Water System Report HI

Mahanalua Nui Subdivison

EPA ID: HI0000251 · 606 people served · 2 ZIP codes

Five clean years on EPA record — Mahanalua Nui Subdivison, 606 residents served.

Data: EPA SDWIS Last verified: 2026-04-02

B · 70
Avg Safety Score
606
People Served
2
ZIP Codes Served
0
Violations (5yr)
Groundwater
Water Source
0.018475 mg/L
Max Lead Level — Exceeds Limit
Zone 3
Radon Risk · Low
0
Contaminants Flagged

Service Area Map

Coverage area for Mahanalua Nui Subdivison Source: EPA SDWIS service area boundaries.

Service area boundary — Grade B

Service Area Demographics

$94,360
Median Household Income
25,889
Service Area Population
15%
Disadvantaged Population
40th
Poverty Percentile
40th
Energy Burden Percentile
60%
Pre-1986 Housing

The Mahanalua Nui Subdivison serves a community with a median household income of $94,360 and an estimated 25,889 residents across its service area. Approximately 60% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.

💧 Where Does Your Water Come From?

Groundwater

Mahanalua Nui Subdivison's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.

Low Risk
Source Contamination Risk
20th
Wastewater Discharge Proximity
0th
Superfund Site Proximity

About 2% of homes in Maui County, Hawaii rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.

Infrastructure Risk

55 yr
Avg Pipe Age
Copper
Pipe Material
15 yr
Est. Remaining Life
Stable
Decay Status
Installed 79% of expected lifespan used End of life

Comparable Water Systems

Similar-sized systems in Hawaii

Camp Stover
595 people
0 violations
Honomu
645 people
C 0 violations
Kunia Village
650 people
A 0 violations
Kawela Plantation
553 people
0 violations
Hanalei
500 people
B 0 violations

Estimated Remediation Costs

Average estimated costs across ZIP codes served by this system

Lead Pipe Replacement Flood Insurance
Lead Pipe Replacement $1,800
Flood Insurance $1,500
Total Estimated Cost $3,300

Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.

Cost of Inaction

If water quality issues in this service area are not addressed, the estimated financial impact per household is:

Lead Exposure — Child Lifetime Cost $10,000

Per affected child (EPA est.)

Estimated Cumulative Cost Per Household

5 years
$2,780
10 years
$5,560
20 years
$11,120

Compare: Estimated remediation cost is $3,300 (one-time) vs. $5,560 in estimated inaction costs over 10 years.

Estimates based on published EPA, CDC, and peer-reviewed research. Individual costs vary by household size, property, and health factors. These are conservative lower-bound estimates intended for awareness, not financial advice.

System Overview

Mahanalua Nui Subdivison (EPA ID: HI0000251) is a community water system in Hawaii that serves approximately 606 people from groundwater sources.

This system provides water to 2 ZIP codes across 1 community.

Average Home Safety Score: B (70/100)

Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.

Violation History

No violations recorded — This water system has no recorded EPA violations in the past 5 years.

Lead & Copper

EPA Lead and Copper Rule sampling data for ZIP codes served by this system:

ZIP Code Lead Level Exceeds Limit Sample Date
96733 0.018475 mg/L Yes N/A
Lead exceeds EPA action level in at least one sampling location. Consider using a certified NSF/ANSI 53 or NSF/ANSI 58 filter rated for lead removal.

Radon Risk in Service Area

Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)

Need help with your water quality?

Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400

Find the Right Water Filter

Free tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.

ZIP Codes Served

Data Sources

This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Mahanalua Nui Subdivison (HI0000251) on EPA.gov.

Frequently Asked Questions

Is Mahanalua Nui Subdivison water safe to drink?

Based on EPA records, Mahanalua Nui Subdivison has no recorded violations in the past 5 years — a positive indicator of water quality management.

How many people does Mahanalua Nui Subdivison serve?

Mahanalua Nui Subdivison serves approximately 606 people across 2 ZIP codes in Hawaii.

Where does Mahanalua Nui Subdivison get its water?

The primary water source is groundwater.

Lead Service Line Inventory

Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:

0
Confirmed Lead
0
Galvanized — Replacement Required
0
Unknown Material
395
Confirmed Non-Lead

This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.

Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.

Federal Regulatory Status · 2026Q1
LCRR inventory submission: Reported all required service line types
Latest tap sample on 2019-01-01 did not exceed the federal lead action level.
Population served: 606
Reported to Hawaii

Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026

ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.

Learn about lead in drinking water →

Frequently Asked Questions

Is water from Mahanalua Nui Subdivison safe to drink?
Mahanalua Nui Subdivison earns a B safety grade with 0 violations in the past 5 years. Tap water meets EPA standards for most contaminants.
Should I use a water filter?
Mahanalua Nui Subdivison meets EPA standards, but a water filter can reduce trace contaminants below detectable levels for added peace of mind.
How many people does Mahanalua Nui Subdivison serve?
Mahanalua Nui Subdivison serves approximately 606 people with drinking water across 2 ZIP codes.
What is Mahanalua Nui Subdivison's water source?
Mahanalua Nui Subdivison draws water from groundwater sources. Source type affects which contaminants are most likely to be present.
Is there lead in Mahanalua Nui Subdivison's water?
The maximum detected lead level is 0.018475 mg/L. This exceeds the EPA action level of 0.015 mg/L. A lead-certified filter is recommended, especially for homes with young children.
What is the demographic profile of Mahanalua Nui Subdivison's service area?
The Mahanalua Nui Subdivison service area has a median household income of $94,360. Demographic data is sourced from the U.S. Census Bureau and EPA EJScreen.
Where does Mahanalua Nui Subdivison get its water?
Mahanalua Nui Subdivison's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Home Water Systems Hawaii Mahanalua Nui Subdivison

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