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Tap water quality report

Gridley, CA

EPA monitoring detected 20 contaminants across the 1 water supplier serving Gridley. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
7,269
people served
20
contaminants found
California rankings Lead in California PFAS in California

What was found in Gridley's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
3300 µg/L 33%
of the EPA limit 10000 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Nitrate-Nitrite
1400 µg/L 14%
of the EPA limit 10000 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2018
1/1 SYR4
Fluoride
1180 µg/L 30%
of the EPA limit 4000 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Nitrite
260 µg/L 26%
of the EPA limit 1000 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Barium
65.125 µg/L 3.3%
of the EPA limit 2000 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Arsenic
13.93 µg/L 139%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Chromium
10.9 µg/L 11%
of the EPA limit 100 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
TTHM
5.525 µg/L 6.9%
of the EPA limit 80 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Bromoform
5.47 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Dibromoacetic Acid
1 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Dibromochloromethane
1 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
1 µg/L 1.7%
of the EPA limit 60 µg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
Bromodichloromethane
0.9900 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2019
1/1 SYR4
PFHXS
0.0128 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2024
1/1 UCMR-5
PFOS
0.0105 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2024
1/1 UCMR-5
PFNA
0.0099 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2024
1/1 UCMR-5
Pfpea
0.0065 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2024
1/1 UCMR-5
Pfhxa
0.0053 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2024
1/1 UCMR-5
Pfhpa
0.0035 µg/L
No EPA limit set
Main supplier: CITY OF GRIDLEY · 7,269 people · 2024
1/1 UCMR-5
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: CITY OF GRIDLEY · 7,269 people · 2023
1/1 LCR
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 the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Gridley

SupplierPopulation served
CITY OF GRIDLEY 7,269

Frequently asked questions about Gridley tap water

Is Gridley tap water safe to drink?

EPA testing detected 20 contaminants in the water serving Gridley. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Gridley?

1 public water supplier report drinking-water monitoring for Gridley, California to the EPA. Each is listed above with its population served.

What contaminants are in Gridley's water?

The contaminants EPA monitoring detected in Gridley include Nitrate, Nitrate-Nitrite, Fluoride, Nitrite, Barium. The full list, with the level at the main supplier and the data source, is in the table above.

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.