WaterVerge

Is Lihue-Kapaa, HI Tap Water Safe to Drink?

Graded A — but Manganese, Vanadium and 1 more were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

35K residents served 1 water system PWSID: HI0000400
Overall Score
93.3 / 100
Violations
2 active
Last Updated
May 2026
Source
Surface water
#28 of 66 in Hawaii Top 6% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
93.3/100
waterverge.com
A 93.3/100

Lihue-Kapaa, HI — Water Quality Report

Lihue-Kapaa's drinking water received a grade of A (93.3 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 34,854 residents using surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 10 violations on record, including 0 health-based violations. 2 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Lihue-Kapaa's water

Lihue-Kapaa ranks #28 out of 66 cities in Hawaii for water quality, placing it mid-range in the state.

The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.

Hexavalent chromium (chromium-6) was detected at 6.80 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

Quality Breakdown

Water quality score

See methodology →
93.3 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
43.9/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
17.4/20
B
No PFAS compounds detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Surface water.
Water Safety

Is Lihue-Kapaa, HI water safe to drink?

Use Caution

Lihue-Kapaa's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (93.3/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 34,854 residents using surface water (rivers, lakes, or reservoirs).

2
Active Violations
0.0 ppb
Lead (90th %ile)
None
PFAS Detected

Recent water quality updates for Lihue-Kapaa

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Lihue-Kapaa's water quality assessment. Grade: A (93.3/100).

Violation
3 drinking water violations recorded

Contaminants: E. COLI, Turbidity, Cryptosporidium.

Violation
3 drinking water violations recorded

Contaminants: Gross Alpha, Excl. Radon and U, Radium-226, Radium-228.

Violation
2 drinking water violations recorded

Contaminants: Gross Alpha, Excl. Radon and U.

Key contaminant findings

Based on the most recent EPA sampling data for Lihue-Kapaa's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Chromium-6 (Hexavalent Chromium) Elevated
Detected: 6.80 µg/L Limit: 10 µg/L (California MCL — no federal limit)

The "Erin Brockovich" chemical. There is no federal MCL, but California has set a limit of 10 µg/L. Reverse osmosis filtration is effective at removing hexavalent chromium.

Violation history

Lihue-Kapaa's water system has 10 total violations on record, including 0 health-based violations. 2 remain unresolved.

MR
Most recent violations:
Apr 2018 E. COLI Resolved
Apr 2018 Turbidity Resolved
Apr 2018 Cryptosporidium Resolved
Jan 2004 Gross Alpha, Excl. Radon and U Resolved
Jan 2004 Radium-226 Resolved

Where does Lihue-Kapaa's water come from?

Lihue-Kapaa's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 34,854 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Right Branch Lawai Stream Nr Umauma Rd, Kauai (river), Weoweopilau Stream At Highway 50 Bridge, Kauai (river), Waiahi Str Us Upper Powerhouse, Kauai (river), Sf Wailua River Nr Lihue, Kauai (river), Nf Wailua Riv Abv N Wailua Ditch Int, Kauai (river).

What Lihue-Kapaa residents can do

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
3.7 µg/L
EPA MCL: 60 µg/L · 6% of limit
Within LimitUCMR 4 DataHAA6Br: 5.7 µg/LHAA9: 8.1 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Elevated
6.80 µg/L
CA MCL (no federal MCL): 10 µg/L · 68% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
490.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 33% of limit
DetectedUCMR 3 Data
1,4-Dioxane
Organic
Detected
0.12 µg/L
EPA Health Advisory: 0.35 µg/L · 34% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Over SMCL
57.0 µg/L
EPA Secondary MCL: 50 µg/L · +14% over limit
Over SMCLUCMR 4 Data
Vanadium
Inorganic
Over HA
72.00 µg/L
EPA Short-term HA: 21 µg/L · +20% over limit
Over Health AdvisoryUCMR 3 Data
Chlorate
Disinfection Byproduct
Over HA
220.0 µg/L
EPA Lifetime HA: 210 µg/L · +5% over limit
Over Health AdvisoryUCMR 3 Data
Molybdenum
Inorganic
Detected
1.00 µg/L
EPA Lifetime HA: 40 µg/L · 3% of limit
DetectedUCMR 3 Data
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
0
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

