmal 24 GUldwara Rd" Nep"n Ontali, K2E BA2 B13225'9774 B13225'2972
CUlli, Auencias LId, 3117 UndC/hill Avo" Burnaby, B,C, V5A 3CB 60442B,607B 60442B,9022
POlym.. C'ntrelas Ine, 1375 Boul Chamsi Ouast, SuilO B, Ducbec City, Ducbec GIN 2E7 41B6B2.1690 41B6B2,B743
Walls R'gulal" 'I Can,da LId, 2690 Sabourin, Viii, S\. LaUlenl, Oucb" 114S 1M2 514337,901B 514337,6843
MUllayKrevats Salas Agency 941 C ErinS\., Winnipeg, Manil,ba R382W6 709786,2747 7B9175,31B6
BaYBls.Cenl, Sales LId, 1BOI,IB1hAve, Soulhwast, Calg,lY, AlbC/la T3C BK2 403244,1BI6 403245,9297
W,B,GIOBC/ich Salas LId, IB711amillon Rd" New lIambUlg, Ontari, NBB 2GO 5196B2'2460 519662.2491
HE, FellC/ly& Sen LId, 6OBBVounB SI" SIe, 911, lIalila<, NS B3K 5lB 902454,9377 902454.60B5
WailS R,gulal" 01 NedC/land b,v, P,D, Box 9B, 696BAB EC/beek, 1I,lIand Tel.. 644,35365 (01l)31,B,33B,59026 B'33B,52B73 i J
\."'l'>>')
WOlldCIIIIV,'rt. ~)
~lIWA1TS Beckflow
~,~~ REGULATOR Prevontlon
_$IIlCf 1114 WATTS REGULATOR COMPANY Division
F.SBN.2 915
Printod in U,S,A,
17~
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"
TYPE & PURPOSE
REDUCED PRESSUllE
ZONE BACKFLOW
1 PllEVENTEll
For high hazard cross.
connectiolls and conti/lUOUS
pressure application.
DOUBLE CHECK VALVE
ASSEMBLY
For low hazard cross.
connections and continuous
pressure applications.
DOUBLE CHECK DETECTOR ASSY.
(low H,wdl
REDUCED PRESSURE DETECTOR ASSY.
2 (High H,zard)
DUAL CHECK VALVE
BACK FLOW PREVENTEll
For low hazard cross-
connections in small pipe sizes,
Continuous pressure applications.'
\
SPECIALTY BACK FLOW
PREVENTERS with IN,
TERMEDIATE AT.
~IOSPHERIC VENT
For low hazard cross-connections
in small pipe sizes. Continuous
3 pressure epplicetions.
LABORATORY FAUCET
DOUBLE CHECK VAL VE
with INTERMEDIATE
VACUUM BREAKER
1II,,,,wlll'll'csl,,,, jor 1II0dcm/c
10 low IIo,urd.
AnlOSPHEIIIC VACUUM
BREAKERS
For high hazard cross.connections
not subject to continuous pressure
. 6" oboue {load rim.
4 I'RESSUIlE TYPE
VACUUM BIlEAKEIlS
For MIlI./antard croRR.canllccIiOlI1l.
COlltilluollR IJrr!RRllfr! 111JlllicatiOlI8
.12" alJOt'f' flood rim.
IIOSE CONNECTION
VACUUM IlREAKEHS
For residential and industrial ho,~e
SIII'I'/Y OII1/e/" nnl sll/licello con.
tilllIOlI.~ prc,~surc,
FOUR BASIC TYPES OF BACK FLOW PREVENTERS
DESCRIPTION
Two independent check
valves with intermediate
relief valve. Supplied with
shut.ofr valves and ball
type test cocks.
Two independent check
valves. Supplied with
shut,off valves and ball
type test cocks.
Double check valve
back flow preventers
with a water meter and
double check or RPZ
in by.pass line.
Two independent check
valves. Checks are reo
movable for testing.
Two independent check
valves with intermediate
vacuum breaker and reo
lief valve,
Two independent check
valves with intemlCdiate
vacuum breaker and reo
lief vent.
Single float and disc
with large atmospheric
port.
Spring loaded single float
and disc with independent
1st check, Supplied with
shut.ofr valves and hall
type test cocks.
Single check with atmos.
pheric vacuum breaker
vent.
INSTALLED AT
All cross.connections subject
to back pressure or back.
siphonoge where there is a
high potential health hazard
from contamination, Con.
tinuous pressure.
All cross.connections subject
to backpressure or beck.
siphonage where there is a
low potential health hazard
or nuisance. Continuous
pressure.
Fire protection syetem
supply main. Detects leaks
and unauthorized use ef
water.
Cross-connections where
there is 0 low potentiel
health hazard and moderate
flow requirements.
Cross.connections subject to
backpressure or back.
siphonage where there is
low health hazard. Con.
tinuous pressure.
Pump outlet to prevent
backflow of carbon diox.
ide gas and carbonated
water into the water sup.
ply system to beverage
machines.
Cross.connections subject to
backpreesure or baek.
siphenage where there is a
low health hazard,
Cross.connections not sub.
ject to backpressure or con.
tinuous pressure. Install at
least 6" above fixture rim,
Protection against back.
siphonege only,
This valve is designed
for installation in a con.
tinuous pressure potahle
water supply system 12"
above the overflow level
of the system being sup.
plied, Protection against
back.siphonage only,
Install directly on hose
bihbs, service sinks and
wall hydrants, Not for
continuous pressure,
EXAMPLES
of INSTALLATIONS
Main Supply Lines
Commercial Boilers
Cooling Towers
Hospital Equipment
Processing Tanks
Laboratory Equipment
Waste Digesters
Car Wash
Sewerage Treatment
(~
,
Main Supply Lines
Food Cookers
Tanks & Vats
Lawn Sprinklers
Fire Sprinkler Lines
Commercial Pools
N
o
N
T
o
X
I
C
j
Fire Sprinkler Lines
N
Residential Supply Lines ~
(at the meter) T
Residential fire sprinkler ~
systema I
c
Boilers (Small)
Cooling Towers (Small)
Dairy Equipment
Residential
(-"'.
, '
~
Post.Mix Carbonated
Beverage Machine
,
f:
Laboratory Faucets and
Pipe Lines
Barher Shop and
Beauty Parlor Sinks
Process Tanks
Dishwashers
Soap Dispensers
Washing Machines
Lawn Sprinklers
Laboratory Equipment
Cooling Towers
Comm. Laundry Machines
Swimming Pools
Chemical Plating Tanks
Lg, Toilet & Urinal Facilities
Deb~easers, Photo Tanks
Live Stock Water Systems
Lawu Sprinklers
\
'I
Hose Bihbs
Service Sinks
Hydrants
,
'-..)
2
For additional cross. connection control Information, Bend for F.50 brochure.
~
,
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"
11
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~
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.,..
USC MANUAL PRODUCT PAGE
APPliCABLE STANDARDS 81h EDITION' Sl1ES(lnchesj NO.
Series Slzellnchesj AVAlLA8LE
ASSESld, 1013 AWWACSII.89, OB9 314.3' 112.3 10 REOUCEO PRESSURE lONE BACKFLOW PREVENTERS
~ IAPMO Listed, UL Classilied
ASSESld,I013 AWWACSII.89, .., tr- - ....
CSA BB4,S, JAPMO Listeda SOCCI, 909 314.10' 314.10 6,7
2".10"ULClassiliedEX IBS
1 9B9RPOA 3.10' 3.10 II /'\ ~
,..~ ~. / .
, '
I" .. .' -' ' .
99B 4' 4.8 7 "" - \
I
990RPOA 4' 4.B II
ASSE Sid, lBl~ AWWA Sid. CSW.B9, 992 4' 4-10 7
IAPMO Listed. 14".3', CSA B64
ASSE Sid, lOIS, AWWA Sid, CS10.B9, OB7 314.3' 112.3 OOUBLE CHECK VALVE ASSEMBLIES
UL Classilied No, EX318S, CSA B64,S, 10
SBCCI, IAPMO
ASSE Sid, 101S. AWWA Sid, CS10. 709 2.112.10' 2.112.10 9
CSAB64,S
770 4' 4-B 8 I~
W;,,;:;,.
"~. '.'".
ASSE Sid, 104B, AWWA Sid, CS10'B9, 772 4' 4-10 8
UL Classilied No, EX3IBS, CSA BB4
7090COA 3.10' 3,10 11 ."'"I;;;:'....
2 77BOCOA 4' 4'B 8
ANSI/ASSE Sid, 1024, CSA B64,B 7720COA 4' 4-10 J", ,." o.
8
ANSIIASSE Std. 1024 7 - 112.1-1/4 12,13 OUAL CHECK VALVE BACKFLOW PREVENTERS
7 Series ~ s...
ANSIIASSE Std. 1024 7B - 314 12
~",} ANSI/ASSE Std. I B24, CSA B64,B, A7 - SIB, 3/4 12 ..
NFOA Sid. 130 ..
ULClassiliedEX31BS 07S - 1 13
ANSI/ASSE Std. 1024, CSA, Uli1'M 07F - 4-10 5 _SSClles
ASSE Sid, 1012, CSA 864,3 7C - 31B 16
ASSE Sid, 1032, N.Y. BJ.47, 90 - 112.314 14 SPECIALTY BACKFLOW PREVENTERS
NSFSld.2S with INTERMEOIATE ATMOSPHERIC VENT
3 ANSI/ASSE Std. IB3S, CSA Sid, B64.7 9BO - 3IB"FCT 17
1/4,31BNPTM .
CSABB4,B NLF9 3/B 16 "." .s.~ .
- to: I::') 9D SBrlBS
ASSESld.100lbANSIAI12,1.1, N9 - 1I4,31B lB
CSA B64, IAPM L1sled
ASSE Std. 1001, CSA B64 2BBA 114.3' 114.3 20 ATMOSPH BREAKERS
ASSESld.l001,ANSIAI12.1,1, N3BB - 1/4.31B 20
CSABB4
ASSE Sid. 1020, IAPMO lIsled IBBA 3/4.2' 31H 20 ".;.
,
AN~ASSE 1020, CSA B64.1.2, BOOMOT 112,314' 112,314 lB PRESSURE TYPE VACUUM BREAKERS
lAP OLlsted
4 AN~ASSE 1020, CSA B64,J.2, BBBM30T 112,314' 112,314 lB,19 ~~.JJ 'R
lAP OLlsled ~r Uir
AN~ASSE 1020, CSA B64.1.2, BOBM20T l' 1.2 IB,19 Il
lAP OLlsled 1] 8OOMlOT *t 8OOM30T
ANSI/ASSE 1020, CSA B64,1,2,
, ' IAPMOllsled BOOOT 1114.2' 1.114.2 10,19 t,
,,.}
.. ANSI AI12,1,3, ASSE Sid, 101 I, HOSE CONNECTION VACUUM BREAKERS
SBC - 3/B,112 22
IAPMOllsled -~
ANSIAI12.J.3,ASSESld,1011, 1~'D
IAPMOllsled B,NF8 - 314 HT 22,23 >lJi1
. " '.. : . .""'" ~ . ." .' .', " ' -'~ '. . \ "
, .,','... ' ,-", '~""'" '. '.' I"", "
,<.;, ""'il" "'l:""";" i'__", ,',', ':' ,.,,"......',-: ,-", ',', ") ',,',
l~l< '/," :""1 ~ '_~ l :'~,l;:.' s' I. : ". ':""" ,.,,'.. , ~ " "~
,I \\ "',',. t,' '\~,.",... . , . \ '. ,. ',~ ',II
',,' ,,'~",\. ,'j......~.i I'" ,,:J .!~~ \ '. ": ,',.,'.,:.'. ,"
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'Does nollndlcate approval stalus. neler 110 Englneerlno SpeclllcaJlon Sheels for approved sizes and produCI numbBrs.
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-
w.....~-~lI.fn" JWU~1V'" M""w..,,""...~
:' /: ':::i "J:' ':lr," ;'~":'l:i( :I:jd:::, ': ~ ,. " ::: ;.'~ :;:-,:' :' ': ':.J'...' .,','
~} ", "~~\ ,',.: ~'~l,.'~',\ ..4.,;:, ::~:l?f \', . _ ,,','. :,'\,.,""'" ,.~,:-.lt: r.o',:"
Series 909
"Engineered for High Capacity Relief"
When you buy a safety valve you certainly want the safest one.
Series 909 protects against back-siphonage and backpressure with both checks fouled.
r-
EIBmentary hydraulics and applied mechanics give us the rBduced principlB backllow preventBr which protects againsl backflow
by maintaining reduced prBssure downstrBam of thB safe drinking watBr supply, (Water in a low pressure zone cannot fiow to
a higher pressure zone.)
When thB supply line pressure drops to a vacuum (pressure IBSS than atmospheric), it is impossiblB to mainlain a rBduced
pressure zone. Backflow/back.siphonagB protection thBn can only be achieved by allowing air 10 enter and break the vacuum,
With thB vacuum under control, the Siphonage effect CBaSBS and the polentlally dangerous polluted Dr conlaminatBd water is
then drained out of the reiiBf valve bBfore it reachBs thB safewater supply (See FigurB 3). Vacuum reliel is most important should
thB spring ioadBd checks becomB fouled (SeB Figure 4) during a reversal of ffow which can displace debris.
Back.siphonage through a reduced pressurB principiB dBvice requires some method of preventing IhB vacuum from forming,
Allowing the air to Bnter, which brBaks IhB vacuum, which caused the siphon, is necessary for thB water to salely discharge,
I.e., Alr.lnlWater.Out ConcBpl (SeB Figures 1 and 2).
ThB valve has two channels: one for air in to reliBvB vacuum, onB for water out lor protection of safB water, WhBn the reliBf
valve opens, onB channel admits air to the top of Ihe rBduced prBssure zone; the other channBlthBn drains to almosphere,
All manufacturer's can provide vacuum reiiBf protection. Most don't tell you about it - the Walls 909 has it buill right in!
The principlB is simplB. II is the only backflow prevBntBr to provide so much valve and so much protection.
... ~
Fig. 1 Fig. 2 r
lIIuslraiing thB simple l Schematic of Walls Series 909 , '--
Air.inlWater.out princlpiB. I "How it works".
,
\
Basic AJr.lnfoNalor.Qul Principle 01 , t RELIEF VALVE _
WATTS No, 909 ,
Roduced Pressure Backllow Prevanlor , I
WATER.OUT AIR,IN
lorprolecllon fer
of solowoler vacuum
rollof PotenlIt4.241,752
R.II.,
V.lvl
n.
Vent Pori
4 '
" I
\"...
"'"
\
',,: ::':'''1';' ,,:,:t~' ;",,~:~,". :';tl""::":' ,~""::",,,::::",; ::"':'<.'~,
;~~" . ;1:(: ,'I '.,' ~,.'J.""'l~'~' "'~:'.~:'. ';, :' ",:, ,'!', .: :. \'~: "', :',';'~';
. ( ,," I . 1. 1. I ';,.;.'.,.. I" ~ '. , "" . ~
\", ~,.~t',. \' .;',1. ....~.'.\ ,.,' '. ~. r
INSTALLAT/ON / INSPECTION
8ack"0I' prevenlion assemblies lUST bo Ins/a/lOll by a licensed /oulOyman lradespersen, "ho Is reCIJonizod by the authonly ha.no/unSdlclion, and
Inspected lor compliance with local safety codos. Cei1ified lesling and maintenance are required /0 ensure proper function snd maximum effectiveness
of assemblies. These saMccs must begin upon foslallalion and bo provided at fntemls not to trcced one yeSt and as system conditions waffsnl,
No. TK.DP
fiNo. TK-DR
,
I
1
Tesl KII for Backf/ow Preventers
No. TK.OP 'or Dlgllal Prlnl Oul
No. TK.DR 'or Dlgllol Read Oul
An advanced piece el lesl
equipmenl designed 10
make pressure and ddleren.
lialgauges ebsolele in Iholesling
01 backnow devices,
No. TK.DP
. .0,2%accurate
. meels all slandards
, losl RPZ, Oeuble Cecks, PVB
'sell,calibralien
. provides verified lesl resulls
'on,sileloslresulls
'carryingcaso
Test Kits & Air Gaps
IllU"'IIIf...Hlnl
111ltl~tw~,
.JiIWliIJ..AA.
tIll,I--ZtLi.t:J'J-
11l12ltl1Je..J.t1l_
'Accuracy
'Versalility
'Readability
'Po~ability
'Oocumenlalion
.111 Ie II
I6Im.llITlI
IIIU......).I
C"''''III.. ...)1...
.tI1t1l.lI.IVI...If"1
,rllllllJlltll.
11II1"Ul'fIII."_
lllIIM'Olf"'ltUtl
111/1'1
110( . I I"
"1", ,,, m
"'Mill.' UI,' l.t
"'"UI.I lIl.r 1.1
IIIHUU 11M I.r
"'HIlI,1 111.1 1.1
"'"1/1,1111,1 I.'
IIII'UI.I 11I.1,1.1
""IlI.lm.11.1
ll'IlUM 11M I.'
"'II 11M 111.1 ..,
IlItllIl.IIll.' '"
"'"111.5 III.! l.l
"'II Ill.' lII.r I,r
1I11lm,I JlI.I I.'
N'" Ill.' 111.1 I.t
"'"UI.I 111.1 I.'
""1m,) 11I.1 lot
lIu'lIl.1Ulol J.I
""'I'M In.1 M
"ll" 111,1 1Il.l l.l
""1111ol lll.1 1.1
lUll IU 11.1 1.\
111M n.1 fl.r 1.1
11111 n.1 II.' 1.1
Ill" n.t 11.1 I.'
..., n" 11.1 1.1
11111 ".1 fl.l 1.1
111I111 flll'lml
lI'n.'''_''I"'
-totem....4.f.t...-
'"1.11I"'.
..L!..1!!...!!LoJ..ht
-.""
...t!IJr.l.L!.-
11I1........
.-.2e:....
-:I1!<"--
l!r.L..I,,",,-
rllT~"I.""
~,.{II.J..~,
IIIMIIIII "II
Test kil cenlains hoses, adapters, diligal read,out
and prinl,eul unil wilh complele Instrudions in rugged
case.
DIMENSIDNS.WEIGHT
TK,OA TK,OP
US 9ID5
l11bS 161b$.
W~lIKl'1lcrl~)
V1ti~llllnlnngl
ilulf\'inQtJse
llllTltnSiMs
D~~Sllflcl$el
II",". 1~. "l ...
16\i"11J1i"l6"
to)
If'ln51\''
16H"I1J\'''15''
FOI Addiliona/lnlolmation, sand 101 F. TKDPrrKDR.
Fireline Detector Checks,
@/....FM~Listed
I
,\
,
I
j
Series 07F
Detector Check lor
Automatic FIre Sprinkler Systems
Sizes 4': 6" and 8"
Designed te operate In a nermal~ ciosed posi,
tionllilhlhemelerslepped. The spring lead
pre,ents Ihe main check Irem epening thus
10rcingallloWllowslhreughlhemeteredby.
pass assembly. This seNes to detecl leakage
erlhellelwalerlromlhelirelinesyslem,ln
~e"entelfire,increasednowdemandsepen
Ihe main check allelling lull 1I0w Ihrough beth
Ihe main check and the by,pass,
Supply pressure up 10 175 PSI and waler
temperatures to 1I0'Fmal,
'FOAapprovedapolycoallng,lnaldeandoul
. Ouclile Iron body
. Horizontal or va~lcallnalallltion
. Stalnlau ateal check module
(~
11])
WITH BY.PASS KIT
Designed 10 complyllilh Ihe lellowing slandards lor single deleclor valves,
Ul312 and FM Oeleclor Check Valves:
. B7F.0. same as B7F olcepl wilh lianged inlel by greoved eutiet.
. Oy.PlSS assembly kil available separately, P,'cnINS,072,753
I SI" A a eWer hI
~J ." 111'11 14'/" 7V,. 70
6" ,,/, 11, 7'lJ, 162
· a" 16'/,. 23'1.. gliAl 273
10. 16 241h gilA. 285
FOI Addi/lonal/nlormation, send lor ES.07F and S.07F.
.
No, TK-9A
8ackflow Preventer Test KII
Especial~madelorteslrngall Reduced Pressure < ,..~_
Zene Oac~io" Prevenlion Devices, II is easiiy ~ f
connecled 10 any RPZdevice enabling accurate .
teStin,gOI"'one"andreiielvalveopeningdll'!~~
'erentiallouledcheckv.vesersimiiarproblerns
Ihal,isualinspeclionscannollocale, , -
Mal, pressure 175 psi - Mal, temp, 210'F,
TesIMconlains:gauge,leSlvalves,hoses,
adaplols, Setuling s[/ap, inslruclion guide
and lighlweighl case.
For Additiona/lnformation,
serrd 101 S.FHK9A.
No. TK-? Oackflow Preventer Test KII
T esls Ihe individual check modules olthe WailS Ne, 7 Residential Dual Check,
Also used 10 leSI No, 709 and 1107,
~'
FOI Additiorrallnlormation, send 101IS.TK7.
Series 909AG Air Gaps
For use wilh 909 and 009 Senes backfJow preventers
on horizontal Installations, Can be Basily mounted
to body.
Speci~: 909,AG.A for '0", 909,AG,C lor';' ", I"
909,AG.F lor PI. ". 3", 909.AG,K for 4". 6"
909-AG-M lor B". 1 0"
Series 909EL Venl Eibows
Used with SBries 909-AD air gap lor connections
10 3A"lhrough 2" backflow preventers on vertical
Instailations,
Specity: 90o.EL.A for II", 909,EL.C for';''', I"
909,EL.F lor IY,". 2"
AIR GAP
r-~
ELatil
Iron Body f"No.Seg, OrafnDullel DImensions
No. One, ce9SI", Sin I B Wli hi
gOS,AG.A Air Gap WOOg W 2W 3'11" \llbs,
SOS.AG,C AI/Gap V," and 1" I' 3Vi" 4~" l~lbs,
gOS'AG.f AlrG.p IWlhlll3' 2' ,W 6W 3Vllbs.
'ge9,AG.K AI/Gap "Ihru6'j 3' 5~I' 91-11" 6Vilbs,
'gOS,AG.M AlrG.p 8'lhlUlO' " 7YII" 11W 15~lbs.
909-EL.A Elbow ',7" 009
SOHl.C Elba. Wandl" 2\\' 2\\' \lIb.,
Seg,El.F Elbo. lWthlll2" 3W 3W 21b.,
seS,El,1I Verllcal
Elbo. 2Wand3"
'EporjCoaled jS09MI e', 10'
For Additlonallnlolmallon, sand 101 ES.AG.909.
Inqulro wilh govarnlno aulhorilles for local requirements.
5/7~
......- ~_:- - "..-.-
\
......~..-~-......-r-
, "("""" ':' ,":.",' ..", ,'.'"
I, ", ", '"'" ' _. "8 ' ' , ' '! , , ,
~~',_ f"~';" ;:;,,;:,:, ,; '-,,~l ;,13 ';';,,' ~1 ',,' ',;':, ':":' ": ", ,~,":Y... . ,: >',
I':', 'ii,'.- ,f."'l~' ,t" "",,', ,I ",' ;,
\) I,:,l':l:\"",::,:~t~\',',"",~,,'"r~"'\, ': :',^,,', :t,;~,' ~" ~:',:~.::~r
"Engineered for high
capacity relief"
BACKFLOW PREVENTION FOR HIGH HAZARO
CROSS-CONNECTIONS and CONTAINMENT
INSTALLATIONS WITH CONTINUOUS PRESSURE
To prevent back-siphonage and backpressure of
contaminated water into the safe drinking water
supply, when Installed at each high hazard
cross.connection.
MATERIALS
Bronze body construction, durable tight-seating
rubber check valve and relief valve aBsemblies,
Bronze body ball valve test cocks. Series 9090T,
Celcon" check seats, Suffix HW stainless steel
check seats. Stainless steel relief vaive seats,
shafts, and flange bolts,
Standardly furnished with NPT bOdy connections
and quarter-turn, full port, resilient seated, bronze
ball valve shut-offs No, 9090T. Sizes %" and 1"
have Tee handle shUt-Dffs,
PRESSURE.
TEMPERATURE
Series 909 suitable for supply pressure up to
175 PSI and water temperatures up to 1400F.
Suffix HW stainless steel check modules for
water temperature up to 2100F and harsh
water conditions,
STANDARDS. See page 7,
CONNECTIONS
% ". 1" 9090T has NPT female threaded body
connections,
1 W'. 2" 9090TMl has NPT male threaded body
connections.
CAPACITY
Series 909 Sizes \\ ",1"
10
'"
.
~'5
I
~
~10
.
.
,
5,
.
.
,-
15 JO " 50
fLOW~GPM
Series 909 Sizes 1\\ ", l'h ",2"
10
",V."
. -III."
r" ,-
I
~
~10
.
.
,
5 ,
f
10 " eo " 100 110 '10 '50
6 fLOW-GI'M
REDUCED PRESSURE ZONE
Series 909 Sizes %" 102"
P"'"'14,241,752
ffi
W
Use Series 909 for backflovl protection in cross.conneclion conlrol and conlaln.
ment at the service entrance, Tha 909 hi9h capacity relief incorporates the "air.
in/water.out" principle and substanllally Improves the relief valve discharge per-
formance, The emergency condillon 01 combined back.siphonage and
backpressure with both checks fouled can deleatlhe effecllveness of a stan.
dard RPZ backflow prevenler,
For Series 009 (1'2"- 3") standard RPZ backflow prevenlers see page 10, and
send for ES.009, ES.009L and PL.BPDL,
OPTIONS (can be combined):
Suflix
S. wilh bronze strainer
HW - wilh stainless steel check modules for hot water and aggressive water condilions
LF - wilhout shut,ofl valves
Prefix U - with integral body unions ('14" and 1" only)
Prefix FAE - wilh flanged adapter ends (lVi', IVz", 2" only)
Note: The inslallalion of a drain line is recommended. When inslalling a drain line,
an air gap is necessary (see page 5), For verlical inslallallons, a venl elbow Is also
necessary and the direction of flow may be up or down lor 3A". 2",
FEATURES
. Quarter-turn ball valve shut.olls
. High capacily relief prolecllon agalnsl
combined back.slphonage/backpressure
backflow
. Modular design
. Replaceable bronze seals
. Designed pressure drop
. Simple and economical service
. No speclallools required
for servicing
-H-
Ap~,. OIUEHSIOHS P"hlll
Sill c 0 E F
BOBDT.S
3/4" 211/4 U'14 15/16 4 43/4 1 P/~ 63/4 3110 14 155/0
I" 22lf4 !1J{le75/16 4 43/4 13 7 31fo 15 Ulf1
11/4" 255/0 2G~{0 1m 5 65/0 14 1'/2 51/4 40 423/4
1'12" 213flt. 2P{4 1m 5 65/0 15 1'/2 5'/4 40 44
2" 30'/. 23&{0 lilY. 5 65/0 16 13f4 5114 40 413/0 \..>
Sond for PL-DPDL lor Illustrated price IIsl.
Inquire wllh governing authorilios for iocal requirements,
17~
~_"fII' - nIlWYM',," lft,~~t~
~ -- y-.--
.. ..~'f~--......". ~....... -.......... '-r- ._- ,.--
.. ........,..-...--
:~:> '" ,::,:,:::.i;;;;,,::,:;,:;w\'/. '::Cf..;:' ::",',:"-;>:': .,:,.'-':,:::...,:.'.\,
",,'..: "/'1- ""HI" J, 'I~" ..",7'1; " """":'" '. "'.,'
:~ :',,::': ~~~;.. :::J; .,1~f:; ~', ,4::" ',1,-". "..: .,~. I , :.:.', :' -:: "I \;..,,"1
BACKFLOW PREVENTERS
t'''')
Series 909
Sizes 2V2" 10 10"
No. 9B9NRSRW
Series 909 2v,".10 sizes provide backflow prolecllon In cross conneclion
control and conlalnment with ils unique palenled design incorporaling the
"air.ln/waler.out" principle, Slandardly lurinshed wilh non.rislng slem (NAS)
resilient wedge gale valve shut.offs No, 909NASAW
OPTIONS (can be combined):
Sufllx
S . wilh FDA approved epoxy coaled slrainer
BB . wllh bronze body (2'h ", 3"1
OSYRW . wilh UUFM resilienl sealed oulside slem and yeke gale valve shul efls
"OT . wilh quarter lurn, lull pert, resillenl sealed ball valve shut efts
"OT.FOA . lor FOA epoxy cealed ball valvo shul oils
LF. wilhoulshut elfs valv"
NOTE: The installation 01 a drain iine is recommended. When inslallin9 a drain line,
an air gap is necessary (see page 5), Forverllcallnslalfalions. an air gap should be
labricated and Ihe direction 01 flow must be (down) lor 2v.". 10",
FEATURES
(""') , Resilient Wedge gale valve shut.offs
.",,' ,FDA approvod epoxy coaled check and
rellel valves (Inside and out)
, Replaceable bronze seals
. Slalnless sleellnternal parts
, No special tools roquired
lor servicing
DIMENSIONS-WEIGHTS
Q "-"--1
I-~'~ '-',f-'--:j'I.hl
'I' ,~~Il\..~<~ IAI
I' i,Jbl~i 1~1" ill, ,~,
j :'\.?CU1UlJ:-.:,.1 -~~t '..1 --~lJuu~
J,XI" 'I ":,--_.._,..~-'
l_,' ,--. _._.1
.-., --.,
Sullll BTI"
BaUVaJveShul.oRI
~=
F~(~"', ,~~,E~
r-W~~'.~ H
, '6~irtr~~1
~'Qj<::', '
I ,-
'C-~1
Ho'e:Retio'valvosectjonlsr~efsibro;lhcre!oro,
dimension "F" can bo oneilher side. Slandard~
lumishedas s1lown, SpecllyRH il rcliel valvo is
lobosuppllcdonlho!lflpo5llosidolromslandard
StrlJnel Dlmenllons Wrlghl Clearanco Rcqulrod
Slle I X bl, for Sorvlcln Inchos
21'" I~ 6'/,. 28 SllHnlJ , " ,.
1'.',) " " " N
J' 10' r 3l , " " " "
4' Ir 81/,' 60 . N " " "
. W'. " " "
r 181h' 13'''' ISO " " " " "
8' 21'/'- Wh' 270 I,l,CIfI..-.;.bC",,1.
'hC""III/I(,1oI ;~'.
I~ 2r 181/,. J70 'O$Yff.'G"..,.."
B DIMENSIONSllnchllJ
O.S.&V, C 0 E F G H
1~1/8 ~lf4 261/8 4 9 20518 J~/B
1S'12 51f4 WID 5 9 211/4 151ft
2JJ/. 6 31 6 14Ji U5/1I121h
J21'~ 6 44'/2 11 14J. 323/4 12lh
39'1. PI. 551f, 111/, 19'/6 J9J/e 1m
48 93/. 613/012'/2 21 461la 1911
WtilhllLbl.1
NRS e.S,&Y,'
195 198
m 2Jo
455 410
718 798
',3501,455
2,1602,230
or
182
100
352
762
2286
3716
'"..-/
SIZE A HRS
2lf2"4I1/4IP/o
3"42'/4123/4
4"551/0 15Jfo
6"65'/219J/.
8"1aJ/424If2
10"935/8291/4
or
7
7
ID
15
'9
W4 261/8 4 9 20~f8 15/0
'14 26'/0 ~ 9 211/4 15/8
6 31 6 14li 21&/1112111
644112 11 14li ]1J/4121/1
J/4 ~~1/4 111/41911.. J9J/8 lni
Jf461l/s121f21 W/019V.
2112"411/4
3"421/4
4"5SI18
6" 6~1/2
8"18J/4
lO"935/e
'ULlFM npprovod backflow prllVllOlors mUll includu FM npprovcd OS&Y gale valvos.
. f8" and 10" aT moduls aVililablll, conlnel your It'i:hnieal rllprOSCnlalivll.
New Series 990 Reduced Pressure Zene Bachf/DW Prevenlers . send IDr 1:5.990
MA TERIALS
Series 909 sizes: 2'12".10" have FDA approv.
ed epoxy coated cast Iron check valve bodies
with bronze seats, and FDA approved epoxy
coated casllrDn relief valve with stainless steel
trim.
All sizes furnished with bronze body ball valve
test cocks.
No. 909NRSRW.88 for bronze body CDnstruc.
tlon. sizes 2'12", 3".
PRESSURE.
TEMPERA TURE
Suitable for supply pressure up to 175 PSI
and water temperature to 110' F.
STANDARDS
usc Manual8lh Edition t. Tested and cer.
tlfied under the following standards: A.S,S.E.
No. 1013; AWWA C511.89, CSA 884.5; UL
Classified File No. EX3185 (2".10"), Listed by
IAPMO (UPC); SBCCI (Standard Piumbi'1g
Code).
Consult your Waits representative or factory
for other state, country Dr city acceptances.
tDDes nDt indicate apprDvai stalus. ReIer ID
engineering speclficatiDn sheets IDr epprDved sizes
and prDduct numbers.
@@@
.'or
f 101
"l~
CAPACITY
Series 909 Sizes 2\\ ". 4"
3'.10"''MtHOS&YllATEYAlVES
011
~
'IS
.
o
~1J
w
~11
.
.
w
~ 9
o
3'
."
Zlft'
100 200 300 400 500
FLOW - Q,P,M,
600 700 800
Serlee 909 Slzee 6", B", 10"
14 6"
o
~ 13
~ 12
gll
c
~,o
~ 9
w
~ B
I
,I
I"
10"
o
200400 oeD BOD 1200 1000
FLOW - D,P,M,
2000 Z400
7
17~
~~..- .~--
~,
\
..-' ~ -
----- ... --....- ,.-
. ....... ..... ~~~ -~ ,..... r
,-
. ...... T - ..--' --..-.' - .....
<,'..' ",.,.',' ~--;...;~ ~ ,.< }!i~ < '. ./t'~" ';',,:\. ,"',,',: "<','<;'.:' ",:..<\
,'c' ,."",., ,1.,1,":: /2.:J",.,.i) ,..",..'., '.',' ,L,
11. ',;1".. 1,,::.Ji..;.. ',!;...ill~l.'."'''''''':'~~'\-. ..... :'~.,~~ ",,":",,":,1
'-/\"".1, ..",\..~".",J,., '. \.
BACK FLOW PREVENTION FOR lOW HAZARO
CROSS CONNECTIONS aRd CONTAINMENT.
Inslallallons wllh CDnlinuous PrBSsure
Series 770 Double Check Valve Assembly is de.
signed to preventlhe reverse flow In weter lines and
to prevent non'potabie waler from entering into Ihe
safe drinking water system. This series can be
applied 10 e variety of Installations where the degree
of hazard is considered to be low and where ap.
proved by Ihe authority having jurisdiction.
MATERIALS
Epoxy coaled (FDA approved) duclile iron valve
bodies wilh bronze removable seats and stainless
steellrim. All sizes furnished with bronze body ball
valve lest cocks.
PRESSURE-TEMPERATURE
Suitable for supply wessures up to 175 psi and
water temperalures 10 11 O'F max.
STANDARDS
USC 8" Editiont. Tesled and certified under the
following standards for double check valve backfiow
preventers: ASSE No. 1015, AWNA C510, CSA
864.5,
Consult your WaNs representative or factory for
other state, county and city acceplances,
tOoes not indicate approval. Refer to engineering sheets
for approved sizes and product numbers,
CAPACITY
DOUBLE CHECK
/---
Series 770
Sizes 4" 10 e"
Series 770 features a modular design concepl which facilitales complete
mainlenance and assembly by retaining the spring load. The first and
second check modules are inlerchangeable. Standardly furnished with ball
type test cocks and two resilient seated isolation valves. Can be installed
horizontally or vertically,
No, 770DCDA Double Check Deteclor Assembly for melering unauthorized
water usage and backflow prevenlion, Send for ES'770DCDA
OPTIONS (can be combined):
Suffix
NRSRW ,wilh resilient seated non.rising stem gates
OSYRW, with (ULJFMJ resilient seated outside slem and yoke gates
OT.FDA. epoxy coated quarter turn bait valves
OT . with quarter turn, resilient seated ball valve shutoffs
LF . without shutoffs valves
S . wilh strainer (FDA approved epoxy coating)
10
6
1
o
4"770AW FEATURES
. Replaceable bronze seats
. Stainless ste"1 internal parts
, Maximum flow at iow pressure drop
'Compact for economy combined wilh perlormance
. Design simplicity for easy maintenance
. Duclile iron bodies for maximum strenglh
PS~
I'
100 100 lOO 'DB \00 600 GPM
S 1.5 IB 1\ FPS DIMENSIONS. WEIGHTS (areapproxlmale)
PSJG
"
6" 770AW
.
lB
6
1
o 200 '00 600 600 1000 12BB "00 GPM
\ 7,\ 10 15 FPS
PS~
I'
10
8" 770AW
o
100 IDOO 1500 2000
7.5 10 lS
250B GPM
FPS
'Typical maxImum system now rale (7,5 rVsec,)
8 .,
i
'Q
c
Appro!, DIMENSIONS Onches}
OS&Y NRS Weigh I Obs.)
SIZE A B BeE I N OS&Y NAS
4' 49% 23% 15~ 4~ 9 28'. 14'A, 381 329
6' 59'. 32~ 20 6~ II 37'A fB% 701 6f7
8' 62 39'A 24 7 12 46'. 23'A, 916 1028
For Add/liona/lnlormation, sand for E5.770, E5.770DCDA or 5.770,
Now Sor/os 772 'Nilh redllced born NRSHW or OSYRW shill oils. .1", 10",
Serrcs '/720COA Ooul)le Check Oeleclor Assombly wllh OSYflW shill oils,
FOI ,"1'1'1101111111110 scnd 10' ES.772/ES.772DCDA
I
'-.-
tnqulre wilh governing authorlUes for local requirements.
17~
....,
\
\:' ,: :.':' ,:; , ),"t ",',:.:',:: ,;'- :: ':: ) l'~'; , ,:' :,:,. '~,:~ '-"~";',' :<: ,'::''::: ':<.'
