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Community Water System · PWS HI0000214

Lahaina

Wailuku, Hawaii 96793-2155 - drinking water served from surface water sources to 20,065 people, tracked in EPA SDWIS and UCMR5.

20,065
People served
243
EPA violations
116
Health-based
No PFAS
UCMR5 result

The verdict

EPA records 243 drinking-water violations at Lahaina, 48% of them health-based - above the Hawaii per-system average.

243
Total EPA violations on record
48%
Health-based (MCL / treatment failure)
20,065
People served by this system
0
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Lahaina

Lahaina is a local-owned community water system that delivers drinking water to 20,065 residents in Wailuku, Hawaii (Maui County) through 3,236 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 243 total violations for this system , of which 116 (48%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 80 monitoring and reporting violations are on file. The most recent violation on record dates to 2016.

The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 93 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%).

Lahaina's 243 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.

Population Served
20,065
Total Violations
243
Health-Based Violations
116
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
3,236
County
Maui
School/Daycare
No
MCL Violations
23
Monitoring Violations
80
Treatment Tech Violations
93

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule TT 93 1997
Surface Water Treatment Rule MR 29 1994
Coliform (TCR) MCL 23 1997
Dalapon MR 3 2008
Picloram MR 3 2008
Dinoseb MR 3 2008
Pentachlorophenol MR 3 2008
Di(2-ethylhexyl) adipate MR 3 2008
Diquat MR 3 2008
Endothall MR 3 2008
Nitrate MR 3 2010
Turbidity MR 3 2016
E. COLI MR 3 2016
2,4,5-TP MR 3 2008
CYANIDE MR 3 2008
Di(2-ethylhexyl) phthalate MR 3 2008
Coliform (TCR) Other 3 1994
Cryptosporidium MR 3 2016
2,4-D MR 3 2008
2,3,7,8-TCDD MR 3 2008
Benzo(a)pyrene MR 3 2008
Coliform (Pre-TCR) Other 1 1982

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 555 samples detected PFAS.

Contaminant Date Result MRL Status
NFDHA 9/19/2023 <20.00 ppt 20.00 ppt Not Detected
ADONA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 9/19/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 9/19/2023 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 9/19/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 9/19/2023 <5.00 ppt 5.00 ppt Not Detected
PFMPA 9/19/2023 <4.00 ppt 4.00 ppt Not Detected
PFPeA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpS 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFEESA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 9/19/2023 <2.00 ppt 2.00 ppt Not Detected
PFPeS 9/19/2023 <4.00 ppt 4.00 ppt Not Detected
PFHxA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 9/19/2023 <6.00 ppt 6.00 ppt Not Detected
11Cl-PF3OUdS 9/19/2023 <5.00 ppt 5.00 ppt Not Detected
NEtFOSAA 9/19/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 9/19/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 9/19/2023 <8.00 ppt 8.00 ppt Not Detected
PFBS 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFNA 9/19/2023 <4.00 ppt 4.00 ppt Not Detected
PFOS 9/19/2023 <4.00 ppt 4.00 ppt Not Detected
PFOA 9/19/2023 <4.00 ppt 4.00 ppt Not Detected
PFDA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFDoA 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 9/19/2023 <3.00 ppt 3.00 ppt Not Detected
PFUnA 9/19/2023 <2.00 ppt 2.00 ppt Not Detected
NEtFOSAA 9/15/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 9/15/2023 <6.00 ppt 6.00 ppt Not Detected
PFTrDA 9/15/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 9/15/2023 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 9/15/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 9/15/2023 <8.00 ppt 8.00 ppt Not Detected
NEtFOSAA 9/15/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 9/15/2023 <6.00 ppt 6.00 ppt Not Detected
PFTA 9/15/2023 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 9/15/2023 <7.00 ppt 7.00 ppt Not Detected
NEtFOSAA 9/15/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 9/15/2023 <6.00 ppt 6.00 ppt Not Detected
PFTA 9/15/2023 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 9/15/2023 <7.00 ppt 7.00 ppt Not Detected
NEtFOSAA 9/15/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 9/15/2023 <6.00 ppt 6.00 ppt Not Detected
PFMPA 5/19/2023 <4.00 ppt 4.00 ppt Not Detected
NMeFOSAA 5/19/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 5/19/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 5/19/2023 <7.00 ppt 7.00 ppt Not Detected
PFHpS 5/19/2023 <3.00 ppt 3.00 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 Lahaina.

Federal Source of Truth

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 HI0000214 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

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 SDWIS

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
2016 Turbidity MR 3 SDWIS / HI0000214 / 0100
2016 E. COLI MR 3 SDWIS / HI0000214 / 3014
2016 Cryptosporidium MR 3 SDWIS / HI0000214 / 3015
2010 Nitrate MR 3 SDWIS / HI0000214 / 1040
2008 Dalapon MR 3 SDWIS / HI0000214 / 2031
2008 Picloram MR 3 SDWIS / HI0000214 / 2040
2008 Dinoseb MR 3 SDWIS / HI0000214 / 2041
2008 Pentachlorophenol MR 3 SDWIS / HI0000214 / 2326
2008 Di(2-ethylhexyl) adipate MR 3 SDWIS / HI0000214 / 2035
2008 Diquat MR 3 SDWIS / HI0000214 / 2032
2008 Endothall MR 3 SDWIS / HI0000214 / 2033
2008 2,4,5-TP MR 3 SDWIS / HI0000214 / 2110
2008 CYANIDE MR 3 SDWIS / HI0000214 / 1024
2008 Di(2-ethylhexyl) phthalate MR 3 SDWIS / HI0000214 / 2039
2008 2,4-D MR 3 SDWIS / HI0000214 / 2105

How Lahaina Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Lahaina Hawaii avg Federal benchmark
Total violations 243 38.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 116 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 20,065 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 Lahaina water safe to drink? ▼
Lahaina (PWS ID: HI0000214) has 243 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 20,065 people using Surface Water sources.
How many people does Lahaina serve? ▼
Lahaina serves 20,065 people in Wailuku, Hawaii. It is a Local-owned system using Surface Water water sources with 3,236 service connections.
What type of violations does Lahaina have? ▼
Lahaina has 243 total violations: 116 health-based violations (MCL exceedances or treatment failures), 80 monitoring/reporting violations, and 93 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Lahaina water? ▼
No. Lahaina was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does Lahaina use? ▼
Lahaina uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
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.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

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.