New Jersey Governor Chris Christie imposed a one-year moratorium on hydraulic fracturing for natural gas in the state, pending more research into its safety.

At the same time on Thursday he vetoed a bill that would permanently ban the practice.

New Jersey joins New York as the only two U.S. states to place at least a temporary ban on “fracking” which critics say contaminates ground water with toxic chemicals but which is defended by the gas industry as safe.

“I am placing a one-year moratorium on fracking so that the DEP (state Department of Environmental Protection) can further evaluate the potential environmental impacts of this practice in New Jersey as well as evaluate the findings of still-outstanding and ongoing federal studies,” Christie said in a statement.

Fracking, which forces millions of gallons of water mixed with sand and chemicals deep underground to open gas-bearing fissures in shale, has helped to exploit vast US reserves of cleaner-burning shale gas which has the potential to cut domestic dependence on imported oil while reducing greenhouse gas emissions.

But opponents say the chemicals used can cause cancer and other serious illnesses. They cite numerous individual reports of sickness among people living near gas wells, and argue the process should be stopped until scientific inquiries determine whether it is safe.

The industry insists there have been no proven cases of water contamination from fracking, and says the chemicals are released thousands of feet below drinking-water sources.

Preemptive Policy

Christie said there are no current proposals for shale-gas development in New Jersey. But Jeff Tittel, executive director of the state’s Sierra Club, said there is the potential for fracking in the northwestern part of the state bordering Pennsylvania, where thousands of wells have been drilled in the gas-rich Marcellus Shale since 2008.

“The governor has sold out clean water in New Jersey with his vetoing of the fracking ban bill,” Tittel said in a statement.

The Marcellus Shale Coalition, a Pennsylvania-based industry group, said it was “deeply disappointed” by the moratorium which it said could reverberate beyond New Jersey’s borders.

“This policy send the wrong message to an entire nation benefiting from the responsible production of clean-burning, American natural gas,” said the group’s president, Kathryn Klaber, in a statement.

Christie’s policy runs counter to his promotion of natural gas as part of the state’s energy mix, Klaber said.

Christie noted that state officials have not fully evaluated the prospect of fracking in New Jersey, and that the US Environmental Protection Agency and the Department of Energy are still working on their own studies of the process.

But Democratic Assemblywoman Connie Wagner, a cosponsor of the bill, said the ban may expire before the studies are complete. “This is not a compromise,” she said.

Energy in Depth, which represents the oil and gas industry, said Christie’s move makes no sense in light of growing demand for natural gas.

“It’s unfortunate and ill-advised that Gov. Christie would seek to ban the regulated use of hydraulic fracturing for any period of time, a technology that has been used safely for generations,” said EID executive director Lee Fuller, in a statement.

Where Policy Meets Science

The Republican governor said he “shares many of the concerns” expressed by lawmakers who sponsored the bill and by environmentalists who seek to ban fracking permanently.

“The decision on whether to ban fracking outright or regulate it for environmental protection must be developed on the basis of sound policy and legitimate science,” Christie said.

Temporary bans on fracking also exist in New York State and in the Delaware River basin, where an interstate regulator is deciding whether to lift a moratorium.

Christie has also taken steps to ban the use of coal-fired power generation in New Jersey, read more here. He also has taken steps to remove the state from the Regional Greenhouse Gas Initiative carbon dioxide emissions trading program; Breaking Energy covered that program’s difficulties in depth here.