Is City of Modesto - Grayson Tap Water Safe? Quality Report

Water source: Ground water
Ownership: Local government
Counties served: Stanislaus

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	2003-06-01 → 2003-06-30
MCL	Health-based	Resolved	2003-06-01 → 2003-06-30
MCL	Health-based	Resolved	2003-06-01 → 2003-06-30
MCL	Health-based	Resolved	1998-12-01 → 1998-12-31
MCL	Health-based	Resolved	1998-12-01 → 1998-12-31
MCL	Health-based	Resolved	1998-12-01 → 1998-12-31
MCL	Health-based	Resolved	1997-12-01 → 1997-12-31
MCL	Health-based	Resolved	1997-12-01 → 1997-12-31
MCL	Health-based	Resolved	1997-12-01 → 1997-12-31
MCL	Health-based	Resolved	1995-07-01 → 1995-12-31

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	19000 µg/L 190% of the EPA limit, at the 95th percentile of samples — 10000 µg/L worst single sample: 22700 µg/L	1210/1210	SYR4	2012–2019
Nitrate-Nitrite	18840 µg/L 188% of the EPA limit, at the 95th percentile of samples — 10000 µg/L worst single sample: 22700 µg/L	513/513	SYR4	2012–2018
Bromoform	4.034 µg/L No EPA limit set worst single sample: 4.06 µg/L	14/14	SYR4	2013–2019
TTHM	4.7365 µg/L 5.9% of the EPA limit 80 µg/L worst single sample: 4.86 µg/L	14/14	SYR4	2013–2019
Dibromoacetic Acid	4.6 µg/L No EPA limit set	12/14	SYR4	2013–2019
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L	12/12	LCR	2023
Nitrite	0.3360 µg/L 0% of the EPA limit 1000 µg/L worst single sample: 0.6000 µg/L	12/516	SYR4	2012–2018
Total Haloacetic Acids (HAA5)	4.6 µg/L 7.7% of the EPA limit 60 µg/L	12/14	SYR4	2013–2019
1,2-DIBROMO-3-CHLOROPROPANE	0.0818 µg/L 41% of the EPA limit 0.2000 µg/L worst single sample: 0.0950 µg/L	6/6	SYR4	2012–2017
Chromium	20.85 µg/L 21% of the EPA limit 100 µg/L worst single sample: 21 µg/L	4/4	SYR4	2014–2017
Selenium	11.595 µg/L 23% of the EPA limit 50 µg/L worst single sample: 12 µg/L	4/4	SYR4	2014–2017
Arsenic	2.57 µg/L 26% of the EPA limit 10 µg/L worst single sample: 2.6 µg/L	2/4	SYR4	2014–2017
Combined Uranium	2.97255 µg/L 9.9% of the EPA limit 30 µg/L worst single sample: 2.98 µg/L	2/2	SYR4	2015
Dibromochloromethane	0.6490 µg/L No EPA limit set worst single sample: 0.6500 µg/L	2/14	SYR4	2013–2019
Fluoride	119.5 µg/L 3% of the EPA limit 4000 µg/L worst single sample: 120 µg/L	2/4	SYR4	2014–2017
Chloroform	1.33 µg/L No EPA limit set	1/14	SYR4	2013–2019

39 contaminants tested, none detected

1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-DichloropropaneAntimony, TotalAtrazineBariumBenzeneBeryllium, TotalBromodichloromethaneChlorobenzeneCopperCyanideCadmiumCarbon TetrachlorideDichloromethaneDichloroacetic AcidEthylene DibromideEthylbenzeneLassoLeadMercuryMonobromoacetic AcidMonochloroacetic AcidSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTrichloroacetic AcidTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: MARTINEZ, MANUEL
Phone: 209-342-4592
Email: [email protected]

Frequently asked questions about City of Modesto - Grayson

Is City of Modesto - Grayson tap water safe to drink?

EPA monitoring detected 16 contaminants in City of Modesto - Grayson'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 Modesto - Grayson's water?

EPA monitoring detected Nitrate, Nitrate-Nitrite, Bromoform, TTHM, Dibromoacetic Acid, and others. The full list with the level and data source for each is above.

How many people does City of Modesto - Grayson serve?

City of Modesto - Grayson reports serving 914 people in California, per its EPA record.

Has City of Modesto - Grayson had any water quality violations?

The EPA has 14 violations on file for City of Modesto - Grayson, of which 14 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.