River Rock County Water And Sewer Dist
Published drinking-water records and contacts for River Rock County Water And Sewer Dist. System MT0004082. Review sources and dates; not a real-time water assessment.
- System ID
- MT0004082
- State or territory
- MT
- Published population served
- 4200
- System type (source code)
- CWS
Published records and dates
- PFAS / lithium (EPA UCMR 5): 60 — 2023-11-08 – 2024-05-15
- Lead and copper monitoring summaries: 20 — 2000-01-01 – 2027-12-31
Missing records here do not mean the provider did not test. Published records are not a real-time assessment of your tap water.
Published testing results
Selected recent records are shown below. Different sampling locations and dates are not interchangeable. These excerpts are not a complete testing history.
“<” means below the stated reporting limit, not zero. A reported measurement alone is not a safety verdict. Read an example
| Substance | Published result | Reporting limit | Sample date | Sampling location |
|---|---|---|---|---|
| 11Cl-PF3OUdS | < 0.005 µg/L | 0.005 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| 4:2 FTS | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| 6:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| 8:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| 9Cl-PF3ONS | < 0.002 µg/L | 0.002 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| ADONA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| HFPO-DA | < 0.005 µg/L | 0.005 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| NEtFOSAA | < 0.005 µg/L | 0.005 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| NFDHA | < 0.02 µg/L | 0.02 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| NMeFOSAA | < 0.006 µg/L | 0.006 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFBA | < 0.005 µg/L | 0.005 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFBS | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFDA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFDoA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFEESA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFHpA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFHpS | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFHxA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFHxS | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFMBA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFMPA | < 0.004 µg/L | 0.004 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFNA | < 0.004 µg/L | 0.004 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFOA | < 0.004 µg/L | 0.004 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFOS | < 0.004 µg/L | 0.004 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFPeA | < 0.003 µg/L | 0.003 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFPeS | < 0.004 µg/L | 0.004 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFTA | < 0.008 µg/L | 0.008 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFTrDA | < 0.007 µg/L | 0.007 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| PFUnA | < 0.002 µg/L | 0.002 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
| lithium | < 9 µg/L | 9 µg/L | 2024-05-15 | RIVER ROCK COUNTY WATER AND SEWER DIST / EP502 |
Download all EPA UCMR 5 records (CSV)
Lead and copper: 90th-percentile summaries
These describe a monitoring period across sampled locations, not the result at your home. How to read the 90th percentile
| Substance | Published 90th percentile | Monitoring period | Source quarter |
|---|---|---|---|
| Lead (PB90) | 0.00281 mg/L | 2025-01-01 – 2027-12-31 | 2026Q3 |
| Lead (PB90) | 0.00374 mg/L | 2019-01-01 – 2021-12-31 | 2026Q3 |
| Lead (PB90) | 0.0031 mg/L | 2018-01-01 – 2018-12-31 | 2026Q3 |
| Lead (PB90) | 0.0034 mg/L | 2017-01-01 – 2017-06-30 | 2026Q3 |
| Lead (PB90) | 0.0033 mg/L | 2016-07-01 – 2016-12-31 | 2026Q3 |
| Lead (PB90) | 0.0029 mg/L | 2011-01-01 – 2013-12-31 | 2026Q3 |
| Lead (PB90) | 0.004 mg/L | 2008-01-01 – 2010-12-31 | 2026Q3 |
| Lead (PB90) | 0.005 mg/L | 2007-01-01 – 2007-12-31 | 2026Q3 |
Published compliance history
24 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.
| Rule / record | Period | Recorded status | Health-based (EPA classification) | Source quarter |
|---|---|---|---|---|
| Lead and Copper Rule / Follow-up Or Routine LCR Tap M/R | 2024-10-01 – — | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2024-01-01 – 2024-12-31 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2024-01-01 – 2024-12-31 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2023-01-01 – 2023-12-31 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2023-01-01 – 2023-12-31 | Resolved | No | 2026Q3 |
| Lead and Copper Rule / Lead Consumer Notice | 2021-12-30 – — | Resolved | No | 2026Q3 |
| Nitrate Rule / Monitoring, Regular | 2021-01-01 – 2021-12-31 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2020-08-31 – 2021-08-30 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2020-08-31 – 2021-08-30 | Resolved | No | 2026Q3 |
| Inorganic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Resolved | No | 2026Q3 |
| Inorganic Chemicals / Monitoring, Regular | 2020-01-01 – 2022-12-31 | Archived | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2019-08-31 – 2020-08-30 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2019-08-31 – 2020-08-30 | Resolved | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2018-08-31 – 2019-08-30 | Resolved | No | 2026Q3 |
Source dates and refresh checks
A refresh check is not a sample date. Publication periods, sample dates and checks are shown separately.
- EPA SDWIS lead/copper summaries and service areas — source period: — – —; last checked: 2026-10-17
- EPA SDWIS contacts and compliance records — source period: — – —; last checked: 2026-10-17
- EPA UCMR 5 sample results — source period: 2023-01-03 – 2026-06-17; last checked: 2026-10-17
Administrative contact (EPA filing)
Clarkson, Christine: 406-581-7644
An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.