More Industrial Chemicals Found in Sweetwater Reservoir

New testing shows rising levels of toxic PFAS chemicals in water sent to thousands of households in South San Diego County. Fixing the problem could cost tens of millions of dollars or require decommissioning the Sweetwater Reservoir. 

Sweetwater Authority, which supplies drinking water to roughly 200,000 customers in Chula Vista and surrounding communities, learned last month that its main reservoir contains levels of a toxic industrial chemical that could require expensive treatment or necessitate decommissioning the reservoir entirely. 

The elevated chemical finding came as part of a year-long testing process required by the Environmental Protection Agency, or EPA. An earlier sample taken late last year found PFAS levels high enough to require public notification.

Samples taken last month found even higher levels of one chemical, PFOA, that the EPA has designated a “hazardous substance” posing “a substantial danger to the public health.” 

The levels found last month, if confirmed by follow-up testing, could trigger a state rule that would require Sweetwater Authority either to stop using water from Sweetwater Reservoir, blend reservoir water with cleaner water bought from an outside agency or notify customers that their drinking water contains elevated levels of a hazardous chemical. 

“We don’t have treatment in place” for PFAS chemicals, said Justin Brazil, director of water quality for Sweetwater Authority. “Our options right now are…we could take the [reservoir] out of service or blend” reservoir water with uncontaminated water bought from an outside agency. 

Brazil said installing treatment to remove PFAS chemicals from reservoir water could cost at least $40 million. Buying water from an outside agency could cost up to $10 million per year. 

Asked whether water from the reservoir was safe to drink, Brazil said, “That’s a good question and a valid concern. We’re not physicians here but we do follow the rules for contaminants that are set by the EPA and the state of California.” 

PFAS chemicals are a class of industrial chemicals used in a wide variety of everyday products, ranging from electronic devices to fire retardants. They are known as “forever chemicals” because they remain present in the environment long after their production. 

PFOA, one of the chemicals found in Sweetwater Reservoir, has been linked to numerous health hazards, including pregnancy complications, liver damage and cancer. Recent EPA guidelines found that PFOA is “likely to be carcinogenic to humans.” 

Sweetwater officials said they do not yet know how PFAS chemicals made their way into the agency’s reservoir.  

In an interview late last year, agency general manager Carlos Quintero called the chemicals “one of the sins of civilization” and said anything from storm runoff to decommissioned landfills in the Sweetwater River watershed could have contaminated the reservoir. 

Brazil said the agency took a follow-up sample of reservoir water last week to confirm the January results. Results of the follow-up test will be made available later this month, he said. 

The agency also plans two more rounds of testing in April and June. Those rounds will then be averaged with the agency’s other two rounds of testing to produce an overall assessment of PFAS levels in the reservoir. If that assessment exceeds federal guidelines, the agency will have until 2029 to fix the problem. 

Brazil said agency officials are working with state regulators to determine how best to respond to the immediate problem of high PFOA levels. 

Susanne Bankhead, a spokesperson hired by the agency to conduct public outreach about PFAS chemicals, said the agency’s elected board of directors ultimately would decide how to respond to the problem of reservoir contamination. “We’re looking for a balance of safety, fiscal prudence and rapid response,” Bankhead said. “We don’t yet know what the effect on water rates could be. It’s complicated.” 

Sweetwater Authority will hold two public outreach meetings this month to discuss the presence of PFAS chemicals in drinking water. The meetings will take place at 5:30 p.m. on Thursday, Feb. 13 at the Chula Vista Public Library Civic Center Branch and at 5:45 p.m. on Wednesday, Feb. 19 at the Bonita-Sunnyside Library in Bonita. 

by Jim Hinch | February 11, 2025 | Voice of San Diego

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