Glyphosate in drinking water
758 active public water systems in 31 states had a Glyphosate violation in the past three years, and 33 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 Glyphosate and lists the water systems whose records include a related violation. It does not show measured levels.
Is Glyphosate 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.
Enter a ZIP code, town, or street address.
What it is and where it comes from
Glyphosate is the most widely used herbicide in the United States, applied to crops, lawns, and roadsides. It is the active ingredient in Roundup and related products. It enters water through agricultural and urban runoff.
Health effects
Long-term exposure above the MCL is associated with kidney and reproductive damage in animal studies. EPA's current classification does not designate glyphosate as a human carcinogen, though IARC classifies it as probably carcinogenic (Group 2A). This classification remains a subject of active scientific and regulatory debate.
The standard and what a violation means
EPA limit: 0.7 mg/L (700 ppb).
Water systems with a Glyphosate 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 | 179 | 2% | 8 |
| Oklahoma | 135 | 10% | 0 |
| Oregon | 87 | 3% | 3 |
| Idaho | 39 | 2% | 3 |
| Connecticut | 34 | 1% | 1 |
| California | 30 | 0% | 1 |
| Illinois | 30 | 1% | 6 |
| Indiana | 30 | 1% | 2 |
| Alaska | 25 | 2% | 0 |
| Alabama | 25 | 4% | 0 |
| Wyoming | 23 | 3% | 1 |
| Wisconsin | 18 | 0% | 0 |
| Nevada | 16 | 3% | 0 |
| Arizona | 15 | 1% | 1 |
| Iowa | 14 | 1% | 0 |
| Massachusetts | 12 | 1% | 1 |
| Montana | 9 | 0% | 0 |
| New Jersey | 7 | 0% | 2 |
| Washington | 7 | 0% | 1 |
| Minnesota | 6 | 0% | 2 |
| South Dakota | 3 | 0% | 0 |
| Colorado | 2 | 0% | 1 |
| Michigan | 2 | 0% | 0 |
| North Dakota | 2 | 1% | 0 |
| New Mexico | 2 | 0% | 0 |
| Kansas | 1 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
| New Hampshire | 1 | 0% | 0 |
| Ohio | 1 | 0% | 0 |
| Tennessee | 1 | 0% | 0 |
| Utah | 1 | 0% | 0 |
Largest water systems with a Glyphosate 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 |
|---|---|---|---|---|
|
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 | |
|
Epcor Agua Fria Surprise · Maricopa County |
128,040 | 5 | 0 | |
|
Inima USA / Aquaria LLC Dighton · Bristol County |
105,643 | 1 | 0 | |
|
GW Santa Cruz Water CO Maricopa · Pinal County |
84,000 | 7 | 0 | |
|
Flagstaff City of Flagstaff · Coconino County |
79,796 | 5 | 0 | |
|
Foley, Utilities Board of the City of Foley · Baldwin County |
50,919 | 1 | 0 | |
|
Goodyear Water Department Goodyear · Maricopa County |
50,001 | 4 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Glyphosate, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Glyphosate 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.