1,135 systems serving 2,661,554 people
  This drinking water quality report shows results of tests conducted by water utilities in Iowa, provided to the Environmental Working Group (EWG) by the Iowa Department of Natural 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.

  38 Contaminants Exceeding Health Based Limits

Contaminants detected in Iowa 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
Lead (total) 2,456,856 2,456,856 884 884
Dichloroacetic acid 2,289,579 2,289,579 650 650
Bromodichloromethane 2,279,628 2,279,628 656 656
Dibromochloromethane 2,135,171 2,133,213 640 639
Total haloacetic acids (HAAs) 2,106,501 2,079,000 455 454
Total trihalomethanes (TTHMs) 2,403,577 1,906,200 706 489
Bromoform 1,678,070 1,678,070 402 402
Chloroform 2,444,710 1,673,638 773 404
Combined Radium (-226 & -228) 835,303 835,303 324 324
Radium-228 777,134 777,134 299 299

  Sources of Iowa Drinking Water Contaminants

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

83 Total Contaminants Detected (2004 - 2009)
23 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Nitrate, Nitrate & nitrite, Arsenic (total), Selenium (total), Nitrite, Atrazine, Ethylbenzene, Dalapon, Simazine, Chlorate, 1,2-Dichloropropane, Dacthal, Metolachlor, p-Dichlorobenzene, Phosphorus, 2,4-D, Bromomethane, Alachlor (Lasso), Methoxychlor, Bromacil, Acetochlor, Cyanazine (Bladex), Desethylatrazine

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

Nitrate, Copper, Nitrate & nitrite, Lead (total), Arsenic (total), Tetrachloroethylene, MTBE, Nitrite, Xylenes (total), Dalapon, Antimony (total), Mercury (total inorganic), Dichloromethane (methylene chloride), Benzene, Dacthal, p-Dichlorobenzene, Di(2-Ethylhexyl) adipate, Phosphorus, Di-n-butylphthalate, 2,4-D, Naphthalene, Benzo[a]pyrene, n-Propylbenzene, Phenanthrene, Pyrene, Fluoranthene, Fluorene, Acenaphthene

55 Industrial Pollutants

Aluminum, Arsenic (total), Chlorate, Chlorite, Barium (total), Chromium (total), Lead (total), Manganese, Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Antimony (total), Phosphorus, Di(2-Ethylhexyl) adipate, Di(2-ethylhexyl) phthalate, Chloromethane, Chloroethane, Naphthalene, MTBE, Acenaphthene, Fluorene, Phenanthrene, Fluoranthene, Pyrene, Di-n-butylphthalate, cis-1,2-Dichloroethylene, Dibromomethane, 1,2,4-Trimethylbenzene, 1,3,5-Trimethylbenzene, Bromochloromethane, Xylenes (total), Dichloromethane (methylene chloride), p-Dichlorobenzene, Vinyl chloride, 1,1-Dichloroethane, 1,2-Dichloroethane, 1,1,1-Trichloroethane, 1,2-Dichloropropane, Trichloroethylene, Tetrachloroethylene, Benzene, Toluene, Ethylbenzene, Styrene, n-Propylbenzene, Alpha particle activity (excl radon and uranium), Alpha particle activity (incl. radon & uranium), Combined Uranium (mg/L), Combined Radium (-226 & -228), Radium-226, Radium-228, Combined Uranium (pCi/L), Gross beta particle activity (pCi/L)

22 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, Chlorite, Di(2-ethylhexyl) phthalate, Chloromethane, Chlorate, Bromate, Vinyl chloride, Dibromomethane, Bromochloromethane, Benzo[a]pyrene, Chloroethane, Fluoranthene

23 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 (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, Mercury (total inorganic), Chloromethane, Phosphorus

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

Chlorate, Lead (total), Phosphorus, Acetochlor, Metolachlor, Cyanazine (Bladex), Bromacil, Dacthal, Chloromethane, Bromomethane, Chloroethane, Naphthalene, MTBE, Acenaphthene, Fluorene, Phenanthrene, Fluoranthene, Pyrene, Di-n-butylphthalate, Dibromomethane, 1,2,4-Trimethylbenzene, 1,3,5-Trimethylbenzene, Bromochloromethane, 1,1-Dichloroethane, n-Propylbenzene, Radon

  Testing Summary for Iowa

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

Contaminants reported as tested by water suppliers in Iowa 166
  Contaminants tested due to federal law: 96
  Contaminants tested in addition to those required by federal law: 70
  Violation Summary for Iowa

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

Violation Type Number of Violations
Failure to monitor, Routine Major (Coliform bacteria) 305
Maximum contaminant level, Monthly (Coliform bacteria) 297
Over maximum contaminant level, Average 276
Failure to monitor regularly 275
Monitoring and Reporting Disinfection Byproduct Rule 250
Failure to report information to the public or state agency in the Consumer Confidence Report 127
Record Keeping Violation 106
Over maximum contaminant level, Single Sample 82
Failure to monitor, Routine Minor (Coliform bacteria) 77
Follow-up and Routine Tap Sampling 58
Maximum contaminant level, Acute (Coliform bacteria) 24
Failure to monitor, Repeat Major (Coliform bacteria) 20
Excess Turbidity at 0.3 NTU 12
Excess Turbidity at 1 NTU 6
Operations Report 6
Filter Turbidity Reporting 5
Failure to monitor: Check/Repeat/Confirmation sampling 5
Inadequate reporting of information to the public 4
Variance/Exemption/Other Compliance 3
Treatment Technique (Surface Water Treatment Rule) 3
Improper Treatment Techniques 2
Failure to monitor, Repeat Minor (Coliform bacteria) 2
Optimal Corrosion Control Treatment Study Recommendation 1
Failure to notify public of violation 1
Failure to notify state agency 1
Public Education 1

Sources : EWG (Environmental Working Group)