,"'\" ;/""",,, I,'" !~"'''' ,', '" ' " , "'" :'"
'.~~,~' ~.~'~'" :1'~ ,;lL,;;'~.,),~~ {.' I\"i,"~~ ".:,' . '.,'". ..' ',..
VALVE ASSEMBLY
("'1
I
Series 709
Sizes 2V," to 10"
No, 709NRSRW
I
Series 709 2'/'''. 10" sizes provide backflow protection in cross.
connection control and containment. Standardly furnished with non.
rising stem (NRS) resilient wedge gate valve shut.ofts No,
709NRSRW.
OPTIONS (can be combined):
Suffix
S ' wilh FOA approved epoxy coaled strainer
aa ' with bronze body (2'12", 3")
OSYRW - with UUFM resilienl seated
outside stem and yoke gate valve shutoffs
** or ' with quarter lurn, lull port, resilient seated ball valve shul,ofts
** Or,FOA . for FDA epoxy coated ball valve shut,ofts
LF - withoul shut,ofl valves
Suffix or for G,4QBB Series
ball valvo shul,offs
, "") FEATURES
t. ,,' . Resilient Wedge gate valve shul.olls
.',.' . FDA approved epoxy ceated checks
. Replaceable bronze seals
. Slalnless sleellnlernal parts
. Maximum flow allow pressure drop
. Design slmpllclly for easy malnlenance
. No speclallools required lor servicing
Sl"rner
SIze
2'/,.
J'
l'
6'
A'
10'
Dlmenllons
I X
10. 6th'
10' r
12' Slf"
18'110 13",-
2Jl/.. 15'1,'
26' 18th'
DIMENSIONS-WEIGHTS
(are approximate)
10.;1' 'f!."
i il~~ D ~,'5.~
t. N!~.l~)J..~]0'J. ,.Eft
~.- , I
Cloaranco Rcqulrod
for Sorvlcln Inchos)
IIIH"IJ L '" N'
h,J 10 14 I' :0
4 11 11 14 U
I 1'0 21 Ie J.
I W. n 21 II
'0 18 11 11 52
\l,CIfI"''UI()rC_tI;O
'hC"I'I~1 "" ~ll'
'Osv tt.... ~....l(>l
SIZE A
2V2" J9
J" 40
4" 52
6" 62V,
I" 75
10" 90
lW' 39.1/a
J" 40.1/a
, . . f' 52318
../ 6" 6211s
I" 15
10" 90
Approl. DIMENSIONS (Inch..)
9
NnS OSIV
1 PIa W/s
IH. IIV,
IS3/s 2P/4
19.1/4321/2
24'12391/4
29'/4 48
OT
I
1
10
1\
19
21
r"fT
I~'l'
jJ}~1
~.~f~
WEICHT Lbl,
Nns osev'
161 110
161 110
360 313
621 107
1201 13e7
2e031013
OT
1501
161
115
611
14'9
1486
c 0
JV, 14
J~. I.
41/2 34
51/2411/2
6V, 52
I 6'
E f
l J
5 3
6 6
II J1h
IIV. 9
121/210'/4
31h 241/a 16 3
33/42411s 16 3
4'12 J4l/aI9JJln 6
51/2416/0 26 J1/2
6V, 51 IIV. 9
I 64 11V, lev.
. UL. FM IPP/OVld baekllowpreVli"llflmullll'(ludr FM~pprO~l'd OS&V OJtl ~,I\'t'I,
"8"t1nd 10" or models Dveilllbtll, COnlacl YOur technIcal rllpresenlollvo.
,
MA TERIALS
Series 709 sizes: 2W'. 10" have FDA approv-
ed epoxy coaled cast iron check vaive bodies
with bronze seats. Ail sizes furnished with
bronze body ball valve lest cocks.
No, 709NRSRW.BB for bronze body construc-
tion, sizes 2'h", 3lt,
PRESSURE. TEMPERA TURE
Sizes 2W' through 10" are suitable for
supply pressures up to 175 PSI and water
temperatures to 110'F max,
STANDARDS
usc ManualBth Edition t. Tested and cer-
tified under the foilDwing standards: A.S,S.E.
No. 1015; AWNA C510-B9, CSA B64.5; UL
Classified File No. EX31B5 (2"- 10"). Usted by
IAPMO (UPC); SBCCI (Standard Plumbing
Code).
Consult your Watts representative or factory
for Dlher state, country or city acceptances.
IDoes not indicate approvai status. ReIer to
engineering specification sheets lor approved sizes
and product numbers.
@@@
864 g'"
. ,
..,l.
CAP ACITV
3""0"WlTHOS&VllATEVAl.VES
SerIes 709 Sizes 2'. n, 3", 4"
1B
2W'
3"
~ 0
~
,
.
06
.
o
.
~ .
~
.
~ I
."
o
o
f
10
~
.
o
..
.
o
~
~ I
.
100 '00 '00 'DB '00 600
FLOW-GPM
Serios 709 Slles 6", B", 10"
6"
,..
10"
o
200 400 GOO 800 IlIDO 12001400 1600 1800 2000 2300
flOW-G.P,M,
/7Q.
,.
---
\
~--
'Y'""'-
-
.~
\: :::':', ""t]I....;.' ':.'::9:-"> ....~i< : .'.", :'.:'. ':,'. :',:>,,:: .' .:::'
." . , ,/ .' .', '11{,W. . '. " . ' "
t.'::," .'(,I:~'. :~.~ 'l.,..:; ",.,:,~~....:~ ,~;~;.: ,". ." " "'."'~,:""'."" ',::,
I", ['i'~~-n
EblVo;l)~, iOl'!.HLgJOO~' ~l
ll~''''
'____'c['!'.
--+=A--
Series 009
Standard Reduced Pressure Zone Backflow Preventer
Sizes: 'h ". 3"
Series 009 8ackllow Prevenlers are designed 10 provide proteclion of the safe drink.
lng water supply In accOIdanco with naUona! plumbing codes and waler ulility authori.
ty requirements, They cen be utilized In backflow prevention programs, Including high
hazard cross.conneclions in plumbing syslems, or for containmenl allhe service line
entrance,
This serios fealures (wo In-line, independenl check valves wilh an intermediate relief
velve, All sizes are conslrucled with NPT body connections, Slanderdly furnished wilh
belllype tesl cocks and quarter.lurn, full port, resiliant seated bronze ball valve shut,
oils (II". 2") No. 0090T. %,'.1" have Tee handle shut.ofls, Sizes 2%" end 3" have
resilient wedge NRS flanged gote valve shul.ofls No, 009NRSRW.
. Raplaceable seals . No .pecl.ltcol. required lor ..rvlclng . Modular construcllon
STANDARDS: USC Manual 8th Edllionl, Tesled and cerlified under Ihe follolling standards fOlred",
ed pressure zone backllow plCventers: A.S,S,E, Sid, No, 1013. AWWA Sid, No, CSII.B9, IAPMO
lisled3J4 ".3", IDocsnolindiCJ'capptcl'3/s/atus,R,!Icrlocnginectingspco5cilwnshcclsfOlJappIOI'cd5ilcS
and produdtlumbels.
PRESSURE.TEMPERA TURE
Supply pressure up 10175 PSI. Waler lemp, 'h". 2" 140'F
constanl, lBO.F Intermillen!. 2'h". 3" 110'F
OPTIONS (can be comblnedl
Sizes: Ih ". 2"
Prenx U. unIon connections
sun. S.lIith bronze stralnar
LF .lIilhout shul,olls vawes
Sizes: 2'h II and 3"
sum. S .lIilh epOlY COaled slralnar
OSYRW ' llilh resilianl wedge outside slem & yoke shut,olls
QT.llilh qualar.luln,fullpM,resilienlsealed ball valve shut,ells
LF.llithoulshul,ollvalves
OT,FOA . wllh epoxy coaled ball vawe shut,offs
~
~lt-
~@ ~~
@@ _ Slz8e2'/>" 3"
B~84 DOi~~~ - +~;;:n '
L[ ~-j)J
-H- --D-7A 0 ~J
No,OO9QT
/',
I
Aldimeslons areapplolimale.
Sizes ~11_2"
Dlmuslonllln'hul
co,
<Y,
"
~, - ~
5'1 2Y. 5'1 IY
5 - - &'1,
5 2Y. 6'1. G'I
WIII~l
Ib,
4'1.
S'I
"
"
S,
"
Slm'/>".2"
-:J . .
SIll No.
0090' ro 2'1'1
V' 0090r.s 13 "
". I
V' l)OiQl.S 19'1 "
OOgl,l2QT 11\1, '.
V' 0091,4201-2 16'1 JV
16Y' .
,. OOgOI-S "I
, 4Y
...!L 009UIOf.S 27V
I, 4';
...!r.. OOQI,lllll.S 'I'
II, I
,. 009Ulllf.S 21", 4'1,
7V,
,
5'1 3/': &Y.
IY. 15Y
Sin Ho.
cotOSYRW
2",' COIOY
ootHASRW
ootOSYRW
3" DOtal
OOII1RSRW
For complete informalion. send for engineering spec, sheets E5.0095 and E5,009L
Inqulra wllh govarnlng authoriJles for local raquiraments.
-,
@""
"'" .f,
'" .
~@ ~@ JL,
..,
m\C'i.'
Series 007 Size: % ". 3"
Double Check Valve Assembly
Series 007 Double Check Valve Assembly Is designed 10 provide protection of Ihe safo
drinking water supply In accordance wilh nalional plumbing codes and water utility
aulhorily requlremenls for conlalnment altha service line enlrance. They can be ap.
piled 10 a varlely of Installalions where the degree of hazard is considered 10 be low,
All sizes can be Installed horizontally or verJlcally and are slendardly furnished wilh
beillype lest cocka and quarter.lurn, full port, resllienl seated bronze bell velve shut,
offs IW'. 2"1 No, 0070T. '10".1" hava Tee handle shul,offs, Sizes 2\\" and 3" have
rcalllenl wedge NRS flanged gate valve shul.offs No. 007NRSRW.
. Replaceable leal. II No .pecl.llocll required fer ..rvlclng II Modul.r conslrucllon
. STANOARDS: USC Manual81h Edilionl. Teslod and certified under Ihe following standards fDl dou.
ble chock valve assemblies: A,S,S,E, Sid, No. IBIS, AWWA Std, No, CSIO,B9, IAPMO tislod '1. ".
3", lOt>es not Indicato approval ,Ialus. R~ftl /0 cngiMCriog sheets /(Ii applcved siles and plOOucl lIumtlclS,
~~t.~y',:~~"'lrl;dtc~
D~" Ff
'\,. 007 JA", 1"
PRESSURE. TEMPERATURE
Supp~ pressura up 10 175 PSI. Walerlemp, II". 2" oo7140'F
constent. IBO'F Inlermillent. 211". 3" 110'F.
OPTIONS (can be comblnedl
Sizes: 1'4 ".2"
Prellx U. union conncclions
Sufi. S, willi bronza slrainer
LF.llilhoulshut,ollsvalvos
Slz88: 2\\" and 3"
Sulll. OSYRW .lIilh resilienl wedge "Isida stom & yoke shul,ells
OT. wilh qualer.l"n. full pOll. rasilient seated ball v,we shul,eils
LF.llilhoulshul,ellvalvcs
OT.FDA . wilh epoxy ce,lOd boll valvo shul,oils
~~l.':!!i!JI
No.D07Ml0T(Y,'.2"1
No,OB7M20TII\"1
-I
.
-'
I
,
I
~.
-,
SIZ8S lf4" to 2"
llIl1l1nlJan ~nchlll WI'
A I C 0 , Ib"
ID 2'1'1 . S ,.
IJ 2'J.. , S s.
'2' 'II< $\I, - 'e
II' .' S'L '" - II
13\~ "h< 5\\ - 'I
11'\14 "h< S~ 3" 1\1 - "
, ,.
" '" ,. '" II. ~
23" H\ II. ~
31V/ HI '" "' "
11'.~ 3\\ S
1m 3'.\ s', - SlI
I I
lJ;l~,1 "Wii
, Ibl,
HI 15',) '"
7\. 6 "s
1\1 1m ISl
, '6. ,~
ell , ISl
ell 12\\ '"
17~
Silt No.
. If' 'DOlOI
IOGJOM
* W' 001111101
0011111.
* 1" DOnUOT
oaf/UGH
1"" OOIQT
* 1 ,.
* I" 00101
"TO'"
. \\" oonU01
DOUIlOT.'
SIZ8S 2\1" 8Rd 3"
Model
007M20r
007M20T.S
007M2LF
C Wldlh Welghl
2Vi' Sib..
3 2Vi' 71b.,
2W' 31b.,
51.. A B
~" 11'1.' 3"t
J,l" 14111" 3"."
~" 611t 3'1."
Sin No.
-OOlOSYRW
2YJ"OOJOT
* 001HA$AW
. OOJOnRW
3" OOlOT
OOJIIRSRW
1 ~ ~ For complolo Inform"'ion. send 101 onginooli/lg spec, sheots E5,0075. E5,OOlL .1nd E5,007M20r.
....,
\
.....
~ -
"....
-
.. ............, ...... ~- .....r .,...,...-
--r- ---
I>> \;:~l:" ,,~.;:lit\;',,:';;Zi:'\,:, rn.::',':,~' ~ ,:,:,,'.. :,:'::', ',\:':,"': :~::~i"
\~, . (,'t, ,'",<~J'~:~]I,,~,':,:...EJ. ,L 10. :" : ..,'I ','" ,','I)'.'n.
'. ,....... ,"'\ '~...~\1.' '_ I' '. ,'. . ":. _ j .,r
Double Check Detector Assembly/Reduced Pressure
Detector Assembly
Series 709DCDAl909RPDA
.
i
I
"
t
\
\:
I
No.709DCDAOSYRW.CFM
~
I
i
,
I
,
1
Series 709DCDA and 909RPDA are designed to prevent the
reverse flow of fire protection system substances, Le., glycerin
welling agents, stagnant waler and water of non.potable quality
from being pumped orsyphDned Into the safe drinking water system.
Detects leaks, . . with emphasis on the cost of unaccountable
water; incorporates a meter which allows the waler utility to:
· Detect leaks underground that historically create great
annual cost due to waste.
. It provides a detection point for unauthorized use.
It can help iocate illegal taps.
Modular check desl9n concept lacililales mainlanance and assembly
access. AII709DCDA sizes are slandardly equipped wilh AWWA epoxy
coated UUFM IIsled OS&Y 9ate valves, CFM (cubic feet per minute) %"
x 3,," meter and ball type test cocks.
, .'\ Series 909RPDA Reduced Pressure Delector Assembly: When applications call lor
I ."r' maximum proteclion, use 909RPOA wilh reliel venlto atmosphere.
FEATURES . No specialteols required
. Resilient wedge shut.ofls . ~:~::\c::~ economy
. Body conslrucllon epoxy combined Wllh perlormance
coated cast Iron
. Replaceable bronze seals . Design slmpllclly for easy
maintenance
. Stainless sleel internal parls . Furnished wllh Recordall W' bronze
. Max, flow allow pressure drop meter, model 25, see opllons
j
"
,~
DIMENSIONS-WEIGHTS (are approximate)
"-I
c:::::::,=I_::J L-=:~l=::)
n OPEN ft G
~ t ~,lf )ltEN
~Ir~r
.1Chotkllstl "I ,,2Chock!2ndl I f'\.:J'-:_L
S_I+-S_I.20"'1
A .~E.
F I
-=-
r. 0,,,
E+ I
Size
3"
DIMENSIONS IInch.d
!l' fIl~
tl ~
~~
~. !:5
C 0 E F F 9
7'n 7 B 49 421/, IB~
9 10 9 52 55'/11 13%
11 15 lOin 62'n 65'/2 32~
13 10 lI'n 75 783/, 39%
1622 13 OB 03'/n 48
WElGIIT ILh'"
!l'
{Y" ~~
~ ~
"c:s. ~.
II J OS&Y OS&V
3 14 190 25B
6 15 4B3 40B
8 16 727 B2B
o 171327 1666
IB'I,IB 2B03 2250
. UL, FMopproYlld bockllowprovllnlOrSmU51 includo FMopprovod OS&Y gOlllVlllvos,
Ne~ PQORPOA Reducod Pressure On/oclor Assombly 4". 8" Send lor ES.990RPOA.
MA TERIALS
Epoxy coated cast iron body, bronze seal and disc
holder; slainless steel trim and durable, light.sealing
rubber check valve discs.
All sizes furnished wilh bronze body ball valve test
cocks.
Furnished wlJh oulside slem and yoke (OS&Y) gate
valves.
No. 709DCDA by.pass line unit conslsls of an ep.
proved No. 709 double check valve essembly end
water meier,
No. 909RPDA by.pass line unlJ consists of a
No. 009 reduced pressure zone backfJow preventer
and waler meter.
Send for PL.BPDL for lIIustraled price list.
OPTIONS (can be combined):
Sulll!
CFM. wilh cubic feel per minute meler
OPM . wilh gallons per minute meler
LF.wilhoulshut.ollvalves
PRESSURE. TEMPERATURE
Sizes 3" through 10" are sulJable for supply
pressures up to 175 PSI and waterlemperatures to
110'F maximum.
STANDARDS
USC Manual Blh Ediliont, 709DCDA meets Dr
excseds the following standards for double
check valve assemblies: A.S's,E. Std. No.
1048, (1047 for 909RPDA), AWWA Std,
C510.89 (C511.89) for 909RPDA), UL
classified file No, EX3185, listed under CSA
864 standard.
tDoes not indicate approval stalus. Refer to
engineering specification sheets for approved
sizes and product numbers
~~@,@ ~
'!J~ w...ou.,,,..._
CAPACITY
Series 7090CDA Blzes 3" & 4"
14
~ 12
~
.
I 10
.
~ a
a
w 6
~
~ 4
~
w
~ 2
.
'..10',~
"
."
o
60 100 150200250300350 400450500 550600
FLOW - G,P,M,
SerleB 7090COA Sizes 6," 0" 10"
20
~ Ie
~ 16
114
~ 12
~ 10
~ e
~ 0
~ 4
~
. 2
o
..
.
"
10"
500 1000 1500 200025003000 3500 40004500 5000
FLOW - G,P.M.
I ,1:J.
'"
:;, ",<,'1' : '.. ;':f'tr,'<,', !.Jfd-' ;):;:. ;j~';. "'" ,:-, .-:"-',: \!:. ':',<-::\:
I.. """1 . . 1 \1 . '. "~, ,', . I" 1\,..
j .... ., ~. "" \ ~ :' " . . ' , .' . ' I ", " ' ',,' \ ,.',' '.,
\....:', ,',\'!\ .>,,,:"" ;\~~ ,;,': t~,~~.,'". ':'~\" M ;!'. ," ',', .-' ','I, ' " ' -.i ,',,'
FOR lOW HAZARO APPLICATIONS -
RESIDENTIAL SYSTEM CONTAINMENT -
Installations wllh Conllnuous Pressuro
One er mere cross-connections may exist in any domeslic waler
supply syslem, Cross,conneclions usuaUy are created without the
knowledge 01 local plumbing and heaUh Inspectors. Usually Ihe
individuals responsible lor creating them are not aware 01 it Also,
service COnl/aclors, e~erminalors or ethers using the domestic
waler supply fail 10 lake precautions againsl backllow, Backllew
hazards originating in domestic water supply systems lowner
systemsl are beyond the jurisdiction elthe wator purveyor toconlrel,
The No, 7 Ouel Check pro~des protec~on lor the public waler supp.
Iy (waler purveyer systemsj againsl backllow hazards originating
in Ihe owner syslem, Also, Ihe lowner waler supply syslemj needs
suitable backllow preventers al all cross. connections 10 prelect
drinking waler against backllow hazards, lor the benem of the
homeowner. The No.7 is designed 10 prevent the reverse 1I0w
el waler, Installation is downsteam Irom residenlial waler meters,
II is recommended thai all water outlels including sill cocks, toilel
ball cocks, ets" be downstream and Ihatlhe ewner's supply syslem
must be In compliance with federal, slale and local codes,
A properly instaUed andlnspecleddomeslicwalersupplysyslem
isthe 1st line ofdelense for quali~drinklngwater,lnstallationef
the dual check valve has become relied upon as a 2nd line 01
defense. For more on "2nd line 01 defense", send for F.DCV and
F-BDL.
Anyone or more 01 the fellowing conditions not protected with a
proper backllew preventer oller polential backllow hazards:
. Hose aUached garden spray bollles
. Lawn sprinkler systems
. Balh lub whlrlpeol adaptors
. Hollubs
,Wetercloset bowl deodorizer
. WeUs Iback.up water syslemj
. Photo developing darkrooms
. Exterminator's equipmenl misapplied
Nole: If a known water syslem health hazard Is discovered by
survey, consult stale erlecal health officials for more stringonl
protection.
Quick hook.up flJllngswllhlemplete
for new or retrofIJ Installallon 01 No, 7
No soldering required, Send lor S.DCJ,
No.J.U.OCJ,PJ,No,7"'lhpack~rnl
adaplersoninletandOUllel~,
connections. . .
~. ~. .
, ) ,~' .'"
.. ~ -,.1 . ,
Ho.J.U6-0CJ.SG,No,7I'.ithsuperoripadaplers
oninletandoutletconnections_,."
.. i'~' .
, '"' ~,.
. 11'\ !
Series A7 Angle dual check backllow
preventer. Tested to meel or exceed the 1988 revi,
sion el ANSIIASSE Slandard 1024, Max pressure
175 psi Max, Temp, 140'F, Easy in,line sel'lice, Cost
brenze body, Inlet: II" & ~." yoko er~." melor
couplingconnections,Outlol:~."inlemaleironpipe,
lIared copper, compression tube or super grip lubes
connections, Lenglh 3'1," Height 4'h" Wgtllbs,
tOoz,
,"
.~I",
;!I.
,
12
Inquire wilh governing aUlherities lor local requlremenls,
)
RESIDENTIAL DUAL CHECK V J
(~i
Series 7
Sizes: W' thru 1 V4"
Provides backllow proteclion by containment at the water meter. Th~ Dual
Chotk is a versatile backllow preventer. II operales elficienlly in the horizontal
or the vertical position and under intermillenl or continuous pressure. The
No, 7 valve can be supplied in an extensive combination of inlel/outfet size,
type of Ihread and type of connection,
Send for PI.7 illustrating the diflerent combinations:
INLET/OUTlET CONNECTIONS
The leller "U" is used in prefix to Ihetype of Ihread and designales union
connection, A union conneclion can be supplied on inlel/outfet or both. The
example below indicates a 34" inlet x '4" out/et No.7 wilh 34" NPTthread-
ed female union inlet x 3/,' NPT threaded lemale oullet.
Example: SIZE SEA'"~
INlET OUTlET Ha.
SUFFIX fOR
CONNECTIONS
INlET Dunn
%" X %" - 7 - U2 - 2
SUFFIXiSIl[S:
U.UmonConnec1lonll1",l,'".''', W."' f1,Pack!Ointrnale1f', 1". James Jones
2. NPTf thread female \'2", II"', r' 8. Female s\'jeal Ill", ~l". '"
3. NPTM thread male IIJ", ~'i". 1", moo g. Male S\\'UI','l".l.I". \"
'4. Melerlhread rema!e )1", ''', 11:." 10. Female meter lhread (sWlvelll,f', 1". lW'
'S. Melerlhread male 'r', 1". P,l" 11, HIM Male hose thread W'
6. PaCklcllnt female li". 1" 12.HTF Female hose thread l,\"
CONNECTlONSIABBREVlATlONS:
U. Union PJF. Pack Joinl female \.....
HPTf. National Pipe Tapere<l Female fPJM. Pack Joinl Male. James Jones
HPTM . Nahonal Pipe Tapered Male MTSF . Meter Thread Female (Swivel)
'(4) HHF. Nalional Hose Straight Female HiM. Hose Thread Male (Garden Hose)
lMeler Thread Female) HTF. Hose Thread female,IGardenHosel
'(5) NHM. National Hose Straight Male BSPPF. BulishStandard Pipe Parallel Female
(MeIer Thread Male) BSPPM. BulishStandard Pipe Parallel Male
'Meleltllludconneclions
fRequires cempl,I, pack joinl assembly manul,clured by James Jen,s
When ordering No.7 vBlve wllh m,ler Ihread connecllon, order
Ihe conn,cllon one size lerger thBn Ihe waler meter size.
I, '11" and \\" Wlttl meltl; crder V."meltrlhrud connectlcn.
2. 'n" and v,"wattr meltli order l"melellhuld ccnnetllcn.
3. l"waler melelj older W."meln Ihlud tonnttllon,
'01..
Send lor PL.7 lor illustrated price list.
No. 78 Cempacl
design dual check
backl/ow prevenler
simitar to Iho Se.ios 7
in machined brassconslruclion, Max, pressure 15B psr.
Max.lemp. 140'F, Tested and cortilied 10 meet er ex.
ceed Ihe t98B revlslen 01 ANSI/ASSE Standard 1024,
~, " inlet and eul/ot, NPT Ihroaded connections, No,
7BU2,2 has lomalo union inlet x lemalo euUer.
No.7B3,U2 has male inlet x female union ouUor. No.
7BU2.U2 has lomalo union inlol x lomale union ouUet
Lenglh 4", HelghIIY,", Weight lib,
For additionnl inlolmallon, serd lor ES./B
, ..
~-I''/
17,;2:.-
.
0;,;:.. .:.I',;...,'.....ft'...;',:JiZ,. <";iC0:':,: '-"-":';'.::::: ;",;.',<:;"~;~
i,l 1,1.. , , 1':1. . . \ '~~ " . '~, ,.;..' , , I'. ,. "
1.\,', '. >1\. ;!, ,\~ ,; . :(.~,' '\""~\....;,'; ,(,",'. _'.' .:, ,", ..:~," ',\ . ~'.~'
~1 VE BACKFLOW PREVENTERS
,
r'J
No. 7 can be inslalled in many varied piping cenliguralions and in conjunclion with a
wide varie~ 01 meler horns, copper sellers, easy seller relrolil adaplers and meler boxes,
BACK FLOW PREVENTERS and METER SETTERS
For inlormalion on Walls easy,seller relrefit adapler with dual check backnow prevenler,
send lor S.WES2-/. Fer pil sellers, send ler S.WHPS,
INSTAllATIONS
r.
'I," RESIDENTIAL INSTALATION
Wrenchllats(oplionall
t: PI \ 't"'7'U4'3
.;" ~~~:lP FLOW
:.<.' ~
;*"WaterMeter.PJ .
I . ~ ([,:::::--.-:::;1 CUSTOMER
S'OE
,
.\.:';:' :-::r.~:':o~:"T'.~I~
.:~':; : 'J
. ..,.,.
h~ ., '..
07S INSTALLATION
\
A7 INSTALLATION
~/'
"'b
SUftLy
No. 075 Resldon.
lialfirosprinklorsyslem
dual chock backnow
proventer. No. 075 is
dosigned lor wntainmonl coolrol programs and inslalla.
lion at tho lira sprinkler sovlw enlrnnce. Inquiro with
, governlngauthorilioslorlecallnslallalienrequiremonls,
',.../ Casl bronze body. Max prassura 175 psI. Max lamp.
140'F. ANSI/ASSE Slandard 1024, CSA Slandard No.
B64.G. NFPA SlandBld 130. Sizo I" NPT. Femala union
inial X fomale eullal conneclions. Lenglh 6V. ", Haight
2'r,,", Weight3lbs. 5ez.
For nddiilonallalormalion, send lor 8,078
.,
WES2.7 RESIDENTIAL RETROFIT
1"x1"
" /7'U4'5
;'.. WUH
,;', '-C\ ".pl
" . ;,1'-', ul,Ung
.': (j!~~.!)) melm
.... ~}~I;;ffi?
", ,.
sum, ;~;.. N.1 now
.", .t..:...! =~
..~~ """'......uI_N."'"
.:...1":.................,......-.
'......:'....loUrl"'B._I__
RETROFIT METER BOX
I"x 1",7.U4.5
PIT SETTER
MA TERIALS-
CONSTRUCTION
Cast bronzo body. two durable plasllc check mod UIBS I njeclod
molded 01 ACBlyl RBsln . siliconB disc and Buna "N" seals.
slalnless sleel spljngs, one union and "0" ring union seal.
Slraightline poppellype conslruclion minimizes pressurB
drop and provides smooth flow characlerislics. Ills not
adversely affected by normal line pressure surges, will nol
causewatBrhammBrand oBeraleswithoutchanerolvibralion.
PRESSURE. TEMPERATURE
Max. pressure . 150psl, Mln pressure .IOpsi
Working temperatura. 33F'to 140F' sustained (imermlllent
101BO'F)
CAPACITY
Series 7 sizes: %", 1"
,,'
o
~
I
. "
~
Q
W
.
r
.
"
.-
"
.
"
.
flOW-GPM
STANDARDS
Tesled and cortified to meat or excBBd the 19BB revision of
ANSI/ASSE Sid. 1024. CSA cBrtiffed to Sid. No. B64.6
@@
FIELD TESTING
Each valvB Is packaged with Inslallallon and IBsling procedurBs.
Bolh checkmoduloscan bB removBd from IhB body and check
Independenlly with Wans No. TK.7test kit (m page 5).
DIMESIONS-WEIGHT
-1- T
25116" 13/4"
_L~
--'='I_L
143/8"-+1
Welghl: 1Ib" 12 01,
'0/"', 1" NPT m~del only,
t......
tt..........
ThB answer 10 thermal 1i! ~
.~~~~~~I~~.P!~~t~T~. \;w" \Y.~~
"Watts"') Governor 80" [II I
Ball Cock Relief Valve I
A Iriple purpose producl: loilellank ball cock fill valve,anli.slphon ;
backUew prevenler and Ihermal expansieo reliel volve, In ono 'I'
assembly, II is Lisled by IAPMO ond CSA corllfiod lor anll,slphon ~' I
ball cocks, FOA approved under CFR,21.177.2600, ANSIIA,S,S,E.
No. 1002. II will govern ond limlltho domeslic walor syslam preset ,
sialic pressure 10 BB psi as requirod by plumbing codos,Eliminnle s
Iho need for thermal oxpansion lanks, auxiliary roliol valvos and
Iheir dlschorge linos. Fer more informalian sand lor folder F.BO.
i?,-
'....
,~:"'. . : ;/,'/": ::';'f,i," ",\;~';""> \~' ';', :', '::' -: :.:;', ','0.:',:: .,.:,",:,:",,::,.:'
I I . " ,I t' ." ~. I . f' ' \' , I
,.1 :' ':~'. I '.. ~\ ".:', :'1~"./..,,1~., . ",' ,.', '~ "'1
.,," ,\ . '~'" ~~1 ,,' -t, ." " )1,., " . .,
BACKFLOW PREVENTER WITH
VENT, CONTINUOUS PRESSURE
BACKFlOW PREVENTION FOR lOW HAZARD
CROSS-CONNECTIONS - INSTAllATIONS
WITH CONTINUOUS PRESSURE
Walts No, 90 Is a backflow praventer specially
made for low flow supply lines. Its purpose is to
prevent the flow of polluted water back into the
safe drinking water supply and can be installed
on a variety of low hazard applications.
APPLlCA TIONS
Because It protects against both back-siphonage
and backpressure, No. 90 can be Installed on
laboratory equipment, processing tanks,
sterilizers, dairy equipment and other such in.
stallations, Particularly recommended for residen-
tial boiler feed lines to prevent backflDw when
supply pressure falls below heating system
pressure. Sullable for use under continuous
pressure. Install ellher horizontally or vertically.
INSTALLATIONS
RESIDENTIAL BOilER INSTAllATION
\
SUPPLY
BOILER
liVESTOCK DRINKING FOUNTAINS
UPSTREAM
CBH1ROL
VALVE
~WA1ER
SUPPLY
LINE
onlNKINBCUPS
No. 90
FEATURES
. Backflow preventer alt bronze construction
. Stainless steel Internal parts
. Maximum flow at low pressure drop
. Size \I," and %" furnished with union connections to
facilitate removal and replacement for maintenance
. Inlet and outlet No. 90 threaded or No, 90S sweat
connections
. Compact for economy combined with performance
. Bultt-In strainer
. Design simplicity for easy maintenance
Note: In Canada Supplied With Non-Threaded Vent
To Comply With CSA B64,3.
HOW IT OPERATES
2 5 4
NORMAL FLOW - CHECKS OPEN -
VENT CLOSED
With flow through valve, primary check (1) opens away from
diaphragm seal (2), Atmospheric vent remains closed by
deflection of diaphragm seal (2), Secondary check (4) opens
away from downstream seat (5) permitting flow 01 water
through valve.
.
\"~....,,
141
Inquire with governing authorities lor local roqulromenls,
I~
......
.......,--...... fF--
- r .-__.~_ '-r ., ..... _
...- --
...-...,--~ ,.--
~ ~ T'-----.-~
'(~',:, .,.;.:,:.'~ :,.',..:,;:.. '.:::,.'.'.;;./>':::: .,',' .,..',,:-:,,;::.::.,:,,;<\
" ..I,.,.. J." "LI"", "". . , ..
l~,', I" ~, " ,;."r~, ',"1.; :,.T1,'.:,'. '. ,:~' "." . ,: ,.' '. _ . '" "'. .
\. ", '\\'. \.,,\ .\~\ ."~'.' ..1./\\. ','.,' "
INTERMEDIATE ATMOSPHERIC
TYPE FOR LOW HAZARDS
,~
I \
I
5 4
NEGATIVE SUPPLY PRESSURE-
CHECKS CLOSED - VENT OPEN
With a back-siphonage condition created, secondary check
(4) seals tightly against downstream seat (5). Primary check
(1) seals tightly against diaphragm (2). Atmospheric vent (3)
is now open permitting air to enter air break chamber. In the
event of fouling of downstream check valve, leakage would
be vented to atmosphere through the vent port thereby
safeguarding the safe drinking water system from
contaminalion.
"""""\
I '
....,/
IMPORTANT: This valve should only be used and properly
installed so that spillage of water could not cause damage,
Series 911
Comblnallon BACKFlOW PREVENTER and
HOT WATER BOILER Fill VALVE
No, 90 and No, 1156F in one pre-assembled unit.
The safety of the Walls No. 90 backflow preventer
and the reliability of the
Walls No. 1156F high
capacity feed water
pressure regulator for
hydronlc heating system applications,
No. 911 . W' x W' threaded connections.
No, 911 S . W' union sweat iniet x W' threaded outiet.
No, B911, B911S. Same as above, except bronze,
Height: 5'1<" lenglh: 8'12" Welghl: 4 Ibs.
RESIOENTIAL BOILER INSTALLATION
n;PLY Id9','
lh&~ "'~4 .
-- ~.
DRAINJ
BBlLER
-
nETURN
STANDARDS
Tested and certified under
A.S.S.E. Standard 1012 and
C.SA 864,3,
@@
PRESSURE~EMPERATURE
For working supply pressures up to 175 PSI
and emergency backflow temperatures up to
250 OF. Can be Installed vertically or
horizontally.
CAPACITY
~
~~
~
,M
.
o
~1I
W
~
~IO
~
W
lEI
CONSTRUCTION
No. 90 Is suitable for either hot or cold water
service. It features bronze construction and a
primary check valve utilizing a soft disc which
seats against a rubber mating part to ensure
tight closing.
A secondary check valve utilizes a soft diBC-
to-metal Beating. Double check feature design
assures pDsltlva protection.
Bronze body construction with stainless steel
working parts and durable rubber diaphragm
and disc. Standardly furnished with an integral
strainer,
OPTIONS:
Suffix SC . for satin chrome finish,
Suffix S . tor union end sweat connections,
DIMENSIONS-WEIGHT
N -I
D. 90 i=C-I-D~'
Size DIMENSIONS finches!
finches! A D C 0
1/2,3/4 41/0 21/2 27/0 21/32
Drain connection W' female
Welht
13/4Ibs.
l>;.
"...
", '" ,,' I . . ...., " ,.,.;' "':,1, {""lll
' " ,.~. ....... '8'" '" --' ',,'.,
,," ..:.':: :"" \, i'; ; :,.1",: 'I : ':',"" .:' ','.', ::.'
I; ',' ,",-1", I: ,I.. .. , ",If:/, ) I ",,' '" I ", ..
\:":",~.,'"<\" i~'.'J";I"~~~::-: <:-~'~""", .:~ ,,:. ,.,' '. ',', . .~ . - ~,_
VACUUM BREAI{ERS fOR IN-LINE
APPLICATIONS
FOR LAB FAUCETS
Walls No, NLF9 is a back.siphonage preventer
specially made for laboratory faucets where
hoses can be attached. Its purpose is to prevent
the flow of contaminated water back into the safe
drinking water supply and can be installed on
new or existing faucets without plumbing
changes.
Not deSigned for continuous pressure ap.
pllcatlons. For continuous pressure appllca.
tions, use No, N9 or 'Is" No.7 shown below.
No, NLF9 shouid be Installed on every
laboratory Dutiet where a hose can be allached.
Horizontal or vertical Installallon. Its unique
design offers full protection against back.
siphonage conditions.
To prevent tampering, the NLF9 should be
secured to the laboratory faucet with Loclile.
Leboratory Fauceta
~
'. &~
111'-1\llIDII'''\I'."n.oji_V. -
\
CONSTRUCTION
No. NLF9 for either hot or cold water service.
Brass construction, primary check valve utiliz.
Ing a soft disc which seats against a soft rubber
mating part, A secondary check valve utilizes a
soft disc.te metal seating, better.than.average
flow rate and consequently lower pressure loss.
BraBs body with pol/shed chrome plating,
stainless steel working parts, and durable rub.
ber diaphragm and disc.
STANDARDS
No. NLF9 tested and certified under
ANSIIA.S.S.E, Std. 1035 "Laboratory Faucel
Vacuum Breakers" and CSA STD B64.7,
Model N9
For Conllnuous Pressure Appllcallons
Similar to NLF9 excepl furnished '
with V4" or%" female inlet and oullet
connections, for In.llne conllnuous
pressure appllcallons.
Certified 10 CSA 864.8
No. N9C ' polished chrome,
For additional info, send tor ES.NLF9IN9,
16,."
Tested and Cerlified 10 meel or
No. 7C . Size 3/0" exccedANSI/ASSESlandardI024.
