1,2-Dichloroethane in drinking water
1,945 active public water systems in 42 states had a 1,2-Dichloroethane violation in the past three years, and 87 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 1,2-Dichloroethane and lists the water systems whose records include a related violation. It does not show measured levels.
Is 1,2-Dichloroethane 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
1,2-Dichloroethane (ethylene dichloride) is a chlorinated solvent used as a chemical intermediate in vinyl chloride production and in other manufacturing processes. It is one of the highest-volume chlorinated compounds produced in the US. It enters drinking water through industrial discharge, leaking underground storage tanks, and improper disposal. It is moderately persistent in groundwater.
Health effects
Chronic exposure to 1,2-dichloroethane is associated with liver and kidney damage and neurological effects. EPA classifies it as a probable human carcinogen (Group B2) based on animal evidence of gastrointestinal and mammary gland tumors. Long-term exposure above the MCL is the primary concern; communities near chemical manufacturing facilities and Superfund sites face the greatest risk.
The standard and what a violation means
EPA limit: 0.005 mg/L (5 ppb).
Water systems with a 1,2-Dichloroethane 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 |
|---|---|---|---|
| Illinois | 196 | 4% | 10 |
| Texas | 171 | 2% | 0 |
| Pennsylvania | 169 | 2% | 6 |
| Michigan | 165 | 1% | 4 |
| Alaska | 102 | 8% | 5 |
| Washington | 102 | 2% | 10 |
| Oregon | 85 | 3% | 3 |
| New Jersey | 77 | 2% | 5 |
| New York | 73 | 1% | 2 |
| Oklahoma | 71 | 5% | 0 |
| Colorado | 70 | 3% | 5 |
| Indiana | 66 | 2% | 3 |
| Idaho | 48 | 2% | 3 |
| Wisconsin | 45 | 0% | 5 |
| Montana | 40 | 2% | 0 |
| Connecticut | 39 | 2% | 4 |
| West Virginia | 38 | 5% | 1 |
| Missouri | 34 | 1% | 2 |
| Arizona | 33 | 2% | 3 |
| Virginia | 31 | 1% | 2 |
| Wyoming | 31 | 4% | 1 |
| Vermont | 30 | 2% | 3 |
| California | 29 | 0% | 2 |
| North Carolina | 26 | 1% | 1 |
| Nevada | 26 | 4% | 0 |
| Utah | 26 | 2% | 1 |
| Alabama | 18 | 3% | 0 |
| Maine | 18 | 1% | 0 |
| Iowa | 14 | 1% | 0 |
| Ohio | 14 | 0% | 1 |
| Massachusetts | 12 | 1% | 0 |
| Tennessee | 11 | 1% | 0 |
| Rhode Island | 9 | 2% | 1 |
| Minnesota | 7 | 0% | 1 |
| New Hampshire | 4 | 0% | 1 |
| Kansas | 3 | 0% | 0 |
| Mississippi | 3 | 0% | 1 |
| New Mexico | 3 | 0% | 0 |
| Maryland | 2 | 0% | 0 |
| South Dakota | 2 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
| North Dakota | 1 | 0% | 1 |
Largest water systems with a 1,2-Dichloroethane 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 |
|---|---|---|---|---|
|
Tucson City of Tucson · Pima County |
732,906 | 3 | 0 | |
|
Mesa City of Mesa · Maricopa County |
466,000 | 3 | 0 | |
|
Chandler City of Chandler · Maricopa County |
247,328 | 4 | 0 | |
|
Trenton Water Works Ewing Twp, Hamilton Twp, Hopewell Twp.1106- and 2 more · Mercer County |
217,000 | 8 | 2 | |
|
Corona, City of Corona · Riverside County |
169,380 | 6 | 0 | |
|
City of Sunnyvale Sunnyvale · Santa Clara County |
157,566 | 5 | 0 | |
|
Sandy City Water System Salt Lake County |
99,750 | 2 | 0 | |
|
Epcor San Tan Johnson Ranch · Pinal County |
87,435 | 3 | 0 | |
|
Flagstaff City of Flagstaff · Coconino County |
79,796 | 5 | 0 | |
|
East Orange Water Commission East Orange City · Essex County |
75,000 | 6 | 1 |
About this data
A system is counted once if any of its violations in the past three years involved 1,2-Dichloroethane, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not 1,2-Dichloroethane 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.