A spokeswoman for the Nevada Division of Environmental Protection said Friday that crews have removed 18 to 20 pounds of elemental mercury from an Airport Road apartment at Bella Lago Village.
"It's very concerning that that much mercury was located in the apartment without knowing what it was being used for," said Jill Lufrano.
Carson City investigators are interviewing previous tenants in an effort to determine how the mercury got there and how long it had been there.
There is no law against possession of the powerful neurotoxin that can cause a number of serious health problems including death.
On Tuesday, maintenance crews were replacing the carpeting in the vacant apartment when they began to notice beads of silver mercury, officials said.
A vapor sensor indicated the level of mercury vapor in that unit was 40 times greater than what's considered safe, and the vapor readings in the surrounding 19 units were also above safe levels. The Carson City Health Department deemed the building uninhabitable and the 22 residents were evacuated.
Carson City Fire Chief Stacey Giomi said Friday that although the elemental mercury was removed and hard surfaces cleaned, sensors are still registering high levels of vapor. Crews have now pulled out the flooring, removed the cabinets and taken out some studs from non-weight-bearing walls in the unit.
"It's down to bare concrete so they are working with absorbent materials to prevent the continued vaporization," he said.
In the meantime, tenants remain in area hotels paid for by the property owner, said Giomi.