By Kevin BegosPITTSBURGH -- A top official with the U.S. Environmental Protection Agency is optimistic that a nationwide project examining natural gas hydraulic fracturing and potential drinking water impacts will provide comprehensive guidelines to help scientists and the public identify the key issues to focus on. But the industry said past studies have already shown the process is safe.Glenn Paulson, the EPA's science advisor, said Friday that a progress report on the study -- mandated by Congress in 2010 -- should be released before the end of the year, and a final report in 2014. He spoke at a University of Pittsburgh conference on health impacts of hydraulic fracturing, or fracking.Paulson said the study of fracking and drinking water "is one of the most aggressive public outreach programs in EPA history." He said the progress report will show the "range and depth" of what EPA is looking at, and will be open to public comment."It will really be a lot for experts to chew on in their particular fields," Paulson said, noting that EPA is reaching out to geologists, academic experts, the industry, environmental groups, and even Indian tribes."I think the drinking water study is going to be useful to local governments, and state governments, too," Paulson said. He added that "a lot of people have their minds made up" about fracking, even though many aspects of research are still in the early stages.Paulson said the Obama administration is providing enough support to study the issue. The EPA says in the project overview that natural gas "plays a key role in our nation's clean energy future" but that serious concerns have been raised about potential impacts to the environment and human health.The fracking process has made it possible to tap into deep reserves of oil and gas. Large volumes of water, along with sand and hazardous chemicals, are injected underground to break rock apart and free the oil and gas. Contaminated wastewater from the process can leak from faulty well casings into aquifers, but it's often difficult to trace underground sources of pollution. Some studies also have shown air quality problems around gas wells, while others have indicated no problems.Dan Alfaro, a spokesman for Energy in Depth, an industry group, said it believes the EPA study will show that gas drilling and fracking are safe."There have been numerous studies and a multitude of research on oil and natural gas extraction methods," Alfaro said. The EPA study "will confirm once again previous findings that current industry practices used in development are safe, responsible and effective means of extracting and producing our natural energy resources."Environmental groups and some scientists say there hasn't been enough research on fracking. The industry and many federal and state officials say the practice is safe when done properly, and many rules on air pollution and disclosure of the chemicals used in fracking are being strengthened.Bernard Goldstein, an emeritus professor at the University of Pittsburgh School of Public Health, said that when the conference began three years ago researchers had very little actual data to present. Now, more and more hard data on air and water quality measurements is being collected and shared at the conference. He also praised Shell Oil Co., which explained the steps its takes to protect the environment and public health."I thought the industry presentation by Shell was superb," Goldstein said, adding that Paulson, of the EPA, is "the right kind of person" to make sure that health is included in the research being done on gas drilling.In Pennsylvania, the EPA study is focusing on water quality and quantity issues in Washington, Bradford and Susquehanna counties. There are also study sites in North Dakota, Texas, and Colorado.