Santa Rosa’s Water Supply: The Russian River
Santa Rosa, California — the largest city in Sonoma County with about 180,000 residents — gets most of its drinking water from the Russian River. The Sonoma Water agency operates the system that supplies Santa Rosa and other communities throughout the county, drawing river water and storing it in Lake Sonoma and Lake Mendocino.
It’s high-quality source water — when everything goes right. But several converging issues have complicated Santa Rosa’s water quality picture in recent years.
PFAS at the Charles M. Schulz Airport
The Charles M. Schulz–Sonoma County Airport, located just northwest of Santa Rosa, used AFFF firefighting foam containing PFAS during training exercises and emergency response, consistent with FAA requirements that were in place for decades.
PFAS contamination associated with airport firefighting operations has been documented at airports across California and nationwide. In Santa Rosa’s case, the airport is located near the Laguna de Santa Rosa — a wetland complex that connects to the Russian River watershed. Any PFAS that migrated from airport operations into soil and groundwater has the potential to reach broader water resources.
The California State Water Resources Control Board has been conducting a statewide PFAS investigation, requiring monitoring at airports, military facilities, and other likely sources. Sonoma County Water Agency monitors for PFAS in its treated water supply and has reported results in compliance with California’s notification and response levels.
California has some of the most protective PFAS thresholds in the country, with notification levels of 5.1 ppt for PFOA and 6.5 ppt for PFOS — far lower than the previous federal advisory levels and in line with the EPA MCLs established in 2024.
Wildfire Impacts on Water Quality
The 2017 Tubbs Fire devastated parts of Santa Rosa, destroying over 5,600 structures — including entire neighborhoods in the Coffey Park and Fountaingrove areas. The 2019 Kincade Fire burned another 77,000 acres in Sonoma County. The 2020 Glass and Walbridge fires hit wine country again.
Wildfires affect water quality in several ways that most people don’t think about:
Watershed Damage
When fire strips vegetation from hillsides, the exposed soil erodes much more readily during the next rainstorm. This sends sediment, ash, and debris into rivers and reservoirs that supply drinking water. Increased turbidity makes treatment more difficult and can overwhelm filtration systems.
Benzene in Distribution Systems
After the Tubbs Fire, something alarming happened: benzene and other volatile organic compounds were detected in the water distribution system in fire-affected areas. When plastic water pipes melt or are damaged by extreme heat, they can release chemicals into the water they carry. This contamination persisted in some areas even after water pressure was restored.
Santa Rosa had to conduct extensive flushing and testing of water lines in fire-affected zones before clearing them for use. The lesson — which other fire-prone communities are now learning — is that rebuilding water infrastructure after a wildfire isn’t just about replacing pipes. It’s about confirming that the entire distribution system is safe.
Soil Contamination Mobilization
Fire destroys structures that contain hazardous materials — lead paint, asbestos, pesticides stored in garages, chemicals in commercial buildings. The ash and debris from burned structures concentrate these contaminants in the soil, where rain can wash them into waterways or leach them into groundwater.
Drought and Water Supply Stress
The Russian River’s flow is managed through releases from Lake Mendocino and Lake Sonoma, but prolonged drought reduces both reservoir storage and natural stream flow. During California’s severe drought years, Russian River flows dropped to levels that stressed both water supply and habitat for endangered coho salmon and steelhead trout.
Low flows concentrate whatever contaminants are present in the water — agricultural runoff from vineyards and farms, treated wastewater discharge from upstream communities, and natural minerals from the riverbed.
Sonoma Water has invested in diversifying its supply, including groundwater banking, recycled water programs, and conservation measures. But the Russian River remains the backbone, and its vulnerability to drought is a long-term concern.
Current Water Quality
Santa Rosa’s treated drinking water meets all federal and state standards. Sonoma Water’s treatment process — including coagulation, sedimentation, filtration, and disinfection — effectively handles the contaminant levels typically found in Russian River source water.
The annual Consumer Confidence Report provides detailed testing results. Key things to watch in the Santa Rosa context:
- PFAS results — given the airport contamination concerns
- Disinfection byproducts — trihalomethanes (THMs) and haloacetic acids (HAAs) formed when chlorine reacts with organic matter in the source water
- Turbidity — an indicator of how effectively treatment is removing particles, especially important after fire seasons
What Santa Rosa Residents Can Do
Check the latest water quality report from your water provider (City of Santa Rosa for city residents, or your specific water district). If you were in a fire-affected area and your water service was interrupted, confirm that your specific service line has been tested and cleared.
If you have a private well — particularly near the airport or in areas affected by wildfire — get comprehensive testing done. PFAS, VOCs, and metals should all be on the list.
For additional protection against PFAS, disinfection byproducts, or other trace contaminants, a certified water treatment professional can recommend point-of-use systems appropriate for your water chemistry.
Sources: California State Water Resources Control Board PFAS investigation data; Sonoma Water annual water quality reports; Cal Fire incident reports (Tubbs, Kincade, Glass, Walbridge fires); EPA wildfire and drinking water guidance; USGS Russian River watershed studies; City of Santa Rosa Utilities Department.