Snelling WWTF - Secondary Wastewater Treatment Plant in Snelling, California

Snelling WWTF is a municipal wastewater treatment facility located in Snelling, California, a small community in Merced County. The plant serves a population of approximately 380 residents, reflecting its role as a small-scale treatment system in a rural agricultural region of the Central Valley. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for municipal wastewater. It has a designed capacity of 227.12 million gallons per year and currently discharges 113.56 million gallons annually, indicating it operates well below capacity. As a US facility, it operates under an EPA NPDES permit issued by the California State Water Resources Control Board, which sets effluent limits to protect water quality. The treated effluent is discharged into local waterways that drain into the San Joaquin River system, ultimately reaching the Sacramento-San Joaquin Delta and San Francisco Bay. The plant's operations are important for protecting downstream aquatic habitats and supporting water quality in the agriculturally intensive Central Valley region.

The plant's discharge enters the Merced River watershed, a tributary of the San Joaquin River. This river system flows through the Central Valley, a major agricultural region, and eventually reaches the Sacramento-San Joaquin Delta and San Francisco Bay. The downstream environment supports diverse aquatic life, including salmon and steelhead trout, and is ecologically sensitive to nutrient loading and contaminants. The plant's secondary treatment helps reduce organic pollutants and suspended solids before discharge.