In Sonoma Valley, Calif., work on the next phase of replacing an old and failing sewer main is set to begin this summer. The sewer had been periodically leaking wastewater during heavy winter storms.
According to The Press Democrat, crews will begin tackling three pipeline segments totaling 1.8 miles over the next three years. The project will begin with the section likely to be the most disruptive, given its intersection with a key transportation corridor in northwest Sonoma.
The Sonoma Valley County Sanitation District, who manages the area’s wastewater treatment system, has made plans to make the roughly $15 million project proceed as smoothly as possible, according to officials.
The impact on traffic and daily life are a tradeoff to upgrade a roughly 60-year-old sewer main, according to The Press Democrat. The work is meant to stop the discharge of untreated wastewater that has occurred over several decades when rainfall hits the area.
“We’re going to do some pretty heavy outreach as it gets closer, just so people know,” said Mike Thompson, assistant general manager with Sonoma Water, which operates the system through the sanitation district. “It looks simple but it’s extremely complicated, and we’ll be happy when it’s done.”
The spills usually come during heavy storms which allow rain runoff and groundwater to seep into cracks in deteriorating sewer laterals and collection lines. According to The Press Democrat, this situation is known as inflow and infiltration.
The discharge is highly diluted, according to agency spokesman Barry Dugan. However, it contains untreated sewage and floods onto the and into storm drains. It often works its ways into local creeks, potentially risking the wildlife and water quality, as well as putting the district in violation of the California Environmental Quality Act.
According to The Press Democrat, heavy rains led to eight such overflows on Jan. 6 and 16. This involved a combined 498,843 gal of wastewater.
A separate faulty valve on the Sonoma Valley system failed to close on Jan. 12 and released more than two million gal of wastewater into a slough before being discovered and stopped.