Dual Check Backflow Preventer
(For In.line continuous pressure applications)
Especially recommended for low hazard applicallons, no
relief feature, Used for shampoo sinks or similar applicallons
requiring 'AI" female connection for convenient allachmen!.
OPTIONS,
. '/a" No, 7 - Plain brass (Nol A,S,S.E, cerrified)
. 'Ia" N7C, 'fa" H7 - Slandard No, 7C or
No, 7 willi hose conneclion litllng,
. HK.7 - Conversion kilto connect W' NPT
10 'Ii' hose thread connecllon,
Parlor Slnka
@@
~
No, NlF9
SIZB: !fa"
Weight 6 oz.
HOW IT OPERATES
rr}
Valve Opened Flowing
Under Pressure
Wilh lIow Ihrough valve. primary
check (1) opens away Irom
diaphragm seal (2), Almospheric
pori (3) remain ciosed by dalleclion
01 diaphragm seal, Secondary check
(4) opens away from downslream
seal parmillingliow 01 waler Ihrough
valve.
CAPACITY
Vaive Closed by Beck.slphonage (
In System
Wilh a back.slphonage con dillon,
secondary check seals Iighlly
agaInst downstream seat. Primary
check seals againsl diaphragm, At.
mosp~eric port Is open permilting air
10 enler air break chamber, in Ihe
evenl 01 fouling of downslream
check valve. leakage would be
venled 10 almosphere Ihrough the
venl port,
@@
--
~ ..,' ~
.. , '...,)
."~ '"",,,' 1\<',
, 'i.o'),'iJ, ~,~.l.
- No.7e
".~"./".'''''..
) ~"ID
, 'or~ JIOll UII'
~~,:~'1C
0'"
'\,=
Inquire with governing aulhorilios lor local requirements,
", "i"""~IlIl\~"
" 'f', I . I!,~*~,~';.. ,':'. I ' \
U:'&"~'",'~C'\.I-::; ,IUU ,-.'
, . .'t .,,~ .I,' ,. wn
jJ ,..' '
No. H7C
/7;)"
'~--- "-,.r--
-..,
\
...-" --
-..---- ..-.~~ ,.-
'" ~ ...---~.. ~- ....... ,..... ,
.. ~ -..,.-----....,........-....... -
~(::..-":~~:~ ::"~,' ',::', ,j'f~" : ;,:~: :!;;D.:':';:, \' .~ '" ,,: ',' '; :~:>-.~ ',:: :::'," :::,;~:::.' :.'~:: \,'
I" \ ./1, . l.?1: ,. 'j' "I ~ .' '. "I " . '"" I
I/o',:, ,,)~ !"'.",'~~,.:I,~ ":~~ ", .....,:"..' \ ,~.',.. ~ ',', ".:,~' , ~,
BACKFlOW PREVENTER FOR VENDING
MACHINE WATER SUPPLY LINES
Size:
%" F.C.T,
No. 9BD
1f." NPTM
%" NPTM
HOW IT OPERATES
J
'-.../
Velve Closed by Backpressura
InSyslem
With a backprassure condition, ball
check seals egalnsl ball check seal.
Secondary disc seals against
downstream seal. Primary disc seals
against diaphragm. Atmospheric
pori Is now opan permllling air to
enlar air break chamber. In tha
avent of loullng of downslream
check valve, laakage 01 CO, gas
would be venlad to atmosphere
Ihrough the vent port safeguarding
the po/able waler syslem Irom CO,
~as conlamlnalion.
Valve Opened Flowing
Under Pressure
With 1I0w Ihrough valve, primary
disc (1) opens away from diaphragm
seal (2), Almospheric port (3) reo
melns closed by dellacllon of
diaphragm seal. Secondary disc (4)
opens away from downslream seal
(5). Sail check (6) opens away from
ball check seal permllling flow 01
waler Ihrough valve,
This valve should only be used In areas
where spillage of waler could nol cause
damage, Install a venl discharge line 10 Ihe
venl oUl/et 0' No, 980 and venllo a sefe
place of disposal wiJh adequale venlllal/on
where C02 discharge Is not a hazard.
NOTE: Ownerllnslaller or code
olllclal musllnsure Ihal COI
gas:onlalners only be used In
opon propefly venlllaled area.
DIMENSIONS(are epproxlmele)
CAPACITY
I'
flOWRo\TE.r,rM
"
FOR LIQUID VENDING MACHINES
No, 9BD Is for protection agalnsl backflowof
carbon dioxide gas and carbonaled water Inlo
Ihe waler supply system 10 vending machines,
thus eliminating Ihe hazardous reaction of car-
bon dioxide with copper IUbing,
Fealures unique, double check valve assembly
for positive, dependable seating and also
equipped with a ball check valve which Is a
Ihlrd-check member, its main function being to
prevent backpressures caused by pump cycle,
Inslant check valve response prevents un-
necessary vent discharge during pump
"oil-cycle".
Vent discharges CO2 gas 10 almosphere In
Ihe event 0' fouling or malfunction of check No,
2 Ihereby safeguarding the pOlable water
system from CO2 gas cDnlamlnatlon. Flow
way design fealures minimize pressure drop
across valve for maximum pump performance,
Also recommended for other liquid vending
machines such as coffee, lea elc. Vertical or
horizonlallnstallation,
SPECIFICA TrONS
Max. pressure 150 Ibs. Max. temperalure
140oF. Sullable for initial pressures up 10150
Ibs, All stainless steel body and heavy duty rub-
ber paris assure the longest and most depen-
dable operallng life. All rubber compounds
comply with FDA food additive regulations,
STANDARDS
DeBlgned to meel or exceed A.S.S,E, Std,
1032, Meels Ihe requirements of New York City
Health Code Section 61,47 and NSF Std, No,
25:Revised Items 4,35,2 and 4,35,3. Also ap-
proved by Independent tesl/ng cDmpieting over
2,000,000 successful pump cycles wilh poslllve
backflDw protection and trouble free
performance,
No. 9BO Backl/ow Provonto,
rJ11&-{j}--,1. CJ !~Imlln
I PlASTIC
VAlVE PIPI
FIllER
CARBONATED
BEVERAGE
DISPENSER
PUMP
lOOPSIG
CAROONAIDR
H,DIMeo,
COIOAS
IftIYlnlld.,1I 17
I'..
....
~--'-..r""- V""'--
'~,
- .. .--....-.....~-....". ~......... -
-.... ... ......-------..----
'-r- .....- ,-
~ P,. " " ~., ,'. :. '.' ;' . '.. . " '<-.' . 'I~ ",.j. .. ,:. " , : \ 1
" " , , ..., , ~' "tm ' ,,' . ",,'"
;':"";"1"'" ',HI',',:' ':"'1' ",,' ',,:",:' ' '",':/' '-"';::',.,
O'.:",:~/ ..,:,0~\';\ ',j." :::" _:: ,'.: ",',,::: ',:' J':: ':'~
BACKFLOW PREVENTION FOR HIGH HAZARD
CROSS.CONNECTIONS and CONTAINMENT -
Installations with Continuous Pressure,
No Backpressure
, Designed to prevent back.siphDnage of con.
tamlnated water Into a safe drinking water
supply. Ideally suitable for industrial process
water systems and other continuous pressure
piping system applications where the water
enters the equipment at Dr below its flood rim.
The disc float and check valve are suitable for
temperatures up to 140'F. The durable Bilicone
disc on the float and the check valve have high
heat and shock resistance.
\
APPLICATIONS
PrSBsure vacuum breakers must be Installed
utilizing good plumbing practice. UBe of a
check valve to damper out and shock arrestor
where required is recommended. This valve is
designed for installation in a continuous
pressure potable water supply Bystem 12"
above the overflow level of the container be.
ing supplied, The valve must be installed with
the supply connected to the bOllDm and in a
vertical position where it IB available for
periodic inspection, servicing or testing.
IMPORTANT: This Is a continuous pressure
type vacuum breaker, When there Is less
than 1 V2 PSI water pressure on the vent
disc, some spillage of water may occur,
Therefore, do not locate these valves In
concealed areas Dr where spillage of water
will cause damage.
Important Note: Vacuum breakers are not
designed, teBted or approved to protect against
backpressure backflow or water hammer
shock. For protection against beckpresBure
backflow, Install a Walls #909 or 009 Reduc.
ed Pressure Zone BackflDw Preventer, For pro-
tection against water hammer shock, Install
Walts #15 Water Hammer Arrestor,
MA TERIALS
Vent Disc
Disc Holder Float
Check Valve Disc
Check Valve Seat
Body
Shutoff valves
. SIlicone rubber
. Polyethylene
. SIlicone rubber
. Bronze
. Bronze
. Quarter-turn ball type
FEATURES
. Easy maintenance of Internal parfs
. Serves as an anfl.slphDn valve
. Ball valve test cocks for easy teBtlng
to Insure proper operation
. Ouarter.turn ball valve shutoffs
. "T" handles on Y, ". 1"
PRESSURE TYPE
r.
BOOM30T ('/2", '14')
!.
f
BOOM20T (1 ". 2")
OPTIONS:
Suffix
LF - wilhout shut.olls
Send lor PL.ePDL for iIIuslrated price lisl
BOOOT (1'/.".2") C, I
OPERATIONAL FEATURES
When the line pressure drops to 1 PSI or below, the spring load-
ed disc float opens the atmospheric vent and the spring loaded
check valve closes the Inlet. This prevents the creation of a
vacuum In the discharge line and prevents back-siphonage. As
water flows through the valve, it pushes the check valve open and
lifts the disc float which closes the atmospheric vent thus preven.
ting leakage. The disc float is free floating without close filling
guides which assures freedom from sticking,
COMPACT MODEL
(:#r-
-/,,"'\"- .
Size A
1/2,3/. 4'/2
No, BOOMOr, BOOMCOT
Compact dBslgn model, ideal for Institutional,
OEM and olher applicailBns requiring minimum
spacB, Fealures bullt.ln ball valve shut,olls,
SizesW',J/4",
No, BOOMar ' bronze body
No. BOOMear . chrome Iinlsh
D
W,ighl \,....'
21/2Ib5,
,I II.
18 ' ,I
Inquire with governing aulhorllles for local requirements,
n~
\
~".'" ,,' ,,~ ','" 'Lh ,.':.rl' :.':, '. -: ::-::',,:.-,: ',:'':-: ".' <<';"
I ,/,1,1""::01'" "',', " ",
\~"I'i" ~',~,\:' ,(.. . l;lr~:>I. ;':\".' ~ \ " "::" ....:\ ;'; .:..' . >:': ' <. \ '. ,I ,\ .'..J
VACUUM BREAKERS
INSTALLATION
,I") Ideally suited for the tollowing installations where there is no
danger of freezing and a drain or run-off is available.
. Cooling lower and process water . Large toilet and
. Commercial laundry machines urinal facilities
. Swimming pools . Heat exchangers
. Chemical plating tanks . Degreasers
. Pholo tanks . Livestock water systems
. Sprinkler syslems
or
~l J OUTLET DRAIN
~. ~,. ,".:w.JVAlVE
w to. ~':"i"'I 12"MINIMUMClEARANC E
. , I ABOVE THE HIGHEST
1 ...'~. -POINT OF DOWNSTREAM
~INISH ~~:__ ,. , ,_ U~'~~N, ,Z6~~,~NTAOl . "
,- -, "Q I~' ,
MAIN SHUT.OFF r"1 : ~ ,_C, , I' ., 'I
VAlVE ~ ",-"- "I'
4:;",:'1111"'[ -~-'I" I VAlVE PIT
-.r: .~' -, SPRINKLER
I ~-J FlOW-. SYSTEM
PIPING
UPSTREAM (INLET) DRAIN
STANDARDS
USC Manual 6th Edlliont. Usted by IAPMD.
Tested and certified under the fOllowing sian.
dards for pressure type vacuum breakers: AN.
SI/ASSE No. 1020 and CSA 864.1.2.
tDoes not Indicate approval sralus, Rafa, to
sngfneering sheets (or approved sizes and product
numbers.
PRESSURE-TEMPERATURE
Working temperature: 33'F to 140'F
Maximum pressure: 150 PSI
Minimum pressure: 15 PSI
~
@@
i
,
I
I
I
I
I
I
I
I
I
DIMENSIONS-WEIGHT
PSIi
IS
12
9
6
3
8
0
E
C~D
Slz. Weloht
No. (In.) A 8 C 0 E F (Ibs,)
BOOM30T 'h 4,97 6,19 2,25 3,85 3,69 2,25 3,06
P' "30T 'I. 5,25 6.47 2,3B 4,13 3,97 2,25 3,13
!OT I 4,BB 7,45 6,26 3,16 2,69 3.40 5,00
b,,,.120T 1V, B.5B 9,00 2,75 6,OB 5,75 4,96 10,00
BOOOT 1'1. 11.00 12,00 4,00 7,00 6,00 IB,OO
BOOM20T III B,B5 9,3B 2,B7 6,37 B,12 4,9B 13,00
BOOOT I'h 11.50 12,25 4,50 7,00 B,OO IB,50
BOOM20T 2 9,43 9,BD 3,12 6,95 6,36 4,9B 16,00
BOOOT 2 12,00 12.75 4,25 7,75 7.00 22,50
CAPACITY
600M30T II"
PS~
IS
12
9
6
J
0
PSij
IS
12
9
6
3
B
PSij
IS
12
9
6
J
0
PSIi
IS
12
9
6
3
0
PSIi
15
12
9
6
3
5 IB IS
5 (7,51 10 IS
BOOM30T 'I."
20 GP.tl
2B FP.S,
5 IB IS 2B 25
5 17S) IB IS
BOOM20T 1"
3B 35 GP.tl
20 FP,S,
IB 2B 30 40
5 17.51 IB IS
5B 6B GP.tl
20 FP,S.
BOOM20T 1 '10"
.
10
2030405060
5 75 10
BOOM20T 1 II"
.
70 80 liPH
IS fPS
o
10 20 30 '0 50 60 70 80 90 100 110 llBliPH
'75 10
BOOM20T 2"
.
15
fPS
2B '0 60 80 100 120 "0 160 180 liPH
75 10 15 fPS
, Typical madmum system flow nUll (7.5 felli/sec.)
''''11'...
...
.-
'"
VIti I,....
Ylol'lI~ 111I-11I
'"lhcl..1
No.800M3.0T
Shil~11 V,I.., No. I
1,1~
,
',;
\
';:>:' ':-:"1':" ",*,-::,..:.01' ":IZ,-- ',' :':'::'::",'->:::':',~:::,,,:'
I~'-' -,l~/"! '.:.';~J) '~1.<::121," ..t~~.:' :" ",...' '::1'-':(::"" ':l, ;~
\.,.' " ',\ ,.,' ~ l'flllP:") , - l~' -', .~; \' " "",". . .' '.'
. " , ,. -,.' , " . .
BACKFLOW PREVENTION FOR HIGH HAZARD
CROSS-CONNECTIONS- As required by plum-
bing code cross-connection conlrol-Installa.
tlons thBt Bre not subjecllD contlnuDuB pressure
Designed to prevent back-siphonage of con.
tamlnated water Into a safe drinking water
supply,
APPLICATIONS
Vacuum breakers are used In the water supp-
ly line to all types of equipment and fixtures
connected to a safe drinking water supply
system and on which the water supply enters
the fixture or device below its flood rim, Typical
of this type of equipment are clothes and
dishwashers, beverage dispensers, chemical
and process tanks and similar devices,
INSTALLATIONS
No, 288A _Figure 2
~
OVU1l0WOR
flOOORlfll
--,-
HIOHU'~SITIDH
OIA"L1ANCE
NOTUSS1H"H'~
IlnLY
VALVE
ftxTuREon!
Al'fLlANCI
HOSEllHl
Breaker must be Installed with the supply con-
nected to the bottom and the outlet connected
to the appliance, as shown In schematic (Fig, 1),
The bottom of the vacuum breaker body shouid
be at least 6" above the flood rim of the fixture
or appliance (Fig, 1),
Where a portable appliance Is used, the
breaker-should be Installed at least 6" above
the highest point to which the outlet can be
raiBed (Fig, 2),
The water supply valve must be Installed on the
supply side (ahead) of the vacuum breaker,
and no shut-off vaive should be Installed on the
outlet side (downstream),
Since atmospheric type vacuum breakers are
subject to normal malntenace and replace-
ment, they should be located where emergen-
cy water spillage will create no problem and
where they can be accesBlble for Inspection or
servicing,
No, N3BB ~
~
SUPPL V ~?I~~E6~~
-L
FIXTURE
ATMOSPHERIC
Series 288A %". 3"
Series 288A features a lightweight, durable "disc float" which
closes the atmospheric vent to prevent spilling under all rates
of flow, Suitable for temperatures up to 160'F, Therefore, they
are ideally recommended for iow flow installations such as
laboratory equipment which use such a small amount of water,
They also contain a durable silicone disc which has high heat and
water hammer shock resistance and assures tight-seating with the
lightest of seating contact.
FULL.SIZE ORIFICE - Series 288A have a full-size orifice 10
assure pipe size capacity, Water passages are streamlined to pro-
vide high water 1I0w with minimal pressure loss,
No, N388 Sizes '14", 'Ie"
For bidets, shampoo sinks,
dishwashers, elc,
Features bottom inlet
and outlet connections,
N388-bronze
Suffix SC for satin chrome,
Suffix C for polished chrome,
.,.....
I
\,
t f' No,N388
No, Size Dimensions Welnhl
A C.C ~
N3BB, SC, C '14" I'A" 31." \U,
N3BB, SC, C II" I'A" 'fa" 'Alb,
Series 18BA J..:. ". 2" Imgallon vacuul11 bre<l~cr -. For addllional info Srnd for ISiES./88A
OPERATIONAL FEATURES
When the water supply valve upstream of the vacuum breaker is
open and a negative pressure Is crealed in the suppiy line, the
disc fiDat drops opening the atmospheric vent and althe Bame
time closing Ihe orifice opening, This effectively prevents the crea-
tion of a vacuum In the discharge line downstream of the vacuum
breaker and positively prevenls back-siphonage,
As water flows through the vacuum breaker, it ilfts the disc fioat
and closes the atmospheric venl against water leakage, The disc
fiDat Is free fiDaling wilhout close. filling guides, assuring freedom
from sticking, The durable, silicone disc permits Its use on hot as
weli aB cold water lines,
20 .
Inquire with governing eulhorillBS for local requlremenls.
,
\.../
17;)..
'---r-'
,';\' ".: ;'.;;':/:::>::''01'::-': ',.'ki:.':: 'i.n :"".'-' ..-" .':'.,' ,.:::, :,',,: '.:,,:::':-:::,:'
I.' ,.' l' ',' rj . '. .li71 , rl-...,."" . . . }~!
IF ,', l:l\,~' .::'.: ..,;..'..~,;'r \:: {'.'~~". " ','.~.., ,J " 'j:: "',: ,:' ;. :)I~.,
<
, VACUUM BREAKERS
CAPACITY
'-""'\
Series 288A Sizes V. ". '!4 " ,
IZ 114" 3/8" 3/4"
0 '/2"
~10
, i
. 8
0
. I
o 6
w
.
" 4
.
.
~ z
.
0
5 10 15 Ze 25 30 35
FLOW - G,P,M.
MA TERIALS
Sizes V4" through 1" are available in either plain brass or polish-
ed chrome finish. Durable silicone disc, high heat resistance. Sizes
'14" through 3" standardly furnished with plain brass finish.
PRESSURSTEMPERATURE
Maximum temperature 160'F at 125 Ibs. working pressure. For
speciai higher temperature applications between 210'F and
250'F, consult factory.
Note: This device shall not be subjected 10 continuous pressure
for more than 12 hours, per A.S.S.E. Std. 1001.
For continuous pressure application, specify Watts 800 Series
pressure type vacuum breakers. Vacuum breakers are not design-
ed, tested or approved to protect against backpressure backtlow.
For protection against back pressure backflow, specify Watts
909/009 Series reduced pressure zone backflow preventers or
709/007 Series double check valves.
SerleB 288A Sizes I", lV, ", lV, "
12
~10
~
, 8
.
o
~ 6
w
. 4
"
.
~ 2
.
. 0
1"
1If("
1'/2"
10 20 30 40 50
FLOW - G.P,M,
60 70 80
Series 288A Sizes 2", 2'h ", 3"
12
o
~10
~ 8
o
~ 6
w
~ 4
~
P
..
2"
1'/2"
~ ~',
3"
STANDARDS
use 61h Edillonst, Listed by IAPMO.
Tested and approved In conformance
wilh A,S.S.E. Sid. 1001 and ANSI
AI12.1.1 and eSA 864.1.1.
tDoes nol indicate epprovai slatus. Refer
to eng(neering sheets (or approved sizes
and product numbars,
~
@@
o
5e leo 15e 200 Z50 300 350 400 460 600
FLOW - G,P,M.
015C has high
hBat and waler
hammer shock
resislance
Dry guide
out 01 the
liquid
pressure area No. Size Dimensions Weight
Plain Pali,hed
Bran Chrome A B C
288A 288A.C 1/01" 11111611 11116" 13/10" 3/. lb.
28BA 288A.C J/n" 111/16" IllIG" -13M' 'I. lb.
2BBA 288A.C 1/2'1 2" F'l1li" 17116" 1fzlb.
18SnS8A 288A.C 3/411 21/411 11/2" 171." I'/elb..
188n88A 288A,C I" 2'/a" 111110" 2'/0" J3/4Ibs.
lSOn08A 1'/4" 2111111 113/16" 2lfl1" 21f.lbs.
188n88A 1'/," 3b/8" 23110" 27110" 35/.lbs.
180n08A 2" 4'/8" 21/;l' 27/s" 51f41bs,
288A 2'/2" 63/11" 3" 4J/Ru 161bs.
28BA 3" 63/11" 33111" 45/11" 17'/elbs.
~i..
No. 28BA .l\"
For addition,1i In(o SOlid 101 ES.2BBA
------ .~
,,-'-
- .. ...---.- -...rJ-- ---r ,-.. - - '" r-
-..".- ......
--,
-- "'-
,.,
:::;::,'':,':k'::i':', ~-';'f:1i,;;?:;'i,:~,,:':": ,:iffl c',::' ",,:',','::"',."::.:: ,:::;: ~':,:' ':,::1<'
-'1' "',,~:,\_,Il"':. "~'~Ij ',: ,::;','-',' . >:"1. _ \' .. ',' : I"', ",,' ,: ~-"'" :~:. ~<.I
FOR BACK FLOW PREVENTION AS REQUIRED BY
PLUMBING CODE CROSS.CONNECTiON CONTROL-
Hose Supply Oulletlhat arc not subjeclto continuous
pressure
Series B are unique devices specially made for
hose thread faucets with portable hoses attach.
ed. Their purpose iB to prevent the flow of con.
taminated water back into the safe drinking
water suppiy , , , and installation requires no
plumbing changes, device screws direclly to
the sill cock.
No. BA is furnished with an exclusive "non.
removable" feature that prevents removal from
sill cock. This "Vandal Proof" feature is
preferred by most Plumbing Codes.
(Pat. Nos, 3,459,443 and 3,171,423)
APPLICATIONS
Series B can be used on a wide variety of in.
stallatiDns Buch as service sinks, swimming
pools, deveioping tanks, laundry tubs, wash
racks, dairy barnB, marinas and general out,
side gardening uses.
Series B Is tested and certified under ANSI
A112,1.3 (ASSE 1011), which precludes use
under continuouB pressure.
IMPORTANT: This valv~ should only be
uBed In areas where spillage of water could
not cause damage,
OPTIONS
No, SBC, BC, BAC, BBC or NF8.C are
furnished with chrome finish body.
~ @@
STANDARDS
TeBted and approved In conformance with
AS.S.E. Std. 1011 and C.SA 864.2.
No, SB, BA, B8, NFB and BP are listed by
IAPMO,
CAPACITY
PERFORMANCE CURVE
40
035
~
'30
.
o
'25
~
0"
.
~ 15
~
a 10
s
4 5 6 10
FLOW - aPM
22
HOSE CONNECTION
IfI
~
No, BA
No. BP
W'HT
('j
No. SBC Vl" or %"
Specially made lor use with lub and
shower hand spray sels, Installs
without plumbing changes between
shower.head and hose,
No, S8 plain brass,
Send lor ES.SB,
No, BA for portable hoses aUaches 10
hose thread faucets, requires no plum.
bing changes as It is screwed direclly
10 Ihe sill cock,
No, BP same as 8A excepl body made
of reinforced Ihermoplastic,
Send lor ES.B and ES.BP.
No, BA in closed position Before /low begins, at.
with supply valve shut oil mospherlc ports are seal.
disc (1) seals against ed oil before lower disc
diaphragm (2), At. opens to permil/low,
mospheric porls are open
(3) during no /low,
Lower disc opens away
Irom almospheric
diaphragm seal allowing
/low through the valve
with slight pressure drop, ,.
\,
CONSTRUCTION
DRAINAGE FEATURES TO
PREVENT FREEZING
Wa/ls No. BA, BB and BP are
slandardly equipped 10 allow
sill cocks to be drained, To do
thIs, remove hoso coupling
and Iighlly pull knurled lip of
stem nl oullel of velve 10 ellow
dralnnge of colleclod waler.
E:~
r;"
iW~\
"-
Nole: Do not use No, B. BA,
8B, 8P Hose Bibb Vacuum
Breakers on frost, free
hydranls, Specily No, NFB,
No. SA.Furnishedwilh 8I(clusive" Non- removable"
fealure and slendardly equipped 10 allow sill cock
10 be drained,
Nole: Device should only be Inslalled on 'pproved
sill cocks conlainlng alleasl four lulllhreads and is
non.removable once Inslalled.
No. B . Similar 10 Ihe No, SA excepl ills lurnished
wilhoullhe "Non.removablo.or dmining fealure,
No. sa. Furnished with breakaway sel screw 10
provlda a lamper.reslslant installation end
slanderdly equipped 10 allow sill cock 10 be drained,
No. NFB ' Especially made for well nnd yard
hydranls. PormUs manual draining for froozing
condiUons.
No. BP, Furnished with exclusive palenled 'Non,
romovable' lealure and slandardly equippod 10
allow sill cock 10 be drelned, Conslrucled 01 dureble,
corrosion. resislsnt, reinlorced thermoplastic.
Tamper.prool fealure. Palenl No, 4B21763,
No. HB.1 BrassBody ~ !-A_I
Hose Bibb Type Boller Oraln ~"I IT
wllh 8ulll.ln Vecuum Breaker /!!I' .' III Kj . B
Vacuum breaker provides back,siphonage pro, 1'''' v,,~" 1
leclklll againsl portablo hoses connecled 10 hose I ~
bibblype boiler draias and not subiecl 10 con, l..B ,~,,1, I
linueus pressure, Meels ASSE Sid, 1011. . _I ~
Oimlniionsllllchesl W.ight
No. Silt Oucriplion A 8 C 0 11I11.1
118.1 W' Malel.P.orcopperconnecllon J!I/u 21/0 I 23/16 11/1
For Addilionallnlormnllon, send lor B.SC.HB
\....~i
17~
:.-,:':'.:.:,,'., ',' ':f;'::' '.': ci',.:',,','t':J;i:',' ,.: ':.', ::::':,', ':,,;; -,:\"
~,. ':"'/'.,'\ " "'~:TI, - .'~:7:l' ", .. .1,,1 ",
\.,- ,~..: .;~\;...~, ""\.~j;' :':1,";' .., " ;~"""',' ..:' . ,", .' "',:. . '" :'/
VACUUM BREAKERS
~"o-.,
1tL~
..
h,'u.l
.;L!4,." l
~1 ~
INST ALLA TION
"
INSIDE.SERVICE SINK
No, 8 'A" HT
Similar to No. 8A Series exceplll
is lurnished wilhout Ihe "Non.
removable" or draining fealure,
Send for ES.8.
No, NF8 'A" HT
No. NF8 for waii and yard hydrants.
Perm lis manual draining for freez.
ing conditions.
Send for ES'8
_ I WHAT IS BACK.SIPHDNAGE?
A reversal of normal flow in Ihe system caused by a
" negative pressure (vacuum or partial vacuum) In the
supply piping,
~~ r' " '-~~._~, .
.. -- ....._.J.
, ...=-.....~,
--.:.. ...........
~ ~~~"..
"'--_.-__J,
DIMENSIONS-WEIGHT
C8---j
~
A B
Fuiiy opened valve, II.
lustratlng poppel action to
provide high cepacity wilh
minimum pressure drop
through valve.
Wilh reduction In water With ioss of watersupply,
supply pressure, disc disc seals tightiy against
returns closer to diaphragm preventing
diaphregm. Diaphragm back.siphonage or
sea is ofl atmospheric backflow of waler and
ports preventing un. opens atmospheric po~s.
necessary leakege.
.-'"
,
....-..,/
W~lght
'I,ib,
\lIb.
U.
1\\ 02,
No.
B,8C, B8, BBC
BA,8AC
NFB, NFBC
8P
Size
,",' HI
W' HT
,",' HT
'A" HI
l'h"
n~H
2"
11'11'"
1%"
1W'
'1'h"
W."
Frost-Proof Automatic Draining Wall Hydrants
with Hose Connection Vacuum Breaker Backflow Preventer
r-33/B"1'
lire . Series FHV
W]~~-';"""= ...,---
,~
~
~ t;.........
""'&l!U~~1JIf
Dimensions
Masler Ca~on (Inchesl
Oly, Wgt.llbs,) A
15 20 8.40
15 20'1. 10,41
15 23'h 12,41
15 25\\ 14.42
15 27V. 16.43
15 29 1B.44
15 20 B.40
15 2BV, 16.41
15 23'h 12.41
15 25'h 14.42
15 27'/, 16.43
15 29 IB.44
23
~;.
A
@@
I
r
I
Series FHV
Meets A.S.S.E. Std. 1019
Listed by IAPMO (UPC)
Certified to CSA Std 8125 and 864.2
EOP Inner Pack
No. Cede No, Size Diy.
inlel'h" copper x 'h" male I,P,S,
FHY.1 123B9B 4" I
FHy.t 723692 6" 1
FHY.1 123B94 8" 1
FHy.t 134B9B 10" I
FHY.1 723B9B 12" 1
FHY.l 1231BB 14" I
Inlel ,",' male I,P,S, x 'h" I,male I,P.S,
FIlY.2 1231B2 4" 1
FHY.2 1231B4 6" I
FHY.2 123106 8" 1
FHY.2 123tBB 10" I
FHV.2 72311B 12" I
FHY.2 723112 14" 1
Inquire wilh governing oUlhorilies lor locol requlremenls.
. Seil drains oUlomatically
. Positive seat washer cut oil
. Designed and menu lectured to prevent contamination
of the sofe drinking water suppiy from
eilher back.slphonage or backflow pressure
. No burst feoture
. Cycle tested to provide yeors 01 service
, i
'-J
,
i
I
I
I
,
\
Send for F.FH/FHV
....
(',":,,~ '. ,', : ' .;;' ~ ,: :,'~" ~.", , ":', I "~" '," ) .:', .,.' :. ',.,; {: '.~', ":' >",
.\ ' ./ I" ""fj ," <, 'tjl.'''.' ", ""'"'
lOi' ~, ',; - . ,Co :. ,:.; I (',' II '. ,". ,I'" , j', .' ,
\, .~\ " .,) I, ,~.\ .\' . . , . I .... \ ." .' r
. ".1,',.,,,,., " \ ,', j . .' " ,~,
For Technical Assistance Call Your Authorized Walls Agent Telephone I Faxl
Bruce Pallon, N,E. Reg, IIgl, 815 Cheslnul SI., Nonh Andover, MA BIB45 5BB688.IBII 508794,IB4B
TrayroSales,lnc. P,O, Box 653.lynnfield. MAOl940 617334.607B 617334.2B59
W,P,HaneyCo,.lnc, 51 NorlolkAve" Soulh Easlon, MA B2375 50B23B.2B]B 5BB23B,8353
E,W,leonard,lnc. Ray Palmer Rd,. P,O, 80x 371, Moodus, CT 06469,B37I 203B7J.B691 203B73'8693 r"""
WIIS Sales. Inc, 9580 Coun~ Rd" Clarenco Cenler. NV 14B32 716741,9575 716741,4810 \ f
WMSSales,lnc, 7437 Meadowbrook Dr., Baldwinsville. NY 13027 315622,0763 315622'0764
WMSSales.lnc, 4 McMillen Place, Delmar. NV 12054 51B475,IBI7
Edwards. Plall & Deely, Inc, 931AConklin SI., Falmingdale, NV 11735 516777,3BBB 516777,3B10
J,B. O'CennorCompany, Inc, P,O, Box 12927, Plilsbulgh, PA 15241 412745'530B 412745.7420
Vernon Bilzel Associales, Inc. 13B Railread Dr" Northhamplon Ind, Pl." Ivyland. PA IB974 215953,I40B 215953.125B
BIIIJohnson,5E Reg, DiICclor P,O, Box 140153. Orlando, FL32B14.0153 407695.3461 4B7B95.3462
RMI Glenrierd Bus. Clio, 2535 Mechanicsville Tpk., Richmond, VA 23223 BB464J.7355 6B464J.7380
Smilh&Slevenson 4935 Cha..ainAve., Charlolle. NC 2B21B 704525,33BB 704525,6749
" Conltal Sales Company 1612 Fourth Ave, Norlh. Nash.lle. TN mOB 615259,9022 615259,9B24
Cenlral Sales Company 217BVork Ave,. Memphis, TN 3BIB4 901 27B.2251 9BI272,1614
!i SpolswoodAssociales 6700 Besl Friend Rd,. NorCIOSS, IAllanla) GA3B071'2919 404447.1227 4B4263-6899
Distributor Sales 01 Florida 652035IhSt.North,PinellasPark,Fl33565 BI3527,6651 813528.B602
EarlL Griffin Co, 2776 B,M, Menlgeme~ 51,. Bilmingham, AL 35209 2B5879.3469 205B7B.5B27
EarlL Griffin Co, 6517 Buggy Whip Court. Mobile, Al36695 2B5661,I199
Billingsley & Assoc1ates, Inc. 5609,0 Salmen St., Harahan, IA 70123 50473J.7624 504733-6904
Billingsley & Associales, Inc. 478 Cheyenne lane. MadISon, MS 391 10 601856,7565 6BIB56'8390
FranciscoJ.Olliz&Co.,lnc. P,O, Box 1433. Calolina, Puerto Rico B09B4 BB9769,OBB5 809750,512B
TheJoyceAgency,lnc, 8442 Alban Rd" Springfield. VA 2215B 703666'3111 703B66.2332
Hugh M, Cunningham, Inc, 4309 N, Bellwood Pkwy" Dallas, IX 75244.3294 214661,0222 2144S0,6678
HllghM.Cllnningham,lnc. 1999 Kollahl,Houslen, TX71023 713923,2371 71392J.B.357
Hllgh M. Cllnningham, Inc. 5130 Ser.ice CenlCl. San Anlonio. TX 7B21B 512661,4161 512661,0954
Don Sinsabaugh. MidWesl Reg, Sales IIgl. 42 W, 597 Sleeple Chase, SI. Charles.ll6Bl75 7BB377.3671 70B513.506:J
Mid.Conlinenl Marketing Services Ud, 1724 Aimilage Ct.. Add"on, Il6BI01 706953.1211 7B6953,IBB7
Mkl.Conlinenl I.lar.eling Services lid. 550B Elmwoed Ave" Suile 401, Indianapolis, IN 46203 317782,1515 317762,4]60
Ailvance Indusllial Markeling lid, 1606 Commerce Dr., Sun Plailie, WI 53590 6BB637.5OO5 6B8637.236B
Dave Walson Associales 1325Wesl BeechCl. Adrian, MI 49221 517263,B9B8 517263,232B
lheHarris,BillingsCo. P,O, Box 41304, 1920 Annap~is lane North, Plymoulh,!.IN 55441 612559,94BB 612559.8239
Mack McClain & Assodales.ln. 1537 Ohio SI.. Des Meines,IA50314 51528B.0184 5152BB'5B49
Mack McClain & Assodales, Ine. I5090WesII16IhSI..Olalhe,KS66062 9133.39,6677 9133.39,9518
Mack McClain & Assodalos, Inc. 18201 Soulhl32ndSI..Springfield,NE6BB59 4B225J.2423 402253.2417
PIO,Spec.lnc, P,O, Box 472226, Tulsa, OK 74145 918664,5642 91B664,6B69 ()
J.W. Sullivan Company 7901 MancheslCl Ave" Sl.louis, M063143 314644,5454 314644,5527
Disney,McLano,lnc, 2704 Cole/aln Ave., Cincinnati, OH 45225 513541.1682 513541,0073
Madsen,BayO/ & AssoOales, Inc, 2510 Englewoed 01" COIUlObus, OH 43219 BI4476,I833 614476,184B
Madsen,BayCl! AssoOalos, Inc, 464B WarnCl Rd,. Garliold Heighls, OH 44125 21B641,5B08 216641-5546
Ga~ S, Gilpin Sales Co, 446B ,mberson Ave"louis.Ue, KV 4B209 5B2367,217B 5B2367'9BBB
Jim Eng"d, Wesl Reg, Sales Mgl, 749 Renalo Way, Paso Ro~es. CA 9]44B B05239,BB52 B05239,B859
\ 510" GOVClO. Mallei Mgl. Baclflow 276 Ginger Lane, Paso Robles, CA 93446 B05237.2413 BB5237,2265
R. C, Hartnoll & AssoOalos 3BB52 Hunlwood Ave" Hayward. CA 94544 51B471.72OO 51B471.4441
H.labaugh Brelhors & AssoOares 12606IhAve,Soulh,Sealllo,WA9BI34-13BB 206467,B346 2B6467'636B
Hollabaugh BlOlhelS & Assoclaios 3B2B SE. I7Ih Avo" Perlland, OR 97202 50323B,0313 503235,2824
RE,FilzpalrickSalos,lnc, IB Easl81h Ave" Midvale. UTB4B47 B01566,715B BOl566,4979
Fanning & Associales, Inc. 625 Easl701h Ava,. Denver, CO 8B229 303289.4191 3B32B6'9B69
OolcoSalos.lnc, 2267 Valos Avo" los Angolos, CA 9BB40 213BB7,3240 213724,5227
Plllmbing/lndllslrialAepresenlalives 2B12Wes141hSI.. Tempe.AZB52BI 602968,B5B6 6B2829,7682
Rocky Mounlain Markoling 3300 Princolon N,E,. N.27, AlbuQuorQue, NM B71B7 505BB3'44B5 5058BI,3767
Crown Sales 360MokauoaSI.,Honol.ulu,HI96BI9 BBBB45,7BBl BOB 84J.4504
Walls RegulalO/Cempany,
DMsionolWallslnduslrioslCanadajlnc, 441 Hanlan Rd,.Woodbridgo, Onlario L4l3TI 416651,B591 416851,B7BB
ReglonalOfficelMonlrealj 269B Sabourin, Vlllo Sl.laUlonl, Oueboe H4S 1M2 514337,90lB 514337.8B43
Felletly&Assodaloslnc, 6BBB Young SI., Suile 91 I. IlalilOl. Nova Scolia B3K 5LB 9B2454'9377 9B2454'BBB5
FOIIO/ly & Assodalos Inc, 3B3 SI. Goorgo SI., Moncion, Now BrunslOck EIC 8TB 506B57.224B 506859,9795
Fellerly & Assodales Inc, 22 Carman.llo SI., St. John's, Nowfoundland AIB 5K8 7B936B'8B87 7Ol36B,B553
Polymox Conlroles Inc. 2800 rue Dallon, Slo, 3, Pare CelbClI, Sle.Fey, Ouebec GIP 3S4 418657,28BB 418657,2700
'Walmal 24 Gu,dwara Rd,. Nopoan, Onlario K2E BAZ BI3225,9774 613225,B673
W,B,GlngO/ichSaleslld, 107 Hamlllon Rd,. New Ilamburg, Onlario NBB 2GO 519662-2460 519662,2491
NOllhern Mechanical Sales 163 Pino Si.. Garson, Onlario POM IVB 705693,2715 7B569],4394
MUrrayKlOvalsAgoncy 941,C Elin SI.. IVInnlpog, Maniloba R]G 2W6 2B47BB'2747 204175.3IB6
lriumphHydronics 1729 Bredor SI., Rogina, Saskalchewan S4N 5N6 3B67B9,2356 306781'B121
. CurrioAgoncios lid, 3117 Undorhill Avo,. BUlnaby, Brilish Columbia V5A 3CB 6B442B,6B7B 6B,142B'9022
. O,C,Salos Corp, 6B31 41h St. S,E" Calg'~, Alberta T2112A5 4B3253,68B8 403259B331
Schnoidor SalosAgoncy Co, lid, RR2, 1444 AivO/ Rd, WOSI, Wasa9na Beach, Onl"io LB12PB 705429,3903 705429,2437
HdQIIIJEXPOR1: WailS Regulalor Company 815 Choslnul SI., Nerlh AndovO/, MABIB45 USA 1,lw04-746B 5BB6BB,I811 50B794,IB4B C)
. SlocklngWarchousos
Wotf~CIIII ~I'.tl @
~,wms Boehl/ow C.BPD 9249 Prinled In U,S,A,
REGULATOR Prevention
_Sinn 1114 wms REGULATOR COMPANV D/~'Jslon
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BACKFLOW - The unwanted reversa flow of liquids in
a water supply piping system, It can be caused by back.
siphonage, backpressure or a combination of both.
