Central Marin Sanitation Agency

Child Splashing in rain

During wet weather, stormwater and groundwater inflow and infiltration into the sanitary sewer collection system causes high wastewater flows to the treatment plant.

During these conditions, CMSA blends chemically enhanced primary-treated effluent from the primary clarifiers with fully-treated effluent from the secondary clarifiers prior to chlorination, dechlorination, and discharge into the Central San Francisco Bay.

Below are the blend events for the current wet weather season. The Agency maintains records of blend events from prior wet weather seasons.

 

Blending Events

Start End Duration
(Days)
Volume
(Million Gal.)
Rainfall*
(in)

Apr 6, 2017 - 22:55Apr 8, 2017 - 17:351.7819.021.04

Mar 24, 2017 - 10:20Mar 24, 2017 - 23:250.557.450.17

Mar 21, 2017 - 10:10Mar 21, 2017 - 12:350.100.430

Feb 20, 2017 - 02:15Feb 22, 2017 - 13:452.4876.542.58

Feb 19, 2017 - 18:30Feb 19, 2017 - 23:300.210.80

Feb 17, 2017 - 10:10Feb 18, 2017 - 19:201.3817.970.98

Feb 5, 2017 - 18:55Feb 10, 2017 - 23:205.18168.277.08

Feb 2, 2017 - 10:25Feb 4, 2017 - 21:552.4824.850.76

Jan 18, 2017 - 15:35Jan 24, 2017 - 11:405.8485.730

Jan 7, 2017 - 08:45Jan 13, 2017 - 13:256.19138.390

Jan 3, 2017 - 14:15Jan 5, 2017 - 11:101.8724.890

Dec 15, 2016 - 12:05Dec 16, 2016 - 14:591.1231.670

Dec 9, 2016 - 23:43Dec 12, 2016 - 20:192.863.570

Nov 20, 2016 - 09:31Nov 20, 2016 - 10:590.060.170

Nov 19, 2016 - 12:00Nov 19, 2016 - 16:530.201.640

*CMSA began automatic rainfall data collection Jan 25, 2017.

CMSA