From the hard-hitting investigative team at ProPublica comes an important story today about drinking water in Wyoming that’s been contaminated by chemicals commonly used in the gas drilling process of hydraulic fracturing.

Responding to concerns from residents, scientists at the Environmental Protection Agency sampled 39 wells near the ranching town of Pavillion, Wyo (pop. 160). They found the common gas drilling chemical 2-butoxyethanol in three water wells and found traces of other contaminants in 11 more wells.

Just about the only industrial activity in Pavillion is gas drilling, or, more specifically horizontal hydraulic fracturing—in which drilling companies spike millions of gallons of water with toxic chemicals, then blast the water thousands of feet beneath the ground into horizontally drilled wells, blasting the gas out of the rock pores.

The EPA’s findings could put to rest once and for all a favorite refrain of the gas drilling industry: that hydraulic fracturing is perfectly safe. Arguably that’s an easy claim to make when investigating agencies are hamstrung by a loophole in federal law exempting the drilling industry from the Safe Drinking Water Act. Among other things, the Halliburton loophole—as it’s known—allows the gas industry to keep secret the chemicals they use in drilling. A bill introduced in Congress, the Fracturing Responsibility and Awareness of Chemicals (FRAC) Act, would repeal that exemption. But in the meantime, it’s proving very difficult and expensive for agencies to investigate contamination when they don’t know precisely what chemicals to look for.

The dilemma is summed up by one frustrated Pavillion resident quoted in the ProPublica piece:

How in God’s name can the oil industry dump s**t in our drinking water and not tell us what it is?

Colorful language aside, a good question indeed.