The most bountiful Marcellus Shale well in Pennsylvania - a single well in Susquehanna County - produced in nine months enough natural gas to heat 29,600 homes for a full year.

The two most prolific counties for Marcellus Shale production last year were Bradford and Susquehanna, both on the New York border. Together, the counties - where hardly any gas wells existed three years ago - accounted for nearly half of the state's Marcellus production.

Production data such as these, which show the dramatic growth of the natural-gas industry in the last three years, are included in a new website presented Monday by the Pennsylvania Department of Environmental Protection.

Under a new state law, Marcellus gas operators are required to report the production of their individual wells every six months. The data are expected to be useful to environmental activists as well as industry analysts, who can scour the numbers to check on their competitors.

"The public-reporting website will create much-needed transparency that allows for citizens and policy-makers to be aware of the increasing amount of natural gas being generated in Pennsylvania," DEP Secretary John Hanger said.

Actually, the most recent production data, which cover the 12 months ending June 30, were inadvertently released by DEP in raw form in September. The new website, with a searchable interface, makes the data accessible to the public.

Included are current and historical production statistics for oil and gas wells. The website also includes waste-production data.

In addition, a separate web page lets users view violation data, by operator, as well as the DEP's enforcement measures.

"This is an industrial activity that is taking place widely throughout the state," Hanger said. "It's important that families know what is happening in their backyards, and whether or not the company drilling there has a good track record of safe and environmentally sound operations."

The DEP's site is part of a growing outpouring of online information about the Marcellus Shale, a mile-deep formation that lies under more than half of the state.

Pennsylvania State University's Marcellus Center for Outreach and Research recently launched a website that includes an animated map showing the spread of shale-gas drilling since 2007.

Since 2005, 2,300 Marcellus wells have been drilled in the state.

Under Pennsylvania's old law, oil and gas production information remained confidential for five years. Though the state's new reporting requirements provide a more immediate sense of the industry's activity, some other states like Texas post well-production data even more frequently - every 30 days.

Pennsylvania's Marcellus wells produced about 180 billion cubic feet of gas last year. A typical residential customer consumes about 96,000 cubic feet a year.

The well data are very specific. The most productive well was the Clapper 2H well, drilled by a subsidiary of Chesapeake Energy Corp. The Susquehanna County well produced 2.8 billion cubic feet of natural gas in nine months of operation.

The most productive well in Pennsylvania, measured by daily production among those that were producing for more than 30 days, was Cabot Oil & Gas Corp.'s Smith 3H well, also in Susquehanna County.

Over four months, the well produced an average of 11 million cubic feet of gas a day, enough to supply the annual gas demand for 115 homes.

Go to the Pennsylvania DEP's Oil & Gas Reporting website via http://go.philly.com/marcellus4

Go to Penn State's Marcellus Center for Outreach and Research via http://go.philly.com/marcellus5EndText