Is Stockton, CA Tap Water Safe? Quality & Contaminants

What was found in Stockton's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

Contaminant	Level vs EPA limit	Suppliers	Source
Nitrate-Nitrite	825000 µg/L 8250% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 960000 µg/L — STOCKTON EAST WATER DISTRICT · 50 people · 2019	39/48	SYR4
Nitrate	5857 µg/L 59% of the EPA limit 10000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 10730.5 µg/L — CORRAL HOLLOW PWS · 145 people · 2019	43/48	SYR4
Copper	544 µg/L 42% of the EPA limit 1300 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 8200 µg/L — CARIBOU MOBILE PARK PWS · 180 people · 2019	25/48	SYR4
Barium	290 µg/L 14% of the EPA limit 2000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 355.65 µg/L — SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2019	40/48	SYR4
Fluoride	160 µg/L 4% of the EPA limit 4000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 300 µg/L — SAN JOAQUIN COUNTY-RAYMUS VILLAGE · 1,086 people · 2019	30/48	SYR4
TTHM	88.85 µg/L 111% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 121.5 µg/L — SAN JOAQUIN COUNTY - LINCOLN VILLAGE · 5,841 people · 2019	10/48	SYR4
Chloroform	62 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019	7/48	SYR4
Dibromochloromethane	26 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 50.485 µg/L — SAN JOAQUIN COUNTY - LINCOLN VILLAGE · 5,841 people · 2019	10/48	SYR4
Total Haloacetic Acids (HAA5)	48 µg/L 80% of the EPA limit 60 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019	10/48	SYR4
Bromoform	23 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 36.76 µg/L — SAN JOAQUIN COUNTY - COLONIAL HEIGHTS · 1,841 people · 2019	9/48	SYR4
Combined Uranium	16.688 µg/L 56% of the EPA limit 30 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 32.7725 µg/L — SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2019	28/48	SYR4
Bromodichloromethane	22 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 31.795 µg/L — SAN JOAQUIN COUNTY - LINCOLN VILLAGE · 5,841 people · 2019	10/48	SYR4
Lead	30.2 µg/L 201% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019	29/48	SYR4
Bromate	26.95 µg/L 270% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019	1/48	SYR4
Dichloroacetic Acid	26.41 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019	4/48	SYR4
Chromium	11.8 µg/L 12% of the EPA limit 100 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 25.5 µg/L — ACAMPO WATER SYSTEM · 231 people · 2018	35/48	SYR4
Arsenic	7.62 µg/L 76% of the EPA limit 10 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 25 µg/L — OAKWOOD LAKE WATER DISTRICT-SUBDIVISION · 1,479 people · 2019	39/48	SYR4
Trichloroacetic Acid	17.3 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 21 µg/L — STOCKTON EAST WATER DISTRICT · 50 people · 2019	5/48	SYR4
Tetrachloroethylene	14.06 µg/L 281% of the EPA limit, at the 95th percentile of samples — 5 µg/L Highest in the city: SAN JOAQUIN COUNTY - WILKINSON MANOR · 851 people · 2019	5/48	SYR4
Selenium	5.885 µg/L 12% of the EPA limit 50 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 13.2 µg/L — PAR COUNTRY ESTATES CSA-16 · 178 people · 2018	23/48	SYR4
Dibromoacetic Acid	10.75 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 12.85 µg/L — SAN JOAQUIN COUNTY - COLONIAL HEIGHTS · 1,841 people · 2019	10/48	SYR4
Monochloroacetic Acid	9.99 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019	3/48	SYR4
Toluene	7.1 µg/L 0.7% of the EPA limit 1000 µg/L Highest in the city: ENCLAVE AT THE DELTA · 39 people · 2016	2/48	SYR4
Monobromoacetic Acid	2 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 3 µg/L — SAN JOAQUIN COUNTY - COLONIAL HEIGHTS · 1,841 people · 2019	6/48	SYR4
Gross Beta Particle Activity	1.3185 pCi/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2012 Highest in the city: 2.55 pCi/L — STOCKTON EAST WATER DISTRICT · 50 people · 2015	2/48	SYR4
cis-1,2-Dichloroethylene	2.15 µg/L 3.1% of the EPA limit 70 µg/L Highest in the city: SAN JOAQUIN COUNTY - WILKINSON MANOR · 851 people · 2019	1/48	SYR4
Trichloroethylene	0.6100 µg/L 12% of the EPA limit 5 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 1.075 µg/L — SAN JOAQUIN COUNTY - WILKINSON MANOR · 851 people · 2019	3/48	SYR4
Mercury	0.2950 µg/L 15% of the EPA limit 2 µg/L Highest in the city: SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2019	9/48	SYR4
1,2-DIBROMO-3-CHLOROPROPANE	0.0100 µg/L 5% of the EPA limit 0.2000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 Highest in the city: 0.2160 µg/L — ACAMPO WATER SYSTEM · 231 people · 2019	9/48	SYR4
Ethylene Dibromide	0.1150 µg/L 230% of the EPA limit, at the 95th percentile of samples — 0.0500 µg/L Highest in the city: MORADA ESTATES PWS · 290 people · 2019	1/48	SYR4
PFOS	0.0048 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2025 Highest in the city: 0.0135 µg/L — SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2025	2/48	UCMR-5
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2026 Highest in the city: 0.0130 mg/L — EL RIO MOBILE HOME PARK · 60 people · 2024	47/48	LCR
PFBS	0.0085 µg/L No EPA limit set Highest in the city: SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2025	1/48	UCMR-5
PFOA	0.0083 µg/L No EPA limit set Highest in the city: SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2025	1/48	UCMR-5
PFHXS	0.0047 µg/L No EPA limit set Highest in the city: SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2025	1/48	UCMR-5
Pfhxa	0.0035 µg/L No EPA limit set Highest in the city: SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2025	1/48	UCMR-5
Pfpea	0.0033 µg/L No EPA limit set Highest in the city: SAN JOAQUIN COUNTY-MOKELUMNE ACRES · 3,802 people · 2025	1/48	UCMR-5