BACK.SIPHONAGE is due to a vacuum or partial vacuum
in a water supply system. It is caused by:
(a) Ordinary gravity - when the water supply is
lost and a fixlure Ihat is elevated is opened
allowing air into the system, water will, by
gravity, reverse fiow.
(b) Undersized piping - high velocity water
traveilng through undersized piping can cause
an aspirator effect and draw water out of
branch pipes causing a partial vacuum and
a reverse fiow.
(c) Vacuum - caused by pumping water from
supply system (example: a fire truck) causing
a pressure drop or negative pressure in the
syslem. A break in the main or excessive
usage at a lower level in the system can aiso
be a cause.
BACKPRESSURE - A condition whereby a pressure
higher than the Incoming supply pressure is created on
the premises and causes reversal of fiDW back into the
incoming waler supply (example: pumps, thermal expan.
siDn from boilers),
CROSS CONNECTION - Any actual or potenllal connec.
lion betwaen the drinking water supply and a source of
contaminallDn Dr pollution, There are two Iypes of cross
connacllons. One iB callad iniet type and the other a direct
or pressure type cDnnecllDn.
Inlet Type Connection is a connecllon used for fiiling
a receptacle open to atmosphere. They can be below
rim Dr submerged, such as a bottom inlet 10 a piatlng
rinse tank, They can be the over rim type wherein a
water line enters a receplacle over the top rim and
telminates at some point below the lop rim. In theBe
Iypes of cross cDnneclIDns, backfiow occurs due to
back.slphonage only,
Direct or Pressure Type is one wherein the water
supply is connecled to another i1ne or a pressurized
vessei, A good exam pie is a feed water line to a boiler
or a primer line to a pump. In cases of direct or
pressure type connections, backfiow occurs due to
backpressure when the system pressure exceeds the
suppiy pressure,
PROPER SYSTEM PROTECTION - To properiy protect
the potabie (drinking) water system, you must flrsl deter.
mine Ihe degree of hazard Involved. Since all cross con.
necllDns do not create the same degree of hazard, we
should make our choice on a common sense basis.
Degree of hazard is dependent on whether the substance
in the non'pDtable system Is toxic or non.toxic. Toxic
subslance iB any liquid, solid Dr gas, which, when inlroduc.
ed into Ihe water suppiy, creates, or may create a danger
to health and well.being of Ihe water user, An example
is treated boiler water. A non.toxic substance iB any
substance that may create a moderate hazard, is a
nuisance or is aesthellcally DbjecllDnabie. For example,
food sluff, such as sugar, soda pop, etc. Secondiy, you
must select the proper backfiDw prevenllDn device accor.
ding to the type of cDnnecllon and degree of hazard, There
are five basic devices that can be used to control cross
connecllons (see page 2).
11 wIns HDDlRS,Rle, 114 & Chcslnul Sl. No, Andover, MA BI845
MAIL' Bo< 828, Lawrence, MA DIB42 r.I." 94-7460
r.1. (50BI6B8.1811 F."(5B8) 794,IB,I~794.1674
REGUL A'mR Inlornal/onal SUblldl"I."
M Wal/S Regulalor 01 Canada Lid 1.1..06527137
WATTS REGULATOR COMPANY WailS Regul,lOIllIcderlandl bv, Tel..; 35365
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THE FIVE BASIC BACK FLOW PREVENTION DEVICES
THA T CAN BE USED TO CONTROL CROSS CONNECTIONS
1 AIR GAP [c e r,
-!. _ ,-.l._
Air Gap Is the physical separation of the potable and non.potable system '"
by an air space, The vertical distance between the supply pipe and the flood ,--
level rim should be two times the diameler of the supply pipe, but never iess
than 1", The air gap can be used on a direct Dr inlet connection and for all
loxic substances (high hazard),
.
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2 ATMOSPHERIC VACUUM BREAKERS
Atmospheric Vacuum Breakers are used only on conneclions to a non.potable
syslem where the vacuum breaker Is never subjecled to backpressure and
Is Installed on the discharge side of the last control valve. It must be Inslall.
ed above the usage point. It cannot be used under continuous pressure.
Hose connection vacuum breakers are used on sill cocks and service sink
hose bibbs,
AlmosphoricType HosoConneClion
Vacuum Breaker Vacuum Bleaker
3 BackllowPrevonler
PRESSURE TYPE VACUUM BREAKERS for Laboralory
Faucets
Pressure Type Vacuum Breakers are used as protection for connections to
all types of nDn'potable water systems where the vacuum breakers are not
subject to backpressure. These unlls may be used under continuous supply
pressure, They must be installed above the usage point.
Backflow Prevenlers with intermediate atmospheric vents may be used as
an alternate equal for 112" and '4" pressure type vacuum breakers and in
addition, provide prolection against backpressure,
\ 4 DOUBLE CHECK AND DUAL CHECK DoubloChoCk
BACKFLOW PREVENTERS Backllow Provonlor
Double Check Back/low Preventers are used to protect
direct connections where foreign material mighl enter the
potable water system in concentration which would con.
stitute a nuisance Dr be aesthetically objectionable, such
as air, steam, food, Dr Dlher materials which do not con.
stitute a health hazard (low hazard),
Dual Check Backflow Preventers are IImiled application
backflDw preventers used for low hazard and iow flow Dual Chock
requirements, Backllow Preventer
5 Aeduced Pressure
REDUCED PRESSURE ZONE Zona Backflow
BACK FLOW PREVENTERS Provonlor
Reduced Pressure Zone Backflow Preventers are used
on direct connections of potable and non.potable water i
systems which may be subject to backpressure or back.
BiphDnage, and where there is the possibility 01 contamlna.
tion by any malerlal that can constitute a potential heaith
hazard (high hazard), '-
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SYSTEM PROTECTION BY DEVICE SELECTION~," Type To Be Used
~:'''I' = Better Selection
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L~ TYPE OF DEVICE TO BE USED
I I TYPE OF CONNECTION
Atmospheric Pressure Double Reduced
Vacuum Vacuum Check Pressura
Air Gap Breaker Breaker Valve Zone
DIRECT WATER CONNECTIONS
SUBJECT TO BACK.PRESSURE FROM:
1. Pumps, tanks and lines handling'
(al Sewage substances . .
(bl Toxic substances . .
(cl Non'Toxic substances . Ill. g2rY'.i;;~;,t.i .
2. Steam lines & steam boilers
(al Boiler or steam connection to toxic substances . ;~.7~~~
(bl Boiler or steam connection to non.toxic substances ;~[o1Jll ~~-;:"?,;ff'~
{boiler blow'off nor connecred direcrly to sewer} . 111 . ;;:~:;'i'.,:!I'1;':~
3, Car Wash Installation ';_i.J::,."'.'\,,~.1':
i~";!~',.;':'<i_~
INLET TYPE WATER CONNECTIONS
NOT SUBJECT TO BACK,PRESSURE:
1. Waste line {not subject to back'pressure due ro waste line
stoppages} e . . .
2, L. I. to receptacles containing toxic substances . . . ~r~.:;.~:i~:
3. L. I. to receptacles containing non. toxic substances . &',f~:l.:',\:;-'. 'i/:i~';'(' (11 . . .
.!..;;t,,",.jl~. :<~.",.>l'!
4, Lawn Sprinkier Systems . ~~?;M~:.~~:~\~~l~' . . .
5. Lawn Sprinkler Systems with fertilizer injection ')hf~:\'.-~~~~
'''\ 6. Coils or jackets used as heat exchangers in compressors,
I , degreasers or other equipment:
,
',,./ ~t~.~U:
lal In toxic substances . . .
" ,
7. Flush valve toilets .
B. Toilet and urinai tanks 0 .
9. Valve outlets or fixtures with hose aUachmenls which may
constitute a cross connection:
. '12m.4'''''''W. . .
lal Toxic substances ': 2 r"\'-!~'I~t;..1.
, .fI. ". ..r,....,~
(bl Non.toxic substances . f (2)"/~"'~~;1~'~~ . . .
'- '", ,.."..,
10. Plating Tanks . N::~/;..:~_;;j~
11. Vats and vessels used for degreasing, descaiing, stripping, ~r:~~.~~'7i~TS:
plckiing, dipping . ;~\IJ/..~{',_)~,
12. Water cooied equipment which is sewer connected . :-:~f,.'::~.5\~~~
13. Fire fightinB systems which are treated for scale or algae . ~&:i';r;m:
formation or contain anti,freozc, Fomite or other chemical
14, Fire fighting system untreated . T~:\.~._,,?{,( .
'I>'", :/'~
15, Greenhouse , ~,:.ti:!.;:~~~~~t
Note: L.I, = Low InlCl
III = Oackllow Preventer with Intermediate Atmospheric Vent. Sizes W' and W'. (See Item 3 on Page 2.1
(21 = Hose Connection Vacuum Breaker.
A.S,S,E. and ANSI STANDARDS APPLICABLE TO TIlE FIVE BASIC DEVICES
THAT CAN BE USED TO CONTROL CROSS CONNECTIONS
, 1. Alt Gap - ANSI Slandard MOA
'-' 2. Almospherlc Vacuum Breakers - A.S,S,E, Standard 1001,
ANSI A112,1.1 and C,SA B64
Hose Connecl/on Vacuum Breakers - A,S,S.E. Standard 1011,
ANSI A112.1.3 and C,S,A, 654,2
3. Pressure Type Vacuum Breakers - A.S.S,E, Standard 1020 and
C,S,A.664,1.2
Beckf/ow Prevenlers wllh IRlermedlate Almospherlc Venl _
A.S,S,E, Slandard 1012 and C,S,A, B64
4. Double Check 6ackf/ow Prevenlers - A,S,S.E. Standard 1015 and
A.S,S,E, 1024 Dual Check
5. Reduced Pressure Zone Backf/ow Preventers - A,S,S.E,
Slandard 1013 and C.S,A, B64.4
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INSPECTION CHECK LIST
NAME OF FIRM
MAILING ADDRESS
TIME
DATE
WATER PRESSURE
PH
CHLORINE RES,
\
Air Conditioning
Air Washers
Air Conditioned Chillwater
Air Conditioned Condenser Water
Air Conditioned Cooling Towers
Air Compressors
Autopsy Tables
Aspirator, Medical
Aspirator Weedicide and Root Feeders
Autoclave & Sterilizer
Boiler Feed Line
Baptismal Fount
Bathtub Below Rim Filler
Bedpan Washer, Flushing Rim
Bidet
Brine Tank
Bottle Washer
Chemical Feeder Tanks
Chlorinator
Coffee Urn
Cuspidor, Dentai
Chiller Tanks
Cooking Kettles
Condensate Tank
Demineralized System
Dishwasher
Drinking Fountain
Degreasing Equipment
Dye Vats & Tanks
Developing Tanks
Dairy Barn Equipment
Etching Tanks
Stills
Starch Tanks
Sitz Bath
Sprinkler System, Fire Protection
Shampoo Basin Hose Rinse, Beauty Shop
Sinks, Wash.up
Serrated Faucets
Sizing Vats & Boxes
Solution Tanks
Urinal, Siphon Jet Blow,out
Urinal, Trough
Fountain, Ornamental
Detergent Dispenser
Fioor Drains Flushing
Garbage Can Washer
Garbage Disposers
Hydro. Therapy Baths
Humidifier Tank & Boxes
Hose Faucets
Hot Water Heater & Tanks
Ice Maker
Janitor Closets
Lab Equipment
Laundry Machine
Lavatory
Lawn Sprinkler
Boat, Marina
Make.up Tank
Pump, Prime Lines
Pump, Water Oper Eject
Photo Lab Sinks
Photostat Equipment
Pump Pneumatic Eiect
Pipette Washer
Potato Peeler
Processing Tanks
Re,circulated Water
Sewer, Sanitary
Sewer, Storm
Swimming Pool
Sewer, Flushing Manhole
Steam Cleaner
Steam Table
Digesters, Hospital
Ultrasonic Baths
Vats
Telephone, Showers
Water Closets, Tank
Water Closets, Flush
Water for Cooling
Water Oper Equipment
Water Treatment Tanks
Water Well Secondary System
Wash Tanks
REMARKS:
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Prlnled In U,S,A,
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, ,United Slates, " .
, ">: Environmental Protection,
.,'\~gsney;' ,,'
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allies of Water
,(I'I~,550A) .
June 1989 ,
EPA570/9'89,Ooi
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oEPA
Cross-Connection
Control Manual
United States
Environmental Protection Agency
Office of Water
Office of Drinking Water
First Printing t973
Reprinted 1974, 1975
Revised 1989
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Preface
--~--_._._-
Plumbing cross.connections,
whicharo defined as actual
or potential connections
between a potable and
non-polable wnter snpply,
conslitute a serious pnblic
health hazard, There are
numerous, well.docnmented
cases where
cross-connections have been
responsible for conlamination
of drinking water, and huve
resulted in Ihe spread of
disease, The problem is a
dynamic one, becuuse piping
systems are continually being
installed, ultered, or
extended.
Control of
cross.connections is possible,
but only Ihrough thorough
knowlOljge and vigilance,
Education is essenllal, for
even those who ure
experienced in Iii ping
installations Cai 10 recognize
cross-connection possibilities
end dangers, All
municipalities with public
water supply systems shonld
have cross.connection control
programs, Those rosponsible
for institutional or private
water supplies should also be
familiar with Ihe dangers of
cross.connections und should
exercise careful surveillunce
of their syslems,
This Cross.Connection
Control Mnnuol hus been
designed us e tool for health
offlciels, walerworks
personnel, plumbers, and any
others involved directly or
indireclly in wuter snpply
distribution systems, II is
inlended 10 be used for
educatlonnl, ndminislrative,
nnd technlcnl roference In
conducting cross.conn"ction
conlrol programs, This
mnnualls n r"vision oC an
enrli"r book "ntlllud Wnter
Supply and Plulllblng
Cross.Connections (PIIS
Publlcntlon Nnlllber !I57),
which Was produced und"r
thu direction of Fioyd 0,
Tnylor by Mnrvin T, SkodJ",
who wrot" th" tuxtnnd
designed the Illustrations,
Ii
...~-_. -..-----.--------- ._--...
Many of the originel
illustrations and text hnve
been retained in this edition,
Previous revisions were done
by Peler C. Knrnlekas, Jr. with
guidnnce from Roger D. Lee
incorporating suggestions
made by the staCf of the EPA
Waler Supply Division, other
govern menial agencies, and
interested individunls,
This 3rd editiou Was
produced as a resull of an
updated need for
cross.connection control
reference lIIaterial renecting
an increase in
cross.connection control
activity throughoutlhe
United States, II hes been
revised and re.issued
reflecting a demand for its
Use, togelher with requests
for a document thai covers
the broad spectrum of
cross,connection conlrol frem
bath the basic hydraulic
concepls Ihrough the
inclusion of a sample
program that can be a guide
for n program at the
municipal leveL New
backflow devices have been
included in this revision Ihat
ere now being produced by
manufacturers reflecting the
needs of the market. Updated
actual cross.connectlon case
histories have been added
containing graphic schemetic
illuslrations showing haw the
incldenls occurred nnd how
cross.connecllon conlrol
practices could be npplied 10
eliminnte future
re.occurrence, A more
detniled explnnntion of
cross.connection control
"contninment" pracUce hns
been included together with
the Use for "Internlll bllcknow
protective devices" and
"fixture oullel protnctlon",
This new edllion WIIS
prepllred by lIownrd D,
Hendrickson, PE, vice
presidellt of Wnter Snrvice
Consultllnts, with nssistllnce
frolll PUlnr C. Knrelekns, 1r, of
Region 1, EPA, Basion,
. ----..-----------..-..-.------.. --_._.~----
/"
Contents
--..-.---.-. n --.. ---.-.. "..- -------...--..----------...--_..____n__
AmoriculI Waler Works Association Po/ic\' 011
Cross,Colllleclions ,.....,.,.." ".,. ,. .:,....... ,..,. ..iv
Chnp/er
I. Purpnse & Scope '.., ,,'..,.., ".. ....,....,,,,,..,,, I
2. Public Health Significance of Cross-COIlIl!lclioIlS.. . .. .. 2
3. Theory of Backflow and DlIcksiphollilgn.. . . . . " .. . .. . 12
4. lvlethods and De\'ices for the Pro\'{lIlIiOIl of
lIackllllll' alld Bar.ksiphollage """"""'" """" Iii
5. Testing Procedures for Backflo\\' PWvlllllcrs ..........25
6. Adminislration or iI CroSS,COllllCctiolJ Conlrol Program 30
7. Cross-Connection Conlrol Ordinance Provisions."... 33
Appcm[i;tws
()
A. Parlillllisl of plumbing hazllnls. .. . . . . ,. . . . . . .. . . . . . 38
B,lIIuslralions of backSiphonngc.. ...... ....... ........:18
C, II/uslmllolls IIf hackl/oil'""" """"""" "",", ~o
D.lIluslrnliolls of air gaps...... ....................... ~1
E. lIIuslrations of vacuulll breakers.. . . . . .. . . . . . ... .. . .. ~ 1
r. Glossary.................... .......,....... ,..... ,. ~2
G, Biol/lIgm"hy""",,,,,,,,,, "'''"",,,..,,,,,,,,, ~J
H. Salllple croSS-colIllCClioll sun'n}' rorm .,............. 4~
I. Slllllplo cross-conllCl.:t!olllcsl form. . . . . ... .. . ,. ... . .. ~5
Index
\...
17;-
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----~---------_._--~~--_.
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._-_._---_.~-----~._--_._---
Illustrations
-------------~-_..._-~--------_._~
Uuman blood in the walor systom ',.'....,....,..,..,.. 2
Burned in the shower ".... ".."... .................. 3
Healing system anti-freeze inlo polaulo waler """"'" J
Salty drinks """,""',","" """"""""""" 4
Paroquat In Ihe wllter system. .. . .. . .. .. . .. .. .. . .. .. .. " 4
Propano gas inlhe walor Illllins ..........,...,......,.. 5
Chlordane and heplachlor at tho I-lousing AUlhority "'" 5
Boiler woler enters high school drinking wilier,..,...,.. Ii
Pcsllcido in drinking waler ............"...""....." 6
Car wash waler in Iho waler main ..............."..... 7
Shipyard backfloll' contaminal/on ","","","',' "', 7
,.--Chlordane in Ihe waler main ""'" ..... .......... ...., 6
,. loxavalcnl chromium in drinking walor ,...,..,.".,.,. II
'....---Employeo health proulems duo 10 cross.(:nllller.:liolJ .,.", 9
Dialysis machino COil tam illation . ., . . ,. , , ., . , .. . . .. ,. .. 10
Creosote In 1110 wilter mains. .. . , . .. , . , . .. .. . , . , , . .. ." 11
Kool aid laced lI'ilh chlordane "" "", ""," """" II
Fignre
1 Prossure exerted by 0110 fool of \\'ilter al sea Im'l!l .,.. 12
2 Pressure exerled by Iwo feet of \\'lIler III sea luvlll .... 13
3 Pressure 011 tho freo surrllco of iI liquid nt SlHl lu\'!!1 .. 1:1
4 ErfeclofevaclIatlnguirfromilcolulllll ...".........1:1
5 Pressure relaliollships III a cOlllillUOllS
fluid SYSlfllll allhn salllO el!!vation .,..,.,.,..,..,... 13
6 Pressure rolatlonships ilia cOlllitlllClUS
flllld syslr"" ill differenl eluvlllions """""""'" 14
7 Bnckslphollllgo In a Jllumblng SYSIIHII ..",..,..,.,., 14
8 Negallve pressure created hy cOlIslricllttl flo\\' ...,... J.I
o Dyu.nnlcally rednced pip" 1""ss"',,lsl, " "" " " "" 14
10 Vlllvod COlllIlJ[:lion bolwctlll Jlotahln wulnr and
lIC1npolablo fluid......"...".."...,...,...."." 15
11 Valvod cOllllectlon huh\'I!I!Jl polahll! walor
i1/UISillJilar.l'SOWllr "",.....",.,..,.".."..,.,..15
12 Airgap '"'''' "'"'' "," " " " " "" " " " """ IIi
13 Air gall III II plplnl-l sysl!!lll .....".................. Hi
14 llnromelric loop """" "'"'''''''''''''''''' "" 17
15 AlmosJlheric \'I1CUurn bmakur ,.."...".,.,..,."" 17
16 Atmosphorlc \'i1CIIIIIIl brollkur lyplcallllslallnlion .,., 17
'7 t\ll1IosJlhorie \'i1Cllllrn hrunkllr
V In plllllllJilll-lsupplysyslnm "'.."...".,.".".,.,17
18 1I0se hlhb "lIcnnm bwaker """""""""""'" III
10 Typical inslalllllionnl hnsll hlhh Val:ullln h"",kllr ",' III
20 Pressure Vill:lIl1l11 bwaker ....,..,...,."".".,.", III
21 Typical ngricnltllrll! and Induslrial applical/nnlll
pwssuru \'IICIIIIIII !Jwukllr ',."..",.",....,..,.,., 1!1
22 Doublo chuck vnlve wilh allllosphork \'0111 ,...,..,.. 19
23 Residenlinl use of doublecheck lI'ilh atmospheric venl, IU
24 DOllble check valve ",," ''''',,'' "" """ ",,'" IU
25 Double check valve deluclor check "","",""',' 211
26 Residential dual check "", ""," "" """ "" '" 20
27 Residolllial insinUation .....,.. ..,...." ....,.... ,. 20
28 Copper horn "'" "" """","",, "" "",,' ", 20
29a Reducod Jlrossure zone uackflow IlrtJ\'enlcr.....,... 21
29b Reduced pressure zone backrlow IHtJ\'enlur,.,....,. 21
30 Reduced prcssure zOlle backrlow pre\'l!l11cr-
princlpleofoperalion '" """,,,,,,,,,,,,,,,,,,,,22
31 Plating plant iestaflalion """""'"'''''''''''''' 22
32 Cor II'nsh ieslnflalion ,,"","'," """" """",22
33 Typical by.pass configufillion, reduced pressure
principle dovices.. . " " ... , .. . .. .. ." , .... . .. . " " 23
34 Typical installalion. reduced prussurn principle
11l!\'il:c. horizontnl illuslration ,.....,.."........,.23
35 TYJlicallnSlallation, rcdlu::ed prossuru Ilrinciple
devir:e, verlieal inslnllnlion ","" ","" """",,23
38 Typical instal/nlinn, doublo check vllll'll,
horiwnla! nud vcrlicallnslullatioll .........'....... 2.1
37 Typleal installalion, lOsldenlial dUll! chod
wllh slfllighl sollllJd coppor horn ..,....",...,....24
38 PruSSllflJ vacuull1 hrcaker ..""....,,,...,.........26
3U Heduced press",e principle backl/OIv plOventor, Step I 27
.10 Reduced pressure principle budrJow prc\'lJlller. SIllJl2 27
41 Doubln check valvu assembl/es, Melhntll """"',' 2B
42 /luuble check valve nssemhl/es, ~Illlhod 2 """"",20
43 Cross-collllection proluclioll, cOllllllureinl,
illduslrinllll1d residonllal .".,....,.".,..".,.....30
44 BlI(:ksiphonage, Cnso 1 ....,.......,,,..,..,,,,..... 38
45 B,,:kslphonage, Case 2" """','" ",',' """'," 3R
oIB Bnckslphnnnge, Cnse 3 ","""'''" '" "",,,,,,,,:10
'17 IlndsiplHlllllgo, Casll 4 .....,.,,, , " .. , . . , , ... . , . " . 3U
4B Bncksiphonngn, CIISU 5 """ "'" """ """",," 30
4U Backsiphnnage. Cnse 6" ""',""","'" "",",' 3U
56 Backfloll' ClIse 1 """" """'"'' "" ", """" ,III
51 Backfln\\' Cnse 2 '"'''' '''' "" '",,''' "'" """ 40
52 Bnckflo\\' Case:i ,',"" """""" "" """"'" ,III
53 IIl1ckllo\\' Cnse -I """" '" """" "" "", """ 40
54 J\lr gnJlto silwer slIb/octlo backllressllrc-rorce mnin .\ t
55 Alrgal' to snwersublOl:lto hnckprussuru-gruvlly t1rnin 41
5li Flru syslolllll1l1kuul' lank for 1I dunl wlIlur system,.., 41
57 VncuIIlIl hronkllrs """""""" '" ....., ,......,. .11
511 Vm:lIl1l1l brcakor arrangemonl ror nn oulsldo
hnsn hydrnnl "',"" '''''''' ", '''''' ,,,,,,,,,-11
il//'1~
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An AWWA
Statement of Policy
on Public Water Supply Matters.
Cross Conneclions IAdopted
by the Board of Directors on
Jan. 26,1970, and revised on
Juno 24,1979, and reaffirmed
June 10, 1964)
The American Water Works
Association recognizes Ihal
Ihe water purveyor has a
responsibilily 10 provide its
customers althe service
connection with waler Ihal is
saCe under all foreseeable
circumstances. Thus, in Ihe
exercise oC Ihis
responsibility, Ihe waler
purveyor musl take
reasonable precaulion to
prolect the community
dislribution syslem from the
hazards originating on the
premises of its cuslomers Ihat
may degrade Ihe water in the
community distribution
syslem,
Cross-connection control
and plumbing inspections on
premises of waler customers
arc regulatorv in nature Ulul
shouid be Illindled through
the rules, regulations and
recommendatiens of the
health autherlty or the
plumbing.code anforcement
agencies having jurisdiction.
The waler purveyor,
however, should be awere of
any situation requiring
inspection ondlor
reinspection necessary to
detect hazardous conditions
rosulting from
ii'
r
cross-connections. If, inlhe
opinion of Ihe ulility,
effective measures consislenl
with the degree of hazard
have not been taken by the
regulatory agency, the waler
purveyor should take such
measures as he may deem
necessary to ensure thatlhe
community dislribution
system is protecled Crom
contamination. Such action
would include Ihe
ins lallation of a backfiow
prevention device, cousisleut
with Ihe degree of hazard al
the service connection or
discontinuance oC the service.
In addition, customer use
of water from the community
dislribution syslem for
cooling or olher purposes
withiu the customer's system
and laler return oC the weter
to the community
dislribution system is nol
acceplable and is opposed by
AWWA.
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Chapter One
,..-..."
Purpose
and Scope
P"blic bealth offidals have
long belm cUllclmwd
abotll crOSS'COIIIWclioIlS i1lld
baekflO\\' cOl1l1ccliollS in
plumbing systems IInd in
pllblic drillkillg wal"r SIIppl)'
distriblltioll svstmns. SIIch
crosS-t;ol1l1ecllollS, \\'llich
milke posslbl" Ihe
contamination of potable
waler, me ever-present
dangers. One example of
what Ciln happen is all
epidemic thnt occurred in
Chicilgo ill 1933. Old,
defective, alld improperly
desiglled plumbing ilnd
fix lures permill"d Ihe
conlamination of drinking
water. As u result, 1,409
persons contracled amebic
dysentery; Ihere Were 93
dealhs. This epidemic, ulld
olhers reslllting from
conlamination inlroduced
into a water snpply throngh
impro!,er plumbing, mude
clear tIC responsibility o(
public health officials and
waler purveyors for
exercising conlrol over public
water dislribution syslems
and all plumbing syslems
connected to them. This
responsibilily inclndes
advising and instrucling
plumbing installers in the
recognition and elimination
of cross-connections.
Cross.connections ure Ihe
links thrungh which it is
possible (or contaminating
malerlals to enter II potable
water supply, The
contaminonl enlers the
polable water syslolll when
I ,;~~}:~;<f~:'}~~::~(;~l~
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the pressum uf Ilw pullUlud
source Hxctwcls the pmsslIW
of Ihe polahlu sourw. The
",:tion OWl' hu callud
backsipl",nagu or hackflow,
Essonlinll\' il is reversal of
thu hydruiili<: grailieollhal
call be produced hy il \'ilril!ly
of circlIIllslilllCOS,
Ilmight be assullled thai
sleps for dutuctiog and
eliminating eross.
connections would be
nlomcnlary and olJ\'iolls.
t\cluafl)', cross'l:Onnections
may appear illlllilll)' slIblle
forms and in IInsuspncted
plncos. Reversal of pressure
in the watur mil)' be freakish
and unprediclable. The
prohability of coulamination
of drinking water through a
cross.conncclion occurring
within a single plumbing
system Illay seom femole:
bul, considering the
multitude nf similar syslems,
the probability Is great.
Why do such
cross.cDnnectiDns exist7
First. plumbing is fre'luonll)'
inslalled by I,ersons who ure
nnaware of t In inherent
dangers of cross,connections.
Second, such connections arn
made as a simple mailer nf
convenience without regord
to Ihe dangerous situation
thalmighl be cmnled, And,
third, they are mode with
reliance on inade'luale
prolectiou such as a single
valve or other mechanicnl
device.
To cOlnballhe dengers of
cross. connections and
backfIow connections,
educolion in their recognition
ond prevenlioo is neoded,
First, plumhlng inslallers
must know thol hydranllc
nud pollutional factors may
combine 10 prodnce a
sonltary hezard if a
cross-connecllon is present.
Second, they must reollze
thollhere aro avo liable
rellahle nnd simple stondord
hackfIow provoollon devleos
ond methods Ihol may be
.-....._w._...____
subsllluled for Ihe
convenient hut dungorous
direct connection. And Ihird,
it should he made clear 10 all
Ihatthe hazards resulJing
from direclconuections
greall)' oUlweigh Ihe
cOII\'Cniencll gained.
This manual does nol
descrihe ullthe
cross.connections possible in
piping systems. It does
allempllo reduce Ihe subject
10 a state men I of Ihe
principles involved and to
make it clear to the reader
that such inslallations are
potentially dangerous. The
primary purpose is to define,
describe, nnd illustrate
typicol cross-connections and
10 suggest simple methods
and devices by which they
may be eliminaled without
inlerfering with IIw functions
of plumbing or water supply
dislriblltion systems.
17~
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- .. -...--~ ..,.,.,---...........
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Chapter Two
Public Health
Significance of
Cross-Connections
\
2
Public health officials hove
long heen aware of the
impact that cross.connections
ploy os 0 threat to the public
health, Because plumbing
defecls ore so frequent and
11m opportunity for
contaminants to invade Ihe
public drinking water
through cross.counections ore
so general, enteric infeclions
caused by drinking water
may occur at most any
location and at any time.
The following documented
cases of cross.connection
problems illustrate and
emphasize how actual
cross.connections havu
compromised Ihe water
quality and the public Iwalth.
-~~..._._.._~- ...-.---..- . ---
----------------------
Human Blood in
the Water System
Health Deparlmenl officials
cut off the waler supply
to 0 funeral home localed in
u large southern city, after it
was determined Ihal human
blood hod contaminated the
fresh water supply. City
water and plumbing officials
said that they did not think
that the blood conlamination
hod spread beyond Ihe
building. however, inspeclors
were senl into the
neighborhood 10 check for
possible conlamination. The
chief plumbing inspector hod
received 0 lelephone call
advising Ihal blood was
coming from drinking
fountains within the
building. Plumbing and
couuty health departmeul
inspectors went to the scene
and found evideuce thatlhe
blood had been circulating in
the water syslem within the
building. They immediately
ordered the building cut 0[1
from Ihe water system althe
meter.
(~
Investigation revealed that
the funeral home had been
using a hydraulic aspirator to
drain fluids frem Ihe bodies
of human "remains" as part
of the embalming process.
The aspirator directly
connected to the water
supply system at a faucet
out lei located on 0 sink in
the "preparation"
[embalming) reom. Water
flow through the aspiralor
created suction that was
utilized to draw body fluids
through a hose and needle
attached 10 the suction side
01 Ihe aspirator.
The contamination 01 the
funeral home potable water
supply was caused by a
combination 01 low water
pressure in conjunclion with
the simultaneous use of the
espirator. Instead of Ihe bod)'.",
fluids flowing into the \,,,.'
sanitary drain, they were
drawn in Ihe opposite
direclion-into Ihe pOlable
water supply of the funeral
home!
Normaloperalion
PDSlllveSUPPlypreSSUrepOlablewa~..
Closed .'...
Negalive 5Upplj'prcssure .......
Rcvefscllowlhrough
aspirator due 10
backsrphonage
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r~urned in the
,)hower
A resident of a small town
in Alabama, jumped in
Ihe sbower 01 5 a.m, one
morning in October. 1986,
and when ho got out his
body was covored wilh tiny
blisters. "The more I rubbed
it, the worso it got," the 60
year old rosidont sold. "It
looked like someone took a
blow torch and singed me."
Ho and several other
rosidonts received ",edical
treatmont at the emergency
room of the local hospital
after the water system was
contaminated with sodium
hydroxide, a strong caustic
solution.
Other residents claimed
that, "It (the walor) bubbled
up and looked like Alka
"',
',,-.hemical bulk storage and holdmg lan~s
SeItzer. I stuck my hand
under the faucet and some
blisters came up." Ono
neighbor's head was covered
wilh blisters after she washed
her hair and others
complained of burned throats
or mouths after drinking the
water.
The incidenl began after an
B-inch water main, that fed
the town, broke and was
repaired. While repairing the
water main, one workman
suffered leg burns from a
chemical in the water and
required medicaltreatmenl.
Measuremenls or the ph of
the water were as high as 13
in some sections of the pipe.
Investigation into the couse
of tho problem led to a
possible source of the
contamination from a nearby
chemical company that
dislributes chomicals such os
sodium hydroxido. The
sodium hydroxide is brought
10 the plant in liquid form in
bulk tanker trucks and is
transferred to a holding tonk
and Ihen pumped into 55
gallon drums. When the
waler main broko, a truck
drivor was edding tho waler
from the bollom of tho tank
truck instead of tho top, and
sodium hydroxldo
bock-siphoned into tho walor
main,
u
_...".~---~...._~-
Heating System
Anti-Freeze into
Potable Water
Bangor Moine Water
Dopartmont employees
discovered poisonous
anti.freeze in a homeowner's
heating system and waler
supply in November, 1981.
The incident occurred when
they shut off the service line
to tho home to make repairs.
Wilh the flow of water 10 tho
house cut off, pressuro in the
linos iu the house dropped
and the anti.freoze, placed in
the heating system to prevenl
rreeze.up of on on used hot
wator heating system,
drainod out of the heatiug
syslem into house water
lines, and flowed out 10 the
streel. If it hod uot been
noticed, iI would hove
entered the homeowner's
drinking waler when tho
water pressure was reslored.
CurhSlODl'Illh Slopaf'(jW,l~lc(jrall'
.~-
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Salty Drinks
In January, 1981, a
nationalll' known fast food
restauront ocated in
southeaslern United States,
complained 10 Ihe water
deparlmenlthat all their soH
drinks were being rejecled by
their cnstomers as tasting
"salty." This included seda
founlain beverages, coffee,
orange juice, etc, An
investigation revealed that an
adjacent water customer
complained of sally water
occurring simultmwously
with the reslauront incidenl.
