Is Stockton, CA tap water safe?

Data: U.S. EPA · How we read the data · How we check it

City of Stockton, the largest system here, had PFAS above the 2024 federal limits (PFOS) in EPA's 2023–2025 testing.

Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility issues a boil-water or do-not-drink notice, follow it.

5 public water systems serve parts of Stockton. The largest, City of Stockton, serves 192,702 people, and one system here had PFAS above a federal limit. Your water bill names your system.

Largest system

City of Stockton

192,702 people · Surface water · EPA ID CA3910012

Buys treated water from Stockton East Water District.

PFAS	Highest average	Limit	Status
PFOA One sample above limit	3.35 ppt	4 ppt	One sample above limit
PFOS Above limit	14 ppt	4 ppt	Above limit
PFHxS Not detected	–	10 ppt	Not detected
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

For context: the PFOS average is higher than at 92% of the California systems EPA tested.

Lead: 0 ppb at the 90th percentile (Nov 2026, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 3

Full City of Stockton results

Across California, 129 of 691 water systems EPA tested had PFAS above a 2024 federal limit, and 26 systems were above the lead action level in results from the last five years. California results.

Stockton homes and lead pipes

51%

of homes built before 1980 (California 56%, US 50%)

14%

built before 1950 (California 14%)

46%

of households rent (California 44%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Stockton city (tables B25034, B25003). Estimates for small places have a margin of error.

Which system serves your ZIP code

Based on the ZIP codes each system reported serving. Boundaries don't follow ZIP lines exactly, so your water bill is the final word.

System	ZIP codes in Stockton
City of Stockton 192,702 people	95205, 95207, 95209, 95210
California Water Service – Stockton 182,775 people	95202, 95203, 95204, 95211

Other water systems serving Stockton

California Water Service – Stockton
182,775 people · Purchased surface water · California · reported ZIPs here
PFOS detected
San Joaquin County – Lincoln Village
5,841 people · Purchased surface water · California · reported ZIPs here
No PFAS above limits
Cdcr California Health Care Facility Water System
2,186 people · Purchased surface water · California · lists this city
Total trihalomethanes (TTHM) violations
Wine Country Apartments Water System
40 people · Groundwater · California · reported ZIPs here
No PFAS above limits

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Lodi 10 mi City of Lodi	City of Lodi	Above limit	0 ppb
Lathrop 12 mi City of Lathrop	City of Lathrop	Above limit	0 ppb
Manteca 14 mi City of Manteca	City of Manteca	Above limit	0.4 ppb
Tracy 19 mi City of Tracy	City of Tracy	None above limits	0 ppb
Mountain House 19 mi City of Mountain House	City of Mountain House	None above limits	0 ppb
Galt 20 mi City of Galt	City of Galt	None above limits	0 ppb

Questions

Is Stockton tap water safe to drink?

City of Stockton had 3 health-based violations since 2016, and EPA testing found PFAS above the 2024 federal limits, which it must meet by 2029. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Stockton, CA?

5 public water systems serve parts of Stockton. The largest is City of Stockton (192,702 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Stockton tap water have PFAS?

Yes. EPA's 2023–2025 testing found entry-point averages above the 2024 federal limits for PFOS at City of Stockton. Systems have until 2029 to meet them.

Do Stockton homes have lead pipes?

Census estimates put 51% of Stockton homes as built before 1980 (California: 56%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. City of Stockton's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.