Water Reuse

Our Water Reuse System

Santa Rosa Regional Water Reuse System is comprised of the Laguna Treatment Plant, Water Reuse Operations and Biosolids Distribution System and serves approximately 230,000 residents in Santa Rosa, Rohnert Park, Cotati, Sebastopol, and unincorporated portions of Sonoma County.

The hub of the Water Reuse System is the Laguna Treatment Plant, which cleans sewage from homes and businesses throughout the region so that it can be reused safely with beneficial outcomes. The Plant recycles approximately 7 billion gallons of wastewater each year. During dry to normal water years, nearly 100% of the tertiary treated recycled water is beneficially reused. 

Our state accredited environmental laboratory, located at the Plant, analyzes drinking water, sewage, and industrial waste to ensure compliance with applicable federal, state and local regulations, public health and protection of the Laguna de Santa Rosa watershed.

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Water Treatment Plant

Treatment Process

The Laguna Treatment Plant is a tertiary-level treatment facility that has a 17.5 million gallon average daily flow. The plant utilizes a 60 KV Power Substation, a 2.2 megawatt UltraViolet Disinfection system and a co-generation facility with four 1.1 megawatt Cummins engine/generator sets.

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Sprinklers watering a field.

Recycled Water

Water is cleaned at the Laguna Treatment Plant, and pumped through the recycled water distribution system. The system is comprised of 6,130 acres and utilizes 45 pump stations to deliver recycled water.

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Biosolids Facility


Biosolids provide nutrients and organic matter to soil and help it maintain moisture. The Biosolids Compost Facility is an agitated, aerobic, naturally heated, biological process that produces approximately 12,000 cubic yards of compost annually.

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Laguna de Santa Rosa

Natural Resources

Santa Rosa Water staff and the community take great pride in being stewards of our watershed. The Natural Resources Program aims to balance the use of recycled water to grow food with the need to preserve and promote biodiversity in the Laguna.

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Colgan Creek

Nutrient Offset Program

The nutrient offset program allows Santa Rosa Water to reduce nutrient loads elsewhere in the Laguna De Santa Rosa watershed by an amount at least equal to the amount discharged to meet requirements set forth in the NPDES Reclamation Discharge Permit.

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