Pacifica Fined $2.3 Million for Sewage Spill


By on Sat, October 31, 2009

The City of Pacifica faces a $2.3 million fine imposed by the Regional Water Quality Control Board (RWQCB) for discharge of partially treated sewage estimated at 6.9 million gallons into the Pacific Ocean during a rainstorm on January 25 and 26, 2008.

See the article headlined "Sewage spill costs Pacifica" by Julia Scott in the San Mateo County Times for Thursday, October 29, 2009 - available online at for the full story.

Midcoast residents may remember that storm also, because areas in Montara and Moss Beach were flooded. Fortunately, San Mateo County has completed stormwater drainage improvement projects in the Cedar Street and Harte Street vicinity in Montara, and several areas in Moss Beach, in time to prevent or reduce the severity of flooding in the coming rainy season.

Sewer Authority Mid-Coastside (SAM) also had a spill resulting from that same rainstorm in 2008, but the improvements already completed in SAM’s Wet Weather Flow Management Program were able to capture and store 579,656 gallons that would otherwise have spilled within the SAM service area - at the treatment plant in Half Moon Bay, near Surfer’s Beach in El Granada, or at the old Montara wastewater treatment plant.

Prior to 1999, SAM was experiencing an average of ten spills per year from the Intertie Pipeline System (IPS), which collects sewage from within the City of Half Moon Bay, Granada Sanitary District, and Montara Water and Sanitary District for transport to the wastewater treatment plant in Half Moon Bay. After careful studies and consideration of cost-effective alternatives, the SAM member agencies agreed on improvements that currently provide 579,656 gallons of wet weather equalization storage within the system. These existing improvements prevent overflows in all but the most severe storms - down from an average of 10 per year to about 0.5 per year. It has been estimated that these existing improvements have already saved ratepayers approximately $1,323,473.58 in potential fines by the RWQCB.

Completion of the SAM Wet Weather Flow Management Program improvements should eliminate IPS overflows for storms with an intensity likely to recur only once every five years or longer, on average. SAM’s exposure to fines from the RWQCB will be significantly reduced once these improvements are completed.

Further details on the Wet Weather Flow Management Program can be found on the SAM website at which is a report summarizing the problem (as of 1999) and examining solutions.

For comparison with our recent storm on October 13, where 3.71 inches of rain was recorded at Montara and there was no overflow within the SAM IPS, the rainfall on January 25, 2008 totalled 4.06 inches and on January 26, 2008 was an additional 0.44 inches. Pacifica is closest to Montara of the SAM member agencies and has similar hilly topography, so the Montara rain gauge presents the best basis for comparison.