A hearing by state lawmakers Tuesday on problems in California's protection of drinking-water aquifers from the state oil and gas industry also is slated to focus attention on the way oil companies in the state use high-pressure steam to force up petroleum. State oil and gas regulators have acknowledged “routinely” allowing oil and gas producers to inject steam underground at pressure so high that it cracks open underground rock formations, in violation of state and federal regulation, according to a state Senate report prepared for Tuesday's joint hearing by the Senate's environmental quality and natural resources and water committees.