Loads of soil contaminated with mercury have been excavated from a neighborhood right in the armpit of I-84 and the Connector, but as of press time the source of the mercury had not been determined.
The mercury was discovered on July 24 after two neighborhood children, who had been playing with several pellets, showed signs of mercury poisoning. As of Tuesday, seven children had been tested and cleared of mercury poisoning, according to Michael Sibley II, the Environmental Protection Agency's on-scene coordinator.
Six dump-truck loads of contaminated soil had been removed from the front of an abandoned townhouse and an inhabited duplex on S. Whitecloud Drive in Boise, Sibley said, and some of the sidewalk and driveway may need to be removed.
Sibley and investigators are talking to former residents of the houses in an effort to determine where the mercury came from.
"This is a lot of mercury to have in your home," he said.
Mercury is used in mining and also in electronics repair, dental products and jewelry making, but it must be handled correctly and disposed of at a hazardous materials facility.
The spill on Whitecloud is contained to about one third of an acre, but EPA officials are finding they need to dig deeper than they expected.
"We've pretty much got it delineated where the contamination is," Sibley said. "The problem is once we start digging, we have to go down deeper."
That indicates that the spill has been present for some time, though Sibley is not sure how long.
Some of the mercury had also been tracked inside one of the homes, and two families have been relocated and some of their furniture destroyed.
"We're finding more and more contamination as we get into this," Sibley said, "but that was to be expected. I think we have a handle on it right now. It's just finding who brought it in, how long it's been here, and who may still have it and not be aware of the dangers that we're concerned about."
For more information on the mercury spill visit the EPA's On-Scene Coordinator.