McLaren Tailings: The McLaren Tailings project was completed in October 2014. The project successfully removed a potentially unstable tailings impoundment, turning a previously unusable area back to its historical landscape while cleaning up contamination in Soda Butte Creek and preserving an important fishery and the natural resources of Yellowstone National Park. The project incorporated innovative techniques to dewater the tailings impoundment, allowing safe working conditions during the excavation of the tailings below the water table, and in incorporating lime into the tailings, ensuring repository stability. Over one billion pounds of tailings were excavated, stabilized, and placed in the repository, and approximately 100 million gallons of contaminated groundwater were treated during the project. Project execution included two years of investigation and design and five years of construction work. It has been awarded an Engineering Excellence Award from the American Council of Engineering Companies and the Environmental Excellence award from the Montana Contractors Association.
Streamside Tailings: After 16 years of cleanup, the Silver Bow Creek/Streamside Tailings cleanup reached completion in summer 2015.
Cleanup consisted of excavation of tailings (mine waste containing heavy metals) and related impacted soils from the floodplain of Silver Bow Creek, and the reconstruction of the stream channel and floodplain, and total revegetation. 5.8 million cubic yards of tailings were hauled, or enough to fill Grizzly Stadium to the brim 21 times. The contaminated waste was hauled to Opportunity Ponds. Approximately 1,550 acres along Silver Bow Creek have been remediated and restored.
Fish surveys show that populations of Westslope cutthroat, brook trout, sculpins, and suckers have reestablished in the creek. Shrub and tree planting activities have enhanced wildlife habitat, along with a DEQ-implemented weed management program. Sightings of over 100 bird species, including bald eagles, osprey, swans, blue heron, and sandhill crane are common in the floodplain and wetland areas, as well as deer, elk, moose, beaver, muskrats, and mink.
DEQ will implement a "final pass" cleanup before subareas are transitioned into operations and maintenance status. The final pass will address very small deposits of remaining remnant tailings-impacted soils to improve and enhance the remediation as a whole.
Clark Fork River: The Clark Fork River cleanup, Reach A, Phase 1 construction was completed on April 4, 2014. Monitoring plans for vegetation and streambanks have been developed to ensure that the remedy is successful in the long term. Construction for Phases 5 and 6 began summer 2015. The remediation project will consist of tailings removal on 4.5 river miles and is scheduled to be completed in spring 2016, with revegetation activities to follow. Construction on Phase 2 began summer 2015. The remediation project will consists of tailings removal on 1.9 river miles and is scheduled to be completed by fall 2016 with revegetation activities to follow. Sampling and design on future phases is also in the works.
Upper Blackfoot Mining Complex: Cleanup at the UBMC, also known as the Mike Horse, began in July 2014. In summer 2015, the Mike Horse Dam and the tailings behind it were removed and Beartrap Creek is flowing in the bottom of the valley for the first time in nearly 75 years. New channel is currently being built where the tailings had been. By 2017, the haul should be complete and the river restored. In 2018 the repository will have its final cover and the project will be complete.
2014 Special Legislative Funding: The Montana Legislature appropriated $400,000 to the DEQ Remediation Division's Petroleum Tank Cleanup Section to help address petroleum tank sites during Fiscal Year 2014 (July 1, 2013 through June 30, 2014). The money was used to closed abandoned USTs at four facilities and to conduct remediation work at 11 petroleum release sites. Releases were confirmed at all four UST closures and funding was available to assist with cleanup work at three of the sites. Other effects of the funding were renewed momentum at several release sites, it highlighted the efficiency of DEQ contractors, and it assisted in the PTRCB co-pay process.