Is Ripon, City of Tap Water Safe? Quality Report

Water source: Ground 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.

health-based violations

violations on file

still open

Violation	Type	Status	Period
MCL	Health-based	Resolved	2001-12-19 → 2002-03-19
MCL	Health-based	Resolved	2001-12-19 → 2002-03-19
MCL	Health-based	Resolved	2001-07-23 → 2001-10-22
MCL	Health-based	Resolved	2001-07-23 → 2001-10-22
MCL	Health-based	Resolved	2000-12-01 → 2000-12-31
MCL	Health-based	Resolved	2000-12-01 → 2000-12-31
MCL	Health-based	Resolved	2000-09-01 → 2000-09-30
MCL	Health-based	Resolved	2000-09-01 → 2000-09-30
MCL	Health-based	Resolved	1999-11-01 → 1999-11-30
MCL	Health-based	Resolved	1999-11-01 → 1999-11-30

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).

Contaminant	Max	Detection rate	Period
PFHXS	0.0035 µg/L	2/10	2025
PFOA	0.0052 µg/L	2/10	2025
PFOS	0.0120 µg/L	2/10	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.

Contaminant	Level vs EPA limit	Detection rate	Source	Period
Nitrate	9760.3 µg/L 98% of the EPA limit 10000 µg/L worst single sample: 12000 µg/L	438/438	SYR4	2012–2019
TTHM	5.6 µg/L 7% of the EPA limit 80 µg/L worst single sample: 7 µg/L	48/115	SYR4	2012–2019
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L	34/34	LCR	2023
Bromoform	1.855 µg/L No EPA limit set worst single sample: 2.8 µg/L	30/116	SYR4	2012–2019
Dibromochloromethane	1.48 µg/L No EPA limit set worst single sample: 2.7 µg/L	23/117	SYR4	2012–2019
Arsenic	11.03 µg/L 110% of the EPA limit, at the 95th percentile of samples — 10 µg/L worst single sample: 19.7 µg/L	18/18	SYR4	2012–2018
Chloroform	4.235 µg/L No EPA limit set worst single sample: 5 µg/L	18/118	SYR4	2012–2019
Barium	225.75 µg/L 11% of the EPA limit 2000 µg/L worst single sample: 228 µg/L	16/17	SYR4	2012–2018
Bromodichloromethane	1.7 µg/L No EPA limit set	15/118	SYR4	2012–2019
Chromium	11.43 µg/L 11% of the EPA limit 100 µg/L worst single sample: 12.2 µg/L	12/17	SYR4	2012–2018
Fluoride	200 µg/L 5% of the EPA limit 4000 µg/L	11/17	SYR4	2012–2018
Combined Uranium	26.2016 µg/L 87% of the EPA limit 30 µg/L worst single sample: 26.671 µg/L	8/10	SYR4	2012–2018
Total Haloacetic Acids (HAA5)	2.01 µg/L 3.4% of the EPA limit 60 µg/L worst single sample: 2.1 µg/L	7/98	SYR4	2013–2019
cis-1,2-Dichloroethylene	4.9 µg/L 7% of the EPA limit 70 µg/L worst single sample: 5.4 µg/L	6/23	SYR4	2012–2019
1,2-DIBROMO-3-CHLOROPROPANE	0.0396 µg/L 20% of the EPA limit 0.2000 µg/L worst single sample: 0.0430 µg/L	5/26	SYR4	2012–2019
Trichloroethylene	1.56 µg/L 31% of the EPA limit 5 µg/L worst single sample: 1.6 µg/L	5/23	SYR4	2012–2019
Trichloroacetic Acid	1.385 µg/L No EPA limit set worst single sample: 1.4 µg/L	4/96	SYR4	2013–2019
Dibromoacetic Acid	2.085 µg/L No EPA limit set worst single sample: 2.1 µg/L	2/96	SYR4	2013–2019
Lithium	9.93 µg/L No EPA limit set	2/10	UCMR-5	2025
1,2,4-Trichlorobenzene	3.1 µg/L 4.4% of the EPA limit 70 µg/L	1/20	SYR4	2012–2019
Dichloroacetic Acid	1.5 µg/L No EPA limit set	1/97	SYR4	2013–2019

70 contaminants tested, none detected

1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalAtrazineBhc-GammaBenzeneBeryllium, TotalChlorobenzeneCopperCadmiumCarbon TetrachlorideChlordaneDichloromethaneEthylene DibromideEndothallEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoLeadMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNetfosaaNfdhaNmefosaaNitritePfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPfmbaPfmpaPFNAPfpeaPfpesPftaPftrdaPfunaSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneVinyl ChlorideXylenes, TotalO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: PEASE, JAMES
Phone: 209-599-2108
Email: [email protected]

Frequently asked questions about Ripon, City of

Is Ripon, City of tap water safe to drink?

EPA monitoring detected 24 contaminants in Ripon, City of'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 Ripon, City of's water?

EPA monitoring detected Nitrate, TTHM, Lead, Bromoform, Dibromochloromethane, and others. The full list with the level and data source for each is above.

How many people does Ripon, City of serve?

Ripon, City of reports serving 15,741 people in California, per its EPA record.

Has Ripon, City of had any water quality violations?

The EPA has 30 violations on file for Ripon, City of, of which 17 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.