Tap Water Results

Is Patterson, CA tap water safe?

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

Summary

No federal limits exceeded in EPA data for City of Patterson.

City of Patterson supplies Patterson (24,977 people).

Water system

City of Patterson

24,977 people · Groundwater · EPA ID CA5010017

PFASHighest averageLimitStatus
PFOA
Not detected
–4 pptNot detected
PFOS
Not detected
–4 pptNot detected
PFHxS
Not detected
–10 pptNot detected
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot 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.

Lead: 0 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

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.

Patterson homes and lead pipes

16%
of homes built before 1980 (California 56%, US 50%)
4%
built before 1950 (California 14%)
29%
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. How to check your own line.

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

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
Ceres 13 mi
City of Ceres
City of CeresAbove limit0 ppb
Modesto 14 mi
City of Modesto
City of ModestoAbove limit12 ppb
Turlock 16 mi
City of Turlock
City of TurlockNone above limits0.97 ppb
Riverbank 21 mi
City of Riverbank
City of RiverbankNone above limits21 ppb
Manteca 22 mi
City of Manteca
City of MantecaAbove limit0.4 ppb
Tracy 24 mi
City of Tracy
City of TracyNone above limits0 ppb
Patterson ZIP codes (1)
  • 95363

Questions

Is Patterson tap water safe to drink?

City of Patterson has had no health-based violations since 2016. 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 Patterson, CA?

City of Patterson, which serves 24,977 people.

Does Patterson tap water have PFAS?

None detected above EPA's reporting limits. City of Patterson had no PFAS detected in EPA's 2023–2025 testing. "Not detected" means below the reporting limit (about 2 to 20 ppt), not proven zero.

Do Patterson homes have lead pipes?

Census estimates put 16% of Patterson 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 Patterson'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.