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Tap water quality report

City of Stockton

EPA monitoring tested this supplier for 113 contaminants and detected 27. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

113
contaminants tested
27
detected
191,302
people served
10
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Surface water
Ownership
Local government
Counties served
San Joaquin

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

10
health-based violations
19
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 2023-04-01 → 2023-06-30
MCL Health-based Resolved 2023-04-01 → 2023-06-30
MCL Health-based Resolved 2023-01-01 → 2023-03-31
MCL Health-based Resolved 2023-01-01 → 2023-03-31
TT Health-based Resolved 2016-03-01 → 2016-03-31
TT Health-based Resolved 2016-03-01 → 2016-03-31
MCL Health-based Resolved 2013-01-01 → 2013-03-31
MCL Health-based Resolved 2013-01-01 → 2013-03-31
MCL Health-based Resolved 1999-12-01 → 1999-12-31
MCL Health-based Resolved 1999-12-01 → 1999-12-31

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
PFOS 0.0048 µg/L 2/35 2025

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
TTHM
88.85 µg/L 111%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
worst single sample: 140 µg/L
604/633 SYR4 2012–2019
Chloroform
62 µg/L
No EPA limit set
worst single sample: 120 µg/L
597/619 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
48 µg/L 80%
of the EPA limit 60 µg/L
worst single sample: 96.3 µg/L
593/613 SYR4 2012–2019
Bromodichloromethane
22 µg/L
No EPA limit set
worst single sample: 39 µg/L
585/619 SYR4 2012–2019
Dichloroacetic Acid
26.41 µg/L
No EPA limit set
worst single sample: 43 µg/L
584/613 SYR4 2012–2019
Trichloroacetic Acid
17.3 µg/L
No EPA limit set
worst single sample: 65.5 µg/L
578/613 SYR4 2012–2019
Dibromochloromethane
26 µg/L
No EPA limit set
worst single sample: 57 µg/L
371/619 SYR4 2012–2019
Dibromoacetic Acid
10.75 µg/L
No EPA limit set
worst single sample: 22 µg/L
266/613 SYR4 2012–2019
Nitrate
5857 µg/L 59%
of the EPA limit 10000 µg/L
worst single sample: 7006 µg/L
266/322 SYR4 2012–2019
Bromoform
23 µg/L
No EPA limit set
worst single sample: 57 µg/L
215/619 SYR4 2012–2019
Monochloroacetic Acid
9.99 µg/L
No EPA limit set
worst single sample: 18.3 µg/L
203/613 SYR4 2012–2019
Monobromoacetic Acid
2 µg/L
No EPA limit set
worst single sample: 2.1 µg/L
132/613 SYR4 2012–2019
Arsenic
7.62 µg/L 76%
of the EPA limit 10 µg/L
worst single sample: 9 µg/L
50/77 SYR4 2012–2019
Barium
290 µg/L 14%
of the EPA limit 2000 µg/L
worst single sample: 400 µg/L
50/77 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 35/35 LCR 2026
Bromate
26.95 µg/L 270%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
worst single sample: 36 µg/L
24/89 SYR4 2012–2019
Combined Uranium
16.688 µg/L 56%
of the EPA limit 30 µg/L
worst single sample: 19.221 µg/L
21/21 SYR4 2012–2019
Nitrate-Nitrite
825000 µg/L 8250%
of the EPA limit, at the 95th percentile of samples — 10000 µg/L
worst single sample: 840000 µg/L
16/37 SYR4 2012–2019
Fluoride
160 µg/L 4%
of the EPA limit 4000 µg/L
worst single sample: 200 µg/L
11/75 SYR4 2012–2019
Lead
30.2 µg/L 201%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
worst single sample: 35 µg/L
7/78 SYR4 2012–2019
Chromium
11.8 µg/L 12%
of the EPA limit 100 µg/L
worst single sample: 12 µg/L
3/77 SYR4 2012–2019
Gross Beta Particle Activity
1.3185 pCi/L
No EPA limit set
worst single sample: 1.44 pCi/L
3/4 SYR4 2012
Copper
544 µg/L 42%
of the EPA limit 1300 µg/L
worst single sample: 560 µg/L
2/75 SYR4 2012–2019
Selenium
5.885 µg/L 12%
of the EPA limit 50 µg/L
worst single sample: 5.9 µg/L
2/77 SYR4 2012–2019
1,2-DIBROMO-3-CHLOROPROPANE
0.0100 µg/L 5%
of the EPA limit 0.2000 µg/L
 1/61 SYR4 2012–2019
Trichloroethylene
0.6100 µg/L 12%
of the EPA limit 5 µg/L
 1/71 SYR4 2012–2019
86 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,3,7,8-TCDD2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
LYTLE, MEL
Phone
209-937-8438
Email
[email protected]

Frequently asked questions about City of Stockton

Is City of Stockton tap water safe to drink?

EPA monitoring detected 27 contaminants in City of Stockton's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in City of Stockton's water?

EPA monitoring detected TTHM, Chloroform, Total Haloacetic Acids (HAA5), Bromodichloromethane, Dichloroacetic Acid, and others. The full list with the level and data source for each is above.

How many people does City of Stockton serve?

City of Stockton reports serving 191,302 people in California, per its EPA record.

Has City of Stockton had any water quality violations?

The EPA has 19 violations on file for City of Stockton, of which 10 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.