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Tap water quality report

City of Modesto - Grayson

EPA monitoring tested this supplier for 55 contaminants and detected 16. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

55
contaminants tested
16
detected
914
people served
14
health-based violations
California rankingsLead in CaliforniaPFAS in California
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.

14
health-based violations
14
violations on file
0
still open
ViolationTypeStatusPeriod
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 single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Nitrate
22700 µg/L 227%
of the EPA limit, in the worst sample — 10000 µg/L
 1210/1210 SYR4 2012–2019
Nitrate-Nitrite
22700 µg/L 227%
of the EPA limit, in the worst sample — 10000 µg/L
 513/513 SYR4 2012–2018
Bromoform
4.06 µg/L
No EPA limit set
 14/14 SYR4 2013–2019
TTHM
4.86 µg/L 6.1%
of the EPA limit 80 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
0.6000 µg/L 0.1%
of the EPA limit 1000 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
0.0950 µg/L 48%
of the EPA limit 0.2000 µg/L
 6/6 SYR4 2012–2017
Chromium
21 µg/L 21%
of the EPA limit 100 µg/L
 4/4 SYR4 2014–2017
Selenium
12 µg/L 24%
of the EPA limit 50 µg/L
 4/4 SYR4 2014–2017
Arsenic
2.6 µg/L 26%
of the EPA limit 10 µg/L
 2/4 SYR4 2014–2017
Combined Uranium
2.98 µg/L 9.9%
of the EPA limit 30 µg/L
 2/2 SYR4 2015
Dibromochloromethane
0.6500 µg/L
No EPA limit set
 2/14 SYR4 2013–2019
Fluoride
120 µg/L 3%
of the EPA limit 4000 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
mmartinez@modestogov.com

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.