Valmont Power Station
panorama of valmont power station

Xcel Energy Closure of Valmont Power Station

Overview of the Valmont Power Station

Located at 1800 North 63rd Street, in unincorporated Boulder County, the Valmont Power Station burned coal in electricity production in the mid-1920s. In 2017, Xcel Energy concluded coal-burning operations at the site. Xcel Energy continues to operate three natural gas turbines and two solar arrays at the site to produce and distribute power throughout eastern Colorado.

History of Coal Ash Disposal

During the Valmont Power Station’s coal-burning operational lifespan, coal ash was historically disposed of in a series of onsite landfills on the north end of the property near the Valmont Butte. While modern landfills must have a protective barrier installed below the coal ash, this landfill was constructed before those best practices existed. Xcel Energy must continuously monitor the landfill and the local groundwater quality under their permit requirements with the Colorado Department of Public Health and Environment and the Environmental Protection Agency’s Coal Combustion Residuals regulations.

Coal Ash

Coal ash is a byproduct of the combustion of coal used to produce power at power plants. Fly ash, bottom ash, slag, and flue gas desulfurization materials are all terms that represent the different types of coal combustion residuals (CCR). Coal ash is disposed of in wet form in large ponds (surface impoundments) and in dry form in onsite or off-site landfills. Once an impoundment area has reached capacity or is to be closed for other reasons, the water is drained, and the ponds are dredged. The dredged residuals are then deposited on-site in designated landfills. Coal ash can contain heavy metals and other toxic substances that can harm health if inhaled or ingested. Boulder County Public Health is working with state and federal regulators to better understand and mitigate potential health risks at this site.

Groundwater Monitoring for Contamination & Corrective Measures

Xcel Energy’s ongoing groundwater monitoring at the Valmont Power Station identified localized groundwater contamination near the coal ash landfill and a few neighboring properties. Xcel is required to clean up and permanently resolve the groundwater contamination at Valmont Station. Their proposed plans for addressing the groundwater contamination are outlined below, along with an overview of Boulder County Public Health’s role in the project and information on how the public can share their voice on the cleanup effort.

In 2020, Xcel’s groundwater monitoring at the Valmont Power Station detected two contaminants, lithium and selenium, present in concentrations in some monitoring wells, which were above what is considered safe groundwater protection standards. The standards are set by the Colorado Department of Health and Environment and the Environmental Protection Agency to protect public health and the health of our aquifers. This contamination is linked to the coal ash stored in the landfills on the property.

Additional testing from several privately owned wells on neighboring properties to the northeast has also found concentrations of lithium and selenium above groundwater protection standards. Lithium and selenium are naturally occurring elements in rocks, soil, and groundwater. However, they can be potentially harmful if large amounts are ingested or if there is long-term exposure. The groundwater contamination is not currently believed to impact any public water supplies.

Plans for Remediation

Xcel is developing plans with a contractor to clean up the existing groundwater contamination and permanently prevent any future contamination. The proposed remediation plan involves a combination of groundwater pumping and treatment and source removal of the coal ash landfill. Xcel intends to apply coal ash in a beneficial reuse project, where 85% of the coal ash from landfills will be used to produce a product sold into the local ready-mix concrete market. Coal ash partially replaces cement that must be manufactured from mined limestone. Boulder County Public Health recognizes the potential air quality concerns related to the excavation and processing of the coal ash. We are working to advocate for best management practices and policies to address possible impacts on air quality and reduce potential community exposure.

Xcel has been sharing information about site conditions and their proposed groundwater action plan with Boulder County Public Health, the Colorado Department of Public Health and Environment, and the Environmental Protection Agency.

Health Information about Selenium and Lithium in Drinking Water

Additional resources from Xcel Energy

Boulder County Public Health’s Role

Boulder County Public Health (BCPH) must address the closure of the Valmont Power Plant at the grassroots community level, as it is a large-scale environmental, socio-economic, and equity concern. Collaboration between the local government and frontline community partners is crucial to tackle this issue effectively. Engaging in collaborative efforts with county staff and exchanging ideas and reflections across neighborhoods can create inclusive community-led solutions that lead to equitable outcomes.

Regulations

The proposed site remediation activities at the Valmont Power Plant are subject to various state and federal regulations. The Colorado Department of Public Health and Environment and the United States Environmental Protection Agency are the principal regulatory bodies responsible for ensuring compliance with all regulations. Boulder County Public Health is working closely with these regulatory partners and Xcel Energy to assure compliance with all local, state, and federal requirements and best management practices. Boulder County Public Health is committed to ensuring the community’s safety through this process and engaging with the community around the Valmont Power Station to listen, share information, and answer questions.

Recording of July 29 Meeting

Community Meeting Questions and Answers

Past Events

  • A meeting for community members who live near the Valmont Station was held on June 18 from 9 to 8 p.m. at the Boulder County Recycling Center.
  • A meeting for business members was held on June 18 from 8 to 10 a.m.
  • An engagement meeting was held on Feb. 27, 2024, from 6 to 8 p.m. at the Boulder County Recycling Center.
  • Engagement Cafecito hosted by the Climate Justice Collaborative and Naropa University was held 3:30-5:30 p.m. on Nov. 16, 2023, at Naropa University Nalanda Campus.

Get Involved

The county is ready to support the community with resources, procedural equity, planning, and implementation processes. In the spirit of collaboration, we invite our community leaders to co-create and co-lead these community engagement efforts.

The Colorado Department of Public Health and Environment (CDPHE) announced the start of the public comment period for the Assessment of Corrective Measures Report for the Valmont Power Station, located at 1800 North 63rd Street, Boulder, CO.

The public is encouraged to review the Assessment of Corrective Measures Report and provide feedback on the proposed cleanup solutions. The comment period is open until Nov. 20, 2024. Comments can be submitted by email to Taylor Pierce at taylor.pierce@state.co.us, or by mail to:

Taylor Pierce
CDPHE/HMWMD
4300 Cherry Creek Drive South
Denver, CO 80246

The Assessment of Corrective Measures Report is available for review on CDPHE. Portions of the report have been translated into Spanish, and interpretation services can be requested directly from CDPHE by Oct. 25, 2024.

To learn more about this process and to get involved, please reach out to our staff:

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