Community Water System · PWS RI1858430
Block Island Water Company
Block Island, Rhode Island 02807 - drinking water served from groundwater sources to 9,999 people, tracked in EPA SDWIS and UCMR5.
- 9,999
- People served
- 378
- EPA violations
- 60
- Health-based
- No PFAS
- UCMR5 result
The verdict
EPA records 378 drinking-water violations at Block Island Water Company, 16% of them health-based - above the Rhode Island per-system average.
- 378
- Total EPA violations on record
- 16%
- Health-based (MCL / treatment failure)
- 9,999
- People served by this system
- 0
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Block Island Water Company
Block Island Water Company is a local-owned community water system that delivers drinking water to 9,999 residents in Block Island, Rhode Island (Washington County) through 338 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 378 total violations for this system , of which 60 (16%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 287 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.
The most frequently cited contaminant at this system is TTHM, recorded in 50 violations (MCL, health-based). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.
Across Rhode Island, EPA tracks 463 public water systems serving 1,159,492 people, with 33,766 cumulative violations and 8,949 health-based violations on record. About 96% of systems in the state carry at least one violation, and state-wide the average per system is 72.9 violations. Statewide, 15 of 29 UCMR5-tested systems have reported PFAS detections (51.7%).
Block Island Water Company's 378 violations sit above the Rhode Island average.
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
- 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 58 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHxS | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 6/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 6/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 4:2 FTS | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 6/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFMPA | 6/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| NMeFOSAA | 6/18/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| NFDHA | 6/18/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFOS | 6/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 6/18/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 6/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 6/18/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 6/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 6/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 6/18/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| NEtFOSAA | 6/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 8:2 FTS | 6/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 6/18/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFPeA | 6/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 6/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOA | 12/17/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBA | 12/17/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 12/17/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 12/17/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 12/17/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 12/17/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 6:2 FTS | 12/17/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDoA | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 12/17/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 12/17/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFOS | 12/17/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 4:2 FTS | 12/17/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 12/17/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 12/17/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NEtFOSAA | 12/17/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
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 Block Island Water Company.
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 RI1858430 on SDWISSource: EPA SDWIS Federal Reports Search
Rhode Island Drinking Water Authority
Rhode Island'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 RI 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 |
|---|---|---|---|---|
| 2023 | Di(2-ethylhexyl) phthalate | MR | 11 | SDWIS / RI1858430 / 2039 |
| 2023 | BHC-GAMMA | MR | 8 | SDWIS / RI1858430 / 2010 |
| 2023 | Di(2-ethylhexyl) adipate | MR | 8 | SDWIS / RI1858430 / 2035 |
| 2023 | Simazine | MR | 8 | SDWIS / RI1858430 / 2037 |
| 2023 | Atrazine | MR | 8 | SDWIS / RI1858430 / 2050 |
| 2023 | HEXACHLOROBENZENE | MR | 8 | SDWIS / RI1858430 / 2274 |
| 2023 | Methoxychlor | MR | 8 | SDWIS / RI1858430 / 2015 |
| 2023 | Hexachlorocyclopentadiene | MR | 8 | SDWIS / RI1858430 / 2042 |
| 2023 | LASSO | MR | 8 | SDWIS / RI1858430 / 2051 |
| 2023 | Heptachlor | MR | 8 | SDWIS / RI1858430 / 2065 |
| 2023 | Heptachlor epoxide | MR | 8 | SDWIS / RI1858430 / 2067 |
| 2023 | Benzo(a)pyrene | MR | 8 | SDWIS / RI1858430 / 2306 |
| 2018 | Revised Total Coliform Rule | MON | 5 | SDWIS / RI1858430 / 8000 |
| 2017 | 1,2,4-Trichlorobenzene | MR | 5 | SDWIS / RI1858430 / 2378 |
| 2017 | o-Dichlorobenzene | MR | 5 | SDWIS / RI1858430 / 2968 |
How Block Island Water Company Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Block Island Water Company | Rhode Island avg | Federal benchmark |
|---|---|---|---|
| Total violations | 378 | 72.9 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 60 | 19.3 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 51.7% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 9,999 | 2,504 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 463 regulated public water systems in Rhode Island.
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 (EPA proposed extending to 2031, not yet final as of May 2026) |
| Nitrate (as N) | 10 mg/L | Acute health risk for infants |
Frequently Asked Questions
Is Block Island Water Company water safe to drink? ▼
How many people does Block Island Water Company serve? ▼
What type of violations does Block Island Water Company have? ▼
Has PFAS been detected in Block Island Water Company water? ▼
What water source does Block Island Water Company use? ▼
Where does this data come from? ▼
Read our methodology - how this data is sourced, computed, and verified.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.