STATE COLLEGE — A gas exploration company said the drilling and treatment of wells could at times require withdrawing up to four million gallons of water in one day from sources in three central Pennsylvania counties.

A public notice said Texas-based Anadarko Exploration & Production told the Susquehanna River Basin Commission the water from Centre, Clinton and Lycoming county sources would be used to sink wells into the Marcellus Shale gas-bearing layer.

Company spokesmen said it isn't known how often such amounts of water would be needed. The company has about 300,000 acres under lease in the Appalachian region.