The Colorado Senate has passed a package of regulations on oil and gas drilling that increases protections for drinking water, wildlife and natural resources. The rules, which will be signed by Gov. Bill Ritter in the next few days, are the strongest, most comprehensive regulations in the nation.

A key provision—and the most contentious—will require oil and gas companies to disclose to the state the toxic chemicals used in drilling. Hundreds of chemicals, dozens of them harmful to human health, are routinely injected into wells to increase production.

The oil and gas industry argues that the concentration of chemicals is too low to be hazardous, but there are many well-documented incidents of people or livestock made ill by chemicals that leached into water supplies. Recently, residents in one Colorado town in the gas patch have been alarmed by flammable water—contaminated with methane—coming out of their kitchen taps.

The industry threw everything they had at the rules, resorting at the end to scare tactics by claiming the new regs are responsible for the steep decline in the number orf drill rigs operating in the state. But even some of the leading players in the industry admitted that the declining rig count was more due to the shrinking demand for oil and gas in a recession.

Earthjustice’s Rocky Mountain office in Denver represented the Colorado Environmental Coalition through 18 months of rule-makings, and we also did a blitz of radio ads supporting the rules. Earthjustice members in Colorado sent almost 1,500 email messages to their state representatives, urging them to stand up for public health and safety.

Earthjustice attorney Mike Freeman warns that it may not be over yet (the industry is talking about a lawsuit) but for now, this is a big win for Colorado that could have major ripples in other states, where concern is growing about the use of toxic chemicals in drilling.