Not later than 180 days after August 8, 2005, in addition to any other regulations that may provide royalty incentives for natural gas produced from deep wells on oil and gas leases issued pursuant to the Outer Continental Shelf Lands Act (
43 U.S.C.
1331 et seq.), the Secretary shall issue regulations granting royalty relief suspension volumes with respect to production of natural gas from deep wells on leases issued in waters more than 200 meters but less than 400 meters deep located in the Gulf of Mexico wholly west of 87 degrees, 30 minutes west longitude. The suspension volumes for deep wells within 200 to 400 meters of water depth shall be calculated using the same methodology used to calculate the suspension volumes for deep wells in the shallower waters of the Gulf of Mexico, and in no case shall the suspension volumes for deep wells within 200 to 400 meters of water depth be lower than those for deep wells in shallower waters. Regulations issued under this subsection shall be retroactive to the date that the notice of proposed rulemaking is published in the Federal Register.