Atrazine in drinking water
1,284 active public water systems in 42 states had a Atrazine violation in the past three years, and 62 have one that is still unresolved.
You are on Tapcensus, an independent guide to the EPA compliance records of every public water system in the United States. This page explains Atrazine and lists the water systems whose records include a related violation. It does not show measured levels.
Is Atrazine in the records for your water system?
Enter a ZIP code, town, or street address to see the water systems that serve your area, their status, and which rules and contaminants appear in their violations.
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What it is and where it comes from
Atrazine is one of the most widely used herbicides in the United States, applied primarily to corn and sorghum fields. It is chemically stable and highly mobile in soil, making it one of the most frequently detected pesticides in US groundwater and surface water. Agricultural runoff after spring planting is the primary pathway into drinking water sources.
Health effects
Chronic exposure to atrazine is associated with endocrine disruption — particularly effects on reproductive hormones — and cardiovascular and adrenal effects in animal studies. EPA classifies atrazine as not likely to be a human carcinogen under current guidelines, though its endocrine-disrupting properties remain under research scrutiny. Fetuses and infants may be most sensitive to hormonal effects.
The standard and what a violation means
EPA limit: 0.003 mg/L (3 ppb).
Water systems with a Atrazine violation, by state
Active public water systems that reported at least one related violation to EPA in the past three years. Each state links to the list of its affected systems.
| State | Systems with violations, 3 yr | Share of active systems | Unresolved |
|---|---|---|---|
| Pennsylvania | 195 | 3% | 8 |
| New York | 119 | 1% | 1 |
| Texas | 115 | 2% | 0 |
| Oklahoma | 110 | 9% | 0 |
| Illinois | 75 | 1% | 10 |
| Oregon | 73 | 3% | 3 |
| Washington | 44 | 1% | 8 |
| Colorado | 38 | 2% | 4 |
| Montana | 37 | 2% | 1 |
| Idaho | 36 | 2% | 3 |
| Connecticut | 33 | 1% | 1 |
| Indiana | 32 | 1% | 2 |
| West Virginia | 32 | 4% | 4 |
| Utah | 29 | 3% | 1 |
| Michigan | 28 | 0% | 1 |
| California | 27 | 0% | 1 |
| Alaska | 25 | 2% | 0 |
| Alabama | 25 | 4% | 0 |
| Wyoming | 24 | 3% | 1 |
| Vermont | 22 | 2% | 3 |
| Missouri | 21 | 1% | 2 |
| Wisconsin | 19 | 0% | 0 |
| Nevada | 16 | 3% | 0 |
| Arizona | 15 | 1% | 1 |
| Iowa | 15 | 1% | 0 |
| Massachusetts | 12 | 1% | 1 |
| Maine | 11 | 1% | 0 |
| North Carolina | 11 | 0% | 1 |
| Rhode Island | 9 | 2% | 0 |
| Minnesota | 8 | 0% | 2 |
| New Jersey | 6 | 0% | 2 |
| Maryland | 3 | 0% | 1 |
| South Dakota | 3 | 0% | 0 |
| Tennessee | 3 | 0% | 0 |
| Virginia | 3 | 0% | 0 |
| North Dakota | 2 | 1% | 0 |
| New Mexico | 2 | 0% | 0 |
| Ohio | 2 | 0% | 0 |
| Kansas | 1 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
| Nebraska | 1 | 0% | 0 |
| New Hampshire | 1 | 0% | 0 |
Largest water systems with a Atrazine violation
The ten biggest systems, by people served, whose records include a related violation in the past three years.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Denver Water Board Denver County |
1,287,000 | 3 | 0 | |
|
Pittsburgh Water & Sewer Auth Allegheny County |
520,000 | 3 | 0 | |
|
Gilbert, Town of Gilbert · Maricopa County |
247,600 | 9 | 1 | |
|
Corona, City of Corona · Riverside County |
169,380 | 6 | 0 | |
|
City of Sunnyvale Sunnyvale · Santa Clara County |
157,566 | 5 | 0 | |
|
Naperville Naperville · DuPage County |
156,406 | 1 | 0 | |
|
Epcor Agua Fria Surprise · Maricopa County |
128,040 | 5 | 0 | |
|
Springfield Springfield · Sangamon County |
117,444 | 2 | 0 | |
|
Pasco Water Department Franklin County |
115,102 | 2 | 0 | |
|
Inima USA / Aquaria LLC Dighton · Bristol County |
105,643 | 1 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Atrazine, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Atrazine alone. Counts cover active systems in all 50 states and the District of Columbia.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.