Guy Kovner, THE PRESS DEMOCRAT
Overwhelmed by record rainfall this week, Santa Rosa’s regional wastewater treatment plant has released about 22 million gallons of treated sewage into two creeks and the Laguna de Santa Rosa since Wednesday, and the discharge will continue indefinitely with another storm on the way, officials said Friday.
All three waterways drain into the Russian River.
It was further evidence that the deluge, which swamped Russian River communities and displaced thousands of residents this week, had far-reaching impact.
The releases began Wednesday, a day after Santa Rosa received 5.66 inches of rain, a record for one-day precipitation dating back to 1902.
It took about a day for the added volume of sewage mixed with runoff to reach the plant on Llano Road, which treats wastewater from about 230,000 customers in Santa Rosa, Sebastopol, Cotati and Rohnert Park.
The record-breaking rain from an atmospheric river that stalled over Sonoma County “put a total strain on the system,” said Emma Walton, interim director of Santa Rosa Water.
Santa Rosa’s was at least the second municipal treatment plant overwhelmed or knocked out by this week’s storm. Healdsburg earlier this week declared an emergency stemming from problems at its own flooded facility.
Rainwater seeping into Santa Rosa’s far-flung sewage collection system boosted the flow arriving at the plant to as much as 105 million gallons a day this week, the largest flow ever recorded.
Normal wintertime inflow is 19 million gallons per day, city spokeswoman Adriane Mertens said.