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National Drinking Water Database


Nitrate in Arizona


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 Arizona

664 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)
1Picacho Peak Water Co
Picacho, AZ
5002 of 212 ppm
(11 to 13 ppm)
2Golden Corridor Wc, Inc.
Rushville, AZ
14710 of 149.5 ppm
(0 to 15 ppm)
3American Realty & Mortgag
Wittmann, AZ
506 of 79.42 ppm
(0 to 12.8 ppm)
4Villa Grande Dwid
Eloy, AZ
2633 of 39.17 ppm
(8.7 to 9.9 ppm)
5Eloy Detention Center
Eloy, AZ
1,6003 of 38.3 ppm
(6.5 to 9.2 ppm)
6Florence Water Co
Florence, AZ
3,9554 of 48.15 ppm
(7.8 to 8.4 ppm)
7Dells View Wc
Paulden, AZ
4610 of 118.06 ppm
(0 to 9.94 ppm)
8Country Home Mhp
Litchfield Park, AZ
30020 of 247.94 ppm
(0 to 9.8 ppm)
9Dells Water Company, Inc
Clarkdale, AZ
1804 of 47.65 ppm
(5.72 to 10.1 ppm)
10Diamond Grove Mobile Home Estates
Tucson, AZ
4624 of 47.35 ppm
(7 to 7.6 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 Arizona

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

Violation TypeNumber of Violations
Failure to monitor regularly1,137
Over maximum contaminant level, Single Sample35
Over maximum contaminant level, Average24
Failure to monitor: Check/Repeat/Confirmation sampling5