Drinking water quality · 2024
· Verified
What's in Stockton, CA tap water
25 contaminants were measured in the Stockton, CA water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 25
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound above EPA limits in Stockton, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (1.2×)Where your water comes from · EPA SDWIS
Stockton, CA's drinking water comes from ground water, drawn from 18 sources.
Source
- WELL NO. · 9
- WELL NO. 03 SSS
- WELL NO. 15 - STANDBY
- DWSP-DELTA WATER SOURCE-RAW
- + 6 more
Treatment
- WELL NO. 15 - TREATED - XCLD - STDBY
- WELL NO. 10R - TREATED - XCLD
- WELL NO. 27 - TREATED - XCLD
- + 14 more
Distribution
Also buys water from STOCKTON EAST WATER DISTRICT.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based4 violations on record · most recent Apr 2023resolved
- Treatment technique violationHealth-based1 violation on record · most recent Mar 2016resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 57 ug/LAverageAnnual Average | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 25 ug/LAverageAnnual Average | None set | Within the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.88 mg/LAverageSystem-wide | 4 mg/LMCL | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 2.2 mg/LAverageGroundwater | 10 mg/LMCL | Within the limit |
+By source (2)— Groundwater, Sewd
| |||
| FluorideA mineral often added to drinking water to help prevent tooth decay. | Not detected mg/LAverageGroundwater | 4 mg/LMCL | Within the limit |
+By source (2)— Groundwater, Sewd
| |||
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 3.1 pCi/LAverageSystem-wide | 15 pCi/LMCL | Within the limit |
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 2.2 pCi/LAverageSystem-wide | 20 pCi/LMCL | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.14 mg/LAverageGroundwater | 2 mg/LMCL | Within the limit |
+By source (2)— Groundwater, Sewd
| |||
| CopperA metal that enters water from corroding household plumbing. | Not detected mg/L90th percentileAt the tap | 1.3 mg/LAction level | None detected |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0.0 mg/L90th percentileAt the tap | 0.015 mg/LAction level | None detected |
| AluminumA common element sometimes used as a treatment coagulant. | Not detected mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| BoronA naturally occurring element from rock and soil. | Not detected mg/LAverageGroundwater | 1 mg/LNL | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| CalciumA naturally occurring mineral that contributes to water hardness. | 33 mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 16 mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| PotassiumA naturally occurring mineral from rock and soil. | 4.9 mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| SodiumA naturally occurring salt component. | 23 mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| Vanadium | 19 ug/LAverageGroundwater | 50 ug/LNL | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0MaximumMonthly | None set | None detected |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium | Not detected ug/LAverageGroundwater | None set | Within the limit |
+By source (2)— Groundwater, Sewd
| |||
| Tce | Not detected ug/LAverageGroundwater | None set | Within the limit |
+By source (2)— Groundwater, Sewd
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| AlkalinityA measure of the water's capacity to neutralize acids. | 171 mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| HardnessA measure of dissolved calcium and magnesium minerals. | 150 mg/LAverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| pHA measure of how acidic or basic the water is. | 8AverageGroundwater | None set | Detected — no federal limit |
+By source (2)— Groundwater, Sewd
| |||
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 2.2 mg/LMaximumSystem-wide | None set | Detected — no federal limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Dichlorodifluoromethane | Not detected ug/LAverageGroundwater | 1000 ug/LNL | Detected — no federal limit |
People also ask about Stockton, CA's water
+Is Stockton, CA tap water safe to drink in 2024?
Every one of the 25 contaminants measured in Stockton, CA's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Stockton, CA tap water?
25 contaminants were measured in Stockton, CA's 2024 Consumer Confidence Report, spanning metals, physical & aggregate, and disinfection byproducts. 11 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Where does the data on this page come from?
Every value is transcribed from Stockton, CA's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Stockton, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.