845 systems serving 3,191,117 people
  This drinking water quality report shows results of tests conducted by water utilities in Oregon, provided to the Environmental Working Group (EWG) by the Oregon Department of Human Resources. 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.

  29 Contaminants Exceeding Health Based Limits

Contaminants detected in Oregon 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
Total haloacetic acids (HAAs) 2,857,494 2,837,289 357 352
Total trihalomethanes (TTHMs) 2,928,791 2,718,427 427 278
Arsenic (total) 1,371,971 1,371,971 350 350
Combined Radium (-226 & -228) 1,046,550 1,046,550 46 46
Lead (total) 851,798 851,798 30 30
Di(2-ethylhexyl) phthalate 691,677 691,677 28 28
Alpha particle activity (excl radon and uranium) 344,307 344,307 70 70
Bromodichloromethane 242,280 242,280 14 14
Chloroform 242,310 224,850 15 12
Thallium (total) 169,962 169,962 1 1

  Sources of Oregon Drinking Water Contaminants

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

57 Total Contaminants Detected (2004 - 2009)
16 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Arsenic (total), Cyanide, Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Lindane, Dalapon, Diquat, Glyphosate, Picloram, 2,4-D, 1,2-Dibromo-3-chloropropane (DBCP), Ethylene dibromide (EDB), 1,2-Dichloropropane, Ethylbenzene

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

Arsenic (total), Cadmium (total), Copper, Cyanide, Lead (total), Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Antimony (total), Lindane, Dalapon, Glyphosate, 2,4-D, Benzo[a]pyrene, Xylenes (total), Dichloromethane (methylene chloride), Tetrachloroethylene, Benzene

40 Industrial Pollutants

Arsenic (total), Chlorite, Barium (total), Cadmium (total), Chromium (total), Cyanide, Lead (total), Manganese, Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Antimony (total), Thallium (total), Asbestos, Lindane, Di(2-ethylhexyl) phthalate, Hexachlorocyclopentadiene, Hexachlorobenzene (HCB), Pentachlorophenol, 1,2,4-Trichlorobenzene, cis-1,2-Dichloroethylene, Total polychlorinated biphenyls (PCBs), Ethylene dibromide (EDB), Xylenes (total), Dichloromethane (methylene chloride), 1,1-Dichloroethylene, 1,1,1-Trichloroethane, 1,2-Dichloropropane, Trichloroethylene, Tetrachloroethylene, Benzene, Toluene, Ethylbenzene, Styrene, Alpha particle activity (excl radon and uranium), Combined Uranium (mg/L), Combined Radium (-226 & -228), Gross beta particle activity (pCi/L)

14 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, Monochloroacetic acid, Chlorite, Di(2-ethylhexyl) phthalate, Cadmium (total), Bromate, Asbestos, Benzo[a]pyrene

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

Nitrate, Copper, Nitrate & nitrite, Barium (total), Lead (total), Arsenic (total), Manganese, Alpha particle activity (excl radon and uranium), Combined Radium (-226 & -228), Gross beta particle activity (pCi/L), Chromium (total), Combined Uranium (mg/L), Selenium (total), Nitrite, Mercury (total inorganic), Cyanide

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

Lead (total)

  Testing Summary for Oregon

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

Contaminants reported as tested by water suppliers in Oregon 132
  Contaminants tested due to federal law: 92
  Contaminants tested in addition to those required by federal law: 40
  Violation Summary for Oregon

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

Violation Type Number of Violations
Failure to monitor regularly 10,338
Failure to monitor, Routine Major (Coliform bacteria) 1,535
Maximum contaminant level, Monthly (Coliform bacteria) 466
Monitoring and Reporting Disinfection Byproduct Rule 405
Failure to monitor, Routine Minor (Coliform bacteria) 357
Follow-up and Routine Tap Sampling 254
Inadequate reporting of information to the public 175
Failure to report information to the public or state agency in the Consumer Confidence Report 168
Failure to monitor, Repeat Major (Coliform bacteria) 163
Over maximum contaminant level, Average 58
Maximum contaminant level, Acute (Coliform bacteria) 40
Failure to monitor, Repeat Minor (Coliform bacteria) 36
Treatment Technique (Surface Water Treatment Rule) 34
Over maximum contaminant level, Single Sample 22
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) 19
Excess Turbidity at 0.3 NTU 14
Filter Turbidity Reporting 8
Initial Tap Sampling for Lead and Copper 3
Failure to Filter (Surface Water Treatment Rule) 3

Sources : EWG (Environmental Working Group)