A Comparison of the Sustainability of Air Stripping Treatment to Ozone-Peroxide Advanced Oxidation Treatment at a Large Scale Ground Water Treatment Plant

The United States Air Force contracted Earth Tech, Inc. (now AECOM Environment) to install an ozone-peroxide advanced oxidation treatment system within an existing 5,000 gallon per minute (7 million gallons per day) design capacity Groundwater Treatment Plant located at Air Force Plant 44 in Tucson, Arizona.  The existing treatment plant uses three trains of two stripping towers (six towers total) to treat trichloroethene and associated chlorinated solvents before recharging the treated water into the regional aquifer.  The existing ground water treatment plant does not treat 1,4 dioxane because it is not amenable to the air stripping process.  The new advanced oxidation treatment system treats all contaminants of concern and replaces the 20-year old air stripper system.

Advanced oxidation using ozone and peroxide, the HiPOX^tm process, was selected based on a 2004 technology evaluation by Earth Tech because it could treat all known contaminants with favorable economics.  Installation was planned for 2009, but was expedited in response to an Environmental Protection Agency Region 9 Safe Drinking Water Act Administrative Order issued 13 July 2007.  Installation is now complete and the new system is operational.

This presentation will explore sustainability issues related to the plant upgrade including re-use of existing materials and equipment, electrical and chemical consumption, waste generation and disposal, evaporative water loss, air emissions, life-cycle cost, and the estimated carbon dioxide footprints of these two systems.  Results will show that this relatively new treatment process can be a cost effective and more sustainable method of treating contaminated groundwater than traditional air stripping methods.