Plans to open the Delaware River basin to natural gas drilling were set back on Friday when an interstate regulator announced the last-minute postponement of a meeting that was scheduled to vote on a draft policy that would allow thousands of gas wells into the densely populated region.

The Delaware River Basin Commission, which is charged with ensuring water quality in the watershed between Pennsylvania, New York, New Jersey and Delaware, said it was postponing the meeting scheduled for Monday, November 21 to allow “additional time for review” by the five commission members. Read an EPA hydraulic fracturing water quality study here.

The DRBC’s action follows a statement Thursday by Delaware Governor Jack Markell, one of four governors who set the panel’s policy, saying he would vote against the draft regulations because they “lack critical details on how public health and safety would be protected.”

Postponement of the meeting may reflect doubts among the DRBC that it would have enough votes to approve the policy now that Governor Markell, a Democrat, has shown his hand, critics say.

Markell’s ‘No’ vote could ally him with Democratic New York Governor Andrew Cuomo against the expected approval of Pennsylvania’s Republican Governor Tom Corbett, a staunch supporter of the booming gas industry in his state, and New Jersey Governor Chris Christie, also a Republican, who earlier this year vetoed a bill that would have permanently banned the controversial gas-extraction technique of hydraulic fracturing, or “fracking.”

Over To The Engineers

If the governors were split 2-2, that would leave the swing vote in the hands of the fifth member, the US Army Corps of Engineers, representing the federal government, which would be uneasy with taking the decision on a hotly contested public issue at a time when federal scientists are still investigating whether fracking contaminates drinking water.

“The administration would not want to be the swing vote,” said Tracy Carluccio, deputy director of Delaware Riverkeeper Network, an environmental group that helped to collect almost 70,000 public comments on the DRBC’s drilling plan.

Opponents said the postponement indicates the DRBC is paying attention to public concern about whether the natural gas industry endangers public water supplies.

“This is an important decision but we don’t know how permanent it is,” Carluccio said. “We live to fight another day.”

Kathryn Klaber, president of the Marcellus Shale Coalition, a Pennsylvania-based industry group, said she hopes the DRBC overcomes the delay in its policymaking.

“We remain hopeful that the DRBC will move forward with common sense regulations aimed at responsibly developing clean-burning, job-creating American natural gas in the region,” Klaber said in a statement.

“Blanket calls by some groups, based not on facts and science but rather on hyperbole, to halt this safe development are misguided and will do nothing to create jobs or make America more energy secure.”

Environmentalists say the DRBC’s plan would expose the water supply for 15 million residents of the four commission states to toxic chemicals such as benzene and toluene that are used in or produced by fracking. The technique pumps millions of gallons of water, together with sand and chemicals at high pressure about a mile underground where it breaks open gas-bearing fissures in the shale.

The opponents say the commission should undertake a cumulative impact analysis of gas drilling on the basin before allowing the industry to sink wells into the gas-rich Marcellus Shale that underlies it.

Markell released a letter to DRBC staff saying shale gas is an important national energy source but that more work needs to be done to finalize regulations at state and federal level before any approval is given.

“Once hydrofracturing begins in the basin, the proverbial ‘faucet’ cannot be turned off, with any damage to our freshwater supplies likely requiring generations of effort to clean up,” Markell wrote. “In this case, it is more important to get it right than to be fast.”

Photo Caption: A barrel floats down the Delaware River after flood waters crest from Tropical Storm Irene August 29, 2011 in Lambertville, New Jersey.