By Siobhan Hughes Of DOW JONES NEWSWIRES WASHINGTON (Dow Jones)--U.S. Interior Secretary Ken Salazar will tell lawmakers on Wednesday that he has been working for more than a year on "substantive reforms" of the agency that oversees offshore drilling, defending his efforts as a BP PLC (BP, BP.LN) oil spill in the Gulf of Mexico puts scrutiny on the federal government. "The reforms we have embarked on over the last 16 months, and upon which we will continue to build, are substantive and systematic, not just cosmetic," Salazar will say in the text of prepared remarks. The changes "do not come easily" and have "raised the ire of the industry," but are "crucial" to ensuring "balanced, responsible" energy development. The testimony is his first before the U.S. Senate Appropriations Committee since the April 20 explosion of the Deepwater Horizon rig. BP was leasing the rig from Transocean Ltd. (RIG) to explore for oil by drilling a well into the floor of the Gulf of Mexico, a mile below the sea. The panel, which oversees funding of the Interior Department, is examining his plans to break up the agency, formerly known as the Minerals Management Service, that oversees offshore drilling, with responsibility split among three divisions. The split is intended to address concerns about conflicts of interest within the agency, which focuses on offshore-drilling safety but also seeks to maximize leasing revenue collected for the federal government. Michael Bromwich, a former Justice Department inspector general, will oversee the reorganization of the agency, which was recently renamed the Bureau of Ocean Energy Management, Regulation, and Enforcement. Bromwich will tell the committee that he plans to establish a unit within the ocean-energy bureau to investigate complaints about agency personnel and the industry, alerting the Interior Department's inspector general of his swat team's own investigations. -By Siobhan Hughes, Dow Jones Newswires; 202-862-6654; [email protected] (END) Dow Jones Newswires June 23, 2010 11:22 ET (15:22 GMT)