Winter storms send sewage overflows into Russian River, Sonoma Valley creeks

Heavy downpours in the North Bay this winter have once again triggered significant sewage overflows into creeks and rivers, including an estimated 200,000 gallons of untreated wastewater that flowed this week into Sonoma Valley tributaries feeding San Pablo Bay, according to water officials.

Wastewater also overflowed into the Russian River this week at Guernewood Park, near Vacation Beach, where the Russian River County Sanitation District operates a lift or pumping station.

Brad Sherwood, a spokesman for the Sonoma County Water Agency, said Thursday the agency is still determining how much wastewater made its way into the river.

“Most likely it’s a drop in the bucket compared to the flow in the river today,” he said.

During large storms, it’s not uncommon for water to penetrate cracked sewer lines, sending a fetid brew of untreated wastewater up through manholes.

Aging pipes also have been known to break entirely, as was the case in February 2014, when a 16-inch steel pipe burst in a rural neighborhood outside Guerneville, spilling an estimated 100,000 gallons of raw sewage into the river.

That spill - the largest along the river in a decade - and frequent sewage overflows during major storms cast light on the precarious state of miles of underground wastewater pipes.

Water management officials say they are working to address the problem. That includes, in the Russian River County Sanitation District, rebuilding a pump station every year over the next decade, according to Sherwood.

He said the district, which serves about 3,200 accounts, is “by far” the most complicated collection system pipeline network in the county, requiring 11 separate pumping stations to transfer wastewater from homes and businesses to a treatment plant.

“These stations require constant maintenance and frequent pump rebuilds, and periodically their high-voltage electrical systems must be completely replaced,” Sherwood said.

Sonoma County Supervisor Susan Gorin, a water agency director, said people need to acknowledge that this year has been an extraordinary one in terms of rainfall.

“That makes it very, very difficult for any water treatment plant to keep up,” Gorin said. “This challenge is not unique to Sonoma Valley. It occurs in Santa Rosa and just about every city and county because the infrastructure is old and getting older.”

Besides generating public health concerns, sewage overflows can result in hefty fines for water management agencies.

The Sonoma Valley County Sanitation District was slapped with a $732,000 fine last year following a series of sewage overflows in 2010 and 2014.

The amount of the 2014 overflows was estimated to be 145,860 gallons –- roughly 45,000 gallons less than what is believed to have occurred in Sonoma Valley this week. This week’s totals didn’t include two additional overflows that occurred Thursday afternoon on Boyes Boulevard and Vailetti Drive.

Crews were dispatched to the sites to vacuum up the sewage and take it to a treatment plant.

The Sonoma Valley district in January approved an ordinance requiring home and business owners to have sewer laterals that are 30 years or older inspected and repaired.

The ordinance was mandated by the San Francisco Bay Regional Water Quality Control Board as part of the enforcement action for the 2010 and 2014 sewage overflows.

The Sonoma Valley district serves 17,000 households and businesses from roughly Aqua Caliente Road to the city of Sonoma.

An estimated two-thirds of the sewer laterals in that area are at least 30 years old and likely in need of repair.

The sanitation district will offer free inspections of private sewer laterals and for a limited time offer rebates of up to $1,000 for repairs.

A low-interest loan program also is being considered that would allow qualified property owners to pay for repairs over a period of several years, according to Sherwood.

The program is expected to begin during the summer of 2017. Property owners will be notified when inspections are planned for their neighborhoods.

Gorin, who serves on the sanitation district’s board, acknowledged it will take years for such fixes to be put in place.

“It’s not going to be a fast process, but if we do it methodically over the next decade, then I think we can stay in front of it,” she said.

Sherwood said homeowners across Sonoma County can help reduce the risk of sewage overflows by curbing indoor water use, even during periods of heavy rainfall.

“During these major storms, if we reduce indoor water use, we reduce pressure on the system,” Sherwood said.

You can reach Staff Writer Derek Moore at 707-521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.