A Ross Valley Sanitary District equipment failure caused a 1,000-gallon sewer spill at the Bon Air Shopping Center in Greenbrae Tuesday afternoon.
The spill occurred around 2 p.m. at Pump Station 13, according to sewer district officials.
A pipe leading to an air release valve failed, causing a backup that created the spill. Of the estimated 1,000 gallons of wastewater, 800 gallons were recovered and directed back into the sewer system while approximately 200 gallons flowed from a manhole by the pump station into a storm drain that the district believes drains into Greenbrae Creek.
Crews shut down the pump station to isolate a section of the line so it could be dewatered and repairs made. By 6 p.m., the repair to the pipe leading to the air release valve was completed and the pump station was brought back online.
Telephone notifications were made to CalEMA, Marin County Environmental Health Services (EHS), City of Larkspur Public Works, and Central Marin Sanitation Agency. Water testing of the creek is underway.