Santa Rosa wastewater quandary linked to Kincade fire could get worse as rainy season ramps up
Nearly two months after the Kincade fire was fully contained in northeastern Sonoma County, Santa Rosa is struggling with an after-effect of the massive blaze: its wastewater disposal pipeline at The Geysers was disabled for six weeks, backing up the Sebastopol-area plant with about 400 million gallons of treated wastewater.
As a result, by February city water officials anticipate nearing maximum capacity at the plant’s storage ponds, forcing them to release treated effluent into the nearby Laguna de Santa Rosa, a step that would put customers on the hook for an estimated $400,000 in environmental charges.
The wastewater quandary is one of the lingering repercussions of the county’s largest ever wildfire, which scorched about 77,000 acres and more than 170 homes after igniting near a faulty PG&E transmission line in late October.
A clearer picture of its impact on The Geysers geothermal field - the complex of power plants near where the fire erupted - and the city’s wastewater system, which sends most of its recycled daily output to The Geysers, emerged over the past several weeks in public records and in interviews with city water staff and representatives of PG&E and Calpine, which operates most of the power plants.
PG&E has restored power to most of the lines that went down due to the Kincade fire, but it is still weeks away from reactivating the transmission line where equipment broke shortly before the start of the wildfire, a PG&E spokeswoman said.
That same high-voltage line previously powered the city-owned pumps that deliver water about 40 miles from Santa Rosa’s Laguna Wastewater Plant to The Geysers as part of the city’s wastewater disposal system, in operation since 2003.
Without electricity from that line, Santa Rosa found itself sidelined for six weeks - without the ability to pump the 15 million gallons of wastewater it regularly sends per day on average to help sustain steam power at The Geysers, said Joe Schwall, the city’s deputy director of water reuse operations. The Laguna Road plant is one of the largest sewer operations in the North Bay, serving more than 200,000 ?people not just in Santa Rosa but in Rohnert Park, Cotati, Sebastopol and parts of Sonoma County.
“We knew by the last week in October that Calpine had a real problem up there,” he said. “They notified us, and they kept us abreast from the get-go.”
The six-week outage was far longer than would have been expected under an initial assessment of the situation by Calpine on Oct. 24, the morning after the fire began off John Kincade Road.
“Some of our operations have been temporarily suspended but we expect production will resume very soon,” Calpine spokesman Brett Kerr said then in an email to The Press Democrat.
The company did not elaborate on the extent of damage and did not respond to follow-up questions in late October seeking details on how Calpine operations had been affected.
But on Nov. 8, two days after the Kincade fire was fully contained, Calpine officials told regulators that while they had “limited damage” to their operating equipment, the Kincade fire had done “extensive damage to third-party property in the region,” according to a 57-page filing with the U.S. Securities and Exchange Commission.
“Transmission service owned and operated by PG&E was cut due to the fire and high wind conditions, forcing us to suspend operations for several days,” Calpine said in the filing.
Kerr, the Calpine spokesman, echoed that summary in a more recent response to questions about The Geysers and its ability to accept wastewater from Santa Rosa.
“As we have stated previously,” Kerr said, “our facility sustained minor damage and we look forward to working with PG&E to restore full operational capabilities very soon.”
It’s not unusual for Santa Rosa water officials to store hundreds of millions of gallons of recycled water at any given time - about 1.4 billion gallons can be safely stored at the Laguna plant - but problems at the geothermal field during the Kincade fire caused a sharp spike in storage that city officials hadn’t anticipated.
As Schwall told the Board of Public Utilities in late December, even with millions of gallons diverted for irrigation use, storage pond volumes roughly doubled from late October to early December.
The fire did not damage the city’s pumps, according to Schwall, though it burned at least eight Calpine utility poles that link its system of more than a dozen geothermal power plants to PG&E’s grid. And the transmission line that went down the night the fire erupted remained out of service for about a month after the fire was contained, leaving the pumps without power even after Calpine replaced its poles.