Findett Corp. Superfund Site, St. Charles, Missouri – Fact Sheet, November 2022
Public Comment Period and Public Availability Session for Proposed Consent Decree
Background
The city of St. Charles, Missouri, has expressed concern about volatile organic compound (VOC) impacts originating from the Findett Corp. Superfund Site (site) affecting the Elm Point Wellfield (wellfield), which is a source of drinking water for the city.
Water is pumped from the public water supply wells, or city wells, in the wellfield to the city’s drinking water treatment plant, where the water is treated and blended with other water prior to distribution to the community.
The wellfield lies near an electrical substation operated by Union Electric Company d/b/a Ameren Missouri (Ameren), and near a defunct chemical facility, Findett Corporation, which operated from 1962 to 1973.
Past Response Actions
EPA has been actively investigating, sampling, monitoring, and performing response actions near the wellfield since 2001. Contamination near City Well 8 is being addressed under a 2005 Record of Decision (ROD), which provides a remedy for a contaminated groundwater plume sourced from the Findett Corporation facility. Since 2007, a group of Findett Corporation’s customers have been working to clean up the contamination under a Consent Decree and continue to monitor, sample, and clean up the Findett Corporation groundwater plume.
In 2010, the VOC cis-1,2 dichloroethylene (DCE) was detected in City Well 5. EPA determined that the contamination in this well came from a groundwater plume emanating from Ameren’s electrical substation. This plume is separate from the Findett Corporation plume. EPA and Ameren have been actively investigating the contamination and working to clean up the groundwater plume since its discovery.
Since 2012, Ameren has conducted numerous response actions at the site under EPA oversight. As a result, VOC concentrations in all monitoring wells at the site, except for one, have have been reduced to levels significantly below the Safe Drinking Water Act’s maximum contaminant levels (MCLs) and, in most cases, VOCs are not being detected.
Can I Drink My Water?Yes. The St. Charles drinking water supply meets the drinking water health standards established by Missouri’s Safe Drinking Water Law and EPA’s Safe Drinking Water Act. Water distributed to the public after treatment at the city’s water treatment plant has been sampled regularly for VOCs, including vinyl chloride (VC) and DCE, since 2008 and has never shown any level of contamination. |
Current Investigation
Part of EPA and Ameren’s investigations included the installation of numerous monitoring wells and piezometers to monitor contamination levels in the groundwater plume and around the city wells. Monitoring wells and piezometers do not provide drinking water to the city.
After years of data indicating decreasing contamination, VOC concentrations at two wellfield locations about 100 feet apart (piezometer 11 [PZ-11] and City Well 6 [CW-6]) increased without explanation in December 2021. Since January 2022, Ameren has been sampling PZ-11 and CW-6 biweekly to monitor any increasing trends or potential threats to the city’s water supply.
While some sampling at PZ-11 has shown contaminant levels above the MCLs, this sampling historically has not indicated the presence of VOCs in CW-6 above safe drinking water standards. However, sampling conducted on Oct. 28, 2022, detected VC in CW-6 at 2.0 micrograms per liter, which is the MCL for VC. Per the Safe Drinking Water Act, the highest permissible level of contamination (MCL) is measured at the point of delivery to the consumer, or “at the tap.” While VC was detected at the MCL during this sampling event, due to the city’s treatment and blending process, this level was not present in any water consumed by the public.
EPA has not yet identified the source of the contaminants around PZ-11 and CW-6. EPA has been working with Ameren since February 2022 to use direct push technology to determine the source, rate, and extent of the contaminant plume. This additional characterization is critical in determining the next steps needed to address the increased contaminant concentrations and protect the wellfield.
Record of Decision (ROD)
On June 30, 2021, EPA issued a ROD selecting the remedy to clean up Operable Unit 4 (OU4) of the site. Prior to issuing the ROD, EPA submitted a Proposed Plan for public comment from Feb. 2, 2021, to March 9, 2021, and held a Public Meeting on Feb. 9, 2021. Although EPA and the Missouri Department of Natural Resources recommended a preferred alternative to address the contamination, a final decision in the ROD was not made until EPA considered all public comments.
Most of the elements of the remedy were initiated as four pilot studies conducted between 2014 and 2018. These studies have had a significant beneficial impact on the groundwater plume. VOC concentrations in monitoring wells at the site have been reduced to amounts significantly below MCLs and, in most cases, no VOCs are detected.
Consent Decree
EPA and the state of Missouri have jointly worked to establish a Consent Decree (CD), which requires Ameren to perform the remedy selected in the ROD. This action will be taken under the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the Superfund law. The proposed CD, now pending in federal court, allows future actions if ROD cleanup standards aren’t met, and the CD will not prevent EPA from investigating or conducting cleanup of wellfield contamination or holding liable parties responsible for future response actions. The CD is an essential element in creating legally enforceable obligations that will require Ameren to conduct the necessary work to protect the wellfield.
Public Comment Period
During the public comment period, the CD may be examined and downloaded at the Justice Department website.
Public comments on the proposed Remedial Design/Remedial Action Consent Decree will be accepted until Dec. 5, 2022. Comments should be addressed to the Assistant Attorney General, Environment and Natural Resources Division, and should refer to United States and the State of Missouri v. Union Electric Company d/b/a Ameren Missouri, 22-cv-1038, D.J. Ref. No. 90-11-2-417/6. Comments may be submitted either by email or by regular mail:
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To submit comments: |
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By regular mail |
Assistant Attorney General, U.S. DOJ – ENRD |
On Thursday, Nov. 17, from 6 to 8 p.m., EPA will host a Public Availability Session at Memorial Hall, 1900 W. Randolph St., St. Charles, Missouri. EPA will share information about the Consent Decree and response actions at the site and will also be available to answer questions.
Site project information is available to the public at web repositories. To view cleanup documents and frequently asked questions, please visit EPA’s Site Profile Page. Anyone without internet access can view these documents online at this location during normal business hours:
St. Charles City-County Library
Kathryn Linnemann Branch
2323 Elm Street
St. Charles, MO 63301
636-946-6294
Questions or requests for site information can be submitted to:
Benjamin Washburn
Chief, Public Engagement and Communications Services
U.S. EPA Region 7 (ORA/OPA)
11201 Renner Boulevard
Lenexa, KS 66219
Email: R7PublicAffairs@epa.gov or washburn.ben@epa.gov
Phone: 913-551-7364 or 1-800-223-0425