Advanced Oxidation Process (AOP) Technology Effective in Removing TCE and 1,4-Dioxane from Drinking Water


Tucson Water’s investments in technology to ensure water quality and long-term water reliability have included steps to treat contaminated groundwater at the Tucson International Airport Area Superfund Site.

Trichloroethylene (TCE) was an industrial solvent used in aircraft manufacturing facilities from the 1940s to the 1970s. 1,4-dioxane was a stabilizing agent and was discovered in 2002. Both were detected in groundwater at the Tucson Airport Remediation Project (TARP) well field.


The TARP treatment facility began removing TCE in 1994. Once 1,4-dioxane was also detected at the site, the utility began blending the contaminated water with potable water from another source to lower the 1,4-dioxane levels to below the established Drinking Water Health Advisory. Tucson’s Mayor and Council then directed the utility to build the Advanced Oxidation Process (AOP) Water Treatment Facility, which began operation in January 2014.

AOP technology combines ultraviolet light with hydrogen peroxide to remove not only 1,4-dioxane from the underground plume at the TARP wellfield, but also removes the TCE. This will allow the original treatment facility to be shut down once approved by the EPA.

Together, TARP and AOP treat nearly seven million gallons of water per day which is delivered to approximately 60,000 customers for drinking water.

For more than 20 years, the Unified Community Advisory Board (UCAB) exiting Tucson Water website, the City of Tucson, and other stakeholders have been working closely together to resolve any issues related to the cleanup process at the Tucson International Airport Area Superfund Site exiting Tucson Water website. This group’s participation has made a positive difference in environmental and clean-up efforts.