Although [California] supported dry cleaners in the transition away from PCE [perchloroethylene] through grants to buy new cleaning machines and by offering training on how to safely use other cleaning solvents or do wet cleaning with detergents, many cleaners feel they’ve been left out to dry when it comes to cleaning up the pollution often found under their businesses and neighbor’s water supplies. .. A PCE cleanup typically costs about $1 million to more than $10 million. The high costs come from the extensive mapping of groundwater and soil samples required to determine the extent of a PCE plume — which can flow for several miles in groundwater under cities — and the regular monitoring of how effective the remediation efforts are.