“In a letter to the EPA Assistant Administrator for Water, Chairman Waxman discloses that documents the Committee has received raise new questions about whether EPA is effectively monitoring a 2003 Memorandum of Agreement intended to eliminate the injection of diesel fuel into underground sources of drinking water. The oil and gas industry has had a practice of injecting diesel fuel into underground sources of drinking water in order to fracture wells and make them more productive. Chairman Waxman also wrote to Halliburton, Schlumberger, BJ Services, and the Encana Corporation to request information about what chemicals are currently being injected into underground sources of drinking water.”