(March 10, 2016, 10:05 AM EST) -- NEW ORLEANS — The federal judge in Louisiana overseeing litigation stemming from the oil spill in the Gulf of Mexico following the explosion of the Deepwater Horizon oil rig on Feb. 16 dismissed a majority of remaining claims against companies that responded to the incident, finding that they were entitled to derivative immunity under the Clean Water Act (CWA) and discretionary function immunity under the Federal Tort Claims Act (FTCA) (In re: Oil Spill by the Oil Rig “Deepwater Horizon” in the Gulf of Mexico, on April 20, 2010, MDL 2179, E.D. La.; 2016 U.S. Dist. LEXIS 18248)....