The U.S. Environmental Protection Agency (EPA) has reached a settlement with the Public Service Company of Colorado (PSCo), operator of the Cherokee Station in northeast Denver, Colorado. This agreement mandates PSCo to address groundwater monitoring issues, undertake protective groundwater cleanup, and pay a penalty of $134,500.
The settlement was finalized on September 30 as part of the EPA’s National Enforcement and Compliance Initiative aimed at protecting communities from coal ash contamination. Coal ash is a significant industrial waste byproduct containing contaminants that can cause cancer and other health issues. Historically, it was disposed of in unlined landfills and impoundments often in contact with groundwater.
"Today’s settlement will protect Adams County, North Denver communities and the surrounding environment by ensuring that effective measures are implemented to address groundwater contamination at the Cherokee Station power plant," stated KC Becker, EPA Region 8 Administrator. "We will continue to hold owners and operators of coal ash facilities accountable."
PSCo transitioned Cherokee Station to a gas-fired plant in 2017 and removed all coal ash from its four surface impoundments between 2017 and 2018. Groundwater monitoring has shown lithium levels requiring corrective action.
The EPA claims PSCo failed to meet several requirements under its coal ash program:
- Inadequate preparation of annual groundwater monitoring reports.
- Inaccurate representation of background groundwater quality.
- Non-compliance with performance standards for groundwater monitoring systems.
Under the settlement terms, PSCo must develop remedies for lithium releases from the impoundments using EPA-approved statistical methods for ongoing monitoring. A report assessing potential cleanup measures was completed by PSCo in July 2024.
In April 2015, national rules were established by the EPA for coal ash management to mitigate risks associated with disposal and discharge into groundwater, air pollution from dust, and catastrophic failures of surface impoundments.
For further details on coal ash regulations and activities, visit the EPA's Coal Ash website.
