Serving roughly 25,561 people in Sonoma County, California.
Data current as of July 2026
🔍Straight from EPA
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Results for WINDSOR, TOWN OF
1 water provider directly on file, serving roughly 25,561 people in Sonoma County, California.
Quick answer: WINDSOR, TOWN OF has no violations on file and no single reading stands out against its peers (756 other providers in this area). It serves roughly 25,561 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Totalhaloaceticacids (HAA5)
TTHM
Bromoform
Bromodichloromethane
Dibromochloromethane
Dibromoaceticacid
Chloroform
Dichloroaceticacid
Trichloroaceticacid
Copper, Free
Nitrate
Radium-228
Combined Radium (-226 & -228)
Utility WINDSOR, TOWN OFPopulation served 25,561Owner Local government
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2025
Copper, Free
Detected: 57 UG/L (ppb)
7/24/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 1.7 UG/L (ppb)
8/6/2025
TTHM
Detected: 7.75 UG/L (ppb)
8/6/2025
A group of disinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure above the legal limit has been linked to increased cancer risk in some studies.
Bromoform
Detected: 1.71 UG/L (ppb)
8/6/2025
Bromodichloromethane
Detected: 2.44 UG/L (ppb)
8/6/2025
Dibromochloromethane
Detected: 3.6 UG/L (ppb)
8/6/2025
Chloroform
Detected: 5.37 UG/L (ppb)
8/6/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Nitrate
Detected: 0.7 MG/L (ppm)
3/3/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Other
Additional substances tested that don't fit neatly into the categories above
Dibromoaceticacid
Detected: 1.7 UG/L (ppb)
8/6/2025
Dichloroaceticacid
Detected: 2.8 UG/L (ppb)
8/6/2025
Trichloroaceticacid
Detected: 1.3 UG/L (ppb)
8/6/2025
Radium-228
Detected: 0.616 PCI/L
9/17/2025
Combined Radium (-226 & -228)
Detected: 0.58 PCI/L
9/17/2025
A naturally occurring radioactive element found in some groundwater.
Filtration considerations: See the table below for how whole-house carbon, under-sink reverse osmosis, and under-sink carbon systems compare against what's actually on file here. These are general system types, not a specific product recommendation.