By Tony Romeo

HARRISBURG, Pa., (CBS) — Governor Tom Corbett has followed through on his previously stated intention to allow more natural gas drilling below Pennsylvania state parks and forests.

Governor Corbett has issued an executive order that will allow natural gas companies to drill horizontally beneath state parks and forests from wells on adjacent private lands or on previously leased state lands. The governor’s order prohibits such underground drilling when it would result in additional long-term surface disturbance.

But environmental groups pounced on Corbett’s announcement. The Sierra Club released a statement saying despite the governor’s assurances about preventing surface disturbance, additional air, noise and water pollution will be inevitable.

The governor, meanwhile, has said he expects additional leases will generate around $75 million dollars for what is promising to be a difficult state budget.