Community Water System · PWS HI0000101
Hilo
Hilo, Hawaii 96720 - drinking water served from groundwater sources to 39,477 people, tracked in EPA SDWIS and UCMR5.
- 39,477
- People served
- 170
- EPA violations
- 168
- Health-based
- No PFAS
- UCMR5 result
The verdict
EPA records 170 drinking-water violations at Hilo, 99% of them health-based - above the Hawaii per-system average.
- 170
- Total EPA violations on record
- 99%
- Health-based (MCL / treatment failure)
- 39,477
- People served by this system
- 0
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Hilo
Hilo is a local-owned community water system that delivers drinking water to 39,477 residents in Hilo, Hawaii (Hawaii County) through 14,621 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 170 total violations for this system , of which 168 (99%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. The most recent violation on record dates to 2009.
The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 168 violations (TT, 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 Hawaii, EPA tracks 137 public water systems serving 1,520,931 people, with 5,234 cumulative violations and 2,289 health-based violations on record. About 80% of systems in the state carry at least one violation, and state-wide the average per system is 38.2 violations. Statewide, 2 of 45 UCMR5-tested systems have reported PFAS detections (4.4%).
Hilo's 170 violations sit above the Hawaii 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
- 14,621
- County
- Hawaii
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 0
- Treatment Tech Violations
- 168
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Surface Water Treatment Rule | TT | 168 | 2009 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 290 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHpS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 4/8/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFTrDA | 4/8/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| NEtFOSAA | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 4/8/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFPeS | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| ADONA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 4:2 FTS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 4/8/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| HFPO-DA | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFNA | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 9Cl-PF3ONS | 4/8/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOS | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFUnA | 4/8/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFBA | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 8:2 FTS | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHpA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDoA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 4/8/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 4/8/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 4/8/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 4:2 FTS | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 4/8/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 4/8/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 4/8/2024 | <20.00 ppt | 20.00 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 Hilo.
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 HI0000101 on SDWISSource: EPA SDWIS Federal Reports Search
Hawaii Drinking Water Authority
Hawaii'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 HI 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 |
|---|---|---|---|---|
| 2009 | Surface Water Treatment Rule | TT | 168 | SDWIS / HI0000101 / 0200 |
How Hilo Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Hilo | Hawaii avg | Federal benchmark |
|---|---|---|---|
| Total violations | 170 | 38.2 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 168 | 16.7 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 4.4% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 39,477 | 11,102 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 137 regulated public water systems in Hawaii.
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 Hilo water safe to drink? ▼
How many people does Hilo serve? ▼
What type of violations does Hilo have? ▼
Has PFAS been detected in Hilo water? ▼
What water source does Hilo 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.