HomeMy WebLinkAbout2020-03-24 OrdinanceItem Number: 18.
CITY OF IOWA CITY
COUNCIL ACTION REPORT
March 24, 2020
Ordinance amending Title 16, entitled "Public Works", Chapter 3, "City
Utilities", Article D, "Wastewater Treatment Works Users", Section 6,
"Building Sewers and Connections"; and Article E, "Wastewater Treatment
Works Indirect Discharge", Section 4, "Pretreatment Standards", Subsection
B(2) to establish updated influent limitations for Zinc. (First Consideration)
Prepared By: Ron Knoche, Public Works Director
Reviewed By: Eleanor Dilkes, City Attorney
Geoff Fruin, City Manager
Fiscal Impact: None
Recommendations: Staff: Approval
Commission: N/A
Attachments: Ordinance
Executive Summary:
The ordinance will amend the City Code to clarify the responsibility and location of the
abandonment of building sewers and connections. The ordinance will also amend the local limit
for zinc for the influent of the wastewater treatment plant.
Background /Analysis:
It is a City policy that the abandonment of building sewers and connections occur at the city sewer
main and is done at the expense of the property owner. This ordinance will codify this requirement
which is consistent with water service abandonment.
In 2015, the City calculated the local limits for zinc for the influent of the wastewater treatment
plant. This local limit was calculated using an estimated treatment plant removal efficiency. In
2016, the Iowa Department of Natural Resources (DNR) approved the local limits calculated for
zinc. This limit was calculated using an estimated treatment plant removal efficiency. I n 2017, the
local limits for zinc for the influent of the wastewater treatment plant were approved by City
Council.
Since June 2016, the City has had 74 violations with the daily maximum effluent limitations for zinc
and in February 2019 violated the monthly average effluent limitation for zinc as set forth in the
National Pollutant Discharge Elimination System (NPDES) permit. These violations were self
reported to the Iowa DNR as required by the NPDES permit.
In January 2019, the Iowa DNR conducted an inspection of the Wastewater Treatment Plant.
The Iowa DNR inspection report cited instances of non-compliance which included exceedance
of the NPDES permit effluent limits for zinc. The Iowa DNR issued a notice of violation in April
2019. In April 2019, the Environmental Protection Agency (EPA) performed a Compliance
Sampling Inspection of the Wastewater Treatment Plant. In November 2019, the EPA performed
a pretreatment audit.
After calculating the local limits in 2015 and as zinc violations occurred, the City conducted
increased sampling of the collection system influent and the effluent to try to identify additional
sources of zinc. The City took measures to modify the wastewater plant treatment process to
attempt to reduce zinc levels in the effluent. These measures were not successful in preventing
zinc exceedances.
The EPA Pretreatment Audit determined the City had enough data to more accurately calculate
the removal efficiency of zinc for the wastewater treatment plant. This new removal efficiency was
used to calculate the local limit for zinc. This calculation was approved by the Iowa DNR in
February 2020.
The amendment to the local limit for zinc will be part of the Compliance Plan required as a part of
a consent order by the EPA.
Staff recommends approval of the ordinance updating the City Code.
ATTACHMENTS:
Description
OrdinancE
I?.
Prepared by: Ronald Knoche, Public Works Director, 410 E. Washington St., Iowa City, IA 52240 (319) 356-5138
ORDINANCE NO.
Ordinance amending Title 16, entitled "Public Works", Chapter 3, "City Utilities", Article D,
"Wastewater Treatment Works Users", Section 6, "Building Sewers and Connections"; and
Article E, "Wastewater Treatment Works Indirect Discharge", Section 4, "Pretreatment
Standards", Subsection B(2) to establish updated influent limitations for Zinc.
WHEREAS, the City desires to amend the Wastewater Treatment Works User article to clarify
the responsibility of abandoning building sewers and connections; and
WHEREAS, the local limit for zinc calculated by the City in 2015, approved by the Iowa
Department of Natural Resources (IDNR) in September 2016, and approved by City Council on
January 17, 2017 was calculated using an estimated treatment plant removal efficiency; and
WHEREAS, the IDNR conducted an inspection on January 14, 2019 of the wastewater
treatment plant and the inspection report cited instances of non-compliance which included
exceedance of National Pollutant Discharge Elimination System (NPDES) permit effluent limits for
the parameter of zinc; and
WHEREAS, the Environmental Protection Agency (EPA) conducted a Compliance Sampling
Inspection April 1-4, 2019; and
WHEREAS, the IDNR issued a Notice of Violation on April 16, 2019 for the failure to comply
with the zinc effluent limits listed in the NPDES permit; and
WHEREAS, the EPA determined there was sufficient sewage treatment plant data to determine
a more accurate site-specific removal efficiency for zinc; and
WHEREAS, the City has developed, with the help of the EPA and the IDNR, a revised local limit
for zinc; and
WHEREAS, the IDNR has approved the City's revised local limit and has determined the
modification to be a non -substantial modification; and
WHEREAS, the City is making the modification to the local limit for zinc as a part of the
Compliance Plan required by the EPA; and
WHEREAS, the City desires to amend the Wastewater Treatment Works Indirect Discharge
article of the City Code.
NOW, THEREFORE, BE IT ORDAINED BY THE COUNCIL OF THE CITY OF IOWA CITY,
IOWA:
SECTION I. AMENDMENT. Title 16, Chapter 3, Article D, Section 6 entitled "Building Sewers
and Connections", is amended by adding the following:
G. Abandoned Building Sewers and Connections: All building sewers and connections which are
no longer used must be permanently disconnected and plugged at the city sewer main at the
expense of the property owner. This work shall be completed within one calendar year from the
date of abandonment. If not completed in the required time, the city, after written notice to the
owner, shall complete the work and assess the cost to the owner.
Ordinance No.
Page 2
SECTION II. AMENDMENT. Title 16, Chapter 3, Article E, Section 4, entitled "Pretreatment
Standards", Subsection B(2) is amended by deleting the Zinc limit and replacing itwith the following:
Pollutant Pounds Per Day
Zinc 44.1
SECTION III. REPEALER. All ordinances and parts of ordinances in conflict with the provisions
of this Ordinance are hereby repealed.
SECTION IV. SEVERABILITY. If any section, provision or part of the Ordinance shall be
adjudged to be invalid or unconstitutional, such adjudication shall not affect the validity of the
Ordinance as a whole or any section, provision or part thereof not adjudged invalid or
unconstitutional.
SECTION V. EFFECTIVE DATE. This Ordinance shall be in effect upon publication.
Passed and approved this day of 2020.
TLAU 6:7
ATTEST:
CITY CLERK
pp ove`
City Attorney's Office
It was moved by and seconded by
Ordinance as read be adopted, and upon roll call there were:
AYES:
NAYS:
ABSENT:
Bergus
Mims
Saleh
Taylor
Teague
Thomas
Weiner
that the
First Consideration 03/24/2020
Vote for passage: AYES: Salih, Taylor, Teague, Thomas, Weiner, Bergus, Mims.
NAYS: None. ABSENT: None.
Ordinance No.
Page 3
Second Consideration _
Vote for passage:
Date published