Grindstone Rancheria
PWS ID: 090605004 · Elk Creek, 09 95939
Grindstone Rancheria serves 150 people in Elk Creek, 09 using Surface Water water sources. It has 1,214 recorded EPA violations, including 210 health-based violations. No PFAS contamination was detected in UCMR5 testing.
Water Quality Snapshot: Grindstone Rancheria
Grindstone Rancheria is a native american-owned community water system that delivers drinking water to 150 residents in Elk Creek, 09 through 58 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 1,214 total violations for this system , of which 210 (17%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 705 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.
The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 174 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.
Across 09, EPA tracks 323 public water systems serving 555,721 people, with 48,296 cumulative violations and 3,354 health-based violations on record. About 97% of systems in the state carry at least one violation, and state-wide the average per system is 149.5 violations. Grindstone Rancheria's 1,214 violations sit above the 09 average. Statewide, 30 of 41 UCMR5-tested systems have reported PFAS detections (73.2%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 58
- School/Daycare
- No
- MCL Violations
- 17
- Monitoring Violations
- 705
- Treatment Tech Violations
- 193
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Surface Water Treatment Rule | MR | 174 | 2025 |
| Surface Water Treatment Rule | TT | 174 | 2024 |
| Public Notice | Other | 130 | 2024 |
| Coliform (TCR) | MR | 58 | 2016 |
| Revised Total Coliform Rule | MON | 36 | 2025 |
| Consumer Confidence Rule | Other | 27 | 2024 |
| Revised Total Coliform Rule | MCL | 14 | 2022 |
| Nitrate | MR | 13 | 2024 |
| Revised Total Coliform Rule | TT | 12 | 2022 |
| Chlorine | MR | 8 | 2025 |
| Interim Enhanced Surface Water Treatment Rule | MR | 8 | 2009 |
| BHC-GAMMA | MR | 7 | 2020 |
| Methoxychlor | MR | 7 | 2020 |
| Toxaphene | MR | 7 | 2020 |
| Carbofuran | MR | 7 | 2020 |
| Atrazine | MR | 7 | 2020 |
| LASSO | MR | 7 | 2020 |
| Heptachlor | MR | 7 | 2020 |
| Heptachlor epoxide | MR | 7 | 2020 |
| 2,4-D | MR | 7 | 2020 |
| 2,4,5-TP | MR | 7 | 2020 |
| Pentachlorophenol | MR | 7 | 2020 |
| cis-1,2-Dichloroethylene | MR | 7 | 2020 |
| Total Polychlorinated Biphenyls (PCB) | MR | 7 | 2020 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 7 | 2020 |
| ETHYLENE DIBROMIDE | MR | 7 | 2020 |
| Xylenes, Total | MR | 7 | 2020 |
| Chlordane | MR | 7 | 2020 |
| o-Dichlorobenzene | MR | 7 | 2020 |
| p-Dichlorobenzene | MR | 7 | 2020 |
Verify This Water System
The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Grindstone Rancheria.
EPA SDWIS — Federal Reports
EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:
View PWS ID 090605004 on SDWISSource: EPA SDWIS Federal Reports Search
09 Drinking Water Authority
09's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.
Find 09 regulator via EPA SDWISViolation Timeline
Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.
| Year (latest) | Contaminant | Category | Count | EPA Record |
|---|---|---|---|---|
| 2025 | Surface Water Treatment Rule | MR | 174 | SDWIS / 090605004 / 0200 |
| 2025 | Revised Total Coliform Rule | MON | 36 | SDWIS / 090605004 / 8000 |
| 2025 | Chlorine | MR | 8 | SDWIS / 090605004 / 0999 |
| 2024 | Surface Water Treatment Rule | TT | 174 | SDWIS / 090605004 / 0200 |
| 2024 | Public Notice | Other | 130 | SDWIS / 090605004 / 7500 |
| 2024 | Consumer Confidence Rule | Other | 27 | SDWIS / 090605004 / 7000 |
| 2024 | Nitrate | MR | 13 | SDWIS / 090605004 / 1040 |
| 2024 | Total Haloacetic Acids (HAA5) | MR | 7 | SDWIS / 090605004 / 2456 |
| 2024 | TTHM | MR | 7 | SDWIS / 090605004 / 2950 |
| 2023 | Long Term 2 Enhanced Surface Water Treatment Rule | Other | 4 | SDWIS / 090605004 / 0800 |
| 2022 | Revised Total Coliform Rule | MCL | 14 | SDWIS / 090605004 / 8000 |
| 2022 | Revised Total Coliform Rule | TT | 12 | SDWIS / 090605004 / 8000 |
| 2022 | Stage 1 Disinfectants and Disinfection Byproducts Rule | TT | 3 | SDWIS / 090605004 / 0400 |
| 2020 | BHC-GAMMA | MR | 7 | SDWIS / 090605004 / 2010 |
| 2020 | Methoxychlor | MR | 7 | SDWIS / 090605004 / 2015 |
How Grindstone Rancheria Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Grindstone Rancheria | 09 avg | Federal benchmark |
|---|---|---|---|
| Total violations | 1,214 | 149.5 | SDWA compliance — any non-zero count is a recorded breach |
| Health-based violations | 210 | 10.4 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 73.2% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 150 | 1,720 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 323 regulated public water systems in 09.
Federal MCL reference — Safe Drinking Water Act thresholds ▼
| Contaminant | Federal MCL / Action Level | Note |
|---|---|---|
| Lead | 0 mg/L (Action Level: 0.015 mg/L) | Lead and Copper Rule treatment technique |
| Arsenic | 0.010 mg/L (10 ppb) | Health-based MCL since 2006 |
| Total Coliform | Treatment technique (RTCR) | Indicator organism, monitoring trigger |
| PFOA / PFOS (PFAS) | 4.0 ppt each (final 2024 rule) | Compliance deadline 2029 |
| Nitrate (as N) | 10 mg/L | Acute health risk for infants |
Frequently Asked Questions
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Related Data for 09
Read our methodology — how this data is sourced, computed, and verified.