Cahokia Heights Drinking Water

Public Notice 

Metro East Illinois Area Water Infrastructure and Flooding Matrix Events.

In August 2021, U.S. Environmental Protection Agency ordered the city of Cahokia Heights, Illinois, and the drinking water utilities in the city to take immediate actions to prevent drinking-water contamination and to protect the health of residents. While there was no evidence of contamination in the drinking water, an EPA inspection identified serious problems that could have affected drinking-water safety, especially during sewer overflows. The water systems serve about 21,000 people. Illinois EPA supported EPA in taking the action to ensure public health was protected. Actions taken under the Unilateral Administrative Order (UAO) were intended to protect residents of Cahokia Heights and the safety of their drinking water.

On July 27th, 2023, EPA terminated its UAO issued under the federal Safe Drinking Water Act (SDWA) to Illinois American Water Company (IAWC).  IAWC has demonstrated to EPA that it has satisfactorily completed the terms of the UAO. EPA reviewed IAWC’s monitoring data, weekly reports, and other records to ensure all required deliverables had been submitted. In addition, EPA conducted a SDWA inspection on October 18-19, 2022, to ensure IAWC was in compliance with the UAO. Following this review and inspection, EPA confirmed that IAWC has met the UAO requirements.  In addition, the utility has improved its community outreach by publishing newsletters, holding an open house for residents, and designating staff to answer questions from the community. Termination of the UAO does not relieve IAWC of the ongoing obligation to comply with the requirements of SDWA and its regulations. Termination of the UAO for IAWC also does not preclude EPA from taking additional enforcement actions against IAWC in the future.

Termination of the UAO for IAWC will not affect the requirements for the City of Cahokia Heights.  The UAO for the City of Cahokia Heights will remain in place until the terms of the UAO have been met to EPA’s satisfaction. EPA continues to meet with the City of Cahokia Heights and is working toward addressing community members’ needs and concerns around water infrastructure.

The Safe Drinking Water Act (SDWA) provides EPA with broad authority to act to protect the health of the public. Cahokia Heights, the Illinois American Water Co. (IAWC), Commonfields of Cahokia Public Water District and the Village of Cahokia Public Water System will be required to carry out additional monitoring for bacteria, chlorine and water pressure in areas where sanitary sewer overflows occur, and to address operation and maintenance issues including increasing staffing and making repairs to storage tanks and the distribution systems. 

The order requires several steps that together will help ensure sewage does not contaminate the drinking water supply including:

  • Constant monitoring of drinking water pressure.
  • Increased testing for bacteria.
  • Testing for effective chlorine levels to help ensure that sewage does not enter the drinking water.
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A system under the correct amount of pressure will keep outside contaminants, like dirt and bacteria, from entering the system. A loss of pressure can occur when water lines leak or break. If bacteria is found in the drinking water, EPA may require the systems to:

  • Notify the public.
  • Issue a boil-water notice and provide bottled water until repairs are made.
  • Conduct repeat sampling. 

Documents

Termination Request 

Administrative Order Weekly Progress Reports - Illinois American Water Company (IAWC) 2022

Administrative Order Weekly Progress Reports - IAWC 2021

Administrative Order Weekly Progress Reports - Cahokia Height (CH) 2022

Administrative Order Weekly Progress Reports - (CH) 2021

Miscellaneous Documents and Deliverables 

EPA in Illinois

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Last updated on February 25, 2025