Tell the DEQ that Colstrip deserves cleanup done right! (Units 3&4)

Please submit a comment/letter to the Montana DEQ regarding cleanup plans for the Colstrip Units 3 & 4 ash pond complex by November 22, 2019. Feel free to personalize your letter in whatever way seems appropriate to you–personal stories are strongly encouraged. Thank you! (More information on this issue found below the comment form.)

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It’s an old story in Montana — Butte, Libby, Mill Creek, Zortman-Landusky — corporations shut down overnight and leave the communities that supported them to face job losses and legacy pollution.

This Fall, the Montana DEQ will decide on a long-term cleanup plan to address the groundwater contamination plume resulting from 40 years of leakage from Colstrip’s coal ash ponds. Colstrip Units 1&2 are scheduled to close this winter, and a responsible cleanup plan approved by the DEQ would bring hundreds of jobs to the area, restore water quality to area ranchers, and protect future taxpayers from financing a state-funded cleanup.

The DEQ’s decision must provide a permanent fix to the 367 GALLONS of polluted water that leak EVERY MINUTE from the 837-acre coal ash pond complexes outside the power plant. The companies are lobbying to simply “cap” the ponds in place. The DEQ’s decision will impact local ranchers, power plant workers, and taxpayers around the state.


Dewatering the ponds will stop the pollution at its source. Coal ash contains sulfates and heavy metals which are dangerous to humans, wildlife, and livestock. Wet ash ponds leak this pollution into local aquifers. Agriculture relies on those aquifers to make a living. The Units 3&4 ponds alone leak 400,000 gallons of water every day because our ash is stored in ponds instead of as dry material.

Wet coal ash is also heavy, and the pressure of millions of tons on the pond’s liners forces pollution through this protective barrier. Draining the ponds will release this pressure and keep pollution contained within the ash impoundment.


When the Units 3&4 ponds were built in the early 1980s, a drainage system was built beneath the pond complex. This “underdrain” is designed to collect water leaking down through the pond’s liners and return it to a water treatment facility above ground.

The Colstrip owners have never used this underdrain because they did not want to pay to build a water treatment facility and a new pond to store the polluted water. If the underdrain works as designed, it will play a critical role in dewatering the ponds and halting the spread of new pollution.

In a cleanup plan submitted in 2019, the owners finally proposed building a water treatment plant and turning on the underdrain in 2021. Waiting until 2021, however, is too long to see how well a 40-year-old drainage system works. Please demand that the DEQ require the plant’s owners to turn on the underdrain as soon as possible and build the needed storage reservoirs and water treatment facility.


So much of the cleanup plan for controlling future pollution rests on how well the underdrain works to dry out the ash. If the underdrain does not work, it is imperative that Colstrip owners have a contingency plan to ensure that pollution is stopped. This plan would likely require owners to physically remove the coal ash from ponds through excavation and store the material in a properly designed landfill.

To learn more about the economic benefits of cleaning up Colstrip: