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.
The agency announced Tuesday that the Vancouver Water Stations No. 1 and No. 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.
“The City of Vancouver stepped up, addressed the contamination at these two sites and made these deletions possible,” EPA Administrator Scott Pruitt said in a news release.
The sites are just two of many well fields owned and operated by the city to supply groundwater to its nearly 250,000 residents. In 1988, city workers doing routine monitoring discovered tetrachloroethylene, or PCE, in water at the two water stations. 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. However, the chemical was still found in the groundwater.
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.
Although the cleanup is now finished, Public Works said it plans to leave the air-stripping towers in place because they raise the water pH to a preferable alkaline level.
“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.
“It’s business as usual for us … but we think it’s important because we don’t want it listed as a Superfund site,” Clary said.
The city initiated talks with the EPA to have the two sites removed from the National Priorities List. But a site can only be considered for removal when all cleanup remedies are successfully put in place and the federal and state governments have determined the actions have been effectively completed.
A public comment period on the proposed deletion was held in the fall.
Official notice of removal of the two Vancouver water stations from the National Priorities List was published Tuesday in the Federal Register.