10
Total violations
0
Health-based
2
Active / unresolved
Apr 2018
Most recent violation
Compliance Record

Violations & advisories

10 Total
2 Active
0 Health-based
8 Resolved
Violations by category
Radionuclides and Revised Rad Rule
5
Long Term 2 Enhanced Surface Water Treatment Rule
3
Lead and Copper Rule
1
Jul 1992 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Apr 2018 Resolved
E. COLI
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2018
Apr 2018 Resolved
Turbidity
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2018
Apr 2018 Resolved
Cryptosporidium
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2018
Jan 2004 Resolved
Gross Alpha, Excl. Radon and U
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2007
Jan 2004 Resolved
Radium-226
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2007
Jan 2004 Resolved
Radium-228
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2007
Jan 2000 Resolved
Gross Alpha, Excl. Radon and U
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2003
Jan 2000 Resolved
Gross Alpha, Excl. Radon and U
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2003

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium ND HI µg/L PFAS Not Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 0.0 ppb from 2006 (0.0 ppb) to 2021 (0.0 ppb).
Contaminant Rankings

See how Lihue-Kapaa compares by contaminant

Explore where Lihue-Kapaa ranks among all Hawaii cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Surface Water
Operator
Local Government
Population Served
34,854
Water Systems
1
Water Source

Where Lihue-Kapaa's water comes from

Surface Water

Lihue-Kapaa's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.

Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.

These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.

The system is operated by local government ownership and serves approximately 34,854 people through 1 water system.

Local Hydrology

Water bodies near Lihue-Kapaa

Lihue-Kapaa is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.

Right Branch Lawai Stream Nr Umauma Rd, Kauai
river
Weoweopilau Stream At Highway 50 Bridge, Kauai
river
Waiahi Str Us Upper Powerhouse, Kauai
river
Sf Wailua River Nr Lihue, Kauai
river
Nf Wailua Riv Abv N Wailua Ditch Int, Kauai
river
Infrastructure

Water systems serving Lihue-Kapaa

System Name PWSID Population Source
LIHUE-KAPAA HI0000400 34,854 SW
Regional Comparison

How Lihue-Kapaa compares

Full Hawaii rankings →

Lihue-Kapaa's score of 93.3/100 is on par with the average of 91/100 among major Hawaii cities. It outscores 8 of 10 nearby cities.

Lihue-Kapaa (this city)
93.3
Wailuku
91.4
Hawaii avg
91
City Profile

About Lihue-Kapaa, HI

Wikipedia →

Līhuʻe is an unincorporated community, census-designated place (CDP) and the county seat of Kauaʻi County, Hawaii, United States. Līhuʻe is the second-largest town on the Hawaiian island of Kauaʻi, following Kapaʻa. As of the 2010 census, the CDP had a population of 6,455, up from 5,694 at the 2000 census.

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Frequently asked questions

Is Lihue-Kapaa, HI tap water safe to drink?

Lihue-Kapaa's water quality earned a grade of A (93.3/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #28 out of 66 cities tested in Hawaii.

What contaminants are in Lihue-Kapaa's water?

Lead was measured at 0.0 ppb (90th percentile). No PFAS compounds were detected. 10 violations are on record.

How is Lihue-Kapaa's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Lihue-Kapaa?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Lihue-Kapaa's water come from?

Lihue-Kapaa's water is sourced from Surface water. The city has 1 water system serving approximately 34,854 residents.

How does Lihue-Kapaa's water compare to other cities?

Lihue-Kapaa ranks #28 out of 66 cities in Hawaii (better than 58% of state cities) and #874 out of 15744 cities nationally (95th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.