This second complaint came
from a waler fronl ship repair
facility thai was aiso being
served by Ihe same waler
mainlateraJ. The
.._._~------_.__.__. .+-..-.-. ---- ..--._------_.._..._---_.__._._._-._--_.._--~-- .
investigation cenlered nnlhe
ship repair facility and
revealed Ihe following:
. A bar.kfiow preventer
that had been inslalled on
the service line 10 Ihe
shipyard had frozon and had
boen repiacClI with a spool
piece sleeve.
. The shipyard fire
protection system utilized sea
waler thai was pumped by
both eleclric and diesel
driven pumps.
. The pumps were primed
by polable cily waler.
With the polable priming
line loll open and the pumps
maintaining pressure in the
fire lines, raw salt water was
Ilumped throngh Ihe priming
ines, Ihrongh tho spool
sleevo piece, to Ihe ship
repair facility and Ihe
restaurant.
I
I
I
I
i
j
I
I
I
I
I
I
I
._._._~.._~-_..~
M,linhcshw.1!erlrl'C
~_"_'_M..'~___'
~---_..
Paraquat in the
Water System
"yellow gushy stuff"
pourod from some of
the faucets in a small town in
Maryland, and the Stale of
Maryland placed a ban on
drinking Ihe waler supply.
Residents Were warned 1I0t to
use Ihe waler for cooking,
bathing, drinking or any
olher pnrpose except for
fiushing toilels,
The incidenl drew
widespread allention and
made the local newspapers.
In addition to being the lead
story on the ABC news
affiliate in Washinglon, D.C.
and virlnally all the
Wash i ngto nlBa II i m ore
newspapers Ihal evening, The
news media contended Ihal
lelhal pesticides may have
contaminaled Iho wator
supply and mnong the
contmninanls was parnqual, a
powerful agricullural
horbicide.
The investigation disclosed
thatlho water pressuro in the
town walor mains was
lemporarily reduced duo to a
wator pump failure in the
lown wator supply pumpiug
systom. Coincidonlally, a gate
valvo botwoon a herbicido
chemical holding tank and
r
I
,
tho lown water supply piping
had been left open. A lelhal
cross.connoction had boon
creatod that permllled tho
herbicide 10 flow inlo the
polable waler supply system.
Upon restoration of waler
pressura, Ihe horbicides
flowed Into tho many faucets
and outlets on the town
water distribution system.
This cross.conneclion
created a noedloss and costly
evontlhat fortunalely did not
result in serious illness or
loss of life. Door-to.door
public notificalion, extensive
flushing, waler sample
analysis, emergency
arrangements to provide
temporary poteble waler from
tanker trucks, all contributed
to an expensive and
unnecossary lown burden.
C) .
I\JlllIJleliJ\',I'I'"llt'r..
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,
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Rl:COll1ll1er'IJl'(II!'~tlil(l[IOn of lJ.1C~tlOW preventel
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17ropane Gas in
the Water Mains
.-Uundreds of people were
, :-Ievacuated from their
'-nomes and businesses on an
August afternoon in a town
in Connecticut in 1982 as a
result of propane entering the
city water supply system.
Fires were reported in two
homes and the town water
supply was contaminated,
One five. room residence was
gutted by a blaze resulting
from propane gas "bubbling
and hissing" from a bathroom
toilet and in anothor home a
washing machine explosion
blew a woman against a wall.
Residents throughout the aroa
reported hissing, bubbling
noises, coming from washing
machlnos, sinks and toilets,
Faucets sputtered out small
stroams of wotor mlxod with
gas and residonts In the area
were askod to evacuate tholr
homes,
This near.dlsaster occurrod
In one, 30,000 gallon
capacity liquid propane tank
when the gas company
Initiated Immodlate ropalr
~roceduros, To start tho
'--.J
repair, tho tank was "purged"
of residual propane by using
wator from one of two private
lire hydrants locatod on the
property. Water purging is
tho preferred method of
purging over the use of
carbon dioxide since It is
more posittve and will float
out any sludge os well os any
gas vapors, The "purging"
consisted of hooking up a
hose to ono of Ihe privete fire
hydrants located on the
property' and Initiating
flushing procedures,
Since the vapor pressure of
the propane rosidualln Ihe
tank was 85 to 90 psI., and
tho water pressuro was only
65 to 70 psI., propano gas
backprossure backflowed Into
tho wotor main, It was
osttmatod that the gas f1owod
Into tho wator mains for
about 20 minutes and that
about 2,000 cubic feot of gas
was Involved, This was
approximately enough ges to
fill ono mllo of an 8.inch
water main,
_._._-----~--_._-_._.__._~_..-
Chlordane and
Heptachlor at the
Housing Authority
The sorvices to seventy five
apertmonts housing
approximatoly threo hundrod
peoplo were contaminated
with chlordane and
hoptachlor in a city in
Pennsylvania, in December,
1980. The insecticidos
entered Ihe water supply
system whilo an
oxtermlnating company was
applying them as a
prevontativo measure against
termites. While tho pesticide
contrector was mixing the
chomlcals in a tank truck
with water from a garden
hoso coming from one of the
apartments, a workman was
cutting into a 6-inch main
line to install 0 gate valve.
Tho end of the gardon hose
was submerged in the tonk
containing tho pesticides,
and at tho sarno timo, the
wator to tho aroa was shut off
and the Iinos boing drained
prior to the inslallation of the
.-----..-------------
gato valve. Whon tho
workman cutlhe 6-inch
line, water startod to drain
out of the cut, thereby setting
up a back-siphonago
condition. As 0 result, the
chemicals wero siphonod out
of the truck, through the
gerden hoso, end into tho
systom, conteminating the
sovonty live apertments.
Repeatod efforts to c10an
end flush tho lines wore not
setisfactory end it was linally
decided to replace the wetor
liI,e and all the plumbing
that wos affocted, Thore wero
no reports of illness, but
rosidents of the housing
authority woro told not to use
any tap water for any
purpose and thoy wero givon
water that was truckod into
the area by volunteer lire
department personnel. Thoy
were withoutthoir normal
water supply for 27 days.
/;iJ.
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Boiler Water
Enters High School
Drinking Water
High
school
Recommended installation
SlIeel of oockHow prevcnter;~..
~>
~'TOXlcrUSI,lflhlbltorand
deloamantconlainmg
.;1. sodium dlchlOmate
Pump
A high school in Nell'
Mexico, was closed for
sel'eml days in lune 1!)64
when a home economics
leacher noliced the water in
the potable system was
yellow, City chemists
determined thai samllles
token conteined iel'e s of
chromium as high as 700
parts per million,
"astrouomically higher than
Ihe accepled levels of ,05
parts per million," The head
chemisl said Ihal it was
miraculous that no one was
seriously injured or kilied by
Ihe higb lel'ols of cbromium,
Tho chomicol WIIS identified
as sodium dichromole, 0
toxic form of chromiumuslllj
in healing syslem IlOilurs 10
inhibit corrosion of the motol
porls,
No sludouls or facully wern
known to have consumed
lIny of tho willer; howovllrt
orno pbysicions and bospitals
odvisod thai if nnynno hod
consumed thoso high 101'0ls
of cbromiulll, tho symploms
would bonouslla, dinrrhlla,
Ii
o
o
and burning of Ibll moulb
and throa!. Fortunately, Ihll
homo economics teachor,
who first saw Ihe discolnwd
waler borow scbool starlod,
immediatoly cOl'ewd all
waler fountains witb lowllis
so Ihal no nnll would drink
the waler.
Inl'esligalion disclosed Ihat
chromium used in Ihe
bealing system boilllrs 10
inhibit corrosion of milia I
paris enlermllhe potablll
water supply s)'slem as a
resuit of backflow tbrougb
looking check l'all'Ils on Ihll
boilllr feod Iinos,
Pesticide in
Drinking Water
APeslicide conlaminated a
North Carolina water
syslem in ilpril, lD6fi,
promptiug the town 10 warn
residents of 23 housllholds
nollo driuk the water, Tbe
residents in Ihe affected area
were supplied drinking waler
from a tank truck parked in
till! parking lot of a
downlown office building
unlilthe condiliou conld be
cleared up, Residents
complained of foul smelling
water but Ihero wore no
wporls of illness from
ingesling Ihe waler that bad
been conlmninated with u
pesticide conlaining
chlordane and heplachlor,
ilulborities statlld Ihallhe
problem occnrred when a
water main broke 1I1the same
lime that a pes I conlrol
service was filling II pesticide
trnck with water, The
reduction in pressure caused
the pesticidll from inside tbo
tank to be sucked inlo thll
building's water mllin, The
peslicide contaminated Ihe
polable Wilier supply of the
office bnilding and
neighborhood area,
Car Wash Water
in the Water Main
This car wash
cross-connection and
back pressure incident, whicb
occurred iu February, 1 D7D,
in Ihe state of Wasbington,
resuited in backflow
cbemical conlllmination of
approximately 100 square
blocks of water mains,
Prompt response by the water
deparlmellt prevented a
potent ill Ill' bazardous water
quality degradalion problem
without a recorded case of
illness,
Numerous compleinls of
grey.green and "slippery"
wator were received by the
waler depnrlmenl coming
from Ihe same general urea of
town, iI sample brought 10
the waler deparlment by a
customer confirmed the
reporled problem and
preliminary analysis ('
indicated contamination w\,.~
what appeared 10 be u
detergenl solution, While
emergency crews initiated
flushing operations, furlher
inl'estigalion within the
contaminaled area signaled
Ihe problemll'as probably
Recommendedmstallatlon
01 hose bibb vacuum breaker
bJc~flowprcvoliter
,
I.....
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Shipyard
Backflow
Contamination
caused by a car wash, or
laundry, based ulJOn till!
soapy nature of tlC
contaminant. The source was
quickly narrowed down 10 a
car wash and the proprielor
was exlremely cooperative in
admitting 10 Ihe problem and
explaining how it hed
occurred. The circumslances
leading up 10 the incident
were as follows:
. On Saturday, February
10,1979, a high pressure
pump broke down atlhe car
wash. This pump recycled
reclaimed wash and rinse
waler and pumped it 10 Ihe
initial scrubbers of Ihe car
wash. No potable plumbing
connection is normelly made
10 Ihe car wash's scrubber
system.
'"",' After the pump broke
..)WI1, Iho car wash owner
Ivas able 10 continue
operation by connecting a
2.inch hose section
lemporarily between Ihe
pol able supply wilhinlhe car
wash, and Ihe scrubber cycle
piping.
. On Monday, February
12, 1979, Ihe owner repaired
Ihe high pressure pump and
resumed normal car wash
operations. The 2.inch
hose connection
(cross.connection) was nol
removed!
. Decause of Ihe
cross.connection, the newly
repaired high pressure pump
promptly pumpod a large
quanlity of the reclaimed
wash/rinse water oul of Iha
car wash and inlo a 12.inch
waler main in tho streeL This
in lurn was delivered 10 Ihe
many residences and
commercial eslablishments
connected to Ihe water main.
Within 24 hours of Iho
incident, the owner of the car
wash had inslalled a
2.inch reduced pressure
principle backflow IlIevenlor
on his wator service and 1111
car wash eslablishments in
Saallle Ihalused a wesh
water reclaim system WCfe
notified of Ihe stele
requiremenl for backflow
prevention.
Caletenadunklng lounlalOS
andsanital10nwater
~Q"
C' ~IJ * Reduced pressureprmclple backllow prevenlers
~l~~ should have been Installed at dockSide outlets
./ 1-.~wc andOlherlacalions
/ '?O
,
Water founlains al an Enst
Coast Shipyard were
posled "No Drinking" as
workers flushed the waler
Hnns to oliminnte row river
water thai had enlered the
shipyard following
conllllllination from
incorrnclly conncclnd wllter
lines between ships at tho
pier and the shipyard. Somo
Ihird shin employees drank
the waler before the pollution
wns discovered ilnd lator
complained of stomach
ctllmps and diarrhea.
Tho cnusn of Ihe prohlem
was a dimet cross.connm:lion
between Ihe nn.board sail
walor fire \Jroleclioll Willer
system OIl< the fresh wn",,'
connecled 10 onl! of tho ships
allhe dock. While tho
ship)'ard had bnon awaro nf
lhe nned for h",:kflow
protection 01 the dockside tie
up area, the device had not
been delivered and installed
prior to Ihe lime of the
incident. ils a result, Ihe sail
water on.board fire
prolection system, being at a
grealer pressure than Ihe
potable sUPlll)', forced the
salt waler, luough
back pressure, inlo the
shipyard potable supply.
Forlunately, a small
demand for Ilolable waler at
the time of 110 incident
prevonted widespread
pullution in 1110 shipyard and
Ihn surronnding arens.
\
Wa~inieclors
l~
I
Rmse Rinse
SoaplnieClors
HoscconneCllon
madehcre
I
~'~
Scrubbers
!~
\_ \. r~ 'ccl"m tan~j .J ;I
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,/lnslallatlOnol
backflowprevenler
To IcstrOOf!lS
;. ~
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V
POlablewalcrsuPllly
I.,~
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~':.".:,:i, '," ...:.~.~.~': :;" -., .~,.;~" ~":' ,',:'d"':, ',:....<.~::':.,\
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Chlordane in the
Water Main
In October, 1979,
approximately threa gallons
of chlordane, a highly toxic
insecticide, was sucked back
(back.siphoned) into the
water systam of a residantial
area of a good sized easlern
city. Residents complained
that the water "looked milky,
felt greasy, foamed and
smelled," and as one woman
put it, "It was similar to a
combination of kerosene and
Black Flag pesticide."
The problem developed
while water department
personnel were repairing a
water main. A professional
exterminator, meanwhile.
was treating a nearby home
with chlordane for termite
elimination. The workman
for the exterminator company
left one end of a garden hose
that was connected to an
outside hose bibb tap in a
barrel of diluted pesticide.
During the water service
\
interruption, the chlordane
solution was back.siphoned
from the barrel through the
house and into the water
mains.
Following numerous
complaints. the water
department undertook an
extensive program of flushing
of the water mains and hand
delivered lellers tellhlg
residents to flush their lines
for four hours before using
the water, Until the water
lines were clear of the
contaminant. water was
hand.hauled into homes, and
people went out of their
homes for showers, meals
and every other activity
involving potable water.
Fortunately, due to the
obvious bad teste. odor and
color of the contaminated
water, no one consumed a
sufficient quentity to
endanger health.
8
CHLORDANf
Hexavalent
Chromium in
Drinking Water
In July, 1982, a well
meaning maintenance
mechanic. in allempting to
correct a fogging lens in an
overcooled laser machine,
installed a tempering valve in
the leser cooling line. and
inadvertently set the stage for
a backprp,ssure backflow
incident that resulted in
hexavalent chromium
contamineting the potable
water of a large electronic
manufacturing company in
Massachusolls employing
9,000 people. Quantities of
,'t'....
Temporary ~
chiller
feed purnll
, ,
I ,
, ,
'..'
RccommcndedInSlallallon01
backllowprcvCnlcr ,"~'\
-1:,......".,..,'"
\.....'
HOlwalcr
hCJWI
WI' ... T ---"...~~
50 parts per million
hexavalent chromium were
found in the drinking water
which is sufficient to cause
severe vomiting, diarrhea.
and intestinal sickness.
Maintenance crews working
during the plant shutdown
were able to eliminate Ihe
cross.connection and
thoroughly flush the potable
water system, thereby
preventing a serious health
hazard from occurring,
The incident occurred as
follows:
. Laser machine lenses
were kept cool by circulating
chilled water that came from
a large refrigeration chiller.
(",
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q
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The water used in the chiller
was treated with hexavalenl
chromium, a chemical
additive used as an
anti-corrosive agent and an
algicide. As a result, the
chilled water presented a
toxic, non-potable substance
unfit for human consumption
but very acceptable for
industrial process waler. No
health hazard was present as
long as the piping was
Identified, kept separate from
potable drinking water lines,
and not cross-connected to
the potable water supply.
. A maintanance mechanic
correctly reasoned that by
edding a tempering valve to
the chilled water line, he
could heet up tha water a bit
and eltminate fogging of the
I leser lenses resulting from
' ,;e chilled weter being too
',",old. The problem with the
I installation of the tempering
valve was that a direct
cross-connection had been
I inadvertently made hehveen
the toxic chilled water and
I the potable drinking water
line!
. Periodic maintenance to
the chiller system was
performed in the summer,
requiring that an elternate
chiller feed pump bo
temporarily installod. This
raplacoment pump had an
outlot pressure of 150 psI.,
ond promptly ostabllshed an
imbalance of pressuro at tho
temporlng valvo, thareby
ovor-prossurizing tho 60 psI.
poteblo supply. Hackpressure
beckflow resultad and
pushod the toxic chilled
wator from tho wator hooter
and thon into tho plant
potablo drinking wator
supply, Yellowish groen
wator slartod pouring out of
tho drinking founlains, tho
'ashroom, and all polablo
Jtlets.
Employee Health
Problems due to
Cross-Connection
A cross-connection
incident occurring in a
modorn sevon.story offico
building located in a lerge
city in New Hampshire, in
March, 1900, resulted in
numerous cases of nausea,
diarrhea, loss of time and
employee complaints as to
tho poor quality of the water.
On Saturday, March 1,
1900, a largo fire occurred
two blocks away from a
seven.story office building in
this largo Now Hampshiro
city. On Sunday, March 2,
19aO, tho maintenance crew
of the offico building arrived
to porform the weekly
cleaning, and after drinking
the water from tho drinking
fountains, and sampling the
coffoe frem the coffee
machines, noticed that tho
water smolled rubbery and
had a slrong bitter tasto.
Upon notifying tho
Manchestor Watar Company,
wator samplos were taken
and preliminary analysis
disclosed that tho
conlaminants found Were not
tho typical conlaminants
associated with fire line
disturbances. Invostigating
toams suspectod that oither
tho nearby flro could havo
siphoned contaminants from
adjacont buildings into tho
water mains, or tho
conlamlnants could have
beon caused by a plumbing
deficioncy occurring within
the sovou story building
itself.
Water ph lovols of tho
building wator indicated thet
an inJoctlon of chomlcals had
probably takon placo within
tho sovon.story building,
Tracing of tho wator IInos
within tho building
plnpoinlod a 10,000 gallon
hot.wator slorago tank that
was used for hoat storago In
tho solar hooting systom, It
did not have any backflow
proloction on tho make.up
supply IIno! As this storage
tank prossure Incroasod
obovo the ~llDply prll~suro, ns
a rosult of thormal oxpanslon,
Ihe potential for backpressure
backflow was present.
Normelly, this would not
occur bocauso a boost pump
in tho supply Iino would
keep the supply pressure to
the storage tank always
greator illan tho highest tank
pressuro, The addition of rust
inhibiting chemicals to this
tank greatly increased the
degreo of hazard of the
liquid. Unfortunately, at the
sarno time that tho fire took
placo, the pressuro in tho
wator mains was reduced to a
dangerously low prossure
and the low pressure cut.off
switches simultaneously shuI
off the slorage tank booster
pumps, This combination
allowed tho bailor water,
togethor with its chemicel
contaminants, tho
opportunity to enter the
potablo walor supply within
tho building. When normal
pressure wos reestablished in
tho wator mains, the boostor
pumps kicked in, and tho
contaminated water was
dellverod throughout the
building,
Aoofmouf1ledsolarpanels
~~~~
Heal~
UI'II " exchan er
II V Sln~
srnk~~~
cce i
machj~e I
I
S'k'~r...,
Inl--!I
Walermain
"l
. , ......'. ',' ", :' '.' '. '\',' ',' ", ,.' '"
" .. . Ii ...... . .. " "&t' '.},' ", " ,. I- 'II
:' :, "" ,,";, I~";;'l":";'th::.: " I, ,,' ,; ":,, ,":, ',I':;, ,',,-, " ~.
~ " "r ,.1 . , . ", , 1, \, '", ., I
l, ' ,", "..,' " ;.'.. '" '., '" .' . '.' .
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-----.-.---.- --.----.--.-.--
----- -...-----..--.------.-----.
Dialysis Machine
Contamination
-.--,-- -----.- .-- - ..--- - ----..-------..-- -..._---,- ----.- -
Creosote in the r
Water Mains '
Elhylene glycol. an
anli.freeze addilil'o to air
conditioning cooling 101l'0r
lI'alor, inadl'erlonlly onlorod
Ihe polablo lI'alor snpply
system in a medical cenler in
Illinois in Seplombor, 1982,
and 111'0 of six diall'sis
patients succumbed as a
diroct or indirecl rosull of Iho
contamination.
The glycolll'as addod 10
the air conditioning walor,
and Ihe glycol/lI'alor mix lI'as
slored in a holding lank thai
was an intogral part of Ihe
medical conter's air
conditioning cooling syslom,
Prossnrizod mako.up lI'aler to
the holding tank lI'as
suppliod by a modical conlor
polablo supply Iino and fod
through a nHlIJually oporated
control valve, With Ihis valvo
opon, or partially opon,
polablo mako.up wator
f1oll'ed sloll'ly into tho
glycol/walor mixture in tho
holding lank until it fillOlllo
the poinlll'here Iho pressnre
in the closed tank equalled
Ihe pressure in Iho potable
lI'ater supply food Iino, lis
long as Iho potable feIJd line
prossure lI'as at least oqual
10, or greater Ihan, Iho
holding tank pressure, no
hacklloll' could occnr. The
slago lI'as sol fnr disaster,
however.
IIl1'as theorized Ihal
somoone in the medical
conlor fins hod a loilel nr
turned 011 a rntlccl, which in
turn dropped the pressure in
tho polable supply line to 1110
air conditioning holding
lank. Since Iho manually
operated fill valve was
partially open, this allowed
Iho glycol/lI'aler mixturo 10
onter tho medical center
potable pipelines and flow
inlo Iho dialysis equipment.
The dialysis fillration system
tllkes out truce chemicals
such as Ihoso usod in Ihe city
lI'ater trealmonl planl, bUllhe
syslem could not handle the
hoal'Y load of chomicals Ihat
it lI'as suddenly snbjectod 10,
The effoctupon Ihe
dialysis patienls lI'as
dramatic: patients became
droll'sy, confused and fell
uneollsiollS, and were
promplly remol'od 10
intensive care where blood
samples 1I'0re takon. The
blood samples revealed n
bUild,ull of acid and Ihe
nwdica direclor slalod thai,
"Somelhing has happonml in
dialysis." Dialysis lI'as
ropoalod on Iho !lationls a
socond and Ihl" timo.
Tosls of Ihe lI'aler supply
10 Iho fillration systom
quic:kly dolormined Iho
prosence or "nil lIndusirablll
chomical inlhe lI'ator
purification system." Tho
pmliully OllHll rill valvll was
then fuun( Ihnt it had
pormilled Iho glycnl/ll'ilter
mix 10 drain from the air
conditioning hulding tilnk
inlo tho modienl conter's
polahle sUPllly lines und Ihon
into Ihe dia ysis filtration
systolll equipmellt.
Creosote enternd the water
distribntion systemnf a
sonlheilslern county lI'aler
authoril}' in Georgia, in
NOl'embor, 1984, ns a resull
of cross.connection bot ween
a :y, inch hose Ihat lI'as heing
used as a priming line
between a fire service
connection and the suclion
sido of n creosole pnlllp. The
hose conlinnally supplied
water to Ihe pump 10 ensure
Iho pnlllp was prillled at all
times. However, while
repairs were being made tc a
private fire hydranl, Iho
creosole back.siphoned inlo
the wnter mains nnd
conlaminalod a section of the
walor dislribnlion syslem.
Delailed inl'ostigation of
Ihe causo of Ihe incidonl
disclosed thallhe wood
preservative compnny, as 1>_.'
of their operation, pump",,_
creosole from colloclil'e pils
to olher paris of their
operation. The croosote
pump would anlomatically
shnl off whon Iho croosolo in
Iho pil was lowered to a
pre.dolnrlllined lel'ol. After
tho creosole returned 10 a
higher level, the pUlIlp would
re.start. This pUllIp would
1050 ils prime quile oClen
prior to Iho pil refilling, and
Glycol,water
pressurize<!
holdlnglanl
Recommended I
Dlalvsls room instal/ation
olbac~flowprevcntcr \'....'
RR~IYSIS
fill ration
unit
\
Slightly
open
manual
valve
.~-.-,..~
,
f
I
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;
!
i
i
,
\
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t
,
,
t,
...'Washroom ~
A~'
;
\ Bilnp1cssurObac"low
,
I' ,--
'..",,,,,, '--=-~lalnw'llcrsupply
r--
.......'
Rccommendedmstilllallon
olbilckUowprevenlcf
\...
/7~
111
--;t6' --- y-.
-
-..--..--.........--
~;,~': 'I /" "''-l~,', ': ;l:;/': '::'i~l': , :. ",:' .:- " ':,'; ",: ..'.,.' . "', :.:?
~:::.,,'\/~\" .:.' , , ,)~::'~:/ ,I~l:,< ,~:",.'::,';':' ~(:. '::,",', ,: :' >
,'\
.'1 :r'\..~
Streelmaln
'-""1<\11."
. Streclmilin
!
i
I
10
I
to prevent the loss of prime,
the wood preservative
company would connect a
hose from 0 :V,.inch hose
bibb, located on the fire
service line, tp the suction
side of the pump. The hose
bibb remained open at all
times in an effort to
continuously keep the pump
primed.
Repairs were necessary 10
one of the private fire
hydrents on the wood
preservalive company
property, necessitating the
shutling down of one of two
service lines and removal of
the damaged fire hydrant for
repair, Since Ihe hydrant was
at 0 significantly lower level
than the creosote pit, the
~
l:L> - ,'''''-l .u:....~
creosote back.siphoned
Ihrough II '1,.inch pump
priming hose connecting the
creosote pit 10 the fire service
line.
Afler the repairs were
mode to the hydrant, and the
water service restored, the
creosote, now in the fire
lines, was forced into the
main water dislribution
system,
Kool.Aid Laced
with Chlordane
In August, 1978, a
professionai exterminator
was treating a church located
in a small town in Soulh
Carolina, for termite and pest
coni reI. The highly toxic
insecticide chlordane was
being mixed with water in
small buckets, and garden
hoses were lefl submerged in
the buckets while the mixing
was being accomplished. At
the same time, weter
deparlment personnel camo
by to disconnect the
parsonage's water line from
Ihe church to install a
separato water meler for the
parsonage. In the process, Ihe
water was shut of in the area
of the church building. Since
the church was locoted on a
steep hill, and as Ihe
romaining water in Ihe lines
was used by residents in the
area, the church was among
Iho first places to experience
o negative pressure. The
chlordane was quickly
siphoned inlo tho wator lines
within Ihe church end
became mixed with Ihe
Kool.Aid being prepared by
women for the vacation bible
school. Approximately 0
dozen children and three
adul1s exporienced dizziness
and nausea. Fortunately,
none required hospitalization
or medical allention.
Recommended installation
el hose bibb vacuum
breakerbackllowpreventer
11
/73-
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',j', _1\~",:t(~I~" 'I~ ~.. ~, "
Chapter Three
Theory of Backflow
and Backsiphonage
t2
A cross.conneclion 1 is the
link or channel
connecting a source of
pollution with a polable
water supply. The polluting
substance, in most cases a
liquid, tends to enter the
potable supply if the net
force acting upon Ihe liquid
acts in the direction of the
potable supply. TIVo factors
are therefore essential for
hackflolV, First, Ihere must be
a link between the two
systems. Second, the
resultant force must be
tOIVord Ihe potable supply.
An understanding of the
principles of backflolV and
back.siphonage requires an
understanding of the terms
frequently used in their
discussion. Force, unless
completely resisted, will
produce motion. Weight is a
type of force resulting from
Ihe earth's grevitalional
allraction. Pressure (P) is a
force.per.unit area, such as
pounds per square inch (psi),
Atmospheric pressure is the
pressure exerted by the
weight of Ihe atmosphere
above the earth.
Pressure may bo referred 10
using an absolute scale,
pounds per square inch
absolute (psia), or gage scale,
pOhnds per square iuch gogo
(psig). Absolute pressure and
gage pressuru are related,
Absolute pressure is equal to
the gage pressure plus the
almospheric pressure. At sea
level the atmospheric
pressure Is 14,7 psla, Thus,
I' absolute = I' gage + 14.7 psi
or
)' gogo = P absolute. 14,7 Jlsl
In essenco then, absolulr
pressure is the total pressure.
Gage pressure is simply the
pressure read on a gage. If
there is no pressure on Ihe
gage other Ihan atmospheric,
Ihe gage would read zero.
Then the absolute pressure
would be equal to 14.7 Jlsi
which is the atmospheric
pressure.
The term vocuum indicates
that the absolute pressure Is
less Ihan the atmospheric
pressure and Ihalthe gage
pressure is negalive. A
complete or total vacuum
would mean a pressure of 0
psie or .14.7 psig. Since it is
impossible 10 produce u total
vacuum, the term \'QCUUnl, as
used in Ihe text, will mean
all degrees of parlial vacuum.
In a partial vacuum, the
pressure would renge from
slightly less than 14.7 psia
(0 psig) to slightly greater
than 0 psi a (.14.7 psig).
BocksipilOnoge' results in
fluid flow in an undesirable
or reverse direclion. It is
caused by atmospheric
pressure exerted on a
pollulant liquid forcing it
loward a polable waler
supply system that is under a
vacuum. BockflolV, elthough
literally meaning any type of
reversed flow, refers 10 the
flow produced by the
differenlial pressuro exisling
betweon Iwo syslems both of
which are at prossures greater
Ihan olmospheric.
I Sell formal dnlllllUullln IhoHlnss.lt}'uf
IhllOPllllllllix.
Water Pressure
For an underslanding of the
nalure of pressure and its
relalionship to waler depth,
consider the pressure exerted
on the base of a cubic foot of
waler at sea level. (See Fig.!.)
Tho average weigh I of a cubic
fool of water is 62.4 pounds
por square foot gage. The
base may bo subdivided inlo
144.square inches with each
subdivision being subjected
to a pressure of 0.433 psig.
Suppose another cubic foot
of water wero placod directly
on top of the first (Soe Fig. 2).
Tho pressure on the top
surface of the first cube
which was originally
atmospheric, or 0 psig, would
now be 0.433 psig as a result
of the superimposed cubic
fool of waler. The prossure of _,
the base of the first cube ('
would also be inreased by "-"
the same amount of 0.866
psig, or Iwo limes the
original pressure.
FIGURE 1.
Pressure exerted by 1 feot of
water al sea level,
, ,
\....
I?~,
1'"',
\
'f'!""~ v-' - ~
.. ~ ._.~. ~_ ....~ ,....._____r-...,.-.......... ,.~
.. - -...... -- r- ....,... -....-~
,,;.',.,..',,'~'~ :: . <,;: ':€l'~ ," ",-;,"''.''::',:: :.'\'\
""'"1/"1'''1.',,,[2;.,. ",' "'>,",'
:~~',,:'" .~~~ ~ ,: ' .~;. ")~ :",', :...~~;~~r> : ,',i ;, 4 .~~ :' , .. '.::, "J :.: ',1', .:: -" . ~', \..~.: ~
i
F----------'-..n-
I If Ihis process were
r repealed wilh a third cubic
I' foot of waler, the pressures al
the base of each cube would
, be 1,299 psig, 0,860 psig. and
'I 0.433 psig, respectively. IJ is
, evident Ihat pressure varies
: wilh deplh below a free
I waler surface'. in general
each fool of elevation change.
wilhin a liquid, changes Ihe
pressure by an amount equal
I to Ihe weight.per.unil area of
11 foot of the liquid. The rate
of increase for water is 0.433
psi per foot of depth.
I Frequently waler pressure
is referred to using Ihe ler1l1s
I "pressure head" or jusl
J lIhead." and is expressed in
J units of feel of water. One
foot of head would be
equivalent to the pressure
produced at the base of a
cnlumn of water 1 fool in
.. "!h. One foot of head or 1
Itw! of water is equal to 0.433
I psig. One hundred feel of
head are equal 10 43.3 psig.
I
I
I
I
,
I
I
FIGURE 2.
Pressure exerted by 2 feet of
walor al sea level.
'Sue 10rm,1 doflnition inlho
gloS5nry 01 tho 'ppondl"
Siphon Theory
Figure 3 depicts Ihe
atmospheric pressure on a
water surface at sea level. An
open tnbe is inserted
vertically into the water;
atmospheric pressure, which
is 14.7 psia, acls equally on
Ihe surface of Ihe waler
within the tube and on the
oulside of the Inbe.
FIGURE 3.
Pressure on the free surface of a
flquld at sea level,
~
;;
/;
j,
/f
14.7
14.7psla pSla
If. as shown in Figure 4, Ihe
tube Is slightly capped and a
vacuum pump is used to
evacnale all the air from the
sealed tnhe, n vacnum with a
pressure of 0 psia is croated
within Ihe tubo, Becanse tho
prossuro ot any point in a
slatic fluid is dapnndenl
upon Iho hoighl of Ihal point
abovo a reforonce line, such
es sea lavel, iI follows Ihnl
tho pressuro wllhin Ihe tube
at saa lovel musl stili ba 14.7
psia. This is eqnivalentlo tho
prossuro altho baso of a
column of walor 33.0 faol
high and with Iho colnmn
opon atlho baso, water
wonld riso to fllllho column
10 n doplh of 33.9 foel. In
othor words. Iho woighl of
tho nlmosphoro et soe 101'01
oxnclly hnlnncos Iho woighl
of n column of walor 33.9
feet in height. The nhsolule
pressure within Ihe column
of water in Figuro 4 at a
height of 11.5 foet is equnllo
9.7 psia. This is n partial
vacuum with nn equivalonl
gngo pressure of .5.0 psig.
As a practical examplo,
assume the water pressure al
a closed faucet on the lop of
a 100.fool high huilding to be
20 psig; the pressure on tho
ground floor would then he
63.3 psig. If the prossure at
the ground wero to drop
suddenly duo to a heavy fire
domand in the area to 33.3
psig, Ihe pressure althe top
would ho reduced 10.10 psig.
If the huilding water syslem
wero airtight, tho watar
would remain atlhe level of
the fnucet hecauso of Ihe
parlial vacuum created hy the
drop in pressure. If the faucel
were opened. however, the
Figure 4.
EITect of evocuating air from n
column,
Vacuum pump
'"
,,;
M
01 '5,0 pSlg
14.7 psra 01 0,0 pSlg
vacuum would he broken and
the water level would drop to
a height of 77 feet above the
ground. Thus, Ihe
atmosphere was supporting a
column of water 23 feel high,
Figure 5 is a diagram of an
inverted U.tube that has heen
filled with water and placed
in two open containers at sea
level.
If the open containers are
placed so that the liquid
levels in each container are
at the same height, a static
stale will exist; and the
r.ressure al any specified
evel in either leg of the
U.tnbe will be Ihe same.
FIGURE 5,
Pressure relationships in a
continuous Quid system al the
sarno elevation.
0"
4.7psia
,,'
,
"
,
~
'j
\,
..
~'
~
'.
),
{.
a
M
N
Tho equlllbriulll condition
is altored hy rai~ing one of
the containers so that tho
liquid 101'01 iu oue containor
is 5 fool abovo tho levol of
1:1
I"~
,
J'\;:,',,', . .. .."',.:'~ ; \" ~7 :: ).;t~J" ,,' :" :,\'.,: ; :,:' ""'" ,':<-:"
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. -.-.-----------
- ----. -----, ---------
/',
,
the other.ISee Fig. 6.) Since FIGURE 7. accelerates, as shown in One of the common
both conlainers are open to n"ksiphonoge in a plumbing Figure 8, the pressure is occurences of dynmnically
the atmosphere, Ihe pressure system, redur.ed, As waler flows reduced pipe pressures is
on 11m liquid surfaces in each Ihrough a conslriction such found on Ihe sur.tion side of
container will remain al14,7 Valve open as a converging section of a pump. In many cases
psia. ' pipe, the velocity of the similer to the one iIIustraled
If it is assumed that a static _I~' wator increases; as a result, in Fi~ure 0, the line
state exists. momenlarily, the pressure is reduced. supptng the booster pump
within the system shown in Under such conditions, is un ersized or does not
Figure 6, the pressure in the '- ..~.-._:::.-::_~ negative pressures may be have sufficient pressure to
left tube at any height above developed in a pipe. The deliver waler at the rote 01 I
Ihe free surface in Ihe left simple aspiralor is based which the hump normally
container can be cakuiated, upon this principle. If Ihis operates, T e rote of flow in ,
I
The pressure atlhe : Valve open ftoinl of reduced pressure is the pipe mJ: be increased by
corresponding level in the inked to a source of a furlher re uction in I
righllube above Ihe free Closed supply pollution, backsiphonage of pressure at the pump intake,
surface in the righl conlainer Ihe pollutanl can occur. This often resulls in the I
may also be calculated, creation of negative pressure !
As shown in Figure 6, Ihe atlhe pump intake, This
hressuro 01 all levels in the FIGURE e, oflen results in Ihe creation
eft tube would be less Ihan Figure 7 illustrates how Negative pressure created by of negetive pressure, This
at corresponding levels in the conslricled Doll', negative preSSUre may
right lube. In this case, a Ihis sr,hon principle can be become low enongh in some
static condition cannot exist hazar ous in a plumbing cases 10 cause vaporization of
beceuse fluid will flow from ststem, If Ihe supply valve is the waler in the line. "",
the higher pressure to the cased, the pressure in the - ""':;'~";i ,,~~~.~'!j;:Y:'.:~: Acluelly, in Iha iIIustratio()
line supplying Ihe faucet is
lower pressure; Ihe flow less than the pressure In the shown, flow from Ihe source
would be frem the righltank ~ of pollution would occur
to the left lank. This supply line 10 Ihe balhtnb. t30pSlg t30psig when pressure on the sur.tion
arrangement will be Flow will occur, therefore, side of tho pump is less Ihan
through siphonage, from the
recognized as a siphon. The balhtub to tho open faucet. pressure of Ihe pollution
crest of a siphon cannot bo sourco; but this is bockflo\\',
highor than 33.0 feet abovo The siphon actions r.lted which will be discussed
havo been produced by I
Ihe upper liquid level, since boloII'. I
almosphero cannot support a reduced pressures resulting FIGURE d. The preceding discussion
column of waler greator in from a difforenco in the water Dynamically reduced pipe hes described some of Ihe i
hoight Ihan 33.0 fnet. levels otlwo soparoled poinls pressures, means by which negative !
within continuous fluid lot.ture pressuros Olav be crealod and
system, FlOm poUuhon sourco which froquontly occur to I
Reduced pressure may olso produce bocksiphonogo, In I
FIGUllE fi. be created within II fluid I
Pressure relallonshlps In a system as a result of fluid addition to Ihe negalivo ,
conllnuoos Duld syslem al pressure or reversed force I
dllTerenl elevallons. molion. One of the basic nocessary to cause I
principles of fluid mochnnics bncksiphona~e and back flow, !
