They first had to determine who was responsible for the cleanup and what methods were best to use. Most of the aircraft companies responsible for the problem had ceased operations years earlier. As a result of a consent decree and agreement, the Tucson Airport Authority, U.S. Air Force and others built a treatment plant for the water downgrade from the airport. Nine extraction wells and five miles of transmission mains transport water to the plant. The plant also disinfects the water and adjusts its pH .
Treated water is tested weekly, and no detectable amounts of TCE have been found.
Raytheon, U.S. Air Force, McDonnell Douglas Corp. and the Tucson Airport Authority pay the cost of operating the facility. Routine water testing is generally conducted for common pollutants such as coliform bacteria, nitrogen or sulfur compounds. Where reasons exist to suspect other pollutants such as TCE, tests for those pollutants become part of the testing routine. There are now well over 230 priority pollutants for which water supplies must be tested at least once a year. Standardized testing is unavailable for many uncommon potential pollutants.