On August 23, the National Ground Water Association (NGWA) named the Arizona Department of Environmental Quality (Arizona DEQ) a recipient of a 2022 Outstanding Groundwater Remediation Project Award. It was presented during the NGWA conference in Dec. The honor recognizes Arizona DEQ for completing an expedited site characterization and remediation of PFAS in groundwater to protect the City of Tucson’s drinking water wellfield, referred to as the Central Tucson PFAS Project (CTPP).
Site characterization, remedy design, permitting, construction, and system startup for the CTPP were achieved within an aggressive timeframe of 18 months despite pandemic-related supply-chain challenges. The demonstration groundwater treatment facility using ion exchange treatment technology was completed in December 2021 with close cooperation from multiple stakeholders. The system, which already has treated more than 30 million gallons of contaminated groundwater, is limiting the movement of PFAS toward Tucson Water’s vital Central Wellfield, while also providing a mechanism to evaluate future PFAS remediation technologies.
ADEQ has provided $5.3 million in funding to the City of Tucson, the state’s second largest metropolitan area, to address PFAS in nearby groundwater.
The initial $3.3 million in ADEQ funding in December 2020, delivered from the state water quality assurance revolving fund, was to delineate and capture PFAS-contaminated groundwater to prevent it from impacting additional water production wells.
Groundwater contaminated with PFAS above EPA’s health advisory level waste first detected in Tucson in 2018, leading to a loss of 10 percent of well capacity from the drinking water distribution system. Tucson Water identified PFAS originating from Davis Monthan Air Force Base as a priority threat to the city’s water supply. ADEQ’s assistance expedites action concurrent with a Department of Defense investigation to prevent additional well impacts in the short-term.
The Tucson project work plan called for installation of 16 new groundwater monitoring wells, with additional work to collect and analyze soil, sediment and groundwater data to determine the location and extent of two PFAS compounds. Fieldwork to construct a remedy to prevent movement of the PFAS-impacted groundwater began in October 2020, and there are plans to install a wellhead treatment system near the PFAS-source area to remove PFAS and begin the process of containment.
In June 2021, ADEQ provided $2 million in funding to help Tucson restart a treatment plant that was forced to shut down because of severe groundwater contamination, and to safely continue treating contaminated groundwater in the area.
ADEQ is accelerating an investigation and is designing an early response action north of the Davis-Monthan Air Force Base to protect the city’s central wellfield, an important part of the area’s long-term water supply. In April, Arizona Governor Doug Ducey wrote to U.S. DOD Secretary Lloyd Austin calling on DOD to promptly act to address known PFAS groundwater contamination near Arizona’s four military installations.
Tucson Water has spent more than $8 million to address PFAS to date and expects to spend millions more. The City of Tucson has filed a lawsuit against manufacturers of PFAS compounds to reimburse the city and state’s expenses.