'" is tho principia of thoro mllstn so be the
conservation of onorgy. Bosod cross,collneclion or
B.2PS1a? upon this prinr.iple, it may -.... connectillg link butwoolI tho
bo shown thot as a fluid po tabla walor SliPI'll' IInd tho
T~ sOllrco of pollUlloll, Two
~, bnsic types of cOllnocllons
" may bo crenlod III pipillg
, ,
:!? "
i systllms. Thoso nre tho solid
pipe with vnlved cOllnor.tion
UOOS[Il/ pump and tho submorgod inlet.
'-
17~'
. "",
t', "I ':': . (. ;~"'" .,::~ :',', .' /'1; " " " ;;, "",-,'"""",:., ,: :, "~':I\
, '" "," I' .1" "\." I. ,t.,. ", , ", " ,
h'-: .:'1:1. :: ,t.r::: .'-:' ,\,',_:" ~ ,." ",,.;,',,,: ,.-':~, '" :;';,:. ,o'
. .;."i\ \"\" '~l" \' " , ',~ .. .
------___ _ '_n
(\
FIGURE 10.
Valved connecllon behvu,n
potable water and nonpetabl,
fluid.
,
~~i,,,,,.~..,
1,\"'''111;'. .~.""
~'~''.\'lI.}.:j.1~jJ!;;f.
Ijlf'(1,,,,,,.M..
\~::l-i
I! .'
~. 'I
II .;.
! 1
Non polable POlable
Figures 10 and 11 illustrate
I solid connections, This type
of connection is often
installed where it is
necessary to supply an
auxiliary piping systelll frolll
(') potable source. It is a
'~.rect conneclion of one pipe
to another pipa or receptacle.
Solid pipe connections are
oftenlllade to continuous or
intermillent waste lines
where it is assumed that Ihe
flow will be in one direction
only. An example of this
would be used cooling water
from a water jacket or
condenser as shown in Figure
11. This type of connection is
usually detectable but
creating a concern on the
FIGUllEl1.
Valved tonnecllen between
poteblo water and ,anllary
Sower.
...~-"Qo.'Q..
C,lysupply
part of the inslaller about the
possibility of reversed flow is
often more dillicnlt, Upon
questioning, however. many
installers will agree that the
solid connection was made
because the sewer is
occasionally subjected to
back pressure.
Submerged inlets are round
on many common plumbing
fixtures and are sometimes
necessary [ealures of the
fixtures if Ihey are to
fnnction properly. Examples
of this type of design are
siphon.jet urinals or water
closets, flushing rim slop
sinks. and dental cuspidors.
Oldstyle bathtubs and
lavatories had supply inlets
below the flood level rims,
but modern sanitary design
has minimized or eliminated
this hazard in new fixtures.
Chemical and industrial
precess vats sometimes have
submerged inlets where Ihe
water pressure is used as an
aid in diffnsion, dispersion
and agitation of the vat
contenls. Even thongh the
supply pipo may come frem
the floor abova the vat,
backsiphonage can occur as it
has bean shown Ihatthe
siphon action can raise a
liquid such as water almost
34 feet. Some submerged
inlels difficult to contrel ora
"'11'"~,"JlJtrt1':e-(.,\,'-f.I;i,_,\.lII'l:l"II"~I~
Condenser b
l.
;.tl..rr'\I\",~'('" :'~'f~'~'."'ff,,,.../""J
,~
i,.,
",')jj.{;, ,~";~, ",-:"-!~~\.II"'\",'!v!n,,\.
'~<
"
:l'~,~"i H;O ~"i" ".;.r..~I.\'I(;t,..,~,i;'.".\':
''j
~
'~~:~1Sj~~~[tW&~}:~~~.
---.- ----------..-..-. ---. -------------______n ____
lhasa which arc not apparent
until a significant change in
water level occurs or whare a
supply may be conveniently
extended below the liquid
surface by means of a hose or
auxiliary piping. A
submerged inlet may be
creatod in numerous ways,
and its delection in some of
these subtla forms may be
difficult.
The i1iuslrotions included
in pari B of the appendix are
intanded 10 describe typical
examples of backsiphonage,
showing in each case the
nature of the link or
cross-connection. and Ihe
cause of the negalive
pressure.
Backflow
Backflow', as described in
this manual, refars 10
reversed flow due 10
backpressure other than
siphonic action. Ani'
interconneclad f1ui, systems
in which Ihe pressure of one
axceeds the pressure of Ihe
other may have flow from
one to the other as a result of
the pressure differentiel. The
flow will occur from the zone
of higher pressnre to the zone
of lower pressure. This type
of backflow is of concern In
buildings where two or mure
piping systems are
maintained, The potable
waler supply is nsnnlly
undar pressure directly from
Ihe city water main.
Occnsionnlly, a booster pump
is used. Thlluuxiliary system
Is often pressurizlld by a
cllntrifical pnmp, ulthough
backpressnrD may be caused
by gus or steum prllSSUrD from
a boiler. A revllrsal iu
differnntial prllssurc muy
1 St~n formlll dnflnlUnn In lhn u10ssary {II
Ilwlllll1Ulldlx.
occur when pressure in the
potable system drops, for
some reason, 10 a pressure
lower than that in the system
to which the polable water is
connect ad.
The most positive method
of avoiding this type of
back flow is the lotal or
complele separation of the
two systams. Other methods
used Involve the installation
of mechanical devices. 1111
methods require routine
inspection and maintenance.
Dual piping syslams are
often ins lolled for extra
prolection in the event of an
emergency or possible
mechanical failure of one of
the syslems. Fire protection
systems are an example.
Another exam pia is Ihe use
of dual water connectious to
boilers. These installations
are sometimes
inlerconnected, Ihus creating
a health hazard.
The lIIustrotions in part C
of tha appendix depict
installalions where backflow
under pressura cen occur.
describing the
cross-conuection and the
cause of Ihe reversed flow.
15
I'~
I,~'> 'I: ,'<':.l~': , :, ,;~t ....:"Zt'r..:: ',~: ,'. :.,:,' ,,< (',,:,:'!-::': <.:'
I~(,::,'''.:\': :;, :t~r::.::: ":,,\'"'J: ':"..!t~~ _: ~: 1 '","1. . .;<:,': .>'~
\, l ~\ '," \_ ",1.. " I,......, ) > " """,'
. ....'..,( ,',' .. ~ .".~ ,-", I '. '. .' \ I' .' , .' '" '._'
Chapter Four
Methods and Devices
for the Prevention of
Backflow and
Back-Siphonage
\
III
A wide choice of devices
exists that can be used to
prevent back.siphonage ond
bockpressure from odding
conlaminated fluids or gases
into 0 potable water supply
system. Generally, the
selection of the proper davice
to use is based upon the
degrea of hazard posed by
the cross.connection.
Additional considerations ere
based uponJ,iping size,
location, an Ihe polential
need to periodically test the
devices to insura proper
operation.
There are six basic types of
devices that can ba used to
correct cross-connections: air
gaps, barometric loops,
vacuum breakers - both
atmospheric and pressure
typa, douhle check with
intermediate atmospheric
vent, double check valve
assemblies, and reduced
pressure principle devices, In
general, allmanufacurers of
these devices. with the
exception of Ihe harometric
loop, produce them to one or
mOre of threo basic
slondords, thus insuring tho
public that dependable
devices aro being ntilized
and marketed. The major
standards in the Industry are:
Americun Society of Sanilary
Engineers (ASSEI, American
Water Works Association
(AWWA), and the Unlversily
of California Foundation for
Cross.Connuction Control
and Hydraulic Research.
Air Gap
Air gaps are non.mechanicol
backflow preventers Ihat are
very effective devices to be
used where either
back-siphonage or
back pressure condilions may
exist. Their use is as old as
piping and plumbing i1self,
but only relatively recently
have standards been issued
that slandardize their design.
In general, the air gap must
be twice Ihe supply pipe
diameter bul never less than
one inch. See Figure 12.
FIGURE 12
Air Gap
",E
'20'
I
An air gnp, eltheugh an
extremely ellective backflow
preventer when used to
prevent back.slphonoge ond
backpressure conditions.
docs Intnrruptthe Pil'ing
flow wilh correspon( ing loss
of pressure for subsequent
use. Consequently, air gaps
ore primarily used at ond of
the Iino sorvico where
reservoirs or storage tonks are
desired. Whon contemplating
the uso of on nlr gop, somo
other considerations oro:
(1) In a continuous piping
syslem, each air gap requiros
tho added oxponse of
reservoirs and secondory
pnmping sysloms.
(2) The air gap may bo
oastly defootod in the evont
thatlhe "2D" requiromenl
wos PIIIPosoly er
inadvortently compromlsod.
Excessivo splosh may be
encountorod Inlho oventthot
higher thun onticipated
r
pressures or flows occur. The
splash may be a cosmetic or
true potential hazard - tho
simple solution being to
reduce Ihe "2D" dimension
by thrusting the supply pipe
into tho receiving funnel. By
so doing, the oir gop is
defeoted.
(3) At on oir gop, \VO expose
the woter to the surrounding
oir with its inherent bacterio,
dust porlicles, ond other
oirboro pollutonts or
contaminants. In addition,
the ospiration effect 01 the
flowing woter con drag down
snrrounding pollutonts inlo
the reservoir or holding tonk.
(4) Free chlorine con come
out of treated water as 0
result of the air gop ond the
resulting splosh and churning
effect os the woter enlers th.
holdin.g.tanks. This reducC'"I
the ablllly of the woter to W
withstond bacterio
conlominotion during long
torm storage,
(5) For Ihe above reosons,
air gaps must be inspected os
Irequently os mechanicol
bockflow prevonters. They
ore not exempt from on
in.dopth cross-connection
control program requiring
periodic Inspoction of 011
backflow dovices.
Air gops moy be fobricotod
Irom commorciolly ovailoblo
plumbing componenls or
purchosod os seporote unils
ond integrated into plnmbing
and piping systems. An
example of the use of on oir
gop is shewn in Figure 13.
FIGUllE13
Air Gop to 0 Plplag System
Supply piping
'--
Iilnkor ICscrvou
17~,
.....,
\
"~; ',~:, ':; ,/',,;;,:,.:l'!':':::';;-;'/:: ""n:: :', : ~, :", '-, <:/ ::,,',:>,>
~~<.4' ';,::~t,;...,~ ~':~'~,~1"'~'\I":~ \,:'::.;.,~J::':- ',', : ',' ::~'::::':: \_1 _,,': ~:':~:;
I'
Barometric Loop
The barometric loop consists
of a continuous section of
supply piping that abruptly
rises to a height of
approximately 35 feel and
then returns back down to
the originating level. It is a
loop in the piping system
that effectively protects
against back-siphonage, It
may not be used to protect
against back. pressure,
Its operation, in the
protection against
back.siphonage, is based
upon the principle that a
water column, at sea level
pressure, will not rise above
33,9 feet (Ref. Chapler 3,
Fig, 4 Page 13),
In general, barometric
10ds are locally rabricaled,
l~n are 35 feet high,
I ',.,..IIGURE 14
. Barometric Loop
,
I
,
i
I
I
;
I
I
,
I
I
in
M
'-.-'
Atmospheric Vacuum
Breaker
These devices oro among the
simplest and least expensive
mechanicoltypes of backflow
prevenlors and, when
installed prolJerly, can
provide eXCll lent protection
against back siponage, They
musl not be utilized to
prolect againsl backpressure
couditions, Construction
consisls useally of a
polyelhyleue float which is
free 10 travel on a shorr and
seal in the uppermost
position againsl etmosphere
with an elaslomeric disc,
Water flow lifls the float,
which then causes the disc to
seal. Water pressure keeps
the floal in the npward
scaled position, Termination
of Ihe water supply will
cause the disc to drop down
venting the unit to
atmosphere aud thereby
opening downstream piping
to atmospheric pressure, thes
proventing back-siphonage,
Figure 15 shows a typical
atmospheric broaker,
In general, Ihese devices
are availabla in 'I, inch
through 3 inch sizo and mest
be installed vertically, must
not have shut.ofrs
downstream, and musl ba
installed at least 6 inches
higher thauthe final ouilet.
They cannot ba tesled once
they are installed in the
plumbing system, but are, ror
the most pari, depandable,
troubla.rroe devices for
back.siphonage protection,
FIGURE 15
Atmospheric Vacuum IIreaker
FIGURE 10
Atmospheric Vacuum Drcakcr
Typical Inslallalian
Figure 1 G shows Ihe
generally accepted
installalion reqeirements -
note Ihal no she I-off valve is
downslream of the device
that would otherwise keep
Ihe atmospheric vacuum
breaker under constant
pressure,
Figure 17 shows a typical
inslallalion of an atmospheric
vacuum breaker in a
plumbing supply system,
III
,,-
:Co
l
I
FIGURE 17
Atmospheric Vacuum Urcnkcr
in Plumbing Supply System
F1owcon~i1ion
NonllowconUllion
17
17~
"
".....--
~....- ~ --
- ..~.- ......,,.--.~
-:",:' '.,',,-'. '~:"""'\"."';;"""':'~1~~'1 "".,.:,:'.,:. ,',:',":< '<:~I
, ' " /. "f"I' '--/" I,,, '. '.', ," ' "
,;' " ,,", , ;:..' : ,:', .',\ " " " '. ';., --.' ," ",,', ' . ::.' :,
" . '. ,'. . I. .\1 R' . ~I., , .' , \.,
.,' ,'~'.", ~ ..~., ,<; '. '; ,
Hose Bibb
Vacuum Breakers
These 501011 devices ere 0
speciolized opplicotion of the
otmospheric vocnum breoker.
They ore generally olloched
to sill cocks ond ill turn are
connected to hose supplied
outlets such os garden hoses.
slop sink hoses, sprny
outlels, etc. They consisl or 0
spring looded check volve
that seDls ogoinst nn
atmospheric olltlet when
water supply pressure is
turned on, Typicol
construction is shown in
Figure 18.
When the water sliPI'll' is
turned orf, Ihe device vents
to otmosphere, thlls
protecting ogoinst
back-siphonage conditions.
They should not be used os
beck pressure devices, Manuol
drnin options are available,
logetlter with tamper-proof
versions. A Iypical
installation is shown ill
Figure 19,
FIGURE la
lIese Bibb Vocuum Breaker
\
10
_.~.
FIGURE 10
Typicallnslollotiun of lIuse
Bibb Vacuum Breaker
~
,-
Pressure
Vacuum Breakers
This device is an oulgrowlh
of the atmospheric vocllllm
breaker ond evolved in
response to 0 need to hove an
atmospheric vacullm breaker
that could be utilized under
conslant pressure and that
could he tested ill line. A
spring on tOf of the disc and
float assemb y. two added
gate valves, tesl cocks, and
an odditional first check,
provided Ihe answer to
ochieve this device. See
Figure 20.
These units are avoilable in
the genernl configurntiolls as
shown in Figure 20 in sizes
V, through 10 inch ond have
brood usage in Ihe egricuilure
and irrigation market.
Typicol agricuilurol and
industrial applicotions are
shown in Figure 21.
Again, these devices may
be used under constont
pressllre but do not protect
against bockprcssure
conditions. As 0 resuil,
instollotion must be otlenst 6
to 12 inches higher thon the
existing outlet. '
FIGURE 20
Pressure Vacuum Breaker
( 1
:.;..,
,.'"
Tesl coc~
-,
"~-"~r-
i'\
\)
\...
2Vlinchcs Ihru 10 inches
/7:J-
'::,:" ,;,:,' ',:~ ,':,:'t21,.:.t::, ';',;;:-,< ':ict;', ',: ,<,,:,' ':':,,":,:'.:' ,',",
l:;"',~', <I~~.\ ~ .~; [! ';1 '_',"'~':. :. '::'~:21. . ',.' ,~ " ' "" ", ~:,.../ ",
\ r '" ",1 '.... ~ I ,. ~ ~. ,.,.1 ~ 1\ ! __. , . . "...., ".., ( " .
.'.' " .
---.
-------.------..----....---------------..----.------...--_....~-----
Double Check with
Intermediate
Atmospheric Vent
The need 10 provide a
compact device in V, inch
and 1', inch pipe sizes Ihat
protects againslmoderate
hazards, is capable of being
used under constant pressure
and that protects against
backpressure, resulted in this
unique backflow preventer,
Construction is basically a
double check valve having on
atmospheric vent located
between the two checks (See
Figure 22),
Line pressure keeps the
vent closed, but zero suppll'
pressure or back-siphouage
will open the inner chamber
to almosphere, With this
device, extra protection is
oblained through the
atmospheric vent capability,
I Figure 23 shows a typiceluse
I of Ihe device on a residential
boiler snpply line, ,
~ ,..
'J
FIGURE 21
, Typlcnl AgricuHurnl and
Industrlnt Applicnllnn of
Pressure Vacuum Breaker
FIGURE 22
Double Check Valve with
Atmospheric Vent
FIGURE 23
Typicnl Residentinl Use of
Double Check with
Atmospheric Veat
Supply
.
, ,
Double Check Valve
A donble check valve is
essentially Iwo single check
valves conpled within one
body and furnished with tesl
cocks and two tighlly closing
gates valves (See Figure 24),
The lest capability fealure
gives this device a big
advantage over the use of two
independent check valves in
thai it can be readily t~sted
to determine if either or both
check valves are inoperative
or fouled by debris, Each
check is spring loaded closed
and requires approximately a
pound of pressure to open,
This spring loading
provides the ability to "bite"
through small debris and still
seal- a \lrotection feature
not preva ent in unloaded
swing check valves, Figure
24 shows a cross section of
doublo check valvo complele
with test cocks, Double
checks are commonly used to
protect against low to
medium hazard inslallations
such as food processing
sleam kettles end apartment
projects, They may be used
under continuous pressure
and protect against both
back.siphonage and
backpressure conditions,
Vent
BOiler
Return
L .~
"".-t.y.'."
FIGURE 24
· Double Check Valve
,.......dl~~ ~illIi~JI... I
" .
., "
, "
" ,
, .
'J>
PlOcesstanks
19
I'~
~:' ;",. ,~', , "'~" . ',: t.ir ,.,'"',, .J-:-':' ',,'~tj' ':"~' ':' ': "''<''.'', ",(. :>,:)
...,.,' -""",.1-" './",/- ,0,1 I, ,,:, ..".. :', """".
G",. ': ;.::{\',' I,': ~'~'~l~~i'>'~ "I~;l'."~' ..~ '.t, ;' ,':.::; .: :'.~;' . ~'.,,' . ~ . ~,)'_'
Double Check Detector
Check
This device is an outgrowth
of the double check valve
and is primarily utilized in
fire line installations. Its
purpose is to protect the
potable supply line from
possible contamination or
pollution from fire line
chemical additives, booster
pump fire line backpressure,
stagnant "black water" Ihal
sits in fire lines over
extended periods of time, the
addition of "raw" water
through outside fire pumper
connections (Siamese
outlets), and the detection of
any water movement in Ihe
fire line water due 10 fire line
leakage or deliberate water
theft, II cons is Is of two,
spring loaded check valves. a
by-pass assembly with waler
meter and double check
valve, and two tighlly closing
gate valves. See Figure 25.
The addition of test cocks
makes the device testable 10
insure proper operation of
both the primery checks end
\
FIGURE 25
Double Check Deteclor Check
Ihe by-pass check valve. In
the event of very low fire line
water usage, (Iheft of water)
the low pressure drop
inherent in the by-pass
system permits Ihe low flow
of waler to be metered
through the by-pass system.
In a high flow demand,
associaled with deluge fire
capability, the main check
valves open, permitting high
volume, low reslricled flow.
through the Iwo large spring
loaded check valves,
20
r--
Residential Dual Check
The need to furnish reliable
and inexpensive
back-siphonage and
backpressure protection ror
individual residences
resulled in the debnl of Ihe
residential dual check.
Protection of the main
potable supply from
household hazards snch as
home photograph chemicals,
toxic insect and garden
sprays, lermite control
pesticides used by
exterminators, elc" reinforced
a lrue need for such a device.
Figure 26 shows a cntaway or:
Ihe device. '
It is sized for 1/2, 3/4, and
1-inch service lines and is
installed immediately
downstream of the waler
meter, The use of plastic
check modules and
elimination or lesl cocks and
gale valves kaeps the cost
reasonabla whilo providing
good. depandable prolection.
Typical installations are
shown in Figures 27 and 28.
FIGURE 26
Residential Dual Check
(~,
FIGURE 27
ResidenttallnslalJatlan
FIGURE 2a
Copper Horn
..,~:
','1,
"..:.
~'.',., watcrmcler
\~i;
.... ,.,
~;~j
I'd--
.....,
\
~ - - "..------
.. "~T....,~_
I-I'.' . .: ~,';: .., " J' ':t .',. '.,: ,~:-:-" "'~':;'~l'" :', 0.:": ',:'::, \~,;.::: : ',."0:: <:'
",' "'1 '~., ,.",.. " .1. "., """.' "",
I" _: ','.: ~., , { :""'" /'.' .'. : ", J ~ ""..'. '. J . ~"..' . "
("'\:'.~,t ~:"~,,-':'1~,~.' "\1 -"L'.I 6i',' L '.'... .. d.,
rieduced Pressure
Principle Backflow
Preventer
Maximum protection is
achieved against
back,siphonage and
backpressure conditions
utilizing reduced pressure
principle backflow
prevenlers. These devices are
essentially modified double
check valves with an
atmospheric vent capability
placed between the two
checks and designed such
that this "zone" between the
two checks is always kept at
least two pounds less than
the supply pressure, With
this design criteria, the
reduced pressure principle
backflow preventer can
provide protection against
back,siphonage and
back pressure when both the
first and second checks
become fouled. They can be
used under constant pressure
-'nd at high hazard
,1stallations. They are
~turnished with test cocks and
gate valves to enable lesting
and are available in sizes ",
inch through 10 inch.
Figure 29A shows typical
devices representative ,.f ",
inch through 2 inch sizb and
Figure 29B shows typicai
devices represenlative of 2V,
inch through 10 inch sizes,
-------
...-------~__h..__~._'__________
FIGURE 29t1
Reduced Pressure Zone
D"kflow Preventer
", inch thru 2 inches
..
1,..-
.
-I
Dl
FIGURE 290
Reduced Pressure Zone
Dackflow Prevent"
2V, inch thru 10 inches
....
Reduced pressure zone
lS1 check valve 2nd chec~ \lillv!!
'- t\,~
;j,
J
I" ncllc!villvclrOlllW(/90'!orcl.lrllvj
\
,
21
17~
\
~--
----..~,- .,. ........,..-
_ r .-_----...~-....... ~
',:",'.:' "': ::.':':~,;;~ .":-:'-:,!~"',;.:,,:,,' :,:\' "::<:':::':;'/:":",',;.:
,. '/'/" I" ') , I '1 ., , '," .. , "",
~~( ;.... :~;\' [." ,,~l,r~":':'.::-I\.. ~,':, /, . ., ":', ',',' .: ::" ,.'. " "_','
-~-----------------------
The principles of opera lion
of a reduced pressure
principle backflow preventer
are as follows:
Flow from the left enters
the central chamber against
the pressure exerted by the
loaded check valve 1. The
supply pressure is reduced
thereupon by a
predetermined amoun!. The
pressure in the central
chamber is mainlained lower
Ihan the incoming supply
pressure through the
operalion of the relief vaive
3, which discharges to the
atmosphere whenever the
central chamber pressure
approaches within a few
pounds of the inlet pressure.
Check vaive 2 is lightly
loaded to open with a
pressure drop of 1 psi in the
direction of flow and is
independent of the pressure
required to open the relief
FIGURE 3D
Reduced Pressure Zune
nackflolY Preventer _ Principle
of Operation
valve. In the event that the
pressure increases
downstream from the device,
lending to reverse Ihe
direclion of flow, check valve
2 closes, preventing
backflow. Decause all valves
may leak as a resull of wear
or obslruclion, the protection
provided by Ihe check valves
is not considered sufficien!.
If some obstruclion prevents
check valve 2 from closing
lightly, the leakage back into
the centrel chamber would
increase Ihe pressure in this
zone, the relief valve would
opon, and flow would be
discharged to tho
etmosphore.
When Iho supply pressure
drops to Ihe minimum
differenlial required to
operale the relief valve, the
pressure in tho contral
chember should be
atmosphoric, If tho inlet
pressure should become less
than almospheric pressure,
ralief valva 3 should remain
fully open 10 the atmosphere
to discharge any water which
may be caused to hackflow as
a result of backpressure and
leakage of check valve 2,
Melfunclioning of one or
both of the check valves or
relief valve should always be
indicated by a discharga of
water from Ihe relief pori.
Under no circumslances
should plugging of the relief
port be permined because the
device depends upon an
open porI for safe opera lion.
The pressure loss through tho
device may be expected 10
average between 10 and 20
psi within tlm normal ranga
of operation, depending upon
the size and flow rate of the
device.
Reduced prassure principle
backflow proventers are
FIGURE 31
Plaling Plantln,tallalion
commonly installed on high
hazard installalions such as
plaling plants, where they
would protect against
primarilr. back,siphonaga
potenlia , car washes where
they would protect against
backpressure conditions, and
funeral parlors, hospital
aUlopsy rooms, etc, The
reduced pressure principle
backl/ow preventer forms Ihe
backbone of croSS.conneclion
control programs, Since it is
ulilized to prolect against
high hazard installalions, and
since high hazard
installalions are the first
considerations in protecting
public health and safely,
these devices aro installed in
large quantities over a broad
range of plumbing and water
works installalions. Figures
31 and 32 show Iypical ;
installalions of these device!'''' ,
on high hazard installationsl,," ,I ,
FIGlJllE32
Car Wash Installation
22
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....
fII!---
y-.-
.
. ~.. ~- r- V' ,..........................,...-
....'Y- ....
.-.
, ..
~
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~..... . I . , ' ~ ,'" .' -" '. . , . .
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. -..'
"
--..
.~--.._--------,..._--~_.._-----_._--_._-_._-----~--------
FIGURE 33
Typical By.pass Configura lion
Reduced Pressure Principle
Devices
.-\
~>
1 (o,:::gap
NOlo: Devices 10 be set a min. of 12. and a max, 0130' from the floor and
11' 110m any wall.
FIGURE 34
Typicallnslnllalion
Reduced Pressure Principle Device
IIoriznnlalllluslralinn
"
.:
.
.:
;',
~)
"
"','
.
':~ AiI~::il' ~l
~-. 12- min. 30. max.
\~ NOle: Device 10 be 50112" minimum ftomwall.
::,,'.:. '~".', .....:....' l~.;' ....;~~...~....,4~,.? '~:"~,,,',..: '. ;'t', )',', '.
FIGURE 35
Typical/nstellnlinn
Reduced Pressure I'rlnclple Device
Verllcallnslailallen
!
"
, '
J
I~
"1 Reduced prcssure principle device
. '" Elbow
'1,
:,~' AI/gap
.. f"
i.
"
,'.
.,
"
..
I':
"
'.
.:
:'0
".
"
:'
'\ WillormotOl
'j'
"
9i
.,
,'':
!; w',~o ' "', t', " 't < ~,l ,':, " .
NOlO: 111 Rolor 10 manulilclwCls inslallalion dilli1 (or vo/tical mount,
111Unilloba selal aheighllnpcrmillCadvaccess ICllesllngandseNice,
IJIVerlical installalion only 10 be used il hOlizontalinslilllalioncannotbo
achievcd
23
I'~
..
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''', ", ''', ,I", .,\,1,11" :'I[ "'., """ ,'"
<>".:( :,',' JL> ';);:;1-: .',' L. ," '.. ' ,..' " '., ,', "
~ ; 1 ,
--.._--------_._---_._-~.
FIGURE J6
Typlcallnstollatlon
Double Check Valve
Iforizonlal and Vertical
Instnllalion
I
I
I
I
I
I
I
I
I
I
,
,
I
'.
"
"
'.
"
"
"
"
'\:
Itfo..... ~ .,'. ',';l'.' ' '~..' .\'. .l....,'..~l' ~. . "'."r.....,, i ',.'. " ~ ".
12"min,and3B'ma..
"
'.
0,
0'
,
:'
R
~:
"
~~
--,
:~.
j:
.
lunillO bescl al a heighl
thalpermilsreadyaccess
lorleslingilndserviceJ
i
:'J
0,
::~
'.'
.'
"
"
"
"
,
"
.'
,
.
<,
"
,"
'i
.
::-",...:.0:;
NOlO: Verlical installalion only 10 be usedil
horilOnlalinslallalioncannol boachievod.
24
(1
FIGURE J7
Typlcol Inslollolion
Residential Duol Check with
Slralghl Sel and Copperhorn
"
:1""""".0:;,..,..
.'
'.
~
,
,
.
<,
"
,"
"
"
..
.
,
Residenlialdualcheck
I~
"
'.
'.
'I'
~'~'.... ~ .... "\'1',' 'I'~.I"""'I '.-'I"~!".. .!,'."i.......i.,.'. .'~
",
r ,
.....~ ,
I ,.
\.."...
"
"
"
0,
0'
"
p.
~:
"
'.
"
,',
314' ball val"
I
I
I
,
I
I
,
I
,
j
I
I
,
I
I
I
\....
:.1
),
.
~
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17~
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fIF- -' y-.--
- .. ......----..,~-...... ,.....~..~-....... ,.~
-- .... -..". - ......-. .........--~ - .....
i~:' .' ': ~,;;<,' ',; :,:::',:'C!, ;':' ~: rEi I'" ,::;;,:~:, ':., ' . :'.::: 0: .' , ::;',.:: ~:,-",.::: .:'.
(I" t.: .,:\' ~:~ .,..'..~J~,~' ,1' ').#1;. ~":" ,~\ '. \:- " l"" "', ~,'" "\' " '/,\;.,'
Chapter Five
'\
,
Testing Procedures
for Backflow
Preventers
1'11:1
,'!.FJJ?,'1\~.Y'
f~~~~~P;,
,,;}rt~;?~;~:,:~~P~;9j~':~
;,t"~.,\: . '. '
4,f
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!:t. ~ "!
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l,'l'ip'
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j
Prior 10 initioting 0 lest of
ony bockflow device, it is
recommended thallhe
following procedures be
followed:
1. Permission be obloined
from Ihe owner, or his
represenlotive, 10 shul down
the woter supply. This is
necessory to insure Ihot since
011 testing is occomplished
under no.f1ow conditions, Ihe
owner is owore Ihot his woler
snpply will be lempororily
shut off while Ihe lesting is
being performed. Somo
commerciol ond induslrial
operotions require conslont
ond unlnlerrupled woler
supplies for cooling, boiler
feed, seal pump wOler, elc.
ond woter service
Intorruption con no I bo
lolernled, Tho woter supply
to hospitols ond continuons
process induslrios connol be
shut off withoul plonned ond
coordinoled shul downs. The
request to shut down Ihe
woter supply is thereforo 0
necessory prerequisito 10
prolecllhe cuslomor os well
os limit Ihe Iiebilily of Iho
lester.
Concurrenl with the
reqnesl for pormission to
shul off Ihe wOlor, it is
odvisablo 10 poinl oulto Iho
ownor, or his roprosenliltivo,
Ihetwhile Ihe wiltor is shut
---------_.~.-.__._---..
off during Ihe lesl period,
ony inadvertenlnse of woler
withinlhe building will
reduce the woter pressure 10
zero. Dockslphonoge could
result if unprolecled
cross.connections exlslod
which would conlomlnoto
tho building woter supply
system. In order 10 oddress
this situotion, il is
recommended thotthe owner
coution the inhabitonls of the
building not 10 use tho woler
until the bockflow tesl is
completed ond Ihe Willer
pressure reslored. Additional
options availoble 10 Ihe
building owner would be the
instilllation of two bockflow
devices in parollollhat
would enoble 0 prolecled
by.poss flow oround Ihe
device 10 bo losled. Also, if
allwaler outlels oro protecled
within Iho building with
"fixluro out lei protection"
bockflow devices,
cross.connoctions would not
creato a problem in Iho event
of polenllol bock.siphonage
conditios occnrring while
devicos aro testod, Dr for any
other reason,
2, Determlno Ihe Iype of
devico 10 be losled Le" doublo
check volvo or reducod
pressuro principle devico,
J, Dolermlno Iho flow
dirocllon. (IMoronco
direcllonnl flow arrows or
wording providod by tho
manufaclurer on Ihe dovico.)
4, Number Iho losl cocks,
bloed thom of polontial
debris, and assomblo
approprlato losl cock
adaptors and bushings Ihat
may ho required,
5, Shul off tho downslream
(numbor 2) shut-off valvo,
(RoLltom (1) abovo.)
._-._--_..._._-_..~-
6. Woit severo I moments prior
10 hooking up the tesl kit '
hoses when lesling 0 reduced
pressure principle device, If
wotor exits tho reliof volvo, in
olllikolihood, the first check
volve is fouled ond it is
impractical to proceed with
the lesting unlillhe volve is
~erviced. This woiting period
IS nol necessory when lesting
donble check volves,
7, Hook up tho lest kit hoses
in Iho monnor oppropriote to
tho device being teslod ond
Iho specific lesl being
performed,
Tost personnel ore
coutioned to be owore ond
follow locol municipol,
county, ond state tesllng
requiromonls ond gnidelinos
os moy be dicloled by locol
outhority, The following lest
procodures oro guidelines for
slondord, genernlly
occeploblo lesl procedures
but moy be omonded,
snporceded, or mndified by
locol jurisdiction.
25
1'1).
,""----
,
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- -.
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" I'" t...., ..~" >~r,' "" "'..' '" ,
',',e..:', ,',"; ',' .". '~' /','. . ,:,' "r '_"\_',"1, "'.
" ' " :' , '" '" >, ',' 'II ,," ", , ',' , ,,':- '" ,
I~/ ,. ,1,: .: , \ '. .,; : '- .', . ..~', J to:', ,: ' ',' .:' .~, .: _ ' ','
[~, . . '~.I.:~' ,I......,' _ I ! -....= ,." """". " , ." . "
o l _ _," '_
Test Equipment
For field testing of reduced
pressure principle backClow
preventers and doubla check
valve assemblies, a
differential pressure test
gauge is utilized having a 0
to 15 psi range and a working
pressure of 500 psi.
Appropriala length of hoses
with necassary fillings
accomfany the test gauge,
Severa manufactured test
kits are commercially
evailable that incorporate the
differential gauge, hoses, and
fillings and are packaged for
ease of porlability and come
with protective enclosures or
straps for hanging, Cali bra led
water columns are
commercially available thai
are portable and come with
carrying cases,
lJ is important that alltesl
equipmenl be periodically
checked for calibration,
Pressure Vacuum Breaker
(Figure 36) 4,
Field testing of a pressura
vacuum breaker involves
testing both the internal
spring loaded soft seated
check valve as wall as lasting
tha spring loaded air inlet
valve, The lesting mnst be
performed with Ihe device
pressurized and the air inlat
closed, The number 2
shut.off valve musl also ba
closed and the air inlell'alve
canopy removad,
Method 1
Using a differantiul pressure
gauge
Tesll Teslthe Internel chuck
valvu for tighlnuss of 1 psid
in tho direcllon of flow,
L Wllh the vulve body
under prassure, (numbur 2
shut.off valve closed end
numbor 1 shut.off valve
open) bluud lust cocks
uumber 1 and uumher 2,
2, Hook uplhe high
prossure hoso 10 number 1
tost cock und thu low
pressuro hosuIn numhur
2 lust cock,
26
- .-. --..--_.__h._.u._________ . __'_'n __....._______. .._____ '__.._.___~ .._.__~_._.___..._
FIGURE 38
3. Bleed the high pressure
hose, and low pressure
hose, in that order, and
close the test kit needle
velves slowly.
Record the differential
pressure on the gauge, A
reading of 1 psid is
ecceptabla 10 insuru a
tight chock velva.
Test 2 Tesllhe eir inlel valve
for 0 breakaway of 1 psi.
L Connecllho high
pressure hose 10 lesl cock
number 2, and bleed the
high pressure hose.
2, Shut off number 1
shut-off valve.
3. Slowly open Ihe bleed
valve of the test kll, and
observa and rocord 1110
psi whon Iho air inlot
pop pol opans, This
should he a minimum of
1 psi. Reslore tho valvo 10
normal sorvico.
Method 2
Using a waler column sight
tube and 90 degrea elbow
filling with bleed needle
Test 1 Test the internal check
valve for tightness of 1 psid
in tha direction of flow.
L Assemble sight tube to
test cock number L Opan
tesl cock ond fill the lube
10 a minimum of 36
inches of walor height.
2. Close number 1 shut-off
valvo.
3, Open test cock number 2.
The air inlet valve should
open and discharge water
through number 2 lesl
cock.
4, Open number 1 lest cock.
The sight lube level of
waler should drop slowly
unlil it stabilizes. This
poinl should be a
minimum of 26 inches of
water column which
equals 1 psi.
Test 2 Testlhe air inlel velve
for e breakaway of 1 psi.
L Assemble sighltube to
test cock number 2, Opon
tesl cock number 2 end
fill the lube to e
minimum of 36 inches of
water height.
2. Close number 1 shul.orr
valve.
3, Bleed weter slowly from
the numher 2 test cock
bleed needle and obsorvo
the water column heighl
as it drops,
4, At Ihe poinl when Ihe oir
inlet valve pops open,
rocord the helghl of tha
walor column. This point
should ba a minimum of
26 inches of wutur
column which equals 1
pst.
