Non-Transient Non-Community Water System · PWS WA5310811
Maxwelton Water System
Coupeville, Washington 98239 - drinking water served from groundwater sources to 1,700 people, tracked in EPA SDWIS and UCMR5.
- 1,700
- People served
- 38
- EPA violations
- 11
- Health-based
- Untested
- UCMR5 result
The verdict
EPA records 38 drinking-water violations at Maxwelton Water System, 29% of them health-based - below the Washington per-system average.
- 38
- Total EPA violations on record
- 29%
- Health-based (MCL / treatment failure)
- 1,700
- People served by this system
- N/A
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Maxwelton Water System
Maxwelton Water System is a private-owned non-transient non-community water system that delivers drinking water to 1,700 residents in Coupeville, Washington (Island County) through 5 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 38 total violations for this system , of which 11 (29%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 26 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.
The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 15 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 Washington, EPA tracks 4,557 public water systems serving 9,736,844 people, with 314,648 cumulative violations and 20,590 health-based violations on record. About 92% of systems in the state carry at least one violation, and state-wide the average per system is 69 violations. Statewide, 98 of 247 UCMR5-tested systems have reported PFAS detections (39.7%).
Maxwelton Water System's 38 violations sit below the Washington 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
- Non-Transient Non-Community
- Owner Type
- Private
- Connections
- 5
- County
- Island
- School/Daycare
- Yes
- MCL Violations
- 11
- Monitoring Violations
- 26
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Lead and Copper Rule | MR | 15 | 2011 |
| Coliform (TCR) | MCL | 11 | 2004 |
| TTHM | MR | 4 | 2024 |
| Total Haloacetic Acids (HAA5) | MR | 4 | 2024 |
| Coliform (TCR) | MR | 2 | 1994 |
| Nitrate | MR | 1 | 2024 |
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 Maxwelton Water System.
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 WA5310811 on SDWISSource: EPA SDWIS Federal Reports Search
Washington Drinking Water Authority
Washington State Department of Health, Office of Drinking Water is the primacy agency that licenses and inspects Maxwelton Water System under EPA-delegated authority.
Open WA regulator portalSource: Washington State Department of Health, Office of Drinking Water
Violation 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 |
|---|---|---|---|---|
| 2024 | TTHM | MR | 4 | SDWIS / WA5310811 / 2950 |
| 2024 | Total Haloacetic Acids (HAA5) | MR | 4 | SDWIS / WA5310811 / 2456 |
| 2024 | Nitrate | MR | 1 | SDWIS / WA5310811 / 1040 |
| 2011 | Lead and Copper Rule | MR | 15 | SDWIS / WA5310811 / 5000 |
| 2004 | Coliform (TCR) | MCL | 11 | SDWIS / WA5310811 / 3100 |
| 1994 | Coliform (TCR) | MR | 2 | SDWIS / WA5310811 / 3100 |
How Maxwelton Water System Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Maxwelton Water System | Washington avg | Federal benchmark |
|---|---|---|---|
| Total violations | 38 | 69 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 11 | 4.5 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 39.7% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 1,700 | 2,137 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 4,557 regulated public water systems in Washington.
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 Maxwelton Water System water safe to drink? ▼
How many people does Maxwelton Water System serve? ▼
What type of violations does Maxwelton Water System have? ▼
Has PFAS been detected in Maxwelton Water System water? ▼
What water source does Maxwelton Water System 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.