Petaluma, one of the driest corners of Sonoma County during the past two years of drought, is making a multimillion-dollar advance into recycled water.
Operator of a wastewater treatment plant that serves about 65,000 people and treats about 5 million gallons of effluent a day, Petaluma is seeking grants for four projects with a total cost of $ 42 million.
Six other North Bay agencies – including Sonoma Water and the Sonoma Valley County Sanitation District – are proposing a dozen projects totaling $ 41.2 million, bringing the total to $ 83.2 million, as Gov. Gavin Newsom is backing water reuse as an antidote to drought.
The projects are meant to help offset already strained supplies of North Bay drinking water as California braces for longer and more severe periods of water scarcity amid the escalating climate crisis.
Through expanded treatment, new pipelines and storage facilities, the 16 projects are expected to deliver 5,364 acre feet of water per year – enough to offset potable supplies for about 32,000 people. An acre-foot is 326,000 gallons, about half the size of an Olympic swimming pool and enough for more than two households for a year.
“First and foremost is drought resistance,” said Christopher Bolt, Petaluma’s public works and utilities director. “In the face of climate change we want to make sure we can meet the community’s needs.”
Water recycling – transforming sewage through intensive treatment into water safe for irrigation of landscapes, pastures, playgrounds and crops that are eaten raw – is a high priority throughout California in the third year of a drought that experts say could last another decade.
“Recycled water is a sustainable, nearly drought-proof supply when used efficiently, and the total volume of California water recycles today could triple in the next decade,” said the 2020 California Water Resilience Portfolio, in response to Newsom’s order calling for recommendations. to enable water security for all Californians. ”
California produced 728,000 acre feet of recycled water in 2020, up about 40% from 20 years ago.
The State Water Resources Control Board is currently funding $ 970 million in loans and grants for 12 projects that would provide about 62,000 acre feet of recycled water per year for urban and agricultural irrigation and indirect potable use through groundwater recharge.
Wastewater experts like to say all water on, in and above Earth is recycled and humans are using the same water as the dinosaurs.
Petaluma’s Ellis Creek Water Reclamation Facility commits all treated water to irrigation of parks, schools, commercial properties, golf courses and farms during dry summer months, averting it from discharge into the nearby Petaluma River. In wet months, however, a substantial amount goes into the river, which is a tidal slough from San Pablo Bay.
“We’re looking to expand and grow the water recycling system,” Bolt said. “We have a vision of zero discharge into the river year-round.”
Expansion of the distribution system and developing more storage capacity would reduce the wintertime discharge, he said.
Petaluma’s rainfall to date for this year and 2021 is well below or only an inch above the level for the other 18 communities in The Press Democrat’s weather log.
Sonoma County Supervisor David Rabbitt, a Petaluma resident, is an avid booster of recycled water.
“My mantra is you gotta use water twice,” he said. “In an ideal world we would avoid using potable water for irrigation.”
Purple pipes that carry recycled water should go under every street in newly developed areas, along with power, sewer and regular water lines, Rabbitt said.
Rabbitt has served since 2013 as chair of the North Bay Water Reuse Authority, a collaboration of 11 agencies in portions of Sonoma, Napa and Marin counties dedicated to ending discharge of treated wastewater into San Pablo Bay, largely by diverting it to urban and agricultural irrigation .
The authority’s 350-square-mile territory faces “long-term challenges in providing reliable water supplies” with limited surface and groundwater sources and some groundwater basins “showing harmful effects on water levels and quality,” its website says.
“A warming climate will likely further stress water supplies, and recycled water is a sustainable resource that can help augment regional water supplies,” it says.
The authority’s first round of projects, started in 2012 and completed in 2020 at a cost of $ 104 million, is providing 3,800 acre feet per year for urban and agricultural irrigation along with 46 miles of new pipeline.
Sonoma Valley County Sanitation District’s projects included a fifth reservoir holding about 35 million gallons of recycled water and starting work on a 3½-mile pipeline to carry up to 1,700 acre feet per year for habitat restoration at the Napa-Sonoma Marshes Wildlife Area on San Pablo Bay and along the Napa River.