Not even a month after being confirmed in office, New York State's top environmental official raised the possibility that his agency may not issue permits for the controversial natural gas extraction technique known as hydraulic fracturing, or fracking.

Commissioner Joe Martens of the Department of Environmental Conservation said his agency is reviewing a host of environmental and public health concerns connecting with fracking. Many environmentalists believe fracking could contaminate water supplies.

"If we're not satisfied that we can address all those issues, then permitting may not go forward," Martens said. "But the converse is also true."

Martens said he expects his most important legacy as commissioner will be in shaping the state's approach to fracking. While most states have taken a frack-now, study-later approach, Albany has effectively put the brakes on fracking while regulators consider how — and if — it can be done safely.

In the meantime, Martens said, he has begun meeting twice a week with scientists and division heads as his agency works on a draft environmental review of fracking, due out at the end of this summer.

It is the agency's second draft review of fracking, and Martens hinted it will be different from the first one, which was completed in 2009.

Environmentalists criticized that draft for examining the impact of well development on on a case-by-case basis, rather than looking more broadly at so-called "cumulative impacts" of potentially dense development of gas wells.

"There are aspects of hydrofracking that the cumulative impacts will be looked at," Martens said. "We're trying to figure out how to do that. And if it can be done. I think there's a difference of opinion about whether it's even possible to assess the cumulative impacts not knowing how many permit applications we're gonna get or where they're gonna be."

Martens shared those thoughts with WNYC on the sidelines of a conference on the 40th anniversary of the creation of the Environmental Protection Agency.

(Listen to hear Martens' entire conversation on fracking with WNYC's Ilya Marritz)

Judith Enck, regional administrator of the EPA Region 2 — which includes New York and New Jersey — also attended the conference, and said fracking is one of the most important issues her organization faces.

Recent reporting in the New York Times suggested politics caused the EPA to dilute its official comments on New York's earlier draft environmental review of fracking. An earlier, internal version of the EPA's comments called for a moratorium on drilling near New York City's upstate reservoirs, but the final comments submitted by the EPA stopped short of calling for a ban.

Enck said this was not an instance of self-censorship.

"I was at EPA Region 2 when we were preparing our comments, and there was a debate on whether or not to call for a moratorium on hydrofracking in the New York City watershed," Enck said. "And there was a difference of opinion. Some people did, some people didn't."

In the end, the agency pushed for strong water protections across the state, but no ban, and Enck said she is proud of the comments.

"I didn't feel that we were discouraged," she said. "I think the public would be happy to know lots of internal discussion and analysis goes on, and I think the EPA comments on the state document really went a long way in focusing public attention on the real need to look at water impacts on hydrofracking."

The EPA has also embarked on its own study of fracking.

(Listen to hear Enck's full response on the question of self-censorship)