Emergency crews are on scene at Bella Lago apartment complex, 1600 Airport Road, after officials said they found up to eight ounces of mercury in a unit from which the tenants had been evicted.
Federal, state and local environmental agencies are on scene. Tenants in the19 units surrounding the contaminated apartment were being evacuated.
The name of the tenants in the contaminated apartment have not been released.
Mercury is toxic, and high-level exposure can damage the brain, heart, kidneys and lungs.
Twenty-two people were evacuated from the surrounding apartments. They will be put up in a hotel by the property owner, Red Cross and Salvation Army, said Sheriff's Chief Deputy Ray Saylo.