Larkfield Wikiup WWTF - Santa Rosa, California Wastewater Treatment Plant

Larkfield Wikiup WWTF is a wastewater treatment facility located in Santa Rosa, California, within Sonoma County. It serves a population of approximately 9,306 residents, making it a medium-sized plant for the region. The facility is situated inland, about 50 kilometers from the Pacific coast, and operates under the regulatory framework of the United States Clean Water Act. As a plant serving fewer than 10,000 people, it falls under the category of small to medium publicly owned treatment works (POTWs). Under the Clean Water Act, such facilities are typically required to meet secondary treatment standards through National Pollutant Discharge Elimination System (NPDES) permits issued by the California State Water Resources Control Board. The plant's designed capacity is 1.00 million gallons per day, indicating its scale relative to the community it serves. The treated effluent from the plant likely discharges into local waterways that drain into the Russian River or directly to the Pacific Ocean via the Sonoma County watershed. The region supports diverse aquatic life and is important for migratory fish species. Proper treatment helps protect downstream water quality and ecological health.

The plant is located in the Russian River watershed, which flows southward through Sonoma County before emptying into the Pacific Ocean at Jenner. The river supports critical habitats for steelhead trout and coho salmon, both of which are species of conservation concern. The facility's discharge contributes to the overall water quality of this ecologically sensitive coastal basin.