WICHITA, Kan. (AP) — Concerned Wichita residents are getting few answers about the extent and impact of groundwater contamination caused by dry-cleaning solvents decades ago.

The Wichita Eagle reports that environmental regulators told a few hundred people at a community meeting this week that until well testing is complete it’s unclear how many people will have to stop using their well water.

Bob Jurgens is chief of the Kansas Department of Health and Environment’s Dry Cleaning Remediation Program. He said tetrachloroethylene contamination was first discovered in a monitoring well in late 2009. Funding for testing private wells wasn’t available until this year.

The chemical is a colorless organic liquid believed to be carcinogenic.

Investigators have already found dozens of wells that contain concentrations above allowable limits for drinking water. Testing began weeks ago.