Serving roughly 191,302 people in San Joaquin County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for CITY OF STOCKTON
1 water provider directly on file, serving roughly 191,302 people in San Joaquin County, California.
Quick answer: CITY OF STOCKTON has no violations on file. One reading is worth knowing about: Dibromochloromethane was measured at 17.86UG/L, among the highest of the 571 providers on file in this area. It's the most notable figure in this system's record among its 571 local peers.
Lead Summary
PFOS
Nitrate
Combined Uranium
Gross Alpha Particle Activity
Chromium, Hex
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dichloroaceticacid
Trichloroaceticacid
Bromoform
Dibromochloromethane
Dibromoaceticacid
Utility CITY OF STOCKTONPopulation served 191,302Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2026
Combined Uranium
Detected: 6.4 PCI/L
9/24/2025
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Chromium, Hex
Detected: 2.83 UG/L (ppb)
1/29/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 15.6 UG/L (ppb)
10/8/2025
TTHM
Detected: 47.08 UG/L (ppb)
10/8/2025
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: 42.72 UG/L (ppb)
10/8/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 4.36 UG/L (ppb)
10/8/2025
Bromoform
Detected: 8.18 UG/L (ppb)
10/8/2025
Dibromochloromethane
Detected: 17.86 UG/L (ppb)
10/8/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Nitrate
Detected: 4 MG/L (ppm)
8/12/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Gross Alpha Particle Activity
Detected: 11.3 PCI/L
8/12/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
PFOS
Detected: 0.0042 µg/L (ppb)
2/28/2023
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 8.5 UG/L (ppb)
10/8/2025
Trichloroaceticacid
Detected: 7.1 UG/L (ppb)
10/8/2025
Dibromoaceticacid
Detected: 4.8 UG/L (ppb)
10/8/2025
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.