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Pleasanton residents will have to start paying a little bit more on their water bills after the City Council approved a resolution following a presentation by staff from the Zone 7 Water Agency last week.
The costs will help fund future water treatment and rehabilitation projects such as the construction of a Stoneridge facility for PFAS treatment, staff said during a separate presentation from Zone 7 where they updated the council on several topics concerning chemicals in the Tri-Valley’s groundwater sources.
“These contaminants need to be removed and it’s going to cost money, but these are reasonable costs,” said Mayor Karla Brown during the Dec. 6 council meeting.
Starting Feb. 1, the water agency’s rates will go from $3.61 per 100 cubic feet of water to $3.93 — that change reflects a 5.5% increase that the Zone 7 Board of Directors approved in November for the next four years.
The Zone 7 board will revisit the rate schedules for 2025 and 2026 through a public process and will make any changes to the rates by November 2024.
The water rate increases were just one small piece of the larger discussion Dec. 6 regarding the agency’s recently completed groundwater modeling analysis of the expanding PFAS plume that has been affecting water pumping wells in Pleasanton and the rest of the Tri-Valley.
PFAS, formally known as per- and polyfluoroalkyl substances, are widely used and long-lasting chemicals, components of which break down very slowly over time.
In recent years, city officials have discovered variations of the chemicals in the city’s groundwater supply facilities — specifically in the city-maintained wells — and have been working to address the problem.
The findings from the modeling study were presented to the Zone 7 board on Aug. 31, and Zone 7 General Manager Valerie Pryor along with other Zone 7 staff presented mostly the same information to the City Council.
However, there were some new pieces of information that forced the water agency to relook at some of their treatment options and led to the decision of focusing on continuing to pump and treat the water at the affected wells to stop the westward spread of the plume.
Perfluorohexane Sulfonic acid (PFHxS) is one of the specific PFAS chemicals that the state established health-based notification and response levels for recently in October — Pleasanton’s wells 5, 6 and 8 all exceed these levels now thanks to the new levels, staff said.
Ken Minn, Zone 7 groundwater resources manager, told the council that in order to stop the PFAS plume from spreading, the water agency will be moving away from just blending the water from different sources and instead look to pumping and treating the water more.
“We really have to understand or consider the treatment as a viable means of preserving our local water resource,” Minn said. “That is what the mobilization study told us is that this is what it is going to be … pumping and treating is definitely going to be helpful in effectively treating the plume.”
Councilmember Kathy Narum noted that even if the city were to replace any of the wells, the chance of the chemicals reappearing would still be very high.
“If we’re going to do anything and make any kind of investments in the wells themselves, we really should be putting a treatment system on top,” said Daniel Repp, managing director of utility and environmental services for the city.
“We don’t know how long it would take to get the (PFAS) levels down below,” Repp added. “This stuff is going to be with us for a while. So I think the bottom line, at least from my point of view as an engineer and a technical person, is we probably just think about treatment if we’re going to be looking at groundwater.”
Vice Mayor Valarie Arkin asked Repp if there was any chance the wells could be turned back on to which he said as of now, it’s looking like they will be permanently shut down for the time being.
One of the biggest questions the council had for Minn was one that he couldn’t really answer which was — what was the source of the plume.
Minn said that the state is currently investigating the source and that a regional board will send out inquiry letters to places like firefighter buildings where some of the council members said could be the culprit due to fire foam.
Fire foam is a chemical solvent used to put out fires.
Minn added that while Zone 7 doesn’t have the authority to investigate the cause, they can continue to monitor the areas surrounding the fire stations and any other hot spots.
He also said that apart from the push for more treatment centers, the water agency will be looking to diversify its groundwater sources from the different sub basins located in the Livermore Valley Groundwater Basin, the main aquifer the water agency extracts water from.
“We learned from the past three years that when push comes to shove, this precious local resource is the one that we have to depend on,” Minn said. “Local resources are the one that we have to preserve and we have to relish.”
“We need to diversify our groundwater extraction, so that we will become much more resilient during the drought,” he added.
As the water agency continues to track, monitor, look for grants to fund the treatment centers’ construction and pump the wells in the Tri-Valley, Councilmember Jack Balch said the city needs to also work fast in coming up with a treatment plan.
The council previously voted to pause its PFAS treatment and wells rehabilitation project due to high costs and staff are in the process of looking at different alternatives to the problem. The 20% of the water produced from the water wells will be outsourced to the Zone 7 agency for the time being.
“We’ve got to move with haste on the study on the pause figuring out what we’re going to do,” Balch said. “I thank Zone 7 for the partnership to bridge us on the 3,500 acre-feet of water that we are not pumping now, or would be this summer.”
“With their capital plans and ability to bring on their treatment plant and time, hopefully that all does line out but obviously, we’ve got to move with haste on our side, in partnership, on all solutions for it … We’ve got to work together and work in haste,” Balch added.
Apart from the presentations from Zone 7, Pleasanton city staff also presented the city’s 2022 public health goals report, which found other chemicals like copper and uranium in the drinking water.
As a water purveyor the city prepares this report every three years, which includes information about water quality components detected in the drinking water and how they relate to state public health goals (PHGs).
The California Office of Environmental Health Hazard Assessment establishes these water quality goals, which are levels of chemical constituents in drinking water that do not pose a significant risk to health, and they are not regulatory standards.
“It’s really a policymaking tool and as the governing body for distribution for the city of Pleasanton this is really an opportunity to identify trends and to to make sure that we’re weighing the pros and cons of either newly identified contaminants in our water system or contaminants that we know of, but we’re monitoring the level of contamination,” City Manager Gerry Beaudin said.
“It’s really not, are we concerned or are we not concerned,” he added. “It’s, are we aware and are we able to properly plan for and finance should we need to take specific action.”
Even though city staff did find that PHG’s were exceeded for copper and uranium, they said that the technology needed to treat these issues — which staff say the potential health benefits of treating is not clear — is too expensive.
According to the staff presentation, to install and operate a reverse osmosis system, which is what would be needed to remove copper and uranium, would cost approximately $10.7 million (per year) for the life of the system.
The council agreed and moved with staff’s recommendation to not move forward with the reverse osmosis system because the city’s drinking water meets all state drinking water standards, the effectiveness of the treatment is still uncertain and the health benefits of these potential reductions in copper and uranium are not clear.
