Public water system · HI0000139
ActiveNiulii
At a glance
Niulii (PWSID HI0000139) is an active community water system in Hawaii County, Hawaii. It reports serving 254 people through 94 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is health-based, and the most recent began in October 1992.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
254
Service connections
94
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Niulii compare with other water systems in Hawaii County?
By EPA's size categories, Niulii is a very small system (500 people or fewer). Hawaii County has 39 active public water systems. Its population served is well below the county average of 3,693 people per system, and accounts for 0.2% of the 144,021 people reported by systems filed under the county. Across Hawaii, the 136 active systems average 11,181 people each. Nationally, the average active community water system reports serving 6,703 people, so Niulii is well below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Hawaii has 119 active community water systems, 88% of the state's 136 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 112 Hawaii systems (82%) list groundwater as their primary source.
Who owns and regulates Niulii?
EPA lists Niulii as owned by a local government. The HI state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 23 of the 39 active systems in Hawaii County (59%) are also owned by a local government.
Does Niulii have drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in October 1992. By type: 1 contaminant level above the legal limit. The contaminant or rule involved is Total coliform bacteria (TCR). EPA lists 1 as archived. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1992-10-31 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
The one violation in EPA's records.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Niulii: frequently asked questions
Who runs Niulii?
Niulii (PWSID HI0000139) is a community water system owned by a local government. It is regulated by the HI state drinking water program.
How many people does Niulii serve?
Niulii reports serving 254 people through 94 service connections in Hawaii County, Hawaii.
Where does Niulii get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Niulii have any drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in October 1992. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Niulii's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list one violation for this system; it is health-based, and the most recent began in October 1992. For current results, consult the system's annual water quality report, EPA ECHO, or the HI state drinking water program.
Where can I find Niulii's water quality report?
As a community water system, Niulii must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Hawaii County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Hilo | Hawaii | 39,477 | Community | Groundwater |
| North Kona | Hawaii | 29,581 | Community | Groundwater |
| Waikoloa | Hawaii | 12,100 | Community | Groundwater |
| South Kohala | Hawaii | 9,612 | Community | Surface water |
| South Kona | Hawaii | 6,512 | Community | Groundwater |
| Olaa-Mountain View | Hawaii | 6,467 | Community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Niulii, PWSID HI0000139, Hawaii”, https://aquacensus.com/water-systems/hawaii/niulii-hi0000139 (data as of October 1, 2026).