Pleasanton city staff are close to finalizing a recommendation for the City Council to possibly design and build two new groundwater wells outside of the PFAS contaminant plume following initial discussions with the council last month.

While the council did not vote to officially go with that option of opening two new wells, as it will be set to do so during the Oct. 17 council meeting, several council members did voice their support for doing so despite also expressing some concerns about the so-called forever chemicals potentially being found in those future well locations.

"I definitely think the recommendation is spot on," Councilmember Jeff Nibert said during the Sept. 19 meeting. "But as you allude to, there is some level of uncertainty ... (the) two new wells may not turn out to be the best ones."

Staff had presented four different alternatives to the council that could potentially help the city meet its quota of producing 20% of the city's water supply – with the rest coming from the Zone 7 Water Agency. That quota was previously met by using the city's groundwater wells but ever since the city began finding PFAS chemicals in its groundwater back in 2019, the city had to begin looking for different ways to produce safe, reliable water to its residents.

The council originally began by eyeing plans to construct a water treatment and rehabilitation facility, known as the PFAS Treatment and Wells Rehabilitation Project, to treat and rehabilitate wells 5, 6 and 8 in Pleasanton and to create a new centralized treatment facility for PFAS treatment, disinfection and fluoridation.

But on Sept. 6, 2022, the council paused that project in order to evaluate other options, mainly due to a $46 million pricetag on the treatment facility. That number had since gone up to roughly $60 million, according to staff.

Since then, a water ad hoc subcommittee was formed; the council established a new water supply alternatives study capital project and contracted with Brown and Caldwell -- an engineering and construction firm focused on water and environmental sectors -- in order to evaluate different potential options.

And after several months of collecting and reviewing data from the city and from the Zone 7's groundwater model, staff narrowed the comprehensive list of water supply alternatives down to four options.

The most cost-friendly and reliable in terms of water quality, according to staff, is constructing two new wells outside of the PFAS plume, which has been spreading PFAS contaminants mostly in the East Pleasanton region.

"This really provides the highest reliability at the lowest cost," Jenny Gain, an engineer from Brown and Caldwell, told the council. "Groundwater pumping is within the city's wheelhouse, while treatment is not."

She also said that option could possibly provide the highest-quality drinking water without disturbing the PFAS plume. Staff said Zone 7 would also be looking at addressing the plume in future years through further analysis and by taking measures to pump and treat the sub-basins that the plume has contaminated.

"The idea is to pump and treat in that sub-basin and to move outside of it with the goal of shrinking the plume over time, not letting it leak around or move around to other sub-basins," City Manager Gerry Beaudin said. "Over 20 years the PFAS bloom, at the depth that it's being pumped, would actually shrink and not continue to sprawl but actually pull in."

The other water supply alternatives that staff presented to the council were bringing back the PFAS treatment facility and treating Wells 5, 6 and 8; treating only Well 8 for PFAS contamination; and purchasing 100% of Pleasanton's water supply from Zone 7.

Another potential alternative that staff brought up as a hypothetical was a regional project involving Zone 7 where the agency would have its own groundwater wells outside of the plume. In that proposed scenario, Zone 7 would pump Pleasanton's groundwater quota as part of the regional project.

While staff will be bringing each of these other proposals back to the council as part of a fuller report out and study at that Oct. 17 meeting, each of them have significant cost and water reliability concerns that staff pointed out during the Sept. 19 meeting.

However, while the two new wells option was deemed as the best option moving forward, many on the council had similar concerns about PFAS chemicals possibly popping up in those new wells, which could set staff back and force them to look at other options.

"PFAS is such a big issue that we're trying to address, right?" Councilmember Valerie Arkin said. "What happens if that occurs again in a new well?"

Beaudin said that Zone 7's efforts to contain the plume would help with that but also he wanted to make sure the council and public know that there is a level of uncertainty when discussing this issue and that the city will be using the next year -- if the council does move forward with the two new wells option -- to run tests on the locations where the wells would potentially be located in order to make sure they know what the water looks like in terms of contamination.

"There's a lot of technical work to be done between now and you know, flipping a switch on brand-new groundwater supply," Beaudin said.

Vice Mayor Jack Balch had similar questions about the possibility of the city approving the two new wells option and making all the efforts to test the areas only to find out they are not viable -- which could send the city back to square one.

Beaudin tried to assure Balch that city staff would sort it out quickly and that if staff find out the two new wells are not viable options by next year, they would look at other options -- most likely the reduced treatment option of only treating Well 8 for PFAS chemicals.

But Balch doubled down throughout his comments saying that the city should look at a way to have a backup option in case the two wells approach doesn't prove to be a viable option.

"If we burn 18 months on this path, and we have no alternative, no reliability. And our second path starts at zero ... that would be awfully frustrating to me," Balch said.

He also said he had some issues, as did Arkin, with staff's timeline of getting some type of water supply alternative fully operational by 2027, saying that the city had discovered PFAS in its water supply in 2019 and the fact that a solution is so far out is unfortunate.

But Beaudin said that while he understands the need to address Pleasanton's water supply as soon as possible, having something in place by 2027 or 2028 is the most realistic in terms of scheduling given everything that needs to happen in terms of designing, getting permits and construction.

"This is an idea at this time ... we're sort of laying out a realistic schedule for this," Beaudin said. "I understand that you all want to see new wells as quickly as possible. Water continues to be the top priority that we're working on. For as much as we're talking about it right now, there's just an inordinate amount of work happening."

He also said that based on the study that will be presented to the council, they could vote to approve work on doubling the design work for a second option while staff work on evaluating the two new well locations.

"I think we owe it to the ratepayers and, as from a staff recommendation perspective, to pursue the most cost-effective, beneficial alternative," Beaudin said. "If it doesn't pan out, that's sometimes how it goes, but ... we've got people with expertise all around us, helping us to make these options and these scenarios come to life."