Unsatisfied with responses from the Wyoming Department of Environmental Quality and local operator EnCana Oil & Gas USA, several Pavillion-area residents convinced the EPA to conduct its own investigation of possible drinking water contamination beginning in 2009. A second round of water sampling was conducted in January, and the EPA asked the Agency for Toxic Substances and Disease Registry to provide a health risk analysis based on the sampling.

Those results were revealed for the first time this week.

"In spite of the fact we may or may not know about the source of this contamination ... the citizens of this community need answers and they need it tonight," said Hestmark.

Findings

The EPA collected samples from 41 locations in January and sent them to four different laboratories that analyzed for more than 300 different constituents. Results suggested that two drinking water wells had compounds above the EPA's primary drinking water standard, one well for lead and phthalate and the other for nitrate.

The agency found petroleum hydrocarbons in at least 17 drinking water wells. But the EPA's primary focus for the no drinking and no cooking recommendation is within an area that includes more than 20 drinking water wells.