During wet weather, inflow and infiltration into the sanitary sewer collection systems cause high influent flows to the treatment plant. These collection systems are owned by SASM and its member agencies: City of Mill Valley, Richardson Bay Sanitary District, Almonte Sanitary District, Alto Sanitary District, Homestead Valley Sanitary District and the Kay Park region of Tamalpais Community Services District. During these high flow conditions, primary treated effluent may blend with fully treated secondary effluent prior to chlorination, dechlorination, and discharge into Raccoon Straight in Central San Francisco Bay.
If the wet weather is extreme, minimally treated sewage may bypass the remainder of the treatment process and overflow the 3.3 Million Gallon equalization (holding) ponds designed to manage peak wet weather flows, and flow directly into the Pickleweed Inlet in Richardson Bay. In this case the Marin County Health Department will be notified and the shoreline posted.
When the Wastewater Treatment Plant experiences a blending event, City staff will update this webpage with information, including the approximate volume and duration of the event.
Due to necessary construction and maintenance, the North Overflow Pond on the premises of the Wastewater Treatment Plant will temporarily be used as a holding area for raw sewage. This will take place for several hours on three consecutive Thursdays. The dates are:
· Thursday, March 26, 2015
· Thursday, April 2, 2015
· Thursday, April 9, 2015
Odor control measures will be in place. However, complete odor control is not guaranteed.
Additionally, it is imperative that the public observe the posted “NO ADMITTANCE” signage in the area. For your safety keep pets under control and away from the area.
If you have any questions please contact Chris Monti at 415-388-2402.
||Estimated Volume |
|February 9, 2014
||2.6 M gal.|