Overview
EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Hawaii Department of Health, as well as information from the U.S. EPA Enforcement and Compliance History database (ECHO). For the latest quarter assessed by the U.S. EPA (April 2024 - June 2024), tap water provided by this water utility was in compliance with federal health-based drinking water standards.
Legal does not necessarily equal safe.
Getting a passing grade from the federal government does not mean the water meets the latest health guidelines.
Legal limits for contaminants in tap water have not been updated in almost 20 years.
The best way to ensure clean tap water is to keep pollution out of source water in the first place.
Contaminants Detected
Haloacetic acids (HAA5)
Potential Effect: cancer
This Utility: 0.400 ppb
Legal Limit: 60 ppb
4x
EWG's Health Guideline: 0.1 ppb
Haloacetic acids (HAA5)
Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid.
Haloacetic acids (HAA5) was found at 4 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
Health Risks
The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppb = parts per billionPollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Nitrate
Potential Effect: cancer
This Utility: 0.437 ppm
Legal Limit: 10 ppm
3.1x
EWG's Health Guideline: 0.14 ppm
Nitrate
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.
Nitrate was found at 3.1 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
Health Risks
The EWG health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppm = parts per millionPollution Sources
Agriculture
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Nitrate and nitrite
Potential Effect: cancer
This Utility: 0.437 ppm
Legal Limit: 10 ppm
3.1x
EWG's Health Guideline: 0.14 ppm
Nitrate and nitrite
Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.
Nitrate and nitrite was found at 3.1 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
Health Risks
The EWG health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppm = parts per millionPollution Sources
Agriculture
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Includes chemicals detected in 2021-2023 for which annual utility averages exceeded an EWG-selected health guideline established by a federal or state public health authority.
† HAA5 is a contaminant group that includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. HAA9 is a contaminant group that includes the chemicals in HAA5 and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid and tribromoacetic acid. TTHM is a contaminant group that includes bromodichloromethane, bromoform, chloroform and dibromochloromethane.
Bromoform
This Utility: 0.273 ppb
No Legal Limit
EWG's Health Guideline: 0.5 ppb
Bromoform
Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
Health Risks
The EWG Health Guideline of 0.5 ppb for bromoform is based on the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer, harm to reproduction and child development, and change to fetal growth and development .
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppb = parts per billionPollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Dieldrin
This Utility: 0.00500 ppb
No Legal Limit
No EWG Health Guideline
Dieldrin
Dieldrin is a highly toxic insecticide that was banned in the 1970s due to its persistence in the environment and toxicity to people and wildlife.
How your levels compare
This Utility
National Average
State Average
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppb = parts per billionPollution Sources
Agriculture
Filtering Options
Activated Carbon
Reverse Osmosis
Fluoride
This Utility: 0.680 ppm
Legal Limit: 4 ppm
No EWG Health Guideline
Fluoride
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems to prevent cavities and support oral health in people.
In 2015, the Department of Health and Human Services updated its recommendation of an optimal level of 0.7 parts per million, or ppm, added to drinking water based on the health benefits of tooth decay prevention. Studies have shown that fluoride added to community water systems at this level reduces dental cavities, especially in children.
And studies have conclusively shown that fluoride in toothpaste and mouthwash can also provide these benefits.
How your levels compare
This Utility
Legal Limit
National Average
State Average
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppm = parts per millionPollution Sources
Industry
Treatment Byproducts
Naturally Occurring
Filtering Options
Reverse Osmosis
Monochloroacetic acid
This Utility: 0.400 ppb
No Legal Limit
EWG's Health Guideline: 53 ppb
Monochloroacetic acid
Monochloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
Health Risks
The EWG Health Guideline of 53 ppb for monochloroacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk.a public health goal. This health guideline protects against change to fetal growth and development.
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppb = parts per billionPollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Total trihalomethanes (TTHMs)
This Utility: 0.273 ppb
Legal Limit: 80 ppb
EWG's Health Guideline: 0.15 ppb
Total trihalomethanes (TTHMs)
Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
Health Risks
The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.
Understanding the Data
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2021-2023.
ppb = parts per billionPollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Includes chemicals detected in 2021-2023 for which annual utility averages were lower than an EWG-selected health guideline established by a federal or state public health authority.
Other Contaminants Tested
✕Find A Filter
Explore filter options for each contaminant. See which technologies are effective at reducing specific contaminants to help you make an informed decision on the best water treatment solution for your needs.
| CONTAMINANTS ABOVE HEALTH GUIDELINES | activated carbon | reverse osmosis | ion exchange |
| Haloacetic acids (HAA5) | |||
| Nitrate | |||
| Nitrate & nitrite | |||
| OTHER CONTAMINANTS DETECTED | activated carbon | reverse osmosis | ion exchange |
| Bromoform | |||
| Dieldrin | |||
| Fluoride | |||
| Monochloroacetic acid | |||
| Total trihalomethanes (TTHMs) |
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