Vinyl Chloride in drinking water
1,776 active public water systems in 41 states had a Vinyl Chloride violation in the past three years, and 80 had one in the latest quarter of EPA's data.
You are on Tapcensus, an independent guide to the EPA compliance records of every public water system in the United States. This page explains Vinyl Chloride and lists the water systems whose records include a related violation. It does not show measured levels.
Is Vinyl Chloride 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
Vinyl chloride is an industrial chemical used to manufacture polyvinyl chloride (PVC) plastic and related products. It enters drinking water primarily as a breakdown product of trichloroethylene and tetrachloroethylene in contaminated groundwater, and through discharge from PVC pipe manufacturing facilities. It is highly volatile but can persist in anoxic groundwater.
Health effects
Vinyl chloride is classified by EPA as a known human carcinogen (Group A). It is associated with a rare liver cancer called hepatic angiosarcoma, as well as liver and brain cancers. There is no safe threshold — any exposure carries some cancer risk. Workers in PVC manufacturing and communities near contaminated groundwater sites face the greatest risk.
The standard and what a violation means
EPA limit: 0.002 mg/L (2 ppb).
Water systems with a Vinyl Chloride 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 | In violation, latest quarter |
|---|---|---|---|
| Illinois | 194 | 4% | 10 |
| Texas | 171 | 2% | 0 |
| 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 | 72 | 6% | 0 |
| Colorado | 69 | 3% | 4 |
| Indiana | 66 | 2% | 3 |
| Idaho | 48 | 2% | 3 |
| Wisconsin | 45 | 0% | 5 |
| Montana | 40 | 2% | 0 |
| Connecticut | 39 | 2% | 4 |
| West Virginia | 39 | 5% | 1 |
| Missouri | 34 | 1% | 2 |
| Arizona | 32 | 2% | 3 |
| Virginia | 31 | 1% | 2 |
| Wyoming | 31 | 4% | 1 |
| Vermont | 30 | 2% | 3 |
| California | 29 | 0% | 2 |
| North Carolina | 27 | 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 |
| New Mexico | 4 | 0% | 0 |
| Kansas | 3 | 0% | 0 |
| Mississippi | 3 | 0% | 1 |
| Maryland | 2 | 0% | 0 |
| South Dakota | 2 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
| North Dakota | 1 | 0% | 1 |
Largest water systems with a Vinyl Chloride 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 | |
|
Flagstaff City of Flagstaff · Coconino County |
79,796 | 5 | 0 | |
|
East Orange Water Commission East Orange City · Essex County |
75,000 | 6 | 1 | |
|
Arlington Heights Arlington Heights · Cook County |
73,320 | 3 | 2 |
About this data
A system is counted once if any of its violations in the past three years involved Vinyl Chloride, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Vinyl Chloride 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.