HARRISBURG — Local governments in Pennsylvania are pre-empted by state law from regulating the location of natural gas and oil wells, even if they are in residential developments, the Commonwealth Court ruled Friday.

Overturning the Allegheny County Common Pleas Court, a seven-judge panel of the appellate court said the Legislature eliminated municipalities' authority to restrict well placement when it amended the state Oil and Gas Act in 1992.

The court sent the case back to Allegheny County and directed the Oakmont Borough Council to grant the conditional use permits sought by Huntley & Huntley Inc., an oil and gas exploration company seeking to drill in a residential subdivision.

A lawyer whose firm serves as Oakmont's solicitor said the ruling leaves local governments virtually powerless to control the growing number of gas and oil wells that are being drilled in many parts of Pennsylvania.

Conversely, municipalities are permitted to use their zoning authority to guide the locations of other environmentally sensitive uses, such as landfills and quarries, said the lawyer, Clifford Levine.

The ruling affects virtually every municipality in the state, said Levine, who specializes in land-use cases for the Pittsburgh law firm Thorp Reed & Armstrong.