The Montana Department of Environmental Quality and Talen Energy have reached a handshake agreement for cleaning up 6.7 million cubic yards of toxic coal ash in the storage ponds of Colstrip units 1 and 2.
The deal is nonbinding, but Talen and DEQ have pledged to sign a final agreement later this year based on terms announced June 29.
After six months of negotiations, the two sides settled on a $163 million cleanup bond to cover costs of the remedial plan DEQ picked in November 2020 (CU No. 1981 ). At the time, Talen objected to the department's $285 million cost estimate. In its objection, the Pennsylvania-based company said the state had picked an unnecessarily expensive and invasive option.
The DEQ rejected Talen's counteroffer of $157 million, but agreed to a $163 million bond based on new information provided by the independent power producer, department spokeswoman Moira Davin told Clearing Up.
The new information included the size of trucks that would haul away the toxic material and the design of the well system used to dewater the ash for dry storage, she said.
The poisonous sludge will be moved to lined ponds to be built above the water table near the plant site, DEQ ruled in November.
Once a final agreement is signed, Talen would have two years to study another cleanup option and ask DEQ to amend the plan based on new technologies, regulatory changes or other developments.
Significant proposed changes would undergo a public review. In the meantime, the company must start design work for the cleanup, according to the department. It could be four years before any physical work begins, according to DEQ.
Talen Energy did not respond to Clearing Up's request for comment.
DEQ will review cleanup costs each year and adjust as needed, according to the department.
Burning coal produces ash with toxic levels of boron, sulfates, selenium and heavy metals, including arsenic, chromium, lead and mercury. Ash from Colstrip units 1 and 2 has been stored in nine unlined ponds since the plant first fired up in the mid-1970s. Every day for more than 30 years, the ponds have been leaking the equivalent of an Olympic-sized swimming pool's worth of contaminated water into the ground, according to lawsuits filed over more than a decade.
In 2008, the power plant's owners agreed to pay $25 million to settle a lawsuit filed by 55 Colstrip residents claiming the ponds had contaminated a local aquifer.
Cleaning up the power plant's toxic legacy is covered by an administrative order of consent, an enforcement action DEQ agreed to with Talen's predecessor PPL Montana in 2012 (CU No. 1432 ). The process splits remediation into three areas: the plant complex, the wastewater ponds for units 1 and 2, and the ponds for still-operating units 3 and 4.
Talen and Puget Sound Energy own units 1 and 2, which were retired in early 2020. Units 3 and 4 are owned by Talen and five utilities—Avista, PacifiCorp, Portland General Electric, Puget Sound Energy and NorthWestern Energy. Talen operates the plant for the group. Talen and NorthWestern want to keep Colstrip burning for years to come, while the four other owners want to get out in the next few years. The two groups are locked in litigation stemming from their different timelines (CU No. 2003 ).
The final costs for cleanup and decommissioning have been a major stumbling block when it comes to determining Colstrip's future (CU No. 1932 ). DEQ estimates the costs could be as much as $700 million.