106 systems serving 1,442,030 people
  This drinking water quality report shows results of tests conducted by water utilities in Hawaii, provided to the Environmental Working Group (EWG) by the Hawaii Department of Health. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results from 45 states and the District of Columbia. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources in protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes drinking water quality for this state.

Water Utilities
Population Served
Detected Chemicals
Exceed health guidelines*
Exceed Legal Limits*
Unregulated chemicals detected
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

  21 Contaminants Exceeding Health Based Limits

Contaminants detected in Hawaii drinking water above health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities.

Number of Systems
At Any Level Above Health Limits At Any Level Above Health Limits
Bromoform 1,209,301 1,209,301 71 71
1,2,3-Trichloropropane 1,020,192 1,020,192 13 13
Dieldrin 831,925 831,925 2 2
Heptachlor epoxide 713,330 713,330 2 2
Total haloacetic acids (HAAs) 937,256 266,374 50 47
Dibromochloromethane 261,799 261,799 46 46
Bromodichloromethane 216,608 216,608 31 31
Dichloroacetic acid 215,079 215,079 27 27
Atrazine 270,225 177,937 16 8
Total trihalomethanes (TTHMs) 1,247,127 177,829 81 29

  Sources of Hawaii Drinking Water Contaminants

The contaminants identified in Hawaii drinking water come from a wide variety of sources, including agriculture, industry, water treatment plants, and polluted storm runoff from urban areas.

37 Total Contaminants Detected (2004 - 2009)
11 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Arsenic (total), Nitrate, Nitrite, Selenium (total), Atrazine, Heptachlor epoxide, Dieldrin, 1,2-Dibromo-3-chloropropane (DBCP), Ethylene dibromide (EDB), Chlordane, Ethylbenzene

12 Sprawl and Urban Pollutants
(road runoff, lawn pesticides, human waste)

Arsenic (total), Cadmium (total), Copper, Lead (total), Nitrate, Nitrite, Antimony (total), Xylenes (total), Chlordane, Tetrachloroethylene, m-Xylene, o-Xylene

20 Industrial Pollutants

Arsenic (total), Barium (total), Cadmium (total), Chromium (total), Lead (total), Nitrate, Nitrite, Selenium (total), Antimony (total), Hexachlorocyclopentadiene, 1,2,3-Trichloropropane, Ethylene dibromide (EDB), Xylenes (total), Carbon tetrachloride, Trichloroethylene, Tetrachloroethylene, Toluene, Ethylbenzene, m-Xylene, o-Xylene

12 Water Treatment and Distribution Byproducts
(pipes and fixtures, treatment chemicals and byproducts)

Total trihalomethanes (TTHMs), Total haloacetic acids (HAAs), Chloroform, Bromodichloromethane, Dibromochloromethane, Dichloroacetic acid, Trichloroacetic acid, Bromoform, Dibromoacetic acid, Monochloroacetic acid, Monobromoacetic acid, Cadmium (total)

8 Naturally Occurring
(naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

Nitrate, Copper, Barium (total), Lead (total), Arsenic (total), Chromium (total), Selenium (total), Nitrite

3 Unregulated Contaminants
EPA has not established a maximum legal limit in tapwater for these contaminants

Lead (total), Dieldrin, 1,2,3-Trichloropropane

  Testing Summary for Hawaii

The federal government has set standards for some of the pollutants found in tap water supplies

Contaminants reported as tested by water suppliers in Hawaii 96
  Contaminants tested due to federal law: 76
  Contaminants tested in addition to those required by federal law: 20
  Violation Summary for Hawaii

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Hawaii since 2004.

Violation Type Number of Violations
Treatment Technique (Surface Water Treatment Rule) 23
Failure to monitor regularly 20
Filter Turbidity Reporting 16
Maximum contaminant level, Monthly (Coliform bacteria) 8
Over maximum contaminant level, Average 7
Failure to monitor, Repeat Major (Coliform bacteria) 2
Excess Turbidity at 0.3 NTU 2
Treatment Technique Precursor Removal 1
Failure to monitor, Routine Major (Coliform bacteria) 1
Failure to monitor, Repeat Minor (Coliform bacteria) 1
Failure to Filter (Surface Water Treatment Rule) 1
Failure to monitor, Routine Minor (Coliform bacteria) 1
Maximum contaminant level, Acute (Coliform bacteria) 1

Sources : EWG (Environmental Working Group)