SASM WWTF - Mill Valley, California Wastewater Treatment Plant

SASM WWTF is a municipal wastewater treatment facility located in Mill Valley, California, within Marin County. The plant serves a population of about 19,561 people, classifying it as a medium-sized agglomeration under U.S. regulatory frameworks. Its location in the San Francisco Bay Area places it within a densely populated region with stringent environmental oversight. As a U.S. facility, SASM WWTF operates under the Clean Water Act, administered by the U.S. EPA and the California State Water Resources Control Board. Plants of this scale typically require secondary treatment as a minimum, with potential nutrient removal requirements due to the sensitive nature of the San Francisco Bay watershed. The designed capacity of 1.00 million gallons per day indicates the plant's infrastructure is sized to handle current and projected flows. The plant's treated effluent is discharged into the San Francisco Bay estuary, which ultimately connects to the Pacific Ocean. The Bay is an ecologically significant water body supporting diverse aquatic life, including migratory fish and bird species. The plant's operations are critical to protecting water quality in this urbanized estuary, where nutrient loading and pollutant control are ongoing challenges.

SASM WWTF discharges into the San Francisco Bay, a large estuary that drains into the Pacific Ocean via the Golden Gate. The Bay supports a complex ecosystem with tidal marshes, eelgrass beds, and habitats for species such as Chinook salmon and steelhead trout. The plant's location within 50 km of the coast means its discharge can influence coastal water quality, particularly during low-flow periods. Regional efforts focus on reducing nutrient loads and contaminants to protect the Bay's ecological health and recreational uses.