The Environmental Protection Agency relied on "solely political reasons" to reject a staff recommendation that some oil and gas drilling wastes be more strictly regulated, an agency employee says.

"Politics overrode science and we've never done that before," said Hugh Kaufman, assistant to the EPA's director of the hazardous site control division."This is the first time in the history of environmental regulation of hazardous wastes that the EPA has exempted a powerful industry from regulation for solely political reasons, despite a scientific determination of the hazardousness of the wastes," he said in an interview.

Kaufman, and another staff member who spoke on condition of anonymity, said Sens. Lloyd Bentsen, D-Texas, Phil Gramm, R-Texas, and Don Nickles, R-Okla., pressured the agency, as did the Interior and Energy departments and some states.

EPA administrators deny their call was swayed by political pressure.

The majority of an EPA working group that studied the issue had recommended that a small volume of drilling wastes come under stringent regulation as hazardous.

But EPA Administrator Lee Thomas and J. Winston Porter, EPA's assistant administrator for solid waste and emergency response, said in a June 30 report to Congress they had decided that all oil and gas drilling wastes would remain exempt from hazardous waste rules.