Managing legacy coal operations
Valmont Station in Boulder, Colorado, used coal to produce electricity from the mid-1920s until 2017, when the plant’s coal operations were retired years ahead of schedule. While the plant no longer operates on coal, we continue to monitor and manage legacy coal operations at Valmont.
Valmont Station has played an important role in providing electricity to Boulder residents for nearly a century. After the first unit began operating in 1924, the plant grew to operate four coal-fired units by 1942, making it the largest power station west of the Mississippi River. We built Unit 5 in 1964 and shut down the original four units in 1986.
As part of our company’s clean energy plans and goal to deliver 100% carbon-free electricity by 2050, we shut down Unit 5 in 2017. Xcel Energy plans to close all its coal operations in Colorado and other states by the end of 2030.
At the Valmont site, we currently operate three natural gas combustion turbines and two solar arrays for producing power and a substation that distributes energy to eastern Colorado.
When coal is burned to generate electricity, it leaves behind coal ash, similar to ash from a wood burning stove or fireplace. Coal ash is mainly comprised of rocks, minerals and other natural materials that cannot be burned. Coal ash contains less than 1% of trace elements, such as metals, which are also found in soil and naturally exist when coal is mined from the earth.
From the mid-1980s until September 2018, coal ash from Unit 5 was disposed in a landfill on the property that followed regulations set by the state of Colorado. With the landfill now idle, it is capped with a layer of soil and native vegetation until it can be permanently closed. There is also one older landfill on the property that was used prior to the regulated landfill.
Through an arrangement with Charah Solutions, we plan to permanently close the regulated landfill at Valmont Station by removing the coal ash. Charah will set up operations on our property to excavate and process about 85% of the coal ash from the landfill for sale into the local ready-mix concrete market. Coal ash is used as a partial replacement for cement that would otherwise need to be manufactured from mined limestone.
We have worked with Charah Solutions to minimize noise, dust and traffic from the landfill closure, in addition to any applicable state permit conditions that will address local impacts. Charah’s processing equipment is fully contained to manage dust and is relatively quiet, with sound levels expected to be comparable to or lower than the sound levels of previous plant operations. Truck traffic is expected to be about the same as traffic levels when the plant operated on coal. We expect Charah to set up operations at Valmont in 2024 and begin processing material as soon as summer 2025, with the entire project lasting up to 12 years, depending on the local concrete market.
We follow the Environmental Protection Agency and Colorado rules for groundwater monitoring around Valmont’s regulated landfill. In 2020, our groundwater monitoring on the property detected two constituents, lithium and selenium present in concentrations in some monitoring wells above groundwater protection standards. The standards are set to protect public health, which is important to us too. Exceeding a groundwater protection standard on the Valmont property doesn’t mean there is a specific or immediate concern, only that more testing is needed.
We continue to expand our monitoring network to test groundwater outside our fence line. Testing from several wells at nearby properties has found concentrations of lithium and selenium above groundwater protection standards. Lithium and selenium are naturally occurring elements found in rocks, soil and groundwater. Lithium is also a substance found in rechargeable batteries and in certain medicines. Selenium is an essential nutrient for human health and is often added to vitamins. Like most substances, both can be potentially harmful if very large amounts are ingested. From our current monitoring, there is no evidence that anyone is drinking water with lithium or selenium above the groundwater protection standard.
Find our groundwater monitoring reports for Valmont at xcelenergy.com/coal ash management.
Conducting our business in a safe and environmentally responsible manner is a priority for Xcel Energy, and we are committed to managing impacts caused by our legacy coal operations. We are proposing to remove ash from the regulated landfill for recycling and to install extraction wells at locations around the Valmont property to extract and effectively treat impacted groundwater. We have been sharing information about site conditions and our proposed ground water action plan with Boulder County Public Health, Colorado Department of Public Health and Environment and Environmental Protection Agency. We also will seek public input on our proposed plan during an open house event in spring 2023. Once the selected extraction system is designed and installed, it will begin operating in 2024 and continue for multiple years until the impacted groundwater is cleaned up.
Información en español (PDF)
Public Open House Invitation (PDF)
Open House Public Notice (PDF)
Valmont Station Project Information Sheet (PDF)
Valmont Station Project Frequently Asked Questions (PDF)
Information on Lithium and Selenium (PDF)
Information on Constituents in Coal Ash (PDF)
Groundwater and Remedy Evaluation Presentation (PDF)
Ash Recycling Project Presentation (PDF)
Xcel Energy Area Manager, Community and Local Affairs
Iffie Jennings
iffie.m.jennings@xcelenergy.com
Boulder County Public Health
Erin Dodge
HealthOWS@bouldercounty.org
U.S. EPA Region 8
Doug Knappe
knappe.doug@epa.gov
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