Comments cite toxic history of property
A dozen people and agencies have commented on a proposal by a property owner to build a house on the site of the Red Shirt Mill, which processed ore from the nearby Red Shirt Mine in the 1930s and 1940s.
Kevin and Bonnie Schmidt applied to Okanogan County to build a 4,400-square-foot house on the 7.33-acre parcel on Twisp Airport Road. Water would be supplied by an onsite well.
Most commenters voiced major concerns about the potential for contamination of the environment, since the Red Shirt Mill is ranked at highest risk on the Washington Department of Ecology’s Hazardous Site List.
In its comments to the county, Ecology expressed “serious concerns” about high levels of contamination from metals including arsenic, lead, copper and zinc, all on the federal list of priority pollutants. These metals are known to be harmful to human health, plants and animals, Ecology said.
A 2022 groundwater compliance monitoring report prepared for Ecology showed chemicals in groundwater at the site likely originate from exposed mining tailings along the Methow River. The main tailings pile was approximately 1.5 acres and up to 5 feet deep, according to Ecology.
A detailed site plan is necessary to understand that relation of the proposed construction to existing mine tailings and groundwater monitoring wells, Ecology said. To provide a full picture of potential disturbance of contaminated areas, those plans should identify the ordinary high-water mark and flood zones, as well as building and sewage system plans.
Any workers would need to be informed of hazards associated with the contamination at the site, Ecology said.
Ecology is conducting periodic reviews at the site. The next review, which is currently underway, must be completed before any construction, the agency said.
The Yakama Nation Department of Natural Resources said they have been actively engaged with Ecology since 2013 to encourage additional clean-up and stabilization at the site because toxic tailings harmful to fish are actively eroding into the Methow River. The Yakama Nation is concerned that development at the site will make clean-up there more difficult or impossible.
Consequences of development and future toxic discharges and their impact on the river and fish must be thoroughly analyzed to ensure adequate remediation. The 100-year floodplain needs to be mapped to ensure that contamination isn’t spread during high water, the Yakama Nation said.
Three people supported construction of a house on the site, including neighbors who said they were pleased to see a home proposed because the property has long needed someone onsite to take care of the soil cap and vegetation.
One said that the Schmidts should be allowed to move forward with the project because the house, well and septic system would not be located in the area with the mine tailings. The commenter said that three other lots in the area of the former mill have homes on them.
The Methow Valley Citizens Council (MVCC) expressed concern about the proposal, saying that a full environmental review should be required before considering any ground-disturbing activity at the location.
Although Okanogan County is requiring the proponents to comply with any clean-up action plan issued by Ecology, both MVCC and the Okanogan Highlands Alliance (OHA) said there is no clean-up action plan. A plan must be created and circulated for public comment before any development is allowed, OHA said.
Because of evidence of arsenic, lead, mercury, copper, zinc and cyanide on the property, mitigation and water testing or purification should be required before using water from the well, OHA said.
One commenter who called the parcel “essentially a mining toxic waste disposal site” submitted dozens of pages of documentation to the county, including historical accounts of mining and processing of ore at the site and academic research on the health risks associated with contamination of groundwater by abandoned mines.
Ecology conducted emergency remedial action and other work at the site in the early 2000s. Workers demolished the mill building and removed nearby “hot spots” of contamination. The agency later amended the tailings and revegetated the area. In a 2010 report, metal concentrations in soils were still above cleanup levels, Ecology said.
A 2021 report prepared for Ecology by a geologist and geochemist said that the exposed tailings unit was underwater and in direct contact with the Methow River, which could allow contaminants to flow directly into the river or to enter the groundwater table.
The Okanogan County Planning Department issued a mitigated threshold environmental determination of non-significance that requires soil sampling and compliance with any Ecology clean-up plan. The county said it may add conditions as necessary, based on comments.