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Cleanup of toxic coal ash that contaminated Colstrip groundwater begins

Cleanup of toxic coal ash that contaminated Colstrip groundwater begins


The Colstrip power plants is shown in May 2016.

Talen Energy is shaving time and money from its estimate of how long it will take to cap the toxic coal ash pods at Colstrip Power Plant.

The co-owner and operator of the southeast Montana coal-fired power plant now puts the ash pond capping price at $113.7 million and expects to complete the job by 2049, more than a decade earlier than previous estimates. The details are spelled out in Talen’s revised cleanup report.

The company begins de-watering ash ponds this year. The public has until early February to submit comments to the Department of Environmental Quality about Talen's coal ash plan.

At issue is how the power plant stores ash generated from coal burning. For 30 years, that ash has been stored in ponds, which have contaminated the groundwater beneath the town of Colstrip. It’s estimated that every year, 200 million gallons of contaminated water seep from the ash ponds, rendering the groundwater undrinkable.

The town gets its drinking water from the Yellowstone River, 30 miles away, from a pipeline that also provides water to the power plant.

The highly concentrated coal ash sludge contains lead, arsenic, boron and other toxic chemicals that can cause liver, kidney, brain and testicle damage. The cost of capping the ponds is just a fraction of what’s expected to be spent as cleanup begins and the four-unit power plant edges toward shutdown.

Colstrip Units 1 and 2 will shut down no later than 2022 under a 2016 legal settlement to resolve air pollution concerns. Three of the five of owners of Units 3 and 4 plan to cut ties with Colstrip within nine to 17 years.

Ash pond cleanup is starting this year, said Sara Edinberg of Montana’s Department of Environmental Quality. Talen is expected to de-water its bottom ash by the end of December and begin dry storage of the ash in 2019. Bottom ash is ash captured from the incinerator after coal is burned. The ash is a prime source for the boron.

Edinberg said bottom ash is simpler to de-water than the fine ash caught by air pollution scrubbers in Colstrip’s smokestacks. Talen is running tests now for cleaning up the fine ash.

The plan is to recycle the ash pond water as much as possible for use in the power plant.

Talen’s power plant co-owners are Washington state utilities Puget Sound Energy and Avista Corp.; Oregon utilities PacifiCorp and Portland General Electric; and NorthWestern Energy, which serves half of Montana’s population.

There are concerns that the ash pond cleanup plans will leave Colstrip groundwater vulnerable to future contamination because the coal ash is to be stored on site. The ponds will be de-watered, then capped with a liner, clay and soil.

In 2008, the power plant owners were sued by 57 Colstrip residents over the decades of groundwater contamination from the power plants’ numerous ash ponds, which cover roughly 800 acres. Because of the contamination, the Colstrip community gets its water from the Yellowstone River 30 miles away. The power plant draws the water to service its steam generators. The City of Colstrip’s water needs are met by the power plant’s water delivery.

The Colstrip plaintiffs settled with the power plant owners, but the pollution persisted as the ash ponds continued to leak. In 2012, the Montana Environmental Information Center, The Sierra Club and the National Wildlife Federation sued DEQ and the power plants’ owners, accusing them of doing little to stop the ash pond contamination.

The 2012 lawsuit resulted in a 2016 settlement, in which the power plant's owners agreed to stop pooling toxic coal ash and sludge beginning in 2019.


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