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Tap water quality report

Grindstone Rancheria

EPA monitoring tested this supplier for 70 contaminants and detected 9. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

70
contaminants tested
9
detected
150
people served
210
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Surface water
Ownership
Native American

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.

210
health-based violations
1,083
violations on file
17
still open
ViolationTypeStatusPeriod
TT Health-based Archived 2024-03-01 → 2024-03-31
TT Health-based Archived 2023-09-01 → 2023-09-30
TT Health-based Archived 2023-08-01 → 2023-08-31
TT Health-based Archived 2023-04-01 → 2023-04-30
TT Health-based Resolved 2023-03-01 → 2023-03-31
TT Health-based Resolved 2023-02-01 → 2023-02-28
TT Health-based Resolved 2023-01-01 → 2023-01-31
TT Health-based Resolved 2022-12-01 → 2022-12-31
TT Health-based Resolved 2022-11-01 → 2022-11-30
TT Health-based Resolved 2022-10-01 → 2022-10-31

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
Lead
0.0050 mg/L 33%
of the EPA limit 0.0150 mg/L
 8/8 LCR 2025
Nitrate
300 µg/L 3%
of the EPA limit 10000 µg/L
 8/14 SYR4 2012–2019
TTHM
71 µg/L 89%
of the EPA limit 80 µg/L
 5/6 SYR4 2012–2019
Barium
121 µg/L 6.1%
of the EPA limit 2000 µg/L
 3/3 SYR4 2012–2016
Total Haloacetic Acids (HAA5)
26 µg/L 43%
of the EPA limit 60 µg/L
 3/6 SYR4 2012–2019
Combined Radium (-226 And -228)
0.6250 pCi/L 13%
of the EPA limit 5 pCi/L
 1/1 SYR4 2016
Fluoride
69 µg/L 1.7%
of the EPA limit 4000 µg/L
 1/3 SYR4 2012–2016
Gross Alpha, Excl. Radon And U
2.30119 pCi/L 15%
of the EPA limit 15 pCi/L
 1/1 SYR4 2016
Selenium
3 µg/L 6%
of the EPA limit 50 µg/L
 1/3 SYR4 2012–2016
61 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane2,3,7,8-TCDD2,4,5-TP2,4-DAntimony, TotalArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumCombined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNitriteOxamylPentachlorophenolPicloramSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
Ron Kirk
Phone
5309685365
Email
ronaldkirk1963@gmail.com

Frequently asked questions about Grindstone Rancheria

Is Grindstone Rancheria tap water safe to drink?

EPA monitoring detected 9 contaminants in Grindstone Rancheria'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 Grindstone Rancheria's water?

EPA monitoring detected Lead, Nitrate, TTHM, Barium, Total Haloacetic Acids (HAA5), and others. The full list with the level and data source for each is above.

How many people does Grindstone Rancheria serve?

Grindstone Rancheria reports serving 150 people in California, per its EPA record.

Has Grindstone Rancheria had any water quality violations?

The EPA has 1083 violations on file for Grindstone Rancheria, of which 210 are health-based (a contaminant limit or required treatment was breached) and 17 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.