Advanced Oxidation Plant at the Tucson International Airport Area Groundwater Remediation Project
TW has been operating the TARP remediation wellfields and water treatment plant to remove trichloroethene (TCE) and other volatile organic chemicals (VOCs) from groundwater as part of the Tucson International Airport Area Federal Superfund site remediation since 1994. The treated water is used as a source for Tucson’s potable water distribution system. In 2002, 1,4-dioxane was first detected in TARP groundwater. The process at the TARP water treatment plant was ineffective for 1,4-dioxane removal. TW closely monitored 1,4‑dioxane levels and began blending to reduce concentrations from TARP. Years before revised regulations were published, TW began studying long-term solutions and develop contingency plans for deploying advanced oxidation, the only proven municipal-scale treatment process for this contaminant.
With direction from Tucson’s Mayor and City Council, TW commissioned design and construction of a new Advanced Oxidation Process (AOP) treatment facility adjacent to TARP to treat groundwater from the remediation wells upstream of the existing plant.
Tucson’s AOP facility is the first application of UV AOP technology in Arizona for groundwater remediation producing municipal drinking water and the State’s first drinking water treatment facility targeting 1,4‑dioxane. The facility employs several innovative elements designed to ensure consistent water quality, provides fail-safe automated operation, and minimizes operating costs by optimizing energy and chemical use. It is also the first municipal drinking water UV AOP facility in the U.S. to utilize granular activated carbon (GAC) specifically for excess hydrogen peroxide quenching.