Santa Rosa secures federal funding for work to replace aging sewer pipe

Santa Rosa will replace a section of a nearly 50-year-old sewer line at risk of failing in the next two years with the help of $19.4 million in federal funds recently allocated to the city for critical sewer repairs.

Work will occur on a piece of the Llano sewer trunk that runs along Llano and Todd roads from the city’s southwestern outskirts, Santa Rosa Water spokesperson Elise Miller said.

The 66-inch diameter concrete pipe was installed in 1974 and transports a high volume of wastewater to the Laguna Wastewater Treatment Plant, where it is recycled.

The line is one of the most important in the city’s sewer system and it runs through environmentally critical areas home to endangered plant and animal species.

Addressing repairs now will prevent future failures that would interrupt sewer operations, harm plant and animal habitat and cause health and safety issues, Miller said.

“Timely investments in our water and sewer infrastructure are critical to our local economy, preserving and protecting our natural environment, addressing climate change, and preserving the region’s recycled water supply,” she said.

The U.S. Army Corps of Engineers will carry out the work, Miller said, though it’s not yet known when construction will start.

Funding for the project was made available through the federal Water Resources Development Act. It’s the first funding the city has received under the act since 1992.

“This crucial authorization will allow Santa Rosa to continue to provide essential water and sewer service necessary for the health and safety of the region’s residents and businesses,” Santa Rosa Mayor Natalie Rogers said in a news release announcing the award.

The total project is estimated to cost $23 million, including $17.5 million in federal funding and $5.8 million in matching funds from the city. The $19.4 million in federal funds authorized for the project was adjusted for inflation and the city can request any money that is left over be used for other water and sewer projects, Miller said.

Pipe needs critical repairs

Santa Rosa Water submitted a funding request to Rep. Mike Thompson, D-St. Helena, to help pay for improvements to the city’s aging wastewater system, particularly pipes and infrastructure that had already been identified as needing rehabilitation or replacement.

The city will replace a 7,400-linear-foot section of the Llano pipeline that was identified as needing critical repairs in the city’s Sewer Master Plan because of its age, Miller said.

In addition to the age, water officials are also concerned that potentially heavy flows during rainstorms could add stress to the pipe and that it would be unable to handle the additional flow.

The city will work with the Army Corps to get the project incorporated into the agency’s work plan now that funding has been authorized by the federal government and the city hopes work could start in 2024, Miller said.

Miller said the city would provide updates on the construction timeline as more information becomes available.

Thompson, in the news release, said he was “proud” to have secured the funding for the city.

“Replacing aging pipelines is vital to the health and well-being of our community in Santa Rosa, and this funding is going to deliver the resources necessary to modernize the water system and protect habitats of endangered species,” Thompson said. “I will continue to work with local leaders to identify additional projects that will benefit Santa Rosa and all our district.”

Other sewer improvements

In addition to the pipe work, the city in October broke ground on a $68 million replacement project at the Laguna Plant.

The Llano Road plant, owned and operated by Santa Rosa, treats and recycles wastewater for 230,000 residents living in Santa Rosa, Rohnert Park, Cotati, Sebastopol and unincorporated parts of Sonoma County.

The plant recycles approximately 7 billion gallons of wastewater each year and recycled water is used for agricultural irrigation and to recharge the steamfields at the Geysers that produce renewable energy.

As part of the treatment process, wastewater undergoes ultraviolet, or UV, disinfection before it can be reused. The UV light removes bacteria and viruses from the water.

That system, however, has reached the end of its useful life so the city is replacing it with a new UV system.

While the existing facility was state of the art when it was installed in 1998, “now it’s an old dog” and the equipment is nearly obsolete, said Mike Prinz, project manager and deputy director of regional water reuse operations.

The new system is expected to extend the life of the treatment plant, requires about half the energy to operate and is expected to reduce maintenance costs.

The existing system also no longer has the capacity to treat heavier flows during the heaviest periods of rainfall and runoff, so the new system will provide more reliability under a changing climate, Prinz said.

The treatment plant has seen wastewater flows from the region peak at more than 90 million gallons per day during large storms, a sixfold increase from the 14 million gallons per day during average dry weather, according to the city.

Construction is expected to take three years and is being paid through bonds which will be repaid through customer rates and fees, though customers shouldn’t see a spike in their bill, Prinz said.

The project represents the second largest capital project in the city’s history behind the 41-mile long Geysers Recharge Pipeline completed in 2003 that transports recycled water to the steamfields. That project, a partnership with Calpine, cost $205 million, according to the city.

Mayor Rogers, whose southwest District 7 includes the rural treatment plant, described the project as innovative during the groundbreaking ceremony.

“Projects like these take vision and strong leadership,” she said and thanked city staff and the engineers behind the “critical” project.

You can reach Staff Writer Paulina Pineda at 707-521-5268 or paulina.pineda@pressdemocrat.com. On Twitter @paulinapineda22.