Colorado regulators review Xcel plan to clean coal ash groundwater at Valmont Station

Colorado regulators are reviewing Xcel Energy’s final plan to clean up groundwater contamination caused by decades of coal ash disposal at the Valmont Power Station, a project that could begin construction as early as late summer.

The proposed cleanup system would pump contaminated groundwater from beneath the site and transport it for treatment, a first-of-its-kind approach in Colorado, according to the company and state officials. The plan follows years of contamination that has migrated beyond Xcel’s property and was detected in at least one nearby residential well.

Almost a century of coal burning at the Valmont Station, located just east of Boulder, left behind 1.6 million cubic yards of coal ash stored in landfills on the plant’s grounds. The waste contains contaminants including arsenic, lead and chromium, all of which have been found in groundwater samples from the area, according to state records cited by the Associated Press.

Xcel Energy, Inc. is the utility that owns and operates the Valmont Power Station. The company has said the cleanup plan is the result of extensive study and collaboration with state environmental regulators.

But some environmental advocates say the proposed cleanup may fall short. Erin Dodge, a clean water advocate with a Colorado environmental group, said in comments reported by the AP that the project should account for possible contamination from a second coal ash landfill at the plant that may also be contributing to the pollution.

Lisa Evans, an attorney with Earthjustice who has tracked coal ash contamination nationally, also raised questions about the scope of the cleanup, according to the AP.

The Colorado Public Utilities Commission is reviewing the plan, which includes both the groundwater pumping and treatment system and long-term monitoring of nearby wells. A decision is expected in the coming months.

The plant has since shifted to natural gas but continues to serve as a substation and interconnection point for the regional grid.

Xcel Energy has said the clean water project, if approved, would be among the first of its kind in the Rocky Mountain region. The company estimates it will take several years to fully remediate the contaminated groundwater beneath the site.