The Minnesota Pollution Control Agency will hold a public information meeting Monday in Long Prairie after it found high levels of a cancer-causing gas in several buildings near an old dry cleaner.
Cleanup work has been going on for 25 years at the Superfund site on Central Avenue in Long Prairie.
But last summer the MPCA tested basements nearby and found levels of perchloroethylene and other gases related to dry cleaning solvents that exceeded new state guidelines.
Project leader Nile Fellows said a vacuum system designed to draw the gases out of the ground has not worked well because of clay soils.
"We believe that the PERC has been attached to the clay and been releasing over time so it was not all removed in the first use of the soil vapor system," Fellows said.
Crews will install a new vacuum system to remove more of the gases.
The meeting is set for Monday at 7 p.m. at Long Prairie City Hall.