SITE STATUS
Updated Jan. 22, 2021
Kaiser Mead National Priorities List (NPL) Site Groundwater Cleanup
In 2020, we completed construction of a groundwater extraction and treatment system to address contamination left behind by smelter operations.
The "pump and treat" system:
- Extracts contaminated groundwater.
- Uses biological and physical treatment to remove cyanide and fluoride.
- Returns the treated water to the aquifer.
The new system is in start-up testing and will be in full time operation by the end of the March 2021.
There were other environmental problems on the rest of the former smelter site now owned by Spokane Recycling, LLC. In 2020, the United States Environmental Protection Agency (EPA) conducted an emergency action to remove PCB-containing materials and other wastes.
Learn more about the EPA's workClick image to enlarge |
BACKGROUND
The Kaiser Aluminum Company produced aluminum at the Mead site for more than 50 years. The company went through closure and bankruptcy in the early 2000's.
Waste handling practices used from the 1940s to the late 1970s led to cyanide and fluoride contamination in part of the Spokane-Rathdrum Prairie Aquifer and the Little Spokane River. The groundwater plume is 145 feet below ground, 800 – 1500 feet wide, and travels approximately 2.5 miles to the Little Spokane River. It then discharges into a series of springs.
This part of the former smelter is known as the Kaiser Mead NPL site and cleanup of the groundwater contamination is being done under a Consent Decree finalized in 2004.
When groundwater contamination was discovered, a series of actions were taken to address the problem.
- In the late 1970s, Kaiser changed its waste handling practices and provided alternate water supplies for property owners whose wells were contaminated. The county put restrictions on new wells in the area.
- Wastes remaining on site were covered with an asphalt cap to keep rain and snow from leaching more contamination into groundwater.
- A series of investigations were conducted to understand the extent of contamination and evaluate the potential options to clean it up.
While these actions helped us understand the problem and control the risk posed by the site, monitoring showed that groundwater contamination persisted. In 2019, we finalized the plan to help clean-up groundwater contamination by installing the groundwater extraction and treatment system.
