The Marcellus Shale, which according to some geologists is the world's second-largest natural-gas field, holds the potential to create hundreds of thousands of new jobs for Pennsylvanians - while reducing our dangerous dependence on foreign energy resources.

We've known about the Marcellus Shale for years. But advances - specifically, horizontal drilling techniques coupled with a 60-year-old technology called hydraulic fracturing, in which fluid is forced underground - have finally enabled us to reach its enormous stores of clean-burning fuel.

While Marcellus Shale production in Pennsylvania is still in its infancy, the results so far have been very good. According to Penn State, shale gas exploration in this state has already created 48,000 jobs, along with billions of dollars in economic output and millions of dollars in state and local government revenue. Over the next 10 years, shale gas production is expected to create more than 200,000 jobs directly and indirectly, as well as $13 billion in economic activity.

And every cubic foot of natural gas produced here in the Keystone State represents one less cubic foot that America is forced to import from gas giants such as Russia and Iran. That's good news, right?

Unfortunately, not everyone sees it that way. Last month, Philadelphia's City Council unanimously adopted a resolution calling for a de facto moratorium on shale-gas development on privately owned land throughout the eastern sixth of the state.

The resolution says that the fluids used in the fracturing process, which are more than 99.5 percent water and sand, "are currently not required by law" to be disclosed, and that fracturing has caused "private well contamination." One councilwoman said that gas development "should not occur without an environmental impact statement."

Here are the facts: Hydraulic fracturing, which has been safely employed more than 1.1 million times in America, and is used today in 9 out of 10 wells nationwide, has never been found to contaminate groundwater - not once in 60 years. The Environmental Protection Agency's top water official confirmed this just weeks ago. And the state Department of Environmental Protection has found that hydraulic fracturing "has not impacted local wells" and "is not a threat to water supplies."

As for disclosure, federal law mandates that the fluids used in the fracturing process be identified and available at every well site. The DEP even lists the fracturing fluid's composition on its Web site.

The states have always been the most effective energy regulators. And to help ensure Pennsylvania's environment is protected, Gov. Rendell recently assigned an additional 68 state regulators to monitor Marcellus Shale production.

Unfortunately, by trying to bring the process under EPA oversight, Sen. Bob Casey (D., Pa.) is among those working to strip Pennsylvania and other energy-producing states of their ability to effectively regulate fracturing, which has never been regulated by the federal government.

Council's recent endorsement of such misguided efforts is unfortunate. Higher taxes and layers of unnecessary, duplicative regulations will not produce jobs or environmental benefits for the commonwealth.

Lou D'Amico is president of the Pennsylvania Independent Oil and Gas Association (PIOGA) and an adviser to EnergyInDepth.org. For more information, see www.pioga.org.