New Contaminants Emerge from South Side Superfund Site


Tucson Water records indicate perfluoralkyl substances, or PFAS for short, specifically, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) are in water samples taken at historic sites of TCE contamination throughout Tucson. Tucson Del Sur News requested and mapped well sampling data generated by the water utility from 2012 to 2018.

This map contains the results of samples tested for PFOS, one of two PFAS Tucson Water voluntarily tested for since 2012.

Tucson Water assured in an email, and in other press coverage, that these contaminated wells are not currently used in the public supply. However, data provided shows PFAS contamination correlates with the historic TCE, and other industrial solvents, plume that runs for four plus miles beneath South Side Tucson as well as other historic contamination including the Ina and Flowing Wells areas.

This raises many questions, including: are known historic polluters like Hughes Aircraft the source of PFAS found in the TARP wells? Or, are current users of PFAS in industrial and manufacturing processes contributing to the pollution? Or, both? And, how many types of PFAS are in the pumped groundwater?

Also, whether Tucsonans drinking, cooking and bathing with water from the TARP treatment plant have been exposed to PFAS? If so, for how long and to what degree?

Is the TARP treatment plant, in all its iterations, equipped to remove PFAS from drinking water?

Tucson Water has yet to deliver answers to some of these important questions by the time of publication but this is a developing segment in a long history of water contamination in the Old Pueblo, stay tuned and check back for updates.

This map contains the results of samples tested for PFOA, one of two PFAS Tucson Water voluntarily tested for since 2012.

PFAS are not currently listed as hazardous substances by the EPA nor has an enforceable Maximum Contaminant Level (MCL) been set by the regulatory body. However, Congressional testimony in front of the House Committee on Energy and Commerce, Subcommittee on Environment, in September indicated PFAS are of significant concern.

“PFAS have emerged as one of the most complex environmental challenges of recent times,” said Sandeep Burman, manager for site remediation and redevelopment at Minnesota Pollution Control Agency, in his testimony before Congress, “it is expected that more releases and impacts will be discovered from both historical and current sources.”

Dr. Peter Grevatt, Director of the Office of Groundwater and Drinking Water at the EPA, indicated in his testimony that the agency is taking steps related to PFAS including initiating steps to evaluate the need for a Maximum Contaminant Level, evaluating individual PFAS for designation as hazardous substances and drafting toxicity values for PFAS compounds.

“We need to regulate all PFAS as a class…we don’t have time to individually regulate all of the possible 10,000 PFAS in our water today,” said Emily Donovan, founder of Clean Cape Fear, an organization taking on Chemours and Dow-DuPont over PFAS contamination in North Carolina. Donovan is worried that if the EPA pursues evaluating PFAS per individual chemical compound rather than as a class the problem will inevitably persist and continue to impact human health.

Erin Jordan, public information officer for Arizona Department of Environmental Quality, indicated that the director of ADEQ is restricted by state law from regulating PFAS beyond federal regulation standards. However, Arizona Revised Statute § 49-922 indicates the director does have some discretion in certain cases where impacts to human health are substantial. ADEQ has not returned comment on this point as of time of publication.

The emergence of PFAS as contaminants of concern across the nation does not exclude the Old Pueblo or its South Side, and perhaps only heightens the risks associated with Tucson’s groundwater.

Check back for more updates.