Ellis Creek WRF - Petaluma, California Wastewater Treatment Plant

Ellis Creek WRF is a municipal wastewater treatment facility located at 873 Hopper Street in Petaluma, California, within Sonoma County. The plant serves a population of approximately 59,462, placing it in the medium agglomeration category for US facilities. Its designed capacity is 1.00 million gallons per day, reflecting the scale of the community it supports. As a US-based plant, Ellis Creek WRF operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the California State Water Resources Control Board or the San Francisco Bay Regional Water Quality Control Board. These permits set effluent limits to protect water quality. Plants of this size typically employ secondary treatment with disinfection to meet regulatory standards. The plant's treated effluent is discharged to a receiving water body within the Petaluma River watershed, which flows into the San Pablo Bay, part of the San Francisco Bay estuary. This estuary supports diverse aquatic life, including fish species such as Chinook salmon and steelhead trout, and is an important ecological corridor. The plant's operations are critical to maintaining water quality in this sensitive estuarine environment.

Ellis Creek WRF discharges into the Petaluma River, which flows southward into San Pablo Bay, the northern arm of the San Francisco Bay estuary. This estuarine system supports a rich ecosystem, including migratory birds, fish, and invertebrates. The plant's effluent must meet stringent nutrient and pollutant limits to prevent eutrophication and protect aquatic habitats in the bay.