St. Charles’ largest water well shut down

Published: Dec. 5, 2022 at 5:32 PM CST|Updated: Dec. 7, 2022 at 9:20 AM CST

ST. CHARLES, Mo. (KMOV) – The City of St. Charles is shutting down its largest water well in the Elm Point wellfield due to detections of contamination.

Right now, about 70,000 residents could be impacted by the shut down. City officials, the Environmental Protection Agency (EPA) and Ameren Missouri said the water is still safe to drink. However, moving forward, city leaders said they’re working to protect residents’ tax dollars and making sure the responsible parties pay up.

“I’m super glad the city is doing the right thing and taking the initiative to ensure those chemicals don’t reach our water plant,” Kristin Heideman said.

Heideman’s a St. Charles City resident. She attended the November 17th meeting where the EPA presented data to the city and its residents. In that meeting, the EPA claimed the water is safe to drink and there isn’t additional contamination. However on Friday, St. Charles Public Works shut down its largest water well.

“We feel like we can no longer wait for just monitoring and testing the data,” Public Works Director, Nick Galla, said.

Galla said last week, his team detected abnormal levels of two toxic, cancer-causing chemicals, forcing them to close five of seven wells.

“Our treatment plant was not designed to remove this level of contaminate. It can remove small amounts just naturally by the natural process we take. We don’t wanna continue to pump this well, pull more contaminates into where it’s the point where the treatment process will get into our drinking system,” Galla explained.

Currently, the water treatment plant is operating at around 25% capacity. Galla said they’re pulling millions of gallons of water daily from St. Louis City to make up for their water loss. Eventually, he said the cost will come back on taxpayers.

“Right now, we’re dipping into our reserves and there’s only so many reserves we have to put towards this. We feel like this should not be the burden of our rate payers,” Galla added.

Galla said he believes the responsibility of payment falls on Ameren Missouri, which the city claims, is responsible for contaminating the groundwater near the wells.

Monday night, Ameren Missouri sent the following statement to News 4:

The City of St. Charles and the U.S Environmental Protection Agency have emphasized that the drinking water in St. Charles is safe. Ameren Missouri is committed to the safety of the St. Charles community and remains strongly supportive of additional EPA-directed testing in the Elm Point Wellfield. As the EPA referenced multiple times in a public meeting on November 17, the source of the groundwater contamination is unknown. The contamination source must first be determined before pursuing a remedy and the good news is that EPA says it intends to have that source testing done soon. As EPA stated at its public meeting, Ameren Missouri has voluntarily worked for over a decade to clean up contamination from the Huster substation site and years of monitoring data show that clean-up work has been successful.

- Craig Giesmann, Director of Environmental Services, Ameren Missouri

“The EPA in our public meeting told us, they lamented on all the great things Ameren was doing, and they’re doing the right thing. In my opinion, if they’re doing the right thing, they would be supplementing our water so that we’re not doing that as taxpayers,” Heideman explained.

St. Charles City Leaders gave no time estimate on when this could impact residents. However, they said if they need to replace all of their wells and move them, it could cost them $40M.

“We’re taking the lead and taking the precautions we feel is necessary to keep everyone safe, despite what other agencies are doing,” Galla said.

The EPA sent the below update to News 4 on Tuesday:

“The EPA is committed to investigating recent detections of 1,2 dichloroethylene (DCE) and vinyl chloride (VC) in the Elm Point Wellfield to ensure that there are no current or future threats to human health or the environment. To date, St. Charles residents continue to drink water that meets all federal and state drinking water requirements.

The Safe Drinking Water Act provides that the maximum contaminant levels (MCLs) for DCE and VC are based on long-term exposure. The Missouri Department of Natural Resources, who implements the SDWA for the State of Missouri, bases MCL drinking water violations at the tap on a running annual average of four quarters of sampling data. Based on information the City has provided to EPA, the City chose to shut off City Well 9, a production well, based on a single uncollaborated, estimated data point significantly below the MCL (at the wellhead, not at the tap). Based on EPA’s data, none of the production wells shut down by the City are in violation of the Safe Drinking Water Act.

To investigate the City’s concerns, EPA has repeatedly requested that the City of St. Charles provide EPA access to the site in order to conduct sampling, which is necessary to determine the source of contaminant concentrations in PZ-11, a monitoring well in the Wellfield. On October 13, 2022, the Agency notified the City of its intent to perform important characterization field work at the Site in late November/early December and that access to City property was critical in being able to perform the work in a timely manner. The EPA was prepared to mobilize its contractors to perform this work beginning Monday, December 5, 2022. However late on Friday afternoon, December 2, the City informed EPA of additional requirements needed before the City would allow access. These agreements are extensive and required legal review, which could not have been accomplished in the time between receiving the notification and the long-planned start of work.

Accordingly, without access granted by the City, the EPA was required to cancel the planned sampling event. The EPA is prepared to conduct additional sampling this winter if EPA obtains the City’s consent to access. The sampling is required to determine the next steps needed to address any contaminants in and around the City wells. Given the most recent delay caused by the lack of access, the earliest that EPA anticipates initiating field work would be in January, if the contractor and drilling equipment are available. If they are not available, an additional delay would be likely.

The work EPA had planned to start on December 5 was to evaluate the source of volatile organic compound (VOC) contamination that was unexpectedly found in PZ-11, a monitoring well near City Well 6, in December 2021. Ameren had planned to start this evaluation in April 2022, but due to access issues, EPA eventually took over the work in October. The source for this contamination has not been confirmed to be from the Ameren substation, where previous cleanup measures and routine sampling had shown the contaminated groundwater plume had been shrunk back to within the boundaries of the substation.

It is critical that EPA perform characterization sampling on City-owned property around City Well 6 to determine if the source of the contamination is from the Ameren substation or if there is another unknown source that is responsible for these new concentration levels. Once this determination has been made, EPA can either require Ameren to perform additional cleanup actions if the contamination is determined to be from the substation, or EPA will attempt to identify who is responsible for the contamination if it is not from the Ameren substation.

Once EPA is able to obtain site access from the City and reschedule the work with EPA’s contractor, it will take approximately two weeks to conduct the field work and EPA will be able to share the data with the public after it is analyzed by the lab and shared with the property owners.

EPA does not have any data collected from Ameren on PZ-11, the nearby monitoring well, since November 17, 2022, or from City Well 6 since October 28, 2022. Ameren had been conducting biweekly sampling of City Well 6 and PZ-11 since December 2021. However, on November 17, 2022, the City stopped providing Ameren access to perform sampling.”

The comment period to the EPA on the Consent Decree with Ameren Missouri has been extended to March 6, 2023.