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Community Water System · PWS HI0000231

Maunaloa-Kaluakoi

Maunaloa, Hawaii 96770 - drinking water served from groundwater sources to 1,000 people, tracked in EPA SDWIS and UCMR5.

1,000
People served
140
EPA violations
31
Health-based
Untested
UCMR5 result

The verdict

EPA records 140 drinking-water violations at Maunaloa-Kaluakoi, 22% of them health-based - above the Hawaii per-system average.

140
Total EPA violations on record
22%
Health-based (MCL / treatment failure)
1,000
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Maunaloa-Kaluakoi

Maunaloa-Kaluakoi is a private-owned community water system that delivers drinking water to 1,000 residents in Maunaloa, Hawaii (Maui County) through 358 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 140 total violations for this system , of which 31 (22%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 18 monitoring and reporting violations are on file. The most recent violation on record dates to 2022.

The most frequently cited contaminant at this system is Coliform (Pre-TCR), recorded in 25 violations (Other). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

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%).

Maunaloa-Kaluakoi's 140 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
1,000
Total Violations
140
Health-Based Violations
31
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
358
County
Maui
School/Daycare
No
MCL Violations
10
Monitoring Violations
18
Treatment Tech Violations
21

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (Pre-TCR) Other 25 1990
Surface Water Treatment Rule TT 18 2007
TTHM MCL 10 2016
Surface Water Treatment Rule MR 6 1993
Lead and Copper Rule MR 5 2022
CARBON, TOTAL TT 3 2005
CYANIDE MR 3 2008
Coliform (TCR) MR 3 1998
Gross Alpha, Excl. Radon and U MR 1 2000

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 Maunaloa-Kaluakoi.

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 HI0000231 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
2022 Lead and Copper Rule MR 5 SDWIS / HI0000231 / 5000
2016 TTHM MCL 10 SDWIS / HI0000231 / 2950
2008 CYANIDE MR 3 SDWIS / HI0000231 / 1024
2007 Surface Water Treatment Rule TT 18 SDWIS / HI0000231 / 0200
2005 CARBON, TOTAL TT 3 SDWIS / HI0000231 / 2920
2000 Gross Alpha, Excl. Radon and U MR 1 SDWIS / HI0000231 / 4000
1998 Coliform (TCR) MR 3 SDWIS / HI0000231 / 3100
1993 Surface Water Treatment Rule MR 6 SDWIS / HI0000231 / 0200
1990 Coliform (Pre-TCR) Other 25 SDWIS / HI0000231 / 3000

How Maunaloa-Kaluakoi Compares

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

Metric Maunaloa-Kaluakoi Hawaii avg Federal benchmark
Total violations 140 38.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 31 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 1,000 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 Maunaloa-Kaluakoi water safe to drink? ▼
Maunaloa-Kaluakoi (PWS ID: HI0000231) has 140 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,000 people using Groundwater sources.
How many people does Maunaloa-Kaluakoi serve? ▼
Maunaloa-Kaluakoi serves 1,000 people in Maunaloa, Hawaii. It is a Private-owned system using Groundwater water sources with 358 service connections.
What type of violations does Maunaloa-Kaluakoi have? ▼
Maunaloa-Kaluakoi has 140 total violations: 31 health-based violations (MCL exceedances or treatment failures), 18 monitoring/reporting violations, and 21 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Maunaloa-Kaluakoi water? ▼
No PFAS testing data is available for Maunaloa-Kaluakoi under the EPA's UCMR5 monitoring program.
What water source does Maunaloa-Kaluakoi use? ▼
Maunaloa-Kaluakoi uses Groundwater 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. 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.