In an effort to turn local wastewater into a valuable and potentially drinkable commodity, Palo Alto and the Santa Clara Valley Water District are moving ahead with a deal that would allow the city to build a salt-removal plant in the Baylands and then ship its treated wastewater south for usage throughout the county.
The deal, which the City Council discussed and largely endorsed on Sept. 23, could advance on Nov. 18, when the council is scheduled to approve the terms of the agreement between the city, Valley Water and the city of Mountain View. If approved, it would commit the city to shipping effluent to Valley Water for 63 years, while also giving both Palo Alto and Mountain View the option of buying water from the water district, which serves most of Santa Clara County.
Today, Palo Alto is one of about two dozen Peninsula cities that get their potable water from the San Francisco Public Utility Commission, which operates the Hetch Hetchy system and gets its water from the Tuolomne River in Yosemite National Park. While that isn't expected to change, the agreement with Valley Water would give the city a backup source of both potable and non-potable water from the south.
The deal would allow the city to significantly curtail how much wastewater it dumps into the bay. Today, the wastewater plant discharges about 96% of its output into the bay and treats the remaining 4%, which is then used to irrigate golf courses in Palo Alto and Mountain View.
By reducing the salt content in the wastewater, the city will be able to address anxieties from irrigators about the impact of recycled water on sensitive trees and plants, including redwood trees. In doing so, it will be able to immediately hook up 60 new commercial customers in Mountain View to the distribution system.
For the city, the agreement with the water district represents both a short-term opportunity to expand usage of recycled water and a long-term opportunity to further purify the water and make it potable. According to a new report from the Utilities Department, the salt-removal plant will provide "the first step toward small-scale potable water production for direct or indirect potable reuse in Palo Alto, all of which would displace imported Tuolumne River water." In other words, wastewater could ultimately become drinking water in Palo Alto.
While the deal only calls for a small salt-removal plant, the new report notes that Palo Alto and Valley Water are also currently "assessing the feasibility of constructing a large purification facility in Palo Alto."
"If Valley Water determines that Palo Alto is the best location for a regional purified water facility, Palo Alto will support and cooperate with those efforts at the local, state and federal levels, subject to environmental review and absent new extenuating circumstances," the report states.
The proposed partnership has picked up some momentum since the council's September discussion. Last week, representatives from both the San Francisco Bay Regional Water Quality Control Board (Water Board) and U.S. Environmental Protection Agency had submitted letters supporting the proposed partnership.
David Smith, assistant director for the EPA's Water Division, called water reuse "one of the nation's most promising opportunities to support communities and the economy by bolstering safe and reliable water supplies." Expanding water reuse through the proposed partnership, he wrote, would keep a significant amount of wastewater from being discharged to San Francisco Bay. The discharges of water into the bay, he noted, have created "freshwater marsh conditions" and reduced habitat for endangered species such as the Ridgway's rail and salt marsh harvest mouse.
"Projects that come out of the proposed partnership are expected to decrease these freshwater inputs and restore the more historical salinity regime while providing a more sustainable and reliable water supply for Santa Clara County," Smith wrote in the Nov. 4 letter.
Thomas Mumley, assistant executive officer at the Water Board, similarly touted the environmental benefits of the proposed partnership and called the project "an important step toward expanding water reuse and moving towards a regional water reuse system."
Reusing treated wastewater rather than discharging it into the Bay will "reduce further loading of nutrients and other pollutants to the Bay, while reducing reliance on external sources of drinking water," Mumley wrote.
"There are obvious win-wins in your and our interests in sustainable and reliable water supply and protection of San Francisco Bay," Mumley wrote.
Under the proposed terms, Valley Water would provide about $16 million for the new $20-million plant, which would be built at the Regional Water Quality Control Plant, a facility in the Palo Alto Baylands that serves Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford University and the East Palo Alto Sanitation District. About half of the treated wastewater would then be transferred to Valley Water for use south of Mountain View. The district would pay $1 million to the jurisdictions that commit the effluent to the treatment plant, with the exact amount based on each city's (or agency's) share of wastewater.
Palo Alto would have 13 years to construct the salt-removal plant. If it chooses not to move ahead with the facility, the $16 million from Valley Water may be used for other water reuse and related programs, according to the report. During this 13-year "option period," Valley Water would provide $200,000 annually to be shared by the partners in the regional wastewater facility (of that amount, $100,000 would be shared by the two biggest partners, Palo Alto and Mountain View).
Under the new "water supply" option, Palo Alto and Mountain View will be able to notify Valley Water that they need more water and the district will have four years to respond with a proposal. If the proposal is accepted, the district will have 10 years to deliver the water. If it's rejected, Palo Alto and/or Mountain View will be able to make another request five years later.
At the Sept. 23 discussion, Councilman Tom DuBois noted that the city's effluent is currently a "waste product." The agreement with Valley Water starts to put a value on it, he said. He also indicated his support for a future plant that would make wastewater potable.
"Personally, I'd like to see the large plant end up in Palo Alto," DuBois said at the Sept. 23 study session.
Other council members also signaled support for the proposed partnership, with Councilwoman Alison Cormack lauding the prospect of reducing discharges of wastewater into the Bay. Mayor Eric Filseth noted, however, that if the city agrees to the deal, Palo Alto basically forfeits its right to build its own large-scale potable water project for 76 years (which includes the 13 years that Valley Water has to construct the plant and the 63-year term of the supply agreement).
"Essentially, we're selling a 76-year option for $1 million a year," Filseth asked. "Is that a good deal for Palo Alto? That's the question."