Grown in Marin
University of California
Grown in Marin

Project Background

Tomales Bay supports a two million dollar a year shellfish industry and endangered salmon and steelhead runs, and has been declared an impaired water body by the San Francisco Bay Regional Water Quality Control Board (RWQCB). Livestock-based agriculture, including dairy, beef and equestrian operations, has been identified as contributing sediments, nutrients and fecal-borne pathogens to tributary streams of the Bay, and these sediments and nutrients represent a significant loss of productive potential from Marin County farmlands. Hundreds of tons of nutrients purposefully imported into the region each year in the form of inorganic and organic fertilizers and livestock feeds contribute to the concentration of nutrients in West Marin surface waters. This project is designed to help agricultural operations meet recently established TMDL water quality standards, and anticipate future TMDL standards, for tributaries to Tomales Bay and elsewhere in the region.


For more than 100 years, West Marin dairies have utilized beach sand as a preferred bedding material. As of 2006, this sand was no longer available to dairy farmers. The proposed project will involve co-composting of dairy manure from the partner dairy with stable bedding from local horse facilities and green waste from landscaping and fire-fuel reduction efforts throughout West Marin.  Finished compost will be used to meet nutrient-balancing and low pathogen bedding needs on the partnering dairy, with surplus sold for dairy bedding and other agricultural, landscaping, restoration and erosion prevention and control purposes, throughout West Marin.

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