National Drinking Water Database
Iowa
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.
Chemicals |
Water Utilities |
Population Served |
|
|---|---|---|---|
| Detected Chemicals | 83 |
1,135 |
2,660,281 |
Exceed health guidelines* | 38 |
1,105 |
2,652,899 |
Exceed Legal Limits* | 20 |
262 |
948,676 |
Unregulated chemicals detected | 25 |
70 |
445,496 |
| * 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
| Contaminant | Population |
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 |
Water Utilities in Iowa Reporting Chemicals Exceeding Health Guidelines
Water utilities in Iowa reporting chemicals exceeding health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities, include:
| System | Population |
Chemicals tested |
Chemicals found |
Chemicals exceeding health guidelines |
|---|---|---|---|---|
| Sioux City Water Supply | 85,028 | 61 | 24 | 14 |
| Sergeant Bluff Water Supply | 3,321 | 62 | 19 | 14 |
| Storm Lake Water Treatment Plant | 10,329 | 64 | 23 | 14 |
| Stacyville Water Supply | 469 | 60 | 19 | 13 |
| Iowa Falls Water Department | 5,193 | 62 | 18 | 13 |
| Lawton Water Supply | 697 | 61 | 17 | 12 |
| Creston Water Supply | 7,597 | 63 | 23 | 12 |
| Little Sioux Water Department | 222 | 52 | 20 | 12 |
| Scranton Water System | 604 | 60 | 17 | 12 |
| Nora Springs Water Supply | 1,532 | 64 | 18 | 12 |
| Osceola Water Works | 4,659 | 57 | 17 | 12 |
| Glidden Water Supply | 1,253 | 82 | 20 | 12 |
| Salix Water Supply | 370 | 61 | 15 | 11 |
| Kalona Water Dept | 2,293 | 56 | 18 | 11 |
| Boyden Municipal Water Supply | 687 | 48 | 16 | 11 |
| Odebolt Water Supply | 1,160 | 51 | 17 | 11 |
| Montezuma Muni Water Supply | 1,457 | 58 | 17 | 11 |
| Carson Water Supply | 668 | 59 | 16 | 11 |
| West Des Moines Water Works | 54,293 | 51 | 19 | 11 |
| City of Ankeny | 36,161 | 61 | 19 | 11 |
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.
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 |
| Operations Report | 6 |
| Excess Turbidity at 1 NTU | 6 |
| Filter Turbidity Reporting | 5 |
| Failure to monitor: Check/Repeat/Confirmation sampling | 5 |
| Inadequate reporting of information to the public | 4 |
| Treatment Technique (Surface Water Treatment Rule) | 3 |
| Variance/Exemption/Other Compliance | 3 |
| Improper Treatment Techniques | 2 |
| Failure to monitor, Repeat Minor (Coliform bacteria) | 2 |
| Failure to notify state agency | 1 |
| Public Education | 1 |
| Optimal Corrosion Control Treatment Study Recommendation | 1 |
| Failure to notify public of violation | 1 |
