This week's meeting in Cranberry Township over issues surrounding the extraction of natural gas from the mile-deep Marcellus Shale formation revealed the conflicting interests of gas producers and environmentalists.

And while it's unlikely there will ever be a blissful marriage between gas drillers and environmentalists, recent developments suggest that solutions will be found to allow natural gas to be extracted from Marcellus Shale without causing harm to the environment.

The potential impact of natural gas from the Marcellus Shale formation is hard to overstate. Experts say it could fuel a major energy boom, creating thousands of jobs in Pennsylvania. It could even help reduce the nation's reliance on foreign sources of energy if more vehicles on the road are fueled with natural gas or by electricity generated by gas-fired power plants.

Geologists believe that the Marcellus Shale vein holds 500 trillion cubic feet of gas, enough to supply domestic needs for 20 years or more. And with a variety of forces moving the United States toward sources of energy that are renewable or environmentally friendlier than oil and coal, cleaner-burning natural gas is poised for a period of renewed attention.

Reinforcing the likelihood that natural gas will play a major role in the U.S. energy landscape in the coming years, Exxon Mobil Corp. paid $31 billion early this week to purchase XTO Energy Inc., a big player in Marcellus Shale development.

Advanced drilling techniques have made possible the extraction of natural gas trapped in deep shale like the Marcellus. Drillers have made technological advances in recent years that allow them to drill more than a mile down, and then horizontally. Releasing the gas from the shale also requires using a technology called hydraulic fracturing, which involves pumping up to two million gallons of chemically-enhanced water into the layered rock to facture or "frac" it to let the gas escape.

The problem for environmentalists is that when the frac water returns to the surface it is contaminated with salts, chemicals and some solids. If not treated, it causes harm to waterways, as was discovered in the Monongahela River this summer. Conventional water treatment plants are not set up to remove the chemicals in frac water.

The meeting in Cranberry was the first of four public meetings scheduled across the state to discuss issues with officials from the state Department of Environmental Protection as well as gas producers, land owners and environmentalists. Environmental issues will be front-and-center at the meetings because DEP will have tougher regulations regarding frac water treatment going into effect Jan. 1, 2011.

Not surprisingly, gas producers at the meeting felt the new rules were unnecessarily tough, costly and were being implemented too quickly. Environmentalists, on the other hand, felt the new rules were long overdue and maybe not tough enough given the potential risks.

The opposing viewpoints look like a classic standoff. And because the Marcellus Shale is such a rich vein of natural gas with the potential to bring great economic benefits to Pennsylvania, the stakes are high if overly tough environmental regulations deter gas drillers or scare them off to other states.

Recent developments, however, suggest solutions will be found to satisfy both gas producers and environmentalists.

Already, there are advances in water treatment systems that offer hope.

A New Mexico-based company has installed a portable water treatment system at a Marcellus well near Eau Claire that uses technology similar to that found in water desalination plants to clean up frac water. The company, which has patented the process, says it will economically remove harmful solids and produce water that is cleaner than municipal drinking water.

Another creative idea involves the DEP as a partner in a project in which acid mine drainage water is treated and then used as frac water, thus eliminating the need to take water from clean water sources such as rivers, streams or lakes.

Exxon Mobil's big investment in XTO Energy's Marcellus Shale holdings and other hard-to-reach natural gas deposits reaffirms that natural gas will be a major player in the energy makeup in the United States for years to come.

And surprisingly, some environmentalists are encouraged by Exxon Mobil's move into Marcellus Shale, noting that the energy giant has the technological and financial resources necessary to develop water treatment systems that ensure the environment is protected in areas where natural gas is extracted through the use of frac water techniques.

The Marcellus Shale story will continue to develop, but it's encouraging to see early progress on solutions to environmental concerns.