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Remediation of Abandoned Mine Lands |
In addition to massive mine waste removals and stream reconstruction, effective control, capture, and treatment of contaminated alluvial groundwater has helped improve water quality in Silver Bow Creek. Although the surface water component of the remedy has been successful, the aquifer is technically impracticable to remediate, regardless of the extent of waste removed. Estimates for aquifer cleanup range from centuries to thousands of years. Even under a total removal scenario, heavy metal contaminants could not be flushed from the aquifer to the point where the aquifer would be suitable for domestic use. It is also unlikely that untreated groundwater could ever discharge to surface water without causing water quality exceedances. The determination of technical impracticability led to the controversial decision to leave wastes buried in the floodplain, thus requiring groundwater capture and treatment in perpetuity.
Angela K. Frandsen, CDM Angela Frandsen is an environmental engineer in the Helena, Montana office of the environmental consulting firm CDM. Ms. Frandsen specializes in water quality, aquatic geochemistry/contaminant fate and transport, remediation, and water treatment processes. With CDM, she provides technical support on the Butte Priority Soils Operable Unit site for the EPA Region 8 Montana Office. Ms. Frandsen has supported EPA in various capacities on many of the other federal Superfund sites in Montana.