New York formalized its ban on high-volume hydraulic fracturing for natural gas on Monday, concluding a seven-year environmental and health review that drew a record number of public comments.

“After years of exhaustive research and examination of the science and facts, prohibiting high-volume hydraulic fracturing is the only reasonable alternative,” Department of Environmental Conservation Commissioner Joe Martens said in announcing the decision. “High-volume hydraulic fracturing poses significant adverse impacts to land, air, water, natural resources and potential significant public health impacts that cannot be adequately mitigated.”

In its decision, the DEC noted that more than 260,000 public comments were submitted on its environmental impact study and proposed regulations, an unprecedented number. The agency said most of the comments urged it to severely restrict or prohibit fracking.

New York is the only state with significant natural gas resources to ban fracking, which has allowed other states to tap huge volumes of gas trapped in shale formations deep underground. The technology has produced new jobs, created economic growth and reduced energy prices but has triggered concern that it could pollute air and water, cause earthquakes and pose long-term health effects that aren’t yet known.

While environmental groups praised the ban, drilling proponents have said the decision was based on politics rather than on science.

“Hydraulic fracturing is a proven, 60-plus-year-old process that has been done safely in over 1 million American wells,” said Karen Moreau, executive director of the New York branch of the American Petroleum Institute. “Surging production of natural gas is a major reason U.S. carbon emissions are near 20-year lows.”

Moreau noted an Environmental Protection Agency report earlier this month that found fracking had not caused widespread threat to drinking water, but it warned of potential contamination of water supplies if safeguards aren’t maintained.

“Remaining questions cited by EPA have all been addressed by a wide array of strong state regulations, industry standards, and federal laws,” Moreau said.

Moreau said industry lawyers will review the state’s decision and decide whether to mount a legal challenge.