Environmentalists called them "pathetically weak," but the Colorado Oil and Gas Conservation Commission on Wednesday nonetheless gave its preliminary OK to new rules putting at least 500 feet of space between homes and oil and gas drilling operations.

The oil and gas industry also expressed its dissatisfaction.

Under the new rules:

• Existing setback, or buffer, standards of 150 feet in rural areas and 350 feet in urban areas will be extended to a uniform 500 feet statewide.