222 systems serving 2,429,998 people
  This drinking water quality report shows results of tests conducted by water utilities in Nevada, provided to the Environmental Working Group (EWG) by the State water agency. 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.

  33 Contaminants Exceeding Health Based Limits

Contaminants detected in Nevada 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
Combined Radium (-226 & -228) 2,231,453 2,231,453 52 52
Alpha particle activity (excl radon and uranium) 2,171,306 2,171,306 54 54
Arsenic (total) 2,090,404 2,090,404 132 132
Total haloacetic acids (HAAs) 2,071,848 2,051,313 14 12
Total trihalomethanes (TTHMs) 2,193,984 2,040,288 47 17
Combined Uranium (mg/L) 1,905,680 1,905,680 70 70
Radium-226 1,887,763 1,887,763 49 49
Radium-228 1,648,945 1,648,945 42 42
Lead (total) 1,591,306 1,591,306 26 26
Radon 1,526,989 1,526,989 6 6

  Sources of Nevada Drinking Water Contaminants

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

73 Total Contaminants Detected (2004 - 2008)
12 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Arsenic (total), Cyanide, Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Phosphorus, Diquat, DCPA mono acid degradate, 2,4-D, Foaming agents (surfactants), p-Dichlorobenzene

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

Nitrate, Copper, Nitrate & nitrite, Lead (total), Arsenic (total), Tetrachloroethylene, Nitrite, Xylenes (total), Cadmium (total), Antimony (total), Mercury (total inorganic), m- & p- Xylene, Cyanide, o-Xylene, Foaming agents (surfactants), Benzene, Acetone, Molybdenum, Silver (total), p-Dichlorobenzene, Phosphorus, Di-n-butylphthalate, 2,4-D, Naphthalene, Diethylphthalate, Phenanthrene, DCPA mono acid degradate

55 Industrial Pollutants

Aluminum, Bromide, Arsenic (total), Barium (total), Cadmium (total), Chromium (total), Cyanide, Lead (total), Manganese, Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Silver (total), Antimony (total), Beryllium (total), Molybdenum, Thallium (total), Titanium, Vanadium, Phosphorus, Di(2-ethylhexyl) phthalate, Hexachlorocyclopentadiene, Chloromethane, Acetone, Naphthalene, Phenanthrene, Diethylphthalate, Di-n-butylphthalate, 1,3-Dichloropropane, 1,2,4-Trimethylbenzene, Foaming agents (surfactants), Xylenes (total), p-Dichlorobenzene, 1,1-Dichloroethylene, 1,1,1-Trichloroethane, Trichloroethylene, Tetrachloroethylene, Benzene, Toluene, Styrene, o-Xylene, m- & p- Xylene, Alpha particle activity (excl radon and uranium), Alpha particle activity (incl. radon & uranium), Combined Uranium (mg/L), Uranium-238, Combined Radium (-226 & -228), Radium-226, Radium-228, Alpha particle activity, Strontium-90, Combined Uranium (pCi/L), Gross beta particle activity (pCi/L)

16 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, Bromochloroacetic acid, Monobromoacetic acid, Di(2-ethylhexyl) phthalate, Cadmium (total), Chloromethane, Bromate

29 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, Radium-228, Radium-226, Alpha particle activity, Alpha particle activity (excl radon and uranium), Combined Radium (-226 & -228), Gross beta particle activity (pCi/L), Combined Uranium (pCi/L), Chromium (total), Alpha particle activity (incl. radon & uranium), Combined Uranium (mg/L), Aluminum, Selenium (total), Nitrite, Radon, Bromide, Mercury (total inorganic), Chloromethane, Cyanide, Uranium-238, Silver (total), Phosphorus, Titanium

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

Bromide, Lead (total), Molybdenum, Titanium, Vanadium, Phosphorus, DCPA mono acid degradate, Chloromethane, Acetone, Naphthalene, Phenanthrene, Diethylphthalate, Di-n-butylphthalate, 1,3-Dichloropropane, 1,2,4-Trimethylbenzene, Bromochloroacetic acid, Radon, Strontium-90

  Testing Summary for Nevada

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

Contaminants reported as tested by water suppliers in Nevada 246
  Contaminants tested due to federal law: 110
  Contaminants tested in addition to those required by federal law: 136
  Violation Summary for Nevada

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

Violation Type Number of Violations
Failure to monitor regularly 1,983
Monitoring and Reporting Disinfection Byproduct Rule 271
Failure to monitor, Routine Major (Coliform bacteria) 202
Failure to report information to the public or state agency in the Consumer Confidence Report 182
Maximum contaminant level, Monthly (Coliform bacteria) 102
Over maximum contaminant level, Average 89
Follow-up and Routine Tap Sampling 37
Failure to monitor, Routine Minor (Coliform bacteria) 37
Initial Tap Sampling for Lead and Copper 17
Failure to monitor, Repeat Major (Coliform bacteria) 13
Maximum contaminant level, Acute (Coliform bacteria) 9
Failure to monitor, Repeat Minor (Coliform bacteria) 5
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) 3
Failure to Filter (Surface Water Treatment Rule) 3
Over maximum contaminant level, Single Sample 3
Treatment Technique (Surface Water Treatment Rule) 2
Failure to monitor: Check/Repeat/Confirmation sampling 1

Sources : EWG (Environmental Working Group)