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Agreement outlines change in coal ash disposal at Colstrip plant

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Agreement outlines change in coal ash disposal at Colstrip plant

Coalash from the largest units at the Colstrip power plant in Montana must bestored differently in the future, according to an agreement reached between theplant's owners and environmental advocates.

Theagreement, filedJuly 21 with Montana State District Court in Rosebud County, calls for an endto coal ash waste being disposed of as wet sludge dumped into wasteimpoundments. Under the agreement, by the end of 2018, a portion of bottom ashfrom Colstrip units 3 and 4 must be dewatered before it is disposed of, and byJuly 1, 2022, all waste from the units' scrubbers must be disposed of as a drywaste.

Inreturn, the Montana Environmental Information Center, the Sierra Club and theNational Wildlife Federation will drop a complaint against the MontanaDepartment of Environmental Quality over an agreement between the agency and Colstrip's operator.The groups claimed that the administrative order on consent that the DEQ issueddid not stop pollution from leaking into groundwater.

JennyHarbine, an attorney with Earthjustice, which represented the groups, said thatwhile the waste impoundments are lined, they leak. "The most importantthing we can do to stop that leaking is to dry up that waste and that's whatthis agreement accomplishes," she said July 21.

Harbinesaid there is still the problem of legacy pollution around the plant, but sheexpects that once pollutants are no longer added, efforts to pump contaminatedgroundwater out of area aquifers will see results.

"Ifwe stop contributing to the problem, Colstrip's owners can focus on fixingit," she said.

Ownershipof the four-unit Colstrip plant is split among six companies: , subsidiaryPuget Sound EnergyInc., AvistaCorp., NorthWesternCorp., PortlandGeneral Electric Co. and Berkshire Hathaway Energy subsidiary . Talen is the plant'soperator. The company, however, plans to step back from that role within two years.

Talenmust also file a plan with the DEQ to remediate existing groundwatercontamination caused by Colstrip's waste. That plan will come with a goal ofcleaning up groundwater to meet water quality standards.

Harbinenoted that terms of the conversion to dry disposal of coal ash apply only tounits 3 and 4 because a recent separate proposed settlement could pave the way to the retirementof the two older units at Colstrip on or before July 2022. Thefirst two Colstrip units began operating in the mid-1970s while units 3 and 4,which are larger, began operating in the mid-1980s.

Closureof Colstrip's older units would keep them from polluting in the future, Harbinesaid. The agreement, however, contains provisions relating to how theimpoundments are enclosed once they stop receiving waste, and that applies toall four units, Harbine said.