Endrin in drinking water
1,196 active public water systems in 37 states had a Endrin violation in the past three years, and 59 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 Endrin and lists the water systems whose records include a related violation. It does not show measured levels.
Is Endrin 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
Endrin was a cyclodiene organochlorine insecticide and rodenticide used primarily on field crops such as cotton, grains, and sugarcane. It was banned in the United States in 1991. Endrin is highly persistent in soil and binds strongly to sediment, meaning legacy contamination in groundwater and surface water can persist decades after use.
Health effects
Endrin is acutely toxic to the nervous system and can cause seizures, headache, dizziness, and liver damage at high doses. Chronic low-level exposure is associated with liver and nervous system effects. EPA classifies it as a possible human carcinogen (Group C). Children and the elderly are most vulnerable to acute neurological effects.
The standard and what a violation means
EPA limit: 0.002 mg/L (2 ppb).
Water systems with a Endrin 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 | 197 | 3% | 8 |
| New York | 120 | 1% | 1 |
| Texas | 115 | 2% | 0 |
| Oklahoma | 96 | 7% | 0 |
| Oregon | 73 | 3% | 3 |
| Illinois | 62 | 1% | 12 |
| Washington | 44 | 1% | 8 |
| Colorado | 38 | 2% | 4 |
| Montana | 37 | 2% | 1 |
| Idaho | 36 | 2% | 3 |
| Connecticut | 31 | 1% | 1 |
| Utah | 29 | 3% | 1 |
| Michigan | 28 | 0% | 1 |
| Indiana | 27 | 1% | 2 |
| California | 26 | 0% | 1 |
| Alaska | 25 | 2% | 0 |
| Alabama | 25 | 4% | 0 |
| Wyoming | 24 | 3% | 1 |
| Vermont | 22 | 2% | 3 |
| Wisconsin | 18 | 0% | 0 |
| Missouri | 16 | 1% | 1 |
| North Carolina | 16 | 0% | 1 |
| Nevada | 16 | 3% | 0 |
| Arizona | 13 | 1% | 1 |
| Massachusetts | 12 | 1% | 1 |
| Maine | 11 | 1% | 0 |
| Minnesota | 8 | 0% | 2 |
| Rhode Island | 8 | 2% | 0 |
| New Jersey | 7 | 0% | 2 |
| Maryland | 3 | 0% | 1 |
| South Dakota | 3 | 0% | 0 |
| Virginia | 3 | 0% | 0 |
| North Dakota | 2 | 1% | 0 |
| New Mexico | 2 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
| Nebraska | 1 | 0% | 0 |
| New Hampshire | 1 | 0% | 0 |
Largest water systems with a Endrin 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 | |
|
Tucson City of Tucson · Pima County |
732,906 | 3 | 0 | |
|
Pittsburgh Water & Sewer Auth Allegheny County |
520,000 | 3 | 0 | |
|
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 | |
|
Pasco Water Department Franklin County |
115,102 | 2 | 0 | |
|
Inima USA / Aquaria LLC Dighton · Bristol County |
105,643 | 1 | 0 | |
|
Lehi City Utah County |
93,446 | 2 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Endrin, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Endrin 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.