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National Drinking Water Database


Nitrate in Iowa


Nitrate enters drinking water sources from fertilizer runoff, leaching septic tanks, and erosion of natural deposits; it is also emitted by chemical, petrochemical and metal-finishing industries. [read more]

The Most Polluted Communities in Iowa

631 water utilities reported detecting Nitrate in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Nitrate level

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Hastings Water Supply
Omaha, IA
21463 of 639.71 ppm
(6.7 to 13 ppm)
2Winding Brook Mobile Home Park
Dewitt, IA
15034 of 349.51 ppm
(7.6 to 11 ppm)
3College Springs Water Supply
College Sp, IA
24636 of 368.71 ppm
(6.3 to 12.2 ppm)
4George Water Supply
George, IA
1,05564 of 658.23 ppm
(0 to 9.7 ppm)
5Emerson Water Department
Emerson, IA
48054 of 548.05 ppm
(3.6 to 10 ppm)
6City of Holstein
Holstein, IA
1,47766 of 667.97 ppm
(2.8 to 10 ppm)
7Griswold Water Supply
Griswold, IA
1,03964 of 647.83 ppm
(5 to 9.4 ppm)
8Elliott Water Supply
Elliott, IA
40249 of 497.78 ppm
(2.9 to 9.3 ppm)
9Saints Avenue Apartments
Waverly, IA
12531 of 317.78 ppm
(6.2 to 9.9 ppm)
10Manchester Water Supply
Manchester, IA
5,25728 of 287.58 ppm
(6.1 to 9.4 ppm)

Health Based Limits for Nitrate

StandardDescriptionLevel
Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.10 ppm
Maximum Contaminant Limit Goal (MCLG)A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.10 ppm
California Public Health GoalsDefined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.10 ppm
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.10 ppm
Children's health-based limit for 1-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.10 ppm
Children's health-based limit for 10-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.10 ppm

Violation Summary for Nitrate in Iowa

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

Violation TypeNumber of Violations
Failure to monitor regularly73
Over maximum contaminant level, Single Sample60
Failure to monitor: Check/Repeat/Confirmation sampling2
Over maximum contaminant level, Average2