BLOCK ISLAND WATER COMPANY
PWS ID: RI1858430 · BLOCK ISLAND, Rhode Island 02807
Population Served
9,999
Total Violations
378
Health-Based Violations
60
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 338
- County
- Washington
- School/Daycare
- No
- MCL Violations
- 60
- Monitoring Violations
- 287
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| TTHM | MCL | 50 | 1995 |
| Di(2-ethylhexyl) phthalate | MR | 11 | 2023 |
| Coliform (TCR) | MCL | 10 | 1991 |
| Lead and Copper Rule | MR | 10 | 2000 |
| Coliform (TCR) | MR | 10 | 1999 |
| BHC-GAMMA | MR | 8 | 2023 |
| Di(2-ethylhexyl) adipate | MR | 8 | 2023 |
| Simazine | MR | 8 | 2023 |
| Atrazine | MR | 8 | 2023 |
| HEXACHLOROBENZENE | MR | 8 | 2023 |
| Methoxychlor | MR | 8 | 2023 |
| Hexachlorocyclopentadiene | MR | 8 | 2023 |
| LASSO | MR | 8 | 2023 |
| Heptachlor | MR | 8 | 2023 |
| Heptachlor epoxide | MR | 8 | 2023 |
| Benzo(a)pyrene | MR | 8 | 2023 |
| Consumer Confidence Rule | Other | 5 | 2003 |
| TTHM | MR | 5 | 2015 |
| Total Haloacetic Acids (HAA5) | MR | 5 | 2015 |
| 1,2,4-Trichlorobenzene | MR | 5 | 2017 |
| o-Dichlorobenzene | MR | 5 | 2017 |
| p-Dichlorobenzene | MR | 5 | 2017 |
| Vinyl chloride | MR | 5 | 2017 |
| 1,1-Dichloroethylene | MR | 5 | 2017 |
| trans-1,2-Dichloroethylene | MR | 5 | 2017 |
| 1,1,1-Trichloroethane | MR | 5 | 2017 |
| Carbon tetrachloride | MR | 5 | 2017 |
| 1,2-Dichloropropane | MR | 5 | 2017 |
| Trichloroethylene | MR | 5 | 2017 |
| 1,1,2-Trichloroethane | MR | 5 | 2017 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 60 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHxS | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 6/18/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFBS | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpS | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 6/18/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 4:2 FTS | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFNA | 6/18/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFMPA | 6/18/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| NMeFOSAA | 6/18/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| NFDHA | 6/18/2024 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFOS | 6/18/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFDA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFUnA | 6/18/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 6/18/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 9Cl-PF3ONS | 6/18/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| ADONA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 6/18/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 6/18/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| lithium | 6/18/2024 | <9 µg/L | 9 µg/L | Not Detected |
| PFTA | 6/18/2024 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| NEtFOSAA | 6/18/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 6/18/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTrDA | 6/18/2024 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFPeA | 6/18/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 6/18/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFOA | 12/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFBA | 12/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| HFPO-DA | 12/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| ADONA | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 9Cl-PF3ONS | 12/17/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 12/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 12/17/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 6:2 FTS | 12/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFDoA | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFNA | 12/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHxS | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxA | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NMeFOSAA | 12/17/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFOS | 12/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 4:2 FTS | 12/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 12/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 8:2 FTS | 12/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
PFAS data from EPA UCMR5 monitoring program (2023-2025).
This data is provided for informational purposes only.