Calistoga WWTP - Napa County, California Wastewater Treatment Plant

Calistoga WWTP is a municipal wastewater treatment facility located in Napa County, California, within the renowned Napa Valley wine region. Serving a population of approximately 5,629, the plant is part of the region's essential water infrastructure, supporting both residential and agricultural needs. As a US facility, Calistoga WWTP operates under the Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all discharges. For small to medium agglomerations like this, secondary treatment is typically mandated, with additional nutrient removal if the receiving water body is sensitive. Regulatory compliance ensures that effluent meets state and federal water quality standards. The plant's treated effluent is discharged into the Napa River watershed, which flows south through the Napa Valley and ultimately drains into San Pablo Bay, part of the San Francisco Bay estuary. This watershed supports diverse aquatic life and is critical for the region's ecology and economy, including vineyards and tourism. The plant plays a key role in protecting water quality in this sensitive environment.

Calistoga WWTP discharges into the Napa River, which flows through the Napa Valley to San Pablo Bay and the San Francisco Bay estuary. This watershed supports a rich ecosystem, including salmonids and other native fish, and is vital for the region's agricultural and recreational activities. The plant's operations help maintain water quality in this ecologically sensitive area, which is subject to seasonal variations and urban runoff pressures.