Serving roughly 60,781 people in Sonoma County, California.
Data current as of July 2026
🔍Straight from EPA
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Results for PETALUMA, CITY OF
1 water provider directly on file, serving roughly 60,781 people in Sonoma County, California.
Quick answer: PETALUMA, CITY OF has no violations on file. One reading is worth knowing about: Aggressive Index was measured at 12.68AGGR, among the highest of the 756 providers on file in this area. It's the most notable figure in this system's record among its 756 local peers.
Lead Summary
Copper Summary
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Aggressive Index
Magnesium
Sodium
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
TDS
Sulfate
Chloride
Fluoride
Nitrite
Nitrate
Turbidity
Gross Alpha Particle Activity
pH
Iron
Manganese
Barium
Arsenic
Conductivity (at 25°C)
Odor
Zinc
Utility PETALUMA, CITY OFPopulation served 60,781Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2023
Copper Summary
Detected: 1.6 mg/L (ppm)
12/31/1992
Iron
Detected: 240 UG/L (ppb)
9/10/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 140 UG/L (ppb)
9/10/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Barium
Detected: 200 UG/L (ppb)
3/5/2025
Arsenic
Detected: 2.8 UG/L (ppb)
3/5/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Zinc
Detected: 210 UG/L (ppb)
3/5/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 11.2 UG/L (ppb)
3/5/2025
TTHM
Detected: 30.27 UG/L (ppb)
3/5/2025
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.
Chloroform
Detected: 20.38 UG/L (ppb)
3/5/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 6.99 UG/L (ppb)
3/5/2025
Dibromochloromethane
Detected: 2.9 UG/L (ppb)
3/5/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 19 MG/L (ppm)
3/5/2025
Chloride
Detected: 41 MG/L (ppm)
3/5/2025
Fluoride
Detected: 0.1 MG/L (ppm)
3/5/2025
Often added deliberately for dental health; can also occur naturally.
Nitrite
Detected: 0.22 MG/L (ppm)
3/5/2025
Nitrate
Detected: 1.9 MG/L (ppm)
7/9/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 6.7 MG/L (ppm)
3/5/2025
Sodium
Detected: 56 MG/L (ppm)
3/5/2025
Calcium
Detected: 29 MG/L (ppm)
3/5/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 100 MG/L (ppm)
3/5/2025
Gross Alpha Particle Activity
Detected: 8.48 PCI/L
3/5/2025
pH
Detected: 7.69 PH
3/25/2025
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 220 MG/L (ppm)
3/25/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 5.5 UG/L (ppb)
3/5/2025
Trichloroaceticacid
Detected: 5.7 UG/L (ppb)
3/5/2025
Aggressive Index
Detected: 12.68 AGGR
3/5/2025
Alkalinity, Total
Detected: 220 MG/L (ppm)
3/25/2025
TDS
Detected: 250 MG/L (ppm)
3/5/2025
Turbidity
Detected: 1.4 NTU
3/5/2025
A measure of water cloudiness from suspended particles.
Conductivity (at 25°C)
Detected: 450 UMHO/CM
3/25/2025
Odor
Detected: 2 TON
3/5/2025
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.