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 the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Stockton

Supplier	Population served
CITY OF STOCKTON	191,302
SAN JOAQUIN COUNTY - LINCOLN VILLAGE	5,841
CDCR CALIFORNIA HEALTH CARE FACILITY	5,551
SAN JOAQUIN COUNTY-MOKELUMNE ACRES	3,802
SAN JOAQUIN COUNTY - COLONIAL HEIGHTS	1,841
OAKWOOD LAKE WATER DISTRICT-SUBDIVISION	1,479
FAIROAKS PWS #44	1,172
SAN JOAQUIN COUNTY-RAYMUS VILLAGE	1,086
SAN JOAQUIN COUNTY - THORNTON	964
SAN JOAQUIN COUNTY - WILKINSON MANOR	851
STOCKTON VERDE MOBILE HOME PARK	711
MORADA ESTATES N PWS #46	426
BEL AIR MOBILE ESTATE	325
SANTOS RANCH PWS #5-CSA #35	320
SAN JOAQUIN WATER WORKS #2	310
MORADA ESTATES PWS	290
CLEMENTS WATER WORKS #43	264
TWIN OAKS MOBILE PARK	238
SHADED TERRACE PWS	238
KING ISLAND TRAILER PARK WATER SYSTEM	236
ELKHORN ESTATES WATER SYSTEM	234
ACAMPO WATER SYSTEM	231
SAN JUAN VISTA	201
CARIBOU MOBILE PARK PWS	180
PAR COUNTRY ESTATES CSA-16	178
GAYLA MANOR PWS	178
RANCHO SAN JOAQUIN WATER SYS	172
FAIRWAY ESTATES PWS CSA-18	149
CORRAL HOLLOW PWS	145
MOBILE VILLAS TRAILER PARK	130
WILKINSON MANOR A-ZONE PWS	125
BIG WHEEL MOBILE HOME PARK	120
SPRING CREEK ESTATES PWS	119
MORADA MANOR WATER SYSTEM	112
WALNUT ACRES	106
MORADA ACRES WATER SYSTEM	105
CHERRY LANE TRAILER PARK	100
MAURLAND MANOR WATER SYSTEM	92
A1 WINSTONS MOBILE HOME PARK	75
WAYSIDE MOTEL APARTMENTS WTR SYS	70
SUNNYSIDE ESTATES WATER SYSTEM	69
EL RIO MOBILE HOME PARK	60
ALMOND PARK WATER SYSTEM	60
STOCKTON EAST WATER DISTRICT	50
WINE COUNTRY APARTMENTS	40
ENCLAVE AT THE DELTA	39
FREMONT ONE	39
V & P TRAILER COURT WATER SYSTEM	35

Frequently asked questions about Stockton tap water

Is Stockton tap water safe to drink?

EPA testing detected 37 contaminants in the water serving Stockton. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Stockton?

48 public water suppliers report drinking-water monitoring for Stockton, California to the EPA. Each is listed above with its population served.

What contaminants are in Stockton's water?

The contaminants EPA monitoring detected in Stockton include Nitrate-Nitrite, Nitrate, Copper, Barium, Fluoride. The full list, with the level at the main supplier and the data source, is in the table above.

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.