Members of the public had plenty of opportunity to comment on a hazardous-waste repository near Old Mission State Park, the Environmental Protection Agency’s Office of Inspector General concluded.
But stricter controls may be needed at the repository to keep heavy metals from leaching into the groundwater, according to the inspection report, which was released this week.
The inspector general’s office spent more than $400,000 investigating the East Mission Flats repository after a citizens group raised concerns about storing hazardous waste in the Coeur d’Alene River’s floodplain. The independent office within the EPA is funded by Congress to conduct audits and investigations.
Members of the citizens group, the Silver Valley Community Resource Center, also said they hadn’t received adequate public notice or opportunities to comment on the repository. More than 1,600 people signed petitions protesting its location.
Construction of the 23-acre East Mission Flats repository is scheduled to begin in July. It’s designed to hold more than 400,000 cubic yards of soil contaminated with mining waste from the Bunker Hill Superfund site.
Federal investigators visited the Silver Valley in May and July of 2008. They talked to local residents, as well as officials from EPA and the Idaho Department of Environmental Quality, which are building the repository.
In the report, investigators recapped public-outreach efforts since 2005. The EPA and DEQ held a series of public meetings on the repository, went door to door to talk to residents, and mailed fliers to hundreds of residents, the report said.
In response to public comments, the repository’s height was lowered so the mound of dirt won’t be visible from Old Mission State Park when trees shed their leaves in the fall.
But the inspector general’s report also raised concerns about the potential for heavy metals to seep into the groundwater. Parts of the repository site were flooded last spring when investigators visited. Under the right conditions, metals could leach out of the soil, according to the report, which asked the agencies to provide more information about high-water events.
EPA Project Manager Ed Moreen said the risk of leaching was addressed in later repository designs, which were scrutinized by an independent geochemist.
However, the agencies will work with the Office of Inspector General’s office to make sure those concerns are addressed.
Keeping heavy metals contained at the repository is “something we want to ensure as well,” Moreen said.
Barbara Miller, the Silver Valley Community Resource Center’s president, could not be reached for comment Tuesday.