City of Pleasanton

The Pleasanton City Council recently moved forward on a plan to mend a contaminated groundwater well and prepare to meet future water quality regulations.

The council unanimously approved a contract with Carollo Engineers in the amount of $437,374 to prepare a basis of design report for Per-and Polyfluoroalkyl Substances (PFAS) treatment and the rehabilitation of city-owned and -operated wells 5, 6 and 8.

PFAS consists of a group of manmade water contaminants, derived from shampoo, paints, fast food packaging, firefighting foam, photography, landfill waste, stain resistance products and nonstick cookware.

Todd Yamello, utilities planning manager, presented a staff report on the city’s current treatment status, along with plans to address PFAS for the long-term. The city utilizes three groundwater wells to meet water demand. Because of contamination, well 8 has not operated since testing began in June 2019. This year, well 5 was also out of commission due to a pump motor failure. The city had to rely on its regional partner and water supplier Zone 7 for more water delivery during the summertime.

“Approximately 25% of the city’s yearly demand is supplied from our wells, and we have an allotment of 1,140 million gallons (mg) per year that we’re allowed to use,” Yamello said. “That’s approximately one well running full-time. But probably the bigger issue for us is meeting peak summer demands. Historically, we’ve always had to run two out of three wells to meet our demands in addition to what we’re getting from Zone 7 … If PFAS hits and takes away our ability to pump wells, there needs to be a solution.”

Those solutions included self-implementing PFAS treatment at city groundwater wells, which Yamello called out as the preferred focus. He noted that this option will provide local control on the implementation schedule, which is an important factor given rapidly approaching state regulations. The other option could be to coordinate regional solutions for treatment at another facility or purchase more water from Zone 7.

Yamello explained that many of the city’s treatment systems are reaching the end of their useful lives. The city would need to implement new water treatment vessels, such as granular-activated carbon (GAC) or ion exchange vessels, at its well sites. Wells 5 and 6 are located at a site that presents access challenges and minimal room to expand. The site for well 8 has benefits because of its location.

He provided a projected work plan for rehabilitating the wells and indicated a PFAS treatment feasibility study was already underway. From now through 2023, the plan detailed phases for creating a design along with construction. The staff recommendation entailed proceeding with planning and the design of self-implemented PFAS treatment at all three wells.

In the discussion prior to the 5-0 vote, Councilmember Karla Brown called for the city to seek grants and low-interest loans in the continued effort to address PFAS contamination. Vice Mayor Kathy Narum stressed the importance of continuing to work with Zone 7, but also wanted local control in meeting regulations as it relates to wells.

“It’s important that we continue to have forward motion on this ... we’ve really got to have all three wells operating, particularly during the summer months,” Narum said. “We want to continue to have our drinking water exceed the state and federal quality standards. We want it to be clean, and we want it to be safe, and we owe our residents that.”