The U.S. Environmental Protection Agency has officially removed two Vancouver water stations from a federal list of hazardous waste sites in need of cleanup.
4 Superfund sites were deleted from the National Priorities List after it was determined that no further purification work was necessary.
Although the city’s drinking water meets all federal standards, the city of Vancouver will leave the cleanup equipment in place to continue to reap their benefits.
After the discovery, the city immediately modified pumping rates to protect public health, then, in 1992 and 1993, added several air-stripping towers to remove the chemical from the drinking water supply.
Tetrachloroethylene is a synthetic chemical widely used as a metal degreaser and dry cleaning agent, and is also believed to increase the risks of cancer, harm the nervous and reproductive systems as well damage the liver and kidneys.
In 1992, the EPA set a maximum contaminant level for the chemical, a legal drinking water standard, at 5 parts per billion.
The two sites were then added to the National Priorities List in 1992 and 1994 and the city continued to clean up and monitor the contamination.
The air-stripping treatment towers removed the PCE from the drinking water while also removing it from the untreated groundwater.
“We continue to treat it to what they’d call non-detectable standards in the drinking water, and the untreated groundwater is below the (drinking water maximum contamination level) of 5 parts per billion,” said Tyler Clary, water engineering program manager for the city of Vancouver Public Works.
The city initiated talks with the EPA to have the two sites removed from the National Priorities List.