HomeMy WebLinkAboutEPA Memo
Date: May 21, 2025
To: Climate Action Commission
From: Sarah Gardner, Climate Action Coordinator
Re: Air Quality Testing in Iowa City
The purpose of this memo is to provide an update on actions taken by City, state, and federal
staff in response to concerns brought in 2024 to the Climate Action Commission and City
Council by residents regarding odors believed to originate from industrial operations in Iowa
City. Although addressing air quality and environmental compliance is outside the core
responsibilities of the Commission, this information is being provided for the purposes of
transparency and information sharing.
Background
In response to the concerns raised, and at the request of City management, the Iowa
Department of Natural Resources (DNR) engaged the U.S. Environmental Protection Agency
(EPA) to investigate and identify any potential sources the reported odors.
The EPA deployed a mobile air monitoring system to conduct sampling across the city’s
industrial zones and neighboring residential areas. This system, mounted to a vehicle, included
air sample containers for laboratory analysis, meteorological equipment to detect wind patterns,
and an infrared camera capable of detecting volatile organic compounds, including methane.
To ensure comprehensive results, samples were collected at various times of day over several
days. While City management was informed that testing would take place, specific dates and
times were kept confidential by the EPA to ensure the integrity of blind sampling.
Analysis
Findings from the combined data—including laboratory analysis and thermal imaging—pointed
to a small amount of toluene emissions from the Loparex facility as the most likely source of the
reported odors. Importantly, the levels of toluene detected were measured in parts per billion,
over one hundred times lower than the lowest threshold known to impact human health (20
parts per million).
Toluene is known for its distinct odor and is easily detectable by humans even in extremely low
concentrations. Although it has a similar smell to acetone, toluene is non-flammable and
requires exposure to much higher concentrations than acetone to pose health risks.
Trace amounts of benzene (≤3 parts per billion) were also identified during testing. These levels
are similarly more than one hundred times below the minimum risk level for human exposure.
The benzene detected is likely attributable to multiple environmental and industrial sources and
was not traced to a single origin.
Outcomes
After obtaining the results of the air sample testing, the EPA conducted an unannounced site
inspection at the Loparex facility in order to perform due diligence. This inspection included a
review of manufacturing and emissions control equipment, a compliance records audit, and
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additional optical gas imaging. The facility was determined to be in full compliance with all
current environmental regulations.
The findings from this investigation were shared with City staff, who followed up with the EPA to
discuss the air quality testing results. Staff also met separately with the Loparex facility manager
and environmental health specialist, who expressed a commitment to open communication. No
further action was recommended by the EPA.
More detailed information about these efforts and findings can be found in the attached reports
shared by the EPA with the City of Iowa City.