Jeff Swensen for The New York Times

If the Environmental Protection Agency had hoped that the hundreds of landowners, students, community activists, environmentalists, and oil and gas representatives invited to a hotel ballroom in southwestern Pennsylvania on Thursday night would really stay on point, they were surely disappointed.

The aim of the meeting, which drew well over 1,000 attendees, was to solicit advice from stakeholders on how E.P.A. should focus and design a study of the impact of hydraulic fracturing on groundwater.

The agency’s regional administrator instructed the crowd at the outset that the meeting was not to become a debate on the merits of the practice, which involves injecting a high-pressure cocktail of water, sand and chemicals deep underground to crack the rock and release natural gas deposits.

Much advice was offered, and E.P.A. scientists and regulators took copious notes. Industry supporters, too, were on hand to urge that science trump emotion in any analysis and to point out that hydraulic fracturing has never been definitively linked to groundwater contamination.

But a vast majority of the more than 100 speakers used their two-minute turns at the microphone to unleash furious recriminations at the gas industry, hydraulic fracturing, and state and federal regulators for negligence in allowing it to continue. One resident called the E.P.A.’s pending analysis the equivalent of studying the flammability of Rome while the city was burning, while others offered a litany of personal experiences with ponds, streams and wells — all contaminated, they believe, by nearby natural gas fracking fluids.

“Corporations have no conscience,” said Dencil Backus, a resident of Mount Pleasant Township in Pennsylvania. “E.P.A. must give them that conscience.”

Hydraulic fracturing has been practiced in Pennsylvania and around the country for decades. The gas industry insists that no clear evidence has ever surfaced linking the fluids they use to crack open gas deposits to contamination of drinking water or any other systemic environmental problems.

The E.P.A.’s study — which is just getting started and is expected to be completed in early 2012 — aims to explore the connection further.

Pennsylvania is among several Northeastern states where the natural gas industry is priming for a boom. An industry-sponsored and financed study released this week suggested that the gas play known as the Marcellus Shale could generate some $6 billion in government revenue and create up to 280,000 jobs.

But with oil still washing up on the shores of the Gulf of Mexico, many residents were witheringly skeptical of drillers in general. “If you believe the industry line, it’s all coincidental and it’s not their fault,” Mel Packer, a member of Pennsylvania’s Green Party and a congressional hopeful, said of the dozens of personal stories from landowners complaining of water contamination from nearby gas wells. “I recognize a scam when I hear one.”

Whether the opprobrium is justified or misplaced remains a matter of debate, particularly among those seeking to nudge the nation toward cleaner sources of energy. Many experts consider natural gas, which burns more cleanly than coal or oil, to be a crucial bridging fuel in that process.

“Natural gas has played and will continue to play an important role in our energy portfolio as we transition to a new energy future, and we are fortunate to have domestic resources to help meet our growing needs,” Senator Bob Casey, a Pennsylvania Democrat, said in a prepared statement delivered to the assembly. “But I believe it is important to protect the health and safety of Pennsylvanians as we further develop the Marcellus Shale.”