Heslore Ihu valvuto normul
sllrvico.
t:;;{'l.\
, "
Reduced Pressure
Principle Backf/Dw
Preventer
(Figure 39)
Field tesling of u reduced
prassure principle backflow
prevenler is accomplished
ulilizing a difforential
pressura gauge. The device is
tested for three oplional
characlorislics: i.e., (1) tho first
check valve is tight end
meintains a minimum of 5
psi dirreronliel pressure, [2)
the sacond check valve is
tight ageinsl backpressure
aad (3) the relief valve opens
at a minimum of 2 psi helow
inlet supply pressure. Tesling
is performed as follows:
Step 1 Tasl to insure thotthe
first check volve is tight and
malntoins a minimum
pressure of 5 psi differenlial
pressure.
L Verify that number 1
shut.off velve is open.
Close number 2 shut.off
valve, If there is no
dminaga from Ihe relief
valve it is assumed thut
the first check is light.
2. Close all test kit valves.
3, Connectlhe high
prnssurn hose 10 test cock
number 2.
4. Connecl the low pressure
hose to lesl cock numbor
3.
5. Open test cocks number
2 and number 3.
6. Open high side blaed
needlo valve on test kit
bleeding the air frolll Iho
high hose. Close Iho high
side hleed needle valve,
7. Open the low side bleed
needle valve on lesl kit
bleeding air from the low
hosa. Close the low side
bleed neodle valve,
Hocord Ihe diffe10nliul
gunge p1Ossn1O, it shonll ,I
bon minilllnlll of 5 psid, ~
17,
.'
,., - ~.
-
'W
.---'"
~::;: ':"/: ':::'l"f".;,::: 'l't:; >.~n: '.;,":. ,'::':<'.,...: ,,',
I~;." I~( ,~: " :r[: '/ ',: ~[7J.: '; '~?l' :-',' : ,~,_, . .( .", '.. 'I, ',~ "
c.., '''\, ,,' l,~ ," ,~"\.\~\ {. :,.',:.
. ,".,. . - .
-- _ H-______n
!r'j
-- . -~-_..-..__._-~--_.,---~_._._-- ,-----
Bleed needle valves
HlghSlda hose
(S)
low sidc 110SC
FIGURE 39
Step 2 Test to insure Ihotthe
second check is tight ogainsl
bock pressure. (Figure 40)
1. Leoving the hoses hooked
') up os in the conclusion
'-..J of Step 1 obove, connect
the byposs hose to test
cock number 4.
2. Opentesl cock nnmber 4,
tho high control needle
volvo and Ihe bypass
hose control needle volve
on the test kit. (This
supplies high pressure
water downslrcom of
Temporalyb passhoso
FIGUHE .10
check valve number 2,) If
the diflerential pressuo
gongo foils oIl and woter
comes ont 01 tho reliel
volvo, tho socond chock
is recorded os looking, If
tho dillerentiol pressure
gauge remains steady,
and no woter comos out
of tho relief volve, tho
socond check volve is
considered tight.
3, To chock the tightnoss of
numher 2 shut.off volvo,
1001'0 tho hoses hookod
Tee
up the some os ottho
conclusion of Slop 2
obave, and then close lost
cock numher 2, This
stops the supply 01 any
high pressure woter
downslreom of check
volvo numbor 2. If Ihe
diflerentiol prossure
gouge reoding holds
steody, the number 2
shut.off volve is recordod
as being tight. II the
differential pressure
gaoge drops to zero, tho
number 2 shut.orl valve
is recordod os leaking.
With a leaking number
2 shut-orl valve, the
device is, in most cases,
in 0 flow condition and
tho previous readings
taken are invalid, Unless
o non.f1ow condition can
he achieved, either
Ihrough the operation of
on additional shut.off
downstreom, or the use
01 a compensoting
temporory by.poss hose,
(Ref: Fig.40), occurate test
results will not be
echieved.
Stell 3 To check that the
rolief volve opens at 0
minimum pressure of 2 psi
below inlet pressure.
1. With the hoses hooked
up Ihe some os at the
conclusion of Step #2 (3)
above, slolVly open up
the low control needle
volve on the test kit and
record the differentiol
pressure gauge reading ot
the point when Ihe woter
initially slarts to drip
from the relief valve
opening, This preSJure
reading should not be
below 2 psid.
This completes the
slondard field test for 0
reduced pressure principle
backflow preventer. Before
removal of the test
equipment, Ihe tesler should
insure thot he opens number
2 shut.off valve thereby
reeslobllshing flew, Also, the
test kit should be thoroughly
droinod 01 011 woter to
prevent freezing by opening
all control needle volves and
hleed needle vall'es.
All test dato should be
recorded on appropriate
forms. (Ref: somple Poge 45)
Nolo: The sltlps outlined abovo
nlu)' "lIry In sequence dopondlng
ullonlocol regulations lind/or
preforences.
27
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(( '. , ! ~, ~'" . [. '. t-Yl f ' ~."" " i .. " ",r . 'Ij'
".:' '.~,;'.\I..", :i~,'".":,~:""''':l,....\,..,.T~' ,",. ',,:: ':,'~'\~"I'
..
:':
Double Check Valve ,
,,0 gauge holds steady, the
Assemblies number 2 shut-off valve is
(Figure 41) recorded as being tight. If
Some field test ~rocedures the differential pressure
for testing daub e check gauge drops to zero, the
valve assemblies require that number 2 shut.off valve
the number 1 sbut.off valve is recorded as leaking.
be closed to accomplish the With a leaking number 2
test. This procedure may Bleed needle valves shut.off valve, Ihe device is,
introduce debris such as rust in most cases, in 0 flow
and tuberculin into tho valve High side hose low side hose condition, and the previous I
that will impact against test readings token are
check valva number 1 or invalid. Unless a non-flow
number 2 and cempromiso condition can be achieved, I
the soaling quality. This either through the operation
potential problem should be of an additional shut-off I
considered prior to the dewnstream, or the use of 0
selectien of tho appropriate FIGUllE41 temporary compensating I
,
test method. by-pass hose, accurate test !
Twe test methods, one results will not be achieved.
requiring closing of the This completes tho
number 1 shut-eff valve, and standard field test for a
one without this requirement Step 2 Checking check valvo The lesting is performed as double check valve assembly.
are pres en led below: Prior tn removal of the test
Mothod 1 number 2, follows: equipmont, the tester should'-'
Utilizing tho differential 1. Connect the high hose to 1. Connect the high hose to insura that he opons numbek
pressure gauge and not test cock number 3. number 2 test cock. 2 shut-off volve thoreb]
reestablishing flow. Al lest
shullinr off number 1 2, Connoctthe low hoso to 2. Connect tho low hoso to data should ba recorded on
\ shut-of valve. (Figure 41) last cock numbar 4, numbar 3 test cock. appropriate forms and the
Step 1 checking check valve 3. Open test cocks number 3. Cnnnectthe by-pass hose tost kit drainad nf waler,
numbar1 3 and 4. to numbar 4 lest cock.
1. Verify that the number 1 4, Opon high sldo bloed 4, Open test cocks numbers
shut-off is open. Shut off needlo valvo on test kll 2. 3, and 4, I
number 2 shut-off valvo, bleeding the air from tho 5. Open high sido bloed i
I
2, Connect tho high hoso to hit hoso. Closo the high needle volvo on test kll I
si e bleod neodle valve. ,
tost cock number 2, bloeding tho air from tho I
3. Connect tho low hoso 10 5. Opon low side blood hi9h hoso. Close the high
tost cock numbar 3, neodla volvo on test kit si e bleod noodle volvo. I
4. Opon test cocks 2 and 3. blooding tho air from tho 6, Opon low side bleed I
low hose, Closo tho low noodlo volvo on test kit I
5, Open high sido bleod sido bleod noodle valve, blooding tho air from Iho !
neodle v3lvo on test kit 6. Record Ihe dilferential low hoso. Close the low
bloedlng tho air from tho gouge prossure reading. It sldo bloed neodlo volvo.
hit hose. Close the high should bo 0 minimum of 7. The differential gau~e
sl e blood ueodlo valvo, 1 psid. pressuro should roa 0
6, Opon low sldo blood 7, Disconnocttho hosos. minimum of 1 psld.
noedlo valvo on tosl kll To chock tightness of 6, Oponlho hinh side
bleodlng tho air from the
low hoso, Closo the low number 2 shut.of( valve, both control neOlle volvo and
side bloed noadlo valvo. tho check valves must be Iho bfPass hose control
tight and holding 0 minimum noml e vnlva on the lest
7, Rocord Ihe differential of 1 psid. Also, Iilllu or no kll. (This supplins high
gouge rossure rooding. It fluctuation of Inlol supply pressuro wntor
shaul bo 0 minimum of pressure con bo lolnrnled. downstronm of check ,
1 psld, vnlve numbor 2), '-.'
6, Discouneclthe hoses. D, Close test cock number 2,
(This slops Ihe supply of
any high prossure watar
downstream of number 2
chock volvo), f( Iho
2B dlfferontlal pressuro I'~
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~o ",.' Step 3
,. ","
~o' 1. Open shut.ofr valve
number 1 to repressurize
the assembly.
2. Loosely olloch the
by-pass hose to test cock
number 1, and bleed
from the gouge through
the by-pass hose by
opening the low side
needle valve to eliminate
trapped air, Close low
side needle valve.
Tighten by-pass hose.
Open test cock number 1.
3. Close number 1 shut.olf
valve.
4. By loosening the low side
hose at test cock number
3, lower the pressure in
the assembly about 10 psi
below normal line
conditions,
5. Simulloneously open
both needle valves. If the
check valve is holding
tight the high pressure .
gauge will begin to drop
while the low pressue '
gouge will increase. Close
needle valves. If the
geuge shows that 0 smell
(no more then 5 psi)
beck pressure is created
ond held, Ihen Ihe check
valve is reported es tigh!.
If the check valve leeks. 0
pressure differential is
not maintained os botll
gouges tend to equalize
or move bock towards
each other, Ihen the
check valve is repertee' os
lenking. With both needle
vnlves open enough to
keep the needles onlhe
gouge slotionnry, tho
amount or lookogo Is
visoble os Ihe discharge
from Ihe upstream needle
valve.
Duplex gage
i
I
,
,
,
FtGURE 42
Method 2
(.....\1tilizlng "Duplex Gouge" or
__[ndi~iduol bourdon gouges, _
reqUIres closing number 1
shut-orf, (Figure 42)
Step 1 checking check valve
number 1
1. Connect the high hose to
test cock number 2,
2, Connect the low hose to
test cock number 3.
3. Open tesl cocks number
2 and number 3.
4. Close number 2 shut-off
valve; then close number
1 shul-ofr valve.
5, By means of the high
side needle valve, lower
the pressuro attest cock
number 2 about 2 psi
below the pressure at lest
cock number 3, If Ihis
small difference con be
moinloined, then check
valve number 1 Is
roported os "tight".
Proceed to Slep number
2. If the small difference
cannot be maintained,
proceed 10 Slep number
3.
Individual Bourdon a es mounted on a board
Step 2 checking check valve
number 2.
Proceed exoctiy the same
test procedure os in Slep
number 1, except that the
high hose is connected to lest
cock number 3 and the low
hose connected to tesl cock
number 4.
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20
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Chapter Six
_..._---------~-----~--_.._-_._~.._-_.~
Administration of
A Cross-Connection
Program
FIGURE 43
Air condilioning coolmg lower
\
FIXTURE
OUTLET
PROTECTIVE
DEVICES
ReducdpremrelOflC
b<lcr.lIevprel'cnter
INTERNAL
PROTECTIVE
DEVICES
Hose vacuum breakcr
Reduccdprcs5urlllonc
bJc:kllowprcvcnler
r.........1
.,,'H
Conlilnmoiiidc.ViCC
30
Responsibility
Under the provisions of
Ihe Safe Drinking Waler
Act of 1974, the Federal
Governmenl has established,
through the EPA
(Environmenlal Prolection
Agency), netional standards
of safe drinking water, The
states are responsible for Ihe
enforcement of these
standards as well as Ihe
supervision of public waler
supply systems and the
sources of drinking water.
The water purveyor
(supplier) is held responsible
for compliance to the
provisions of the Safe
Drinking Water Act, to
include a warranty that water
quality provided by his
operation is in conformance
with the EPA standards at
the source, and is delivered
to the customer without the
qualily being compromised
as a result of its delivery
through the distribution
system. As specified in the
Code of Federal Regulations
(Volume 40, Paragraph 141.2,
Section (c)) "Maximum
contaminant level, means the
maximnm permissable level
of a contaminant in wnter
which is delivered to the frea
flowing outlal of the ultimnte
User of a public water
system, except in the cnse of
Inrbidity where the
mnximum permissablo level
is measured at the point of
entry to the distribution
system. Contnminants ndded
to Ihe water under
circumstances controlled by
the user, except those
resuliiug from corrosion of
pipiug nnd plumbing cansed
by wnter quelity, nre
excludod from this
definition,"
Figure 43 depicts several
options Ihal ere open to a
water purveyor when
considering cross.connection
proleclion to commercial,
industrial, and residential
customers. lie may elect to
work initially on the
"containment" theory. This
approach ulilizes a minimum
of backflow devices and
isolates the customer from
the water main. It virtually
insulates the customer from
potentially contaminating or
polluting the public waler
supply system, While it is
recognized Ihal
"containment" docs not
protect the customer within
his building, it docs
effectively remove him from
possible contamination to the
public water supply system.
If the water purveyor electr~
to protect his customers 01"
domestic internal protective'
basis and/or "fixture outlet
prolective basis," then
cross.connection control
protective devices are placed
at internal high hazard
localions as well as at all
locations where
cross.connections exist at the
"last free.f1owing oulle!."
This approach entails
extensive cross.conneclive
survey work on behalf of the
wnter superinteodent ns well
as constnnt policing of Iho
plumbing within each
commorciol, industrial and
residential accoun!. In largo
wntor supply systems, fixturo
outlot proteclion
cross.connoction control
philosophy, in itsolf, is a
virtual Impossibility to
achiovo nnd polico duo 10 tho
'\Unnlity of syslems involved,
tl0 comploxity of the
plumbing systems inhoront in
mnny industrinl sites, and tho
factthnt mnny plumbing
chnngos nrc mnda within j
induslrial nnd com murcia I \".,,1
establishmonts thnt do not '
require tha wntor t1opnrlmont
to Iicunsu or otherwise
endorsu or ratify when
contllmplnted or compluted.
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--------_._._____m_._ .___~._.__~..__.
In addition, inlernal
plumbing cross-connection
conlrol survey work is
generally foreign 10 the
average water purveyor and
is not normally a portion of
his joh description or duties.
While it is admirable for the
wator purveyor 10 m:cepl and
perforlll survey work. he
should be aware thai he runs
the risk of additionalliabilily
in an area Ihalmay be in
conflict with plumbing
inspectors. maintenanco
personnel and other public
heallh officials.
Even where extensive
"fixtnre outlet protection."
cross-connection control
programs are in effect
through the efforts of an
agressive and thorough water
supply cross.connection
~?ntrul program, Ihe water
~thorities should also have
an active IIconlainment"
program in order to addmss
the many plumbing changes
Ihat are made and that are
inherent within commerdal
and industrial
establishments. In essencn,
fixture outlel prolection
becolllns nn oxtnnslon beyond
thn "conlainmnnt" program.
Also, in order for thn
supplier of wnter to provide
maximum protection of the
wntnr distribution syslnm,
considnration should bn
givnn 10 rnquiring the owner
of n premiso (commnrGial,
Industrial, or rusldnutial) 10
providnnt his own nxpense,
odequate proof that his
intornal water systnm
cOlllpllos with Ibe locnl or
stato plumbing codn(s). In
addition, he may bn roqnirnd
to install, hnvn tnsted, l!nd
mainlain, all bm:kflow
prolection dnviens thnl would
bn required - al his own
expensn!
..../
The supplier of waler
should have tbo righl of ontry
to delnrmine degree of hazard
and Ihe existencn of
cross-connnctions in ordnr 10
prolectlhe potable water
system. By so doing he call
assess the overall natnre of
Ihe facility and its pntential
impact ol1lho water system
(detormiue degree of hazardl,
personally see actual
cross.connections thai could
conlmninnlo tho walor
system, und take appropriato
action to insure the
elimiuation of the
cross.counectionur the
installation of required
backflow devices.
To assist the waler
purveyor in the lotal
administration of a
cross-connection conlrol
program requires that all
public health officials,
plumbing iuspectors,
building managers, plumbing
Installers, and mainlouance
mon participato and share in
Ihe responsibility to I"otect
the public health illl[ safoty
of individuals from
cross.connections and
contemination or pollUliou of
thu public walur supply
syslelll,
"-n__..__..__..u..__ -. . .. ____ __.. __ --.__..___.n._____
Method of Action
A completo cross-
connection conlrol
progrum requires 0 carefully
planned and executud inillal
oclion plan followed by
aggressive implmnonlilliol1 ilIHI
conslant follow.up. Propur
slaffing and uducallon of
person nul is a reqnirumentto
insure that an effecllvu
progrum is achieved. tI
recomlllunded plan of acllon
for a cross.counecllou conlrol
program should include the
following charucteristies,
(1) Eslablish a
cross.connection coulrol
ordinance otlhe local level
and have it approved by Ihe
walor commissioners, lown
lT1ilnager, ole., and insure Ihal
it is adopted by the towu or
Ilfiville waler aulhorHy as a
egally euforcuable documenl.
(2) Conducl public
informative meetiugs thai
dofinu the proposud
cross.conuection conlrol
program, ruview Ihe local
cross-conuuction coutrol
ordinance, and ouswor all
quustions Ihalmay arise
coucerning the reason for Iho
progrum, why and how Ihe
survey will be conductud,
oud the potential impacl
upon the industrial,
comnll!rcinl and rusideutiol
wnler cuslomers. I-hl\'o slalu
outhorlties aud the local
pruss aud rndio allend the
moo ling.
[:1) Piece writteu nolices of
thu pnnding cross.counoction
cnntrol proglilm In Ihu locnl
newspapl!r, nud hove thu
Im:al radin station mnkl!
nnnouncemunts abnntthu
prograllllls il public snrvir:n
noticu,
141 Sund llm/,Ioyel!s who will
lldminislur I HI program, 10 n
eOllrSO, or COllrSllS, Oil
hackflow lostur cerllficotinll,
bnckflow sllrvuy COllrses,
hockflow dllViell rupnir
c;ourSIlS, Ille.
(5) Equip Ihe water authority
with backflow device lest
kits,
(6) COllducl mueting(s) with
the locol plumbing
inspecllon pnople, bnilding
inspoctors, and licensed
plumbers in the area who
will be active in Ihe
inspection, installations and
repair of backflow devices.
Inform them of the intent of
the program aud Ihe parllhat
Ihey can play in the
successful implementation of
the program.
(7) Prior to initiating a survey
of the established commercial
and indnslrial installations,
prepare a Iisl of these
eSlablishments from exisling
records, Ihen prioritize the
degree of hazard that they
present to the water syslem,
Le" plating plauts, hospitals,
cor wash facilities, industrial
metal finishing and
fabrication, morluaries, etc.
These will be Ihe initial
facilities inspecled for
cross.connections and will bu
followed by !ess hazardons
installations.
(8) Insure Ihal any new
conslruction plans are
reviewed by Ihu waler
aulhority to assess the degree
of hazard and insure thai the
proper backflow prevunter is
inslolled concurrent with the
pntunlial dewee of hazard
Ihatlhu facility presunts.
(II) Establish a residential
hnckflow proluction \Jrogrnm
that will onlomallcal y insnre
thot a rnsiduntinl dual chock
hockflOlv deviell is inslalled
aUlomoticnlly nl evury null'
fl!sidollco.
(10) tis wntor lIlolnrs eru
rllpairlld nr IIlplncnd al
resldl!nces, Insnru thai a
rusldonllol [hurl check
bockflow pruvenlur is set
with Ihllnl!w or rnworked
wnlnr muter. 1I11 suru to hove
thlluwlHlr nddruss thurmul
uxponsinu provisions,
I'~
- ......------..--..- ...... '
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\
(11) Prepnre n listing of nil
testable bnckflow devices in
the community and insure
that they are tested by
certified test personnel atlhe
time intervals consistent with
the local cross.connection
control ordinence.
(12) Prepare and submit
testing documenlation of
backflow devices to the State
authority responsible for
monitoring this data.
(13) Survey all conunorcial
nnd industrial facilities and
require nppropriate backflow
protection based upon Ihe
containment philosophy
andlor internal protection
and fixture outlet protection.
Follow up 10 insure that the
recommended devices are
installed and tested on both
an initial basis and a periodic
basis consistent with the
cross-connection control
ordinance,
The surveys should be
conducted by personnel
experienced in commercial
and industrial processes. The
owners or owners
representatives, should be
questioned as to what the
wator is being used for in the
facility and what hazards the
operations may present to the
water system (both within
the facility and to the water
distribution system) In the
event that a back,siphonage
or backpressure condition
were to exist concurrent with
a non-protected
cross.connection. in the
eventthet experienced
survey personnel are not
evallable within the weter
aUlhority to conduct the
survey, consideration should
be given to having e
consulting firm perform the
survey on behalf of Ihe water
depertment.
J2
Cross-connection
Control Survey
Work
Cross.connection control
survey work should only
be performed by personnel
knowledgable about
commercial and industrial
potential cross-connections
os well as genoral industrial
uses for both potnble and
process water. If
Ucontainment" is the prime
objeclive of the survey, then
only sufficient time need be
spent in the facility to
determine the degree of
hazard inherent within the
facility or operation. Qnce
Ihis is determined. a
judgement can be made by
the cross-connection control
Inspector as to what type of
backflow protective device
will be needed et Ihe potable
supply entrance, or
immediately downslrenm of
the water meter. In the even I
that the cress-connection
control progrem requires
"total" protection to the last
free flowing outlet. then the
survey must be conducted in
depth to visunlly inspecl for
all cross-connecllons within
Ihe facility and make
recommendations and
requirements for fixture
outlet protective devices,
inlernel protecllve devices,
and conlalnmenl devices.
It is recommended thai
consideratien be given to the
following obJecllves when
performing a
cross.connectlon contrel
survey:
(1) Detormlne If the survey
will be conducted with a
pre-arranged appointment or
unennounced.
(2) Upon entry, identify
yourself and the purpose of
the visitalion and request 10
see the plant manager.
owner, or maintenance
supervisor in order 10 explain
the purpose of the visit and
why the cross.connectlon
survey will be of benefit to
him.
(3) Ask what processes are
involved within the facility
and for what purpose potable
water is used, Le., do the
boilers have chemical
ndditives? Are air
condWoning cooling towers
in use with chemical
additives? Do Ihey use water
savers with chemical
additives? Do they have a
second source of waler (raw
water frem wells, etc.) in
addition to the potable water
supply? Does the process
water cross-connect with
potontially hazardous
chemical etching tanks, elc.?
(4) Request "as-built"
engineering drawings of the
potnble wator supply in order
10 trace out internal potable
lines and potential areas of
cross-connections.
(5) Initiate the survey by
starling at the poteble
enlrance supply (the water
meter in most cases) and
Ihen proceed with the
inlernal survey in the event
that total internal protecllve
dovices and fixture outlet
protective devices are
desired,
(6) Survey the plnnt facilities
with the objective of looking
for cross-connections at all
potablo water outlets such as:
Hose bibbs
Slop sinks
Wash room fadlttles
Cafeteria and kitchens
Fire protection and slnmese
outlets
Irrigation outlets
Boiler rooms
Mechanical rooms
Laundry facilities (hospltnls)
Production floor
(7) Make a sketch of nil areas
requiring backflow prolection
devices.
(8) Review with the host
what you have found and
explain Ihe findings to him.
Inform him that he will
receive a wriiten report
documenting the findings
together with a written
recommendation for
correcllve action. Attempt to
answer ell questions at this
time. Review the findings
with the owner or manager if
lime and circumstances
permit,
(9) Document all findings
and recommendations prior
to preparing the written
report. Include as many
sketches with the final report
as possible and specifically
slate the size and generic "
type of backflow preventeC
required at eech ',..
cross-connecllon found.
I I
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/7'--
,
"
"
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Chapter Seven
Cross-Connection
Control
Ordinance Provisions
I
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The successful promotion
of a cross.conneclion and
backrlow.conneclion control
program in a municipality
will be depend en I upon legal
aUlhority to conduct such a
program, Where a community
has adopted a modern
plumbing code, such as the
Nalional Plumbing Code,
ASA 1\40,6.1955, or
subsequent revisions thereof,
provisions of Ihe code will
govern backrlow and
cross.conneclions. It t1um
remains to provide an
ordinance that will establish
a program of inspeclion for
an eliminalion of cross. and
backrlow conneclions within
the community. Frequently
authority for such a program
may already bo possessed by
Ihe water doparlment or
water outhority. In such cases
no further documont may bo
noeded. A cross-conneclion
control ordinaoce should
havo alloaslllueo basic
parts.
1. Authority for
ostnblishment of n program.
2, Tecimlcnl provisions
rolaling to eliminaling
backrlow nnd
cross-connections.
3. Punnlty provisions for
violnlions.
The following modnl
program is snggesled for
mnnicipnlitins who desire to
ndopln cross-conneclion
controlordinnnce.
Communilios ndollling
ordinnnces shonll chOck
with Slatnlwnllh officials 10
assnro conformancu with
Stnle cndos. Thu form of Ihu
ordinnnco shnuld comply
with locnllognl requitllmnnls
nnd tlIcuivo lugnl nduplion
fromlho community.
._-~-----~~---
CROSS CONNECTION CONTROL
MODEL PROGRAM
WATER DEPARTMENT NAME
ADDRESS
DATE
Approved
Dale
Wator Depurtmonl Namo
Cross.Conneclion Control Program
I. Purpose
A. To prolecttho public polable waler suppl)'
sorved by Iho [ I Wnter Departmnnt from tho
possibilit)' of conlnminalion or poilulion by isolnling,
within its cuslomors inlornnl dislribulion syslem,
such contnminents or poliulanls which could
backrlow or back.siphon inlo Iho public waler s)'stom.
B. To promoto tho oliminalion or control of oxisling
cross-connoclions, nctunl or potunlial, betweon its
customors in-plant potabio walor system, nnd
non-potablo systems.
C, To provido for tho mnintonanco of n conlinuing
program of cross-c:unnlll:lion c:onlrnl whic:h will
offec:livuly provenllho conlnminalion or pnllulion nf
ali polnble wator syslems by cross-c:onnoclion.
II, Authority
A. The Fodoral Safa Drinking Waler Ilcl of 1074,
and Ihn stalntos of Ihe Stnlo of I ) Chnplors
( ) Ihn \~nlor pnrvn)'or hns Iho primnry
rosponsibility for prnvnnling wnlllt fromnnnpprovod
sourcos, or nn)' otbor subslancos, from ontoring Iho
public potnhlo walor systom.
IJ, ( ) Wntor IJopnrlment, Ruins nnd
Hognlatinns, ndoptud,
",-
't;
........ ~ - ...,.-.---.. ...-.........--
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III. Responsibility
The Direclor of Municipal Services shall be
responsible lor Ille protection 01 tile public polable
waler dislribution system from conlamination or
pollulion due to the backflow or back.siphonage of
contaminanls or pollutants Ihrough the waler service
connection. II, in the judgement 01 the Director of
Municipal Services, en approved backflow device is
required althe city's woter service conneclion to any
cuslomer's premises, Ihe Director, or his delegaled
agent, shall give notice in writing to said customer to
inslall an approved backllow prevention device at
each service connection 10 his premises. The
cuslomer shall. within 90 days install such approved
device, or devices, at his own.cxpense, and lailure or
relusal, or inability on Ihe pari of the customer 10
inslall said device or devices withinninely (UO) days,
shall constitule a ground lor discontinuing wllter
service to Ihe premises until such device or devices
heve been properly inslalled.
IV, Definitions
A. Approved
Accepted by Ihe Director 01 Mnnicipal Services
liS meeling an applicabie specification sill led or cited
in this regulation, or as suitable for the proposed nse.
B. Auxiliary Water Supply
Any waler supply, on or aVllilllble, to Ihe
premises other thanlhe pnrveyor's approved public
potable Wilier supply,
C. Bllckllow
The 11011' of water or other liqUids, mixtures or
substances, under positive or reduced pressnre in the
distribution pipes of a polabla waler supply from IIny
source other than its intended source,
D, Backllow Prevenler
A device or means designed to prevenl backllow
or back-siphonllge, Most commonly clllegorized as
lIir gllp, reduced pressure principle device, double
check vlllve assembly, pressure Vllcuum breaker,
almospheric I'acuum breaker, hose bibb vacnum
breaker. residential dual check, double check with
inlermediale almospheric venl, and baromelr!c lonp,
D.1 Air Gap
A physical separation suflicienlto prevenl
backllow between the free.llowing discharge end of
the potable waler system and any olher syslmn,
Physically defined as a dislance equullo 'wlce Ihe
dimneler of the supply side pipe diUlnelnr butnover
less than one (1) inch.
0,2 Almosphorh: Vacunm Breakor
A device which prevenls back-siphonage by
crealing IIn almospharic vont whon Ihore is oithor a
negalivo prossure or sub,ulmnsphoric prossuro in a
wator syslom.
0.3 Baromotrlc Loop
A fabricated piping IIrrong"mont rising ullousl
Ihirly flvo (35) fool 01 its topmosl poinl obnvo tho
highast fixtura it supplios, It Is nlilized in wator
supply systams to protacl ognlnsl back-siphnnugn.
3,
0.4 Donble Check Vulve Assembly
An ass"mbJy 01111'0 (2) independently operaling
spring loaded check valves with tighlly closing shnt
off vulves on "uch sid" of the check valv"s, pins
properly local"d tesl cocks for th" I"sting of each
check valve.
0.5 Double Check Valve with Interm"dial"
Almospheric V"nt
A d",'ice having two (2) spring load"d check
valves separated by an almospheric vent chamber.
0.6 Hos" Bibb Vacnum Breake'
A devic" which is p"rman"nlly allached 10 a
hose bibb and which acls as an almospheric vacuum
break"r.
D.7 Pressure Vacunm Breakor
A device containing one or two indepondently
opera led spring loaded check valves and IIn
independenlly operated spring 10llded lIir inlel valve
localed on the dischorge side of the check or chocks.
Device includes tighlly closing shul.off valves on
each side of tho check vlllves IInd properly localed
tesl cocks for the tesling of the check vlllve(s),
D.n Reduced Pressure Principle Backllow Prevenler
An IIssembly consisting of 111'0 (2) in depend en Ill'
opernting IIpprovod chock vlllves with an
automaticlllly oporating differenlial relief valve
locllted belwoen Ihe 111'0 (2) check valves, tightly
closing sltu/.off vlllvos on oach side of the check
vlllves plus properly locllled lesl cecks for the tesling
of the check vlllves and the raliof 1'1111'0.
0.9 Residenlial Dual Check
An assembly of two (2) spring louded,
independonlly operaling check vlllvos withonltighlly
closing shut.off vulvos and test cocks. Goneraffy
employed immedilltaly downstroam of Iha waler
meter to act liS II conlllinment device.
E. Backpressure
A condition in which Iho owners system prossure
is greater Ihlln the suppliers systom prossuro.
F. Bllck-siphonugo
Tho 11011' of woter or other lilJuids, mixtures or
substlluces iulo tho dislribulion pipos of II polnble
Wilier supply syslem from IIny sourco othor 1I111n its
inlonded source caused by the sudden roduclion of
prossuro in tho potllblo Wilier supply syslem.
G, Commission
Thn SllIte of ( ) Wlllor Supply IIncl I'ollnlion
Conlrol Commission,
H. Couteinment
A 1II0thod of bllckClow prnvenlion whil:h roquirns
II bllckflow prevenlion proventnr ntlho wotnr servico
onlranco.
I. Conllllninllnt
i\ subslonce Ihlll will impuir Iho qunlily of Ihe
wnlor to n degmo thnl it cronies II surlous Iwnllh
hllzerd to Iho public londing 10 pnisoning or tho
sprood of disnuse.
], Cross.cnnnoellon
Any IIclunlnr potonlinl connoclinn holwoon Iho
public wlllllr supply IInd II soureo of cnnlllminlllinn or
pollulion,
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K, Deportment
City of [ ) Woter Deportmenl.
L. Fixture Iso lotion
A method 01 bockflow prevention in which 0
bockflow preventer is locoled to correcl 0 cross
connection ot on in.plontlocotion rnlher Ihon ot 0
water service entrance.
M. Owner
Any person who hos legollitle 10, or license to
Operote or habitot in, 0 property npon which a
cross.connection inspection is 10 be mode or npon
which 0 cross-connection is present.
N, Person
Any individuol, porlnership, compilny, pllblic or
privote corporntion, politicol sllbdivision or ogency of
the Slote Deporlment, ogency or instrllmenlolity or
the United Stotes or eny olher legal enlity.
O. Permit
A documenl isslled by the Deportment which
ollows the use of 0 bockflow preventer.
P. Pollutont
A foreign substonce, thot il perm Wed 10 get into
the public woler syslem, will degrnde its quo lily so os
to constitute 0 modernte hozmd, or impoir the
usefulness or quolily of Ihe water 10 0 degree which
does not creote on octuol hozmd to Ihe pllblic health
but which doos odvorseiy ond unteosollilbly effect
such woter for domestic use,
Q, Woler Service Entrunce
Thot point in the owners woter system beyond
the sonitory control of the Districl; genemlly
considered to be Ihe oullet end 01 the woler meler
ond olwoys before ony unprotecled bfilnch.
R. Direclor of Municipnl Services
Tho Director, or his delegoted represenliltive in
chargo 01 the ( ) Deporlment of Mnnicipol Services,
is invasled with the outhority and responsibility for
the implementation of 0 cross.connectio" conlrol
progrnm ond lor the enlorcemenl of thu provisions of
the Ordinance.
V, Adminislroliou
A, The Depnrtment will opufille 0 cross.conn1l1:tion
conlrol progrnm, to include Ihe kuuping of nl!cussory
records, which lulfills the requiremenls of Ihe
Commission's Cross.Connection Regulaliolls and is
upproved by the Commission.
B. The Owner shall 1111011' his property 10 hll
inspectud for possihle cross-cnnnucliuns and shilll
follow thu provisions 01 thll DllpartlllOnl's prugfllm
and the Commissinn's Hegulutinlls if u
cross-connoctioll is pefmillud.
C, ff the Deportment reqnirus Iin,tthll pllhlic SliPI'll'
bo prolectod by cOlltaillmollt, tho Ownllr shull hll
tosponsiblo for wutur qUlllity bllyolld Ihu nullot olld 01
tho coutoillmollt dovico ond shollld utillzl! flxtllfll
outlet protUCtiOIl for that pllfpOSI!,
110 may 1I11lizo puhlic Iwollh officials, ()f porslllllwl
fromthu Dupnrlmllnl, or Ihuir dolugillml
represuututivlls, to ilssisl him ill tho Sllfvuy 01 his
facllitios alld to ossisl him ill Iiw soll!l:lioo nl propllr
flxlllto outllll dllvic:os, nlld Iho propm' illslnlliltioll 01
Ihoso dllvicus.
VI. Ruquiremonls
A. Dupartment
1. On new inslallotions, the Duportmenl will
providu on-situ evoluotion ond/or inspection 01 pions
ill ordur to deturmine the typu of backflow preventer,
if ony, that wiil he required, wiil issue permit, and
perlorm inspection ond testing. In ilny case, 0
minimllm of n dual check volvu will be required in
any new construction.
2. For premises existing prior to the slart of this
progmm, Ihe Department will perform evalllotions
end inspections 01 pions nnd/or premises ond inform
Ihe owner by leller of ony corrective action deemed
necessary, the method 01 ochieving Ihe correction,
end Ihe lime allowed for the correction 10 be mode.
Ordinarily, ninely (90) duys will be ollowed,
however, Ihis time period may be shorlened
depending upon the degree of hilzard illvolved and
the history of the device(s) in question.
3. The Deportmont will not allow ony
cross.connection to remoin unless it is prolected hy
on opproved backflow preventer lor which a pormit
has been issued ond which wiil be regularly tested to
insure satisfoctory operation.
4. The Department shall illform the Owner by
leller, of ony failure to comply, by the timo 01 the first
re-inspeclion. The Departmenl will allow an
additional fifleen (15) days for the correction. In the
eventlhe Owner fails to comply with the necessory
correction by Ihe time of the second re.inspoction, the
Deportmelll wiil inform the Owner by leller, thai the
water service to the Owner's permises will be
terminated within a period not 10 exceed five (5)
days, In the evollt lImtthe Owner informs tho
Deportmenl 01 extenuating circumslances as to why
the correction has not been made, a timll extension
mny be granted by the Depnrtmenl but in no case will
exceed an addilionalthirty 1301 days.
5. If Ihe Departmenl delermines el an)' lime thnt
n serious threat to the public health exists, the water
service will be terminated inunedilllely,
6. The Depllrlmenl shall have on file, a list of
Privale Contractors who lito certified backllow device
testers, till ch,lrges for these tesls will be paid by the
Owner of Ihc hllilding or propllrty.
7. The Departmonlwill bllgill initinl premise
inspections to determine the 1I11tUto of existing or
potenlial haznrds, following the approval of this
progrnm by Ihe Commission, during Ihe cnlendllr year
( ). Initial locus will be on high hazard
indnstries and commereinl premisus.
n.Ownor
1. The Owner shall be rUS\JIlnSihle lor thu
oliminntion or protection of 111 cross,collnm:lions on
his prelllisos.
2. Thll Ownur, afler hnl'ing bmm informud by a
leller from the lJopnrlmllnl, sballnt his Ilxpllnse,
IlIstnll, mnllltllin, nlld tllsl, or have tustod, any nnd all
bnckflow provelllllrs on his promisos,
:1, The Owner shall cnrrm:tany lllalfu11l:lioll 01
thll bnckflow pruvllntm which is nil'eallld by plJfilldil:
tosling.
ri)..
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4. The Owner shall inform the Departmenl of any
proposed or modified cross.connections and also any
existing cross-connections of which the Owner is
aware but has not been found by Ihe Department
5. The Owner shall nol install 0 by-pass around
eny backnow prevenlor unless there is a backnow
prevenlor of the samo Iype on the bypass. Owners
who can no I shut down operation for losting of tho
device(s) musl supply additional dol' ices necessary 10
allow testing 10 lake place, (Ref. Fig. 33 page 23.)
6, The Owner shall install backnow preventers in
e manner approved by Ihe Deportment. (Ref. Figures 3
through 37, pages 231hrough 24.)
7. The Owner shall install only backnow
preventers approved by Ihe Deportment or Ihe
Commission.
6. Any Owner having a privale well or olher
private woler source, must hove 0 permit if the woll
or source is cross-connected to the Deportment's
system. Permission 10 cross-connect mol' be denied
by Ihe Deparlment. The Owner mol' be required to
install 0 backnow prevenler 01 the service enlrance if
o private woler source is moinloined. even if it is nol
cross-connecled to the Deportmenl's system.
9. In the eventlhe Owner installs plumbing to
provide potable weier for domestic purposes which is
on the Deporlmenl's side of Ihe backnow prevenler,
such plumbing must hove its own backnow prevenlor
inslolled.
10 The Owner sholl be responsible for the
payment of 011 fees for permits, annual or
semi-annual device lesting, re.testing in Ihe cose thai
the device foils to operate correclly, and second
re-inspections for non.compliance with Deparlmenl or
Commission requirements,
VIl, Degree of Hazard
The Deportment recognizes the threat 10 the public
woler system arising from cross.connections. All
threals will be classified by degree of hazard and will
require the installation of approved reduced pressure
principle backflow prevention devices or double
check valves.
31i
V/ll. Permits
The Deportmenl sholl not permit a cross,connection
within Ihe public waler supply syslem unless it is
considered necessary and thai il cannol be
eliminated.
A, Cross.connection permits Ihat are required for
each backnow prevention device are eblained from
the Deporlment. II fee of ( ) dollors will be charged
for the initial permit and ( ) dollars for Ihe renewal
of each permit.
B. Permits shall be renewed every ( ) years and
are non-transferable. Permits are subject 10 revocation
and become inunedialely revoked if the Owner
should 50 change Ihe typo of cross-connoction or
degree of hazard associated with the service.
C, A permit is not required when fixture isolation
is achieved with the ulilization of 0 non-teslable
bocknow prevenler,
IX. Existing in-use bockfiow prevention devices,
Any existing backnow preventer shall bo allowed
by the Departmenllo continue in service unless the
degree of hazard is such as to supercede the
effectiveness of the present backnow preventer, or
result in on unreasonable risk 10 the public health.
Where tho degree of hazard has increased, 05 inlhe
case of a rosidentiol installotion converling 10 0
business eSlablishmenl, any existing backnow
preventer must be upgreded 10 0 reduced pressnre
principle device, or 0 reduced pressure principle
device musl be ins lolled in Ihe evenllhatno
backnow device was present.
X, Periodic Testing
II. Reduced pressuro principle backnow devices
shell be lested and inspecled alleasl semi-onnuolly.
B. Periodic lesting sholl be porformed by tho
Doportmont's cortified tester or his delegaled
represontative. This testing will be done at the
owners's oxpense.
C. The testing sholl be cenducled during Ihe
Deparlment's regulor business hours. Exceptions to
Ihis, when at the requesl of the ownor, mol' requiru
additional charges to cuvor Ihe incruased cosls 10 Iho
Departmont.
D, Any backnow prevenlor which fails during 0
periodic tesl will bo repaired or replaced. When
repeirs oro necessary, upon completion of Ihe repair
tho dol' ice will be re.lusled nl ownurs exponse 10
insure correct operetion. Iligh hazard situations will
nol be allowod to continue nnprotectod if the
bock now prevonter fuils Iho lesl and cennol be
repairod immediutely, In olher situations, a
compllanco dote of not more Ihenlhirly (3D) days nfler
Ihe lost doto will be established, Tho ownor is
responslblo for spure paris, repair tools, or 0
roplacement devico, Parallul inslollation of 111'0 (2)
dovices is un o[fective moans of the owner insuring
thotunlnlerrupled woter service during losting or
ropair of devices and is strongly rocommendod when
Ihn ownur dosires snch continuity, (Rof. Fig. 33 pugu
23.1
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"\ E. Backflow prevention devices will be lesled more
,requenlly than specifjml in 1\. above, ill cases wJwre
' there is a hislory of lesl failnres and Ihe Departmenl
feels thai due to Ihe degree of hazard involved,
additional testing is warranled. Cosl of the additional
tests will be born by Ihe owner.
XI. Records and Reporls
A, Records
The Department will initiate and mainlainlhe
following,
1. Master files on cnslomer cross.conneclion lesls
and/or inspections.
2. Masler files on cross.connection permits.
3, Copies of permits and permit applicalions.
4. Copies of Iisls end snmmaries snpplied 10 Ihe
Commission.
B. Reporls
The Deparlment will submitlhe following to Ihe
Commission.
1. Initial listing of low hazard cross.connections
10 the Slale,
2. Initial listing of high hazard cross-conneclions
to the Slale.
3. Annual update Iisls of items 1 and 2 above.
4. Annual summary of cross.connection
;jnspections 10 the Stale.
XII, Fees and Charges
I The Deparlment will publish a list of fees or
I charges for the following services or permits:
I 1. Tasting fees
I 2. Re-testing fees
I' 3. Fee for re-Inspection
4. Charges for after.hours inspections or lests.
- ..----- -.--.--_ - ._m____________
Addendum
1. Residential dual check
Effective Ihe date of the acceplance of this
Cross.Connection Control Program fa; the Town of
( ) all new residential bnlldings will be required
10 ins loll a residential dual check device immediately
downslream of the water meter. (Ref. Figure 37
page 24.) Instelletion of this residenlial dnal check
device on a relrofil busis on existing service lines will
be inslitnled at a time and al a potential cosl te Ihe
homeowner as deemed necessary by Ihe Deparlment.
The OIVner must be aware Ihat installation of a
residential dual check valve resulls in a potential
closed plumbing syslem within his residence. As
snch, provisions may have 10 be made by Ihe owner
10 provide for Ihermal expansion within his closed
loop syslem, I.e., Ihe ins lallation of Ihermal expansion
devices andlor pressnre relief valves.
2, StraIners
The Dopartmenl strongly recommends Ihat all new
relrofit installations of reduced pressure principle
devices and double check valve backflolVJrevenlers
include Ihe inslallation of slrainers locate
immedialely upstream of Ihe backflow device. The
inslallation of slrainers will preclude Ihe fouling of
backflow devices due 10 belh foreseen and unfereseen
circumslances occurring 10 Ihe water supply syslem
such as walor main repairsl water main breaks. fires.
periodic cleaning and flushing of mains. elc. These
occurrences may "stir up" dehtis withing Ihe waler
main Ihal will canse fonling of backflow devices
installed withonllhe benefit of strainers.
37
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Appendix A Appendix B
-- -- --~---------------
Partial List of Illustrations of (",
Plumbing Hazards Backsiphonage
Fixtures With Direct Tho following illnslrales Iypical Backsiphonage
Connections elulllbing hlstallaliolls where Coso 2 (Fig, 45)
Description acksiphollage is possible. A, Conleel Poinl: A rubber hose
Air conditioning, air washer Is submergod in a laboralory
Air condilloning, chillod waler sink,
Air conditioning, condenser water Backsiphonage B. Cause of Reversed FlolY: Two
Alrlina opposito multi -slory buildings ara
Asplralor. laboralory Case 1 (Fig, 44) connected to the same water
Aspirator, medical A. Conlacl Point: A rubber hose main. which of Ian leeks
Aspiralor. weediclde and fertilizer sprayer is submerged in a bedpan wash ade~uale l"OSSlltO, The building
onllO rig .1 hos luslalled a
Auloclave and slerlllzer sink, booslar pump, When Iho
Auxiliary syslem, iuduslrial B, Causes of Reversed 1'101Y: 111 pressure is inadequale In Iho
Auxiliary system, surfaco water A slerilizer connecled to the m,iu, Iha bulldlug boosler pump
Auxiliary syslem, unapproved woll supply woler supply is allowed 10 cool slarls pumping. producing 0
Boilersyslem without opening the air vont. As negative pressure in the main
Chomicol feoder. pot.lypo it cools, the pressure within tho and couslng 0 reversol of flolY In
sealed sterilizer drops below
Chlorln,lor atmospheric producing a Ihe opposite building,
Coff.. urn vaCUUlI1 which draws the C, Suggested Correction: Tho
Cooling syslem pollutod w,ler Inlo Ihe slerillze, l,boralory sink waler outiat
Dishwasher contaminating its contellts, (21 should bo provided with 0
Fire sl,ndplpe or sprinkler syslolll The flushing of severol flush vacuum breakor. Tho water
Fountain, ornamental valvo lollels on , lower floor servico IIno 10 tha boosler pump
Hydroulic equlpmant which arc connected 10 an should bo equipped with a
undersized waler service line devico 10 cui off Ihe pump whon
Laboraloryequlpmont reduces tho pressure at the water grossure opproilchcs a negative
Lubricallon, pump bearings c1osots 10 atmospheric producing ead or vacuum. ,::J
Photosl,1 oqulpmont , roversal of the flow, C,
Plumber's friand. pneulII,tic Suggested Correclioll: Tho waler
Pump, pnoum8tic ojcclor conncelion 'I tho bedpan wash
Pump, prime IIno sink ,nd Ihe slorlllzer should be 0 [
Pump, \Valor operated ejector /,rovlded with properly Insl,lIed
Sewor,sonllary "dflow provenlers, A
Sewer,slorm o 0 0 [
I Swimming pool I
Fixtures With Submerged o 0 0 [ I
,
Inlets I
Doscrlpllon DO 0 [ I
B'pllslll,1 fount
B,lhlub ,
Bodp,n washer, f1nshing rllll 00 0 [ I
Bldot
Brlno lank ,
Cooling lower DO 0 [ I
Cuspidor
DrJuklng founl,ln IJ 0 [
Floor drain, flushing rilll
Garb'go can washer
lco m,kor
L,boralory sink, sorralnd no"lo Q
L,nndry n"chlno it
L,v,lory
Lnwn sprlnklor syslllm
Phnlo I,boralory sink ('IGUIU': ~5
Sowo, flushing lII,nholo nnckslphnn'ge . Cllse 2.
Slop sink, f1nshlng rllII
Slop sink, Ihrended supply \.....'
Sle,m lablo
Urln,l, slphnn lei hlOlvolI1 F/GIIIU': ~,/
Vogol,blo pool or
Waler c1osel, flush I,nk, bnll cuck 1I111:kslllhul1ll}ll! ol:IIS111,
W,lor c1osel, /llIsh vnlvo. slphnn 1'1
38 17;.
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Backsiphonage
Case 3 (Fig, 46)
A. Con loci Point: A chemical
lank has , submerged In lei,
B, Cause of Reversed Flow: The
plont firo pump draws suction
directly from Iho city waler
supply line which Is insuHielenl
10 servo normal plant
requirements and a major lire at
tho sarno timo. During a fire
emergency, reversed flow may
occur wllhln the pl,nl.
C, Suggesled Correcllon: Tho
water service (0 the chemical
lank should bo provided Ihrongh
an oirgap.
BacksiphonagB
Casa 4 (FIg, 47)
A. Conlnct Polnl: The water
snpply 10 Ihe dishwasher Is nol
prolccted by 0 vacuum breaker,
Also, tho dishwasher has a solid
waste COlllloction to tho sewer.
B, Couse ef Reversed Flow: The
undersizod main serving the
building is subjccllo rednced
pressures, and therefore Dilly the
firstlwo floors of Ihe building
ore snpplied directly with elly
pressure. Tho upper floors arc
sorved from a booster pump
drawing suction directly frolll
the water service line. During
periods of low city plessure. Ihe
booster pump suction creales
l1egativo IJressures in the low
system, tlCreby re\'crsing the
flow,
C, Suggested Corrccllon: The
dishwasher hol ond cold walor
should bo supplied Ihrongh on
oirgap and (he waste from the
dishwosher should discharge
Ihrough an indlrecl wasle, The
boosler pump should bo
equipped wHh 0 low.pressure
cnlofl dovlce,
Backsiphonage
Case 5 (Fig, 481
A. Conlacl Polnl: Tho gasoline
slorage lank is malnlalncd full
and under pressure by means of
a direct connection to the city
water distribution system.
B. C,use of Reversed Flow:
Gasoline may entor the
dislrlbullon syslem by gmvity or
by siphonage in the event of a
leak or break In the water main.
C. Suggested Correction: A
roduced pressure principle
bockfluw prcvenler should be
insl,llcd in the line to the
gasollne storage tank or a surge
I,nk ,nd pump should bo
provided In Ihatline,
.,.
Main
It
('IWIRE"
Backsillhollilge. Case 5.
Backsiphonape
Caso 6 (Fig, 49)
A. Conlacl Point: Thare is a
submerged Inlel in Ihe second
floor b,lhlub,
B. C,usa of Reversed Flow: An
automobile breaks i1l1carby firo
hydrant causing II rush of wator
and a negative pressure ill tho
servico line 10 tho house,
sucking dl,ly IValer oul of Iho
b,thtub,
C. Sugjcsled Corrccllon: The hol
and co d water inlets to the
b,lhlub should be ,bovu Ihe rim
of Ihe lub,
IJ
I
,
I
!
ffitB
I
('IGURE ~fi
Bnckslphunago . coso 3.
Main
FtGlJIU(4!1
t1nckslphuuugu. Cusu It,
o
...
1'11:l1IIE ~,
IIUtkslllhllllllJ;U 0 (:IISIl4,
'.J
39
I , "J,
)':":')1,1",:,','" ,~l~J,':i:.;:'.~i,:':,...,[j;i:" ',' :'~' ':'} .':', ,:/'<':<:,:',:<:
'''',';<.\ I'i, J~t...,~,71")I.a.:",.,,. : ." . .,,'
Appendix C
Illustrations of
Backflow
The following p,esenls
lIIuslratinns of Iypical plllmbillg
Inslallatiolls whoro bnckflow
resulting (rom back pressure is
possible,
Backflow
Casa 1 {Fig, 50}
A. Conleet Poinl: A direct
connection f,om Iho city supply
to tho boiler exisls as a safely
measure ,nd for filling Ihe
syslem, Tho boiler ",Ier syslem
is chamlcally lro"ted for scale
prevcnllol1 and corrosiol1
conlrol.
B, Couse of Reversed Flow: Tho
boiler waler recirculation pump
dishchorgc pressure or
bnckpressura from the boiler
exceeds the city water pressure
and tho chemlcafly Irealod w,ler
Is pumped inlo Iha domestic
syslem Ihrough an opon or le,ky
valve,
C, Suggesled Correction: As
minimum prolectiontwo check
valves In series should be
providod In tho makaup
w,lerlino 10 tho boiler syslom,
An alrg,p separ,tion or reduced
pressure prlnclplo backflow
prevolller Is boller,
Bac~f1ow
Caso 2 {Fig, 51}
A. Contnel Polnl: Sewago
seeping from a residential
cesspool pollules Iho pril',le
woll which is used for lawn
sprillkling, The domestic wator
system, which is served from a
city main, Is cOllnecled 10 the
woll supply by means of , valve,
Tho purpose of Ihe conncction
m,y bo 10 primo Iho well supply
for emergency domestic IIse.
B. Cause of Reversed Flow:
During periods of low cily water
prcssuro, possibly when lawn
sprinkllllg is 'I its pe,k, the woll
pump dischargo pressure
exceeds Ih,1 of Iho city main alld
well w,lor Is pumped Into Ihe
clly supply Ihrough ,n open or
le,ky v,lva,
C. Suggested Correction: The
connection between Iho well
walor and city w,tor should bo
broken,
/ \).
,I
n{:IIIU:,il
IJm:knuw . case 2,
FI(:um;jlt
Ilnckflow . cn" 1.
40
~~
,~
~-
~!ift~~
1: II
') 'I
Backflow
Case 4 (Fig, 531
A. Conine' Polnl: A
slngla,v,lved connection exists
botweonlhe public, pol,hle
w,lor sllpply ,nd Iho
firo,sprlnkler syslom of , mill,
B, Cause of Revorsod f'low: The
sprinkler syslemls 1I0rm,lly
sllpplied frnmII nonrby I,ko
IhTllugh II hlgh,prosslIrtJ PUIlI\',
Aboulllm lako ore lorgo IIUIII JDrS
nf overflowing SllptiC I,nks,
Wh,nlhe v,lve Is left opon,
cOlltnmlnlltod lake \Vnter clln be
pumpnd 10 11m pllhllc sllpply,
C, SlIggestod Correcllnn: The
pnl,ble w,lor sllpply In Ihn firo
systom shollld bo Ihrollgh '"
nlrgofl or n reduced pressure
prlncll'lnlmckflow prnvonlnr
shnlll< bo ",,,,1.
0,
Backflow
Casa 3 (Fig, 521
A, Contact IJoint: A valve
connection oxists between the
pol,blo and Iho 110npolablo
sysloms ,board Iho ship,
B, Cnuse of Rel'ersed Flow:
While Iho ship is connecled 10
Iho city wnler supply syslom for
the purpose of tnking on water
for Iho polable syslem. Iha v,lvo
bolweentho polable ,nd
nonpol,ble sysloms is opened.
permitting contaminated water
10 be pumped into Iho munlcip,1
supply,
C, Suggested Corrccllon: Eneh
pier waler oullet should bo
prolected agninst backflow, Tho
main wator service to the pier
should also bo proleclod agalnsl
backflow by an ,Irg'p or
roduced pressuro principle
bnekflow preventor,
,"-.,
Fll:t!JU': j~
Il,,:kflow . cnso 3.
ACME MillS
Spllnklcrsyslem
;\
~1
~ II
VICIIIlErl:1
III11:knllw oc:nsIl4.
1''-
,
I
<C'
-
v-'~
. ..........-...-....... ,-- ---.....----,,-
; ".'.\' ',' i;i,.'" ',':" "";';'o-,'i':",,:,,:,,>,:,,'~:>
'. , " 'I . "I""'''' CI"'"", ,,' " , '"",' "
{:,'~ {', ~, : '.:)~,,~ ":':Ul":>~; :'" :':: .' ,<::, .",,: . "':',:
Appendix D
.-------------..------.--,----
"Jstrations of
Airgaps
The (allowing lIIuslralions
describe lI1elhods of providing
an airgap dischor8c to a wasto
line which may be occasionally
or conlinuously suujccllo
uilckprcssuro.
o
1
B,lIched
1,0
wnslehnel
f'IGURf:54
Alrg'p 10 sewer subjccllo
backprcssurc . force main.
D
ofu
I
I
I
I
~
i
!
,
,
I
r
I
I
I
I
I
I
1.0
f'IGURf:55
Alrgap 10 sewer su~lecllo
bnckpressuro. gravity drain.
Ballch"l
Supporlvancs
Horizontalwaslc
r-
IIIGlJfmnfi
!'Ire syslem mokouII lonk fnr ,
dunl wolursyslem, '
Tolllosyslem
Appendix E
-~-_._---
Illustrations of
Vacuum Breakers
Vacuum closes gate
Airemelshere ...
preventing riseol
conlaminaledllquids
in fl~IUles
Cowl nul
f'IGLJRI:S1
Vacuum ureakers
· <<n:1J LJ ~.
~
/ Plan :
1f.," or ,Y~H gale valvo
lIJ" or }~' :ich. 40. galY.
'h" or WEll. m, M.I gal....
SectfOn 'A" 'A'
nl;lllu:nu
Vacuum bfllukor llrrnllglllllenl
for ,nnutslde huso hydrunl.
/II)'lwrmlssrun uf Mr, GlIsln\'lll,l\n~uJI)
Sr" 1,li, Furllwrll' Plim! Sl1nJl.u~'
linNhwur, Unlull'clUhhluNuth~ilr
lJJI'Ldllll,OalllItIUI!, Tl!IlIl,1
,It
17~
~ ~p ,..,---- y-.---
--.. -...~-.- .....}.-- ......~
", ',' ,,:: .., , : :',' -r <~". .:..' ": O}tfl'" :'" : ' "', ':'<:: :,,:'
'", , -,' I ' ,I ", ,t] I . " "',
~::J; ,1::" o:"J~'~",,', ~81""", "", ~:,,:,,'_,' ,J :,: '. :',
~', "~ (, '",....:, , 'II ..', ' ~. .'"... ",
" . ,- , " ", . ".., \ ' .
'.
Appendix F
Glossary
\
Alrgap Tho unobslrucled vortical
dislance Ihrough Ihe free
alrnosphere bolween the
lownst opening frolTlllny pipe
or f,ucel supplying waler 10 ,
I,nk, plumbing f1xlu,e. or
other device ond the
f1ood.level rim or the
receplacle,
Backflow Tho flow of w,ler or
other liquids, mixtures, or
substances into Ihe
dislributing pipes of , pol,ble
supply of w,ler Crom any
source or sources other than
its Inlended source,
Bncksiphou'ge is one Iype of
bockflow,
Backflow Connection Any
arrangement whereby
bnckflow can occur,
Bnckflow Preventer A device or
lTIeons to prevent backflow.
Backflow Proven lor, Reduced
Pressure Principle Type Au
O5sembly of dirferenti,1 v,lves
and check v,lves including
,n aUlom,tically oponed
spillage pori to the
olmosphere,
Backsiphonage Bockflow
resulting CromnegaUve
p,essures in Iha dislributing
pipos or a pol,ble Wilier
snpply,
Cross.Connection Any actual or
potonU,1 connacUon bollvean
Iha public w,lor supply and
a sourGe of contamination or
polluUon,
42
~'._P-
,.u~__.__. _n____m_.--__. .,._,.
Effective Opening The minimulII
cross-sectional area al the
poillt of waler sUJlply
discharge, measured or
oxpressed inlerms of 11)
dl,meler of a circle. or (2111
the opening is nol circular,
the diameter of 1I circle or
equivalent cross,sectional
area,
~'lood.Levol Rim Tho edge of Ihe
receptacle from which water
overflows,
Flushomeler Valve A device
which discharges,
predelermiued qu,nlli)' of
water to fixtures for flushing
purposes and is actualed by
direct water pressure.
Free Water Surface A waler
surface lhllt is allltmospheric
pressure,
Frostproof Closet A hopper wllh
no water in the bowlllud
wilh Ihe trap alld water
sur.Ply conlrol valve localed
bo ow froslllno,
Indirect W05le Plpo A drain
pi po used 10 convey liquid
wastes that doos 1I0t COllllect
directly with the drainage
syslem. but which discharges
into lhe drainage system
Ihrongh an alrbroak Inlo ,
venled lrap or a properly
venled ,"d trnppod f1xlllre.
receptacle, or Interceplor.
Plumhlng Tho prnclico,
materials, ond rixtures used
Inlho insl,II,Uon.
maintenance, eXlenslon, aud
,liornUon of ,Ii piping,
flxlures, appli,ncos and
appurlenances in connection
wlih 'ny of the following:
sanitary drainago or storm
draln'go facilities, Iho vonUng
syslorn ,"d Iho puhlic n,
prlv,lo waler.supply syslorns.
withlu or ,djnconlto 'ny
building, slrucluro, nr
conveyance; nhm Iho practice
,"d m,lorl,ls usod In Iho
Insl,Il,Uou, m,lnlon,nco.
extension, or nltcratlon of
,Iorm Wilier, liquid w05I" ur
soweroge, and \Valor.supply
systoms of ony prollllsus 10
Ihol, cnnnocllnn wlih ony
polnl of public dispnsnl or
nlher occnpl,blo lerrnln,1.
.~"-'--'---_._-'__P-'-
-.--.----.------..--..---.---
Polable W,tcr Waler free from
impurities prescntln alllounls
sufficielltto calise disease or
harm Cui physiological effocls,
Its b,clerlologlcal and
chomical qua lily sh,1l
conform to tho requirements
or Iho Public f1e,lth Service
Drinking Waler Slandards or
Iho regul,lIon of Iho public
health oulhorily h,ving
jurisdiction.
Vacuum Any lIbsolute pressure
less Ih,u Ih,1 exerlod by Ihe
'Imosphere,
Vacuum Brl!akcr t\ de\'ico that
permits air into a water
supply dislribullonline 10
prel'enl bncksiphou'go,
Waler Oullel II discharge
opening Ihrough IVhlch IV,ler
is supplied to a fixture, into
Ihe 'Imosphere (except inlo
all open tank which is pllrl or
Ihe IValer supply systoml. 10 a
boiler or healing system, to
'ny dovices or cqulpmenl
requiring wlIter to operate but
IVhich are not part of Ihe
plumbing syslem,
Waler Supply System The w,ler
scrvlce plpa, Ihe
IVnler,dlslrlbullng pipes, ,nd
tho nocesslIry conllecting
pipes. fillings, conlrol valves.
and ollappurtOllllllCOS in or
adj,cenllo Ihe building or
promises, Tho IV,ler supply
syslom Is pari of Iho
plumbing syslem,
_J.
:di\
JT -PJl11l~",UIIJlII'A.."'M
n
"-
\,.,)
I?~
I
~--
v---
.. ........-.,........-,,- ...... .., ---.... - - -.----..-.,---...... ,-
. ~.... ~ _--'1J"""'"'-- ......... __ - ....-
, .-
;:: ,:,,:,;,':',<,:, ::~t'~, :,:'::G(".,' 't'7i:.:':-:,',:',..:,.",:,>, :". :~', ,>:'
r "".1" \, ' .' ~,01' ~., .. , ., '< . . ,
\~; ,:,}~~"..., :'~. \~;~:.,::,,~, ~!',..: 'l~~- \ :.: ,(:. ,',' "1':,.; : "." .,.'\"
Appendix G
Jliography
~
,
"
,
t~
t-
;'
Acceplcd Procedure C1l1d Proclicf!
ill CrosS,Collllcclioll Conlrol
hJonuoJ, American Walcr
Works Association, Pacinc
Norlhwost Suction, .lIh
Edition, Nov,1985,
American Backflow Prc\'olltioll
Association, P.O. Box 15li3
Akron, Ohio 44309.1563,
Angelo. Gllst,ve I"
Cross,Con/lcclioll nlld
Bnckflow PrCl'elltion.
American Waler Works
Association. Supplemel1tary
Reading Iibmry Series - No,
S106, New York 10016,
A Hel'ision of The Nntiollol
Plumbing Gode. AS/I
MO,8.1955. Reporl of Iho
Public Health Service
Technical Commillee on
Plumbing SI,ndnrds, Sopt. t5.
1962, Publtc Health Service.
Washington 25. O,C,
AIVIVA Slnndord For Buckf/oll'
Prel'eotion Oel'icos . Heduced
...-~Jressllrc Principle ancl
" )ollb/e Check Volvo T)'IlCS
'1C509.70). Amorican W,tor
\\'orks Association, Denver,
Colortluo, RcaUirmod 1963.
Bockflow Prevention and
Cross,Colllleclion Conlro',
A\\~Vtl Mnnnnl .111,1,
American Water Works
Assoclotion, Denver, Colorado
1900,
Bnckflow !'revenlionnnd
Gross,Colll1eclioll Conlrol,
Ohio EPA, Offl" of !'nbllc
Wnler SlIpply, Second
Edilion, l\avised Mnr,15,1!177,
,
\
y
i
i
,
i
i
i
I
I
Hackfloll' l'nwc/llion DtJ\'ices .
Seleclion. Inslnllolinn,
Moilllol1f1l1ce, olld Fiolcl
Tosllng. CSiI Slnndnrd
116~,10M1901. C,nndlnn
St,ndnrds Assncl,tinn,
Doc,1901.
Bnckfloll' . 1'1", .IInnnnl nf
Cross,Colll1ccliOIl I'ffll'olllioll
in I'nblic Wnlnr Snpi'lin"
Missnuri Dni'l,ofNnturnl
Rosourcos,
,
J
Cnnlldi{J1l Plumbing Code 19/10.
NIICC. No,17305, Second
Printing, Issued by lhe
Associate COllllllillnc UIl the
National Buildillg Code.
Nnturill Research Council of
Canada, Ottawa.
Control 11I111 Elimination of
CroSS,COllllCctiollS, PlInnl
Discussion, IOllrlwl A/lwricnn
\Vnlcr Works Associolioll.
Vo1.50. Nn,1.1960,
Cross,Connectioll COlllplications.
The Copilol', lieo/th. VolJl,
No, 9, Dee,1953. D,C, Oop!. nl
Public Ilcnlth. Wnshlnglno.
O,C,
Cross,Colllleclion Conlrol.
American Walor Works
Association. Brilish Columbia
Seclion. Secolld Edition,
lan,1980. CrosS,ColllICc:lioll
Conlrol ond lIockfloll'
Pff!\'fmlioll DC\'ice Tcsling.
Now England \Valor \Vorks
Association. J\ugust.1987,
Cross.Canneclioll Ccmlral mId
fjnckfloll' Prfll'elltioll. Pmclice
und Procedure MClllllUI.
Administmlh'c MflllIHI/, City
of Winnipeg. ~lnnil(lba, Third
Edlllno. April 19110,
Cross,Colll1cc/ioll Conlwl,
Backflow Pro\'ention Device
Testor Ccrtificnlloll Training
Coorso. Public Drloklng
WlIter Progrnm. Di\'ison of
EIl\'ironlllental QlInlill"
Depllrllllolll nf Natura
Rosources. SlaIn of Missouri.
Cross,Gonllcc:lioll Conlrol
M(lllllfJI. Division of Sunitary
Engineering, TUllnesseo Dupt.
of Pllhlic IIl!1dlh, t975,
Cross,Co/lllm:liulI Conlrol
Ilegl/lnlilln ill Wushinglou
SllIle. W"hlllglnll Sill Ie Dol'!.
of Social lllltlllealth Stlr\'ictl!i,
Dllllvor, Colorndo, 1!17",
Sncond Edition,
Cross,Coull(u;lillll Gonlrol. Nnw
Ynrk Slnln Dnl't. nf 1I0nllh.
Inn,1911L
Cross,Col1lwcliufl COlltrol
Pwgrfllll, Stnto of Utah,
Ocl,19115, Travis IIlnck,
CWSS,CllIlJwc:lillll Gun/wI, \Vnlm
Qllnllly Dlvisllln. Cllloradll
IJnl'nrlnllllll nl II"nllh,
1\lIvlsnd Mllrch I!III:!.
Cross,CulIllnc:lion Con/wi
Sun'flY, Nllw Englund Watnr
Works (\SSOdlllloll, August
111117,
CSA SIClndllrds Oil VI/cuum
/lmnkers ond /lllckflnn'
I're\'fJ/1lers, B04 Series 1!l76
Canildiun Stillldards
Association, Dec.1976,
Dawson, F. M., and Kulinske, 1\.
II" llel'o,l on
Cross,Col1llec/iolls ullcl
Hncksiphonuge Ileseflrcll,
Technical Bullelin No,l.
NaUonul Association or
Plumbing, Heating, Cooling
Contractors. \Vashington, D.C.
EI'lIlnlltioll IIf Bllckflon'
Pre\'enlionlJe\'ices. A Stole
of Iho flrl.IN II SiR 70, 10701
U,S, Environlllcnlal
Prolcction Agency, \\Inter
Supply Di\'isioll, Washinglon,
I),C" 1111111 1976,
lIendrlcksoll, Howard D,
Cross,Colllleclioll COlllrol,
Pari 1 & 2, I\ugust &
September 1981 issues or
Hee\'cs lourn"l.
How To Prel'lIl1llndllslrllll
Cross,Conlltlclloll Dangers,
\\'nlcr Works Engiueering.
Feb.IU62. Mllllilnbn Plumbing
Clldo 19111. Issned hy Ii",
Dupnrlment of Labour and
t\'lanllower 01 tho Pro\'inco of
Maniloba,
1\lllllt/ClI {If Cross'CO/l,wcliOIl
Cllnlrn/.IJ"I'I, of Ho,/th and
Hospitals, Denver, Colorado,
t9n.
Mnnuul of Cross,ColllwcliO/l
Cunlrol, Foulltlalioll ror
CroSS,COllllcctioll Conlrol nllll
Hydruulic Research,
IInh'nrslly of SOlltlWru
Callfnrula. 7th Edillolls. !lInn
!!I05,
~11I1I1I1I1 of CroSS,COIlI1I)cliUII
COil/wI PrcJ(;liG(),~ 111111
Procedures, Stilte of
Cnlirorniu, Huallh nlld
WnUnro Agency, July IOn!.
Plumbing unci IJrui/ll1gU Ac/
HllgullltjUI1S, Allmrtn. A!i
UlUtllli!m! by Alhurtll
I~l]glllntl(llls (2!15f!111),
lIegt/lnlions Hc/uling '1'0
Cross,Conllecliol1s, excerpt
from the Cnlifornia
Administrative Code, Tille 17,
Public llcnlth, 1956,
SuskolcJlClI'o/l lIeglllnliolls 817B,
Regulations Governing
Plumbing and Drnlnago
Solllr DOllwslic /101 IVolor
Sl'slellls nnd Iho IVnler
p'ur\'c\'or, American Wnter
\Vorks Association. Pacific
Northwcst Sectioll,
Springer. E, K" ,nd Roynolds. K-
C,' Definitions II/lti
Sper.ificolions of DOllble
Check V"I\'e Assemblies cll1d
Heduccd Pressure Principle
BClckflol\' l're\'enlioll Dc\'ices,
Universit\' of Southern
C,lifornla. School IIf
Engineering Depl. 48,101,
/'",30,1959,
Taylor. 1', il" ,nd Skodje. .II, 1'"
Cross,Colll1ecliolls. A /lllZfJrd
in All Buildings. Modern
SClllilulion und Building
Muinlellnnce. Vol. 14, No.8,
Aug,1902,
Usn or Uuekrlow PrtJvenlers ror
Cross,Collllection Control.
Joint COllll1lllloe Report.
IlIIIrlluJ Amcricall \Vuler
Works t\ssocinlion. Vol. 50.
No,t2,Oec,1950,
Van ~leler. R, 0" lIackfloll'
Pnwenliollllnrdwaro,lV,,/er
unci \\'nstt!s I~l1gillcuril1g, 1'1.1,
S"pt.1!170: PI,2. Dct.t970, I
43
17~
'~ -,eY' - ~--------.-.......... ~~ ....., ,.-- .....
:',',,:-, "",',:,' "";~"";~~i,-.:-.,,,,,;,,,,::':"<"
'" " " ., 'I' ,,"(' J ' 'l"I" ,t " · ,," "
l.~:~." '" :{\ .:~ _, '~. ':,<,.~., -,: "J~;" :l~~..I" i::,':.', ~ ,;~' .' ":J> '~:' :.~'~: ,:,: ',,:
AEpel1dix H
-~'--'-'~-
..-. '_.._~"------_.__..---_.--..._--"...~-,._--_.
Cross-Connection
Survey Form
rj;
\ i
,
i
I
i
I
,
I
!
I
,
\
!
Dalc:
Namc of Company. Corporation. or Busincss:
Address:
Nomc of Conlacl:
Typc of Usc: Induslrinl_
COl11mercial_
Govcrnmcntal_
Olhcr
Locotion of Scrvice:
Sizc of Servicc:
Inch
Melcred'!
Yes 0 No 0
Ycs 0 No 0
Yes 0 No 0
Yes 0 No 0
f"
;:4
Ycs 0 No 0
Ycs 0 No 0
Ycs 0 No 0
Ycs 0 No 0
Rcquirc non,inlerrupted walcr servicc'!
Does Boller Fccd utilize chcmic,1 additives?
Is Bnckllow prolcction incorporaled'l
Arc oir conditioning cooling lowcrs utilizcd'!
Is Backllow prolcction incorpornlcd'!
I
Is 0 Wotcr Sovcr utilizcd on condensing lines or cooling lownrs'! N/A 0
Is Iho moko.up supply Iino bnckllow prolcclcd?
Is proccss wolor in use, nnd if so, is it potnblo supply wntcr or "Rnw" wolor NIA 0 Pol,blc 0
Row 0 Prolcclcd 0 Unprolcctod 0
Is lira prolcction wolcr sopornlc fromlhe poloble supply'!
Ycs 0
No 0
Mo Conl,inmenl Devices in pineo'!
Yos 0
No 0
Summary
Dogroo of l1uzard:
High 0 Low 0
RPZ 0 DCV 0 Nono 0
~,4
Yes 0 No 0
Typc of Ilovico rocommondcd [or conlninmcnl:
Fixture Oullol prolcctinn rcqulrod'(
If so, whcre'!
401
17"; "
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1 -. Backflow Prevention Device
:1 Test and Maintenance Report
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/\ttn: Cross.connection Control Section
The cross.conneclion control dm'ice detailed hel'l!on has been tested and maintained ilS
required by the (rules or mgulnlious) of (pu/'l'e,l'ol' nl' mgnln/ol',I' ngmu:,I') and is certified
to comply wilh these (l'IIh!s or regnlnlions),
Make of device
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size
Model Number
locilted al
Serial Number
Reduced Pressure Devices
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Double Check Devices
1st cbeck 2nd check
Relief Villve
Initiol Test
DC.Closed Tight 0
RP, _ psid
Leaked 0
Leilked
Closed Tight 0
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Opened al
psid
Repairs imd
Malerials Used
Tesl
Mtnr Ilepuir
DC.Closed Tigbt 0
Rp. psid
Closnd Tighl 0 Opennd ill
psid
The above is certifind 10 bn true,
Firm Namn
Cel'lified TnshJr
Firm Address
Cnrl. Tester No,
Pressure Vacuum Breaker
Air Inlnl
Opened ul
psid
Did Nol Opnn
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Check Vall'e
_psid
I.eaked 0
OpUlwd at
_psid
psid
Date
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''fIIWA1TS$
W l1 REGULATOR
NOrlh Andover, MA 01845
This manual was reproduced with the per-
mission of the United Slates Environmental
Protection Agency by the Watts Regulator
Company as a public service to the many
Champions of backflow prevention.
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17;2.