Polychlorinated Biphenyls (PCBs) in drinking water
940 active public water systems in 34 states had a Polychlorinated Biphenyls (PCBs) violation in the past three years, and 46 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 Polychlorinated Biphenyls (PCBs) and lists the water systems whose records include a related violation. It does not show measured levels.
Is Polychlorinated Biphenyls (PCBs) 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
PCBs are a family of synthetic chlorinated organic compounds formerly used as dielectric fluids in electrical transformers and capacitors, and as industrial lubricants and plasticizers. Their manufacture was banned in the United States in 1979. PCBs persist in sediment and soil for decades and enter water through runoff from contaminated sites and leaching from old electrical equipment.
Health effects
PCBs are classified by EPA as probable human carcinogens (Group B2). Long-term exposure is associated with liver damage, immune suppression, thyroid disruption, and reproductive and developmental effects. They bioaccumulate in fatty tissue. Developing fetuses and infants are most vulnerable to neurological and endocrine effects.
The standard and what a violation means
EPA limit: 0.0005 mg/L (0.5 ppb).
Water systems with a Polychlorinated Biphenyls (PCBs) 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 |
|---|---|---|---|
| Pennsylvania | 185 | 2% | 9 |
| New York | 122 | 2% | 1 |
| Oklahoma | 94 | 7% | 0 |
| Oregon | 73 | 3% | 3 |
| Illinois | 53 | 1% | 9 |
| Colorado | 38 | 2% | 4 |
| Idaho | 38 | 2% | 3 |
| Connecticut | 31 | 1% | 2 |
| Michigan | 29 | 0% | 1 |
| Utah | 29 | 3% | 1 |
| West Virginia | 29 | 4% | 2 |
| Alaska | 25 | 2% | 0 |
| Alabama | 25 | 4% | 0 |
| California | 25 | 0% | 0 |
| Wyoming | 24 | 3% | 1 |
| Vermont | 22 | 2% | 3 |
| Nevada | 16 | 3% | 0 |
| North Carolina | 13 | 0% | 1 |
| Massachusetts | 12 | 1% | 1 |
| Maine | 9 | 0% | 0 |
| Montana | 9 | 0% | 0 |
| New Jersey | 9 | 0% | 2 |
| Washington | 6 | 0% | 0 |
| Minnesota | 5 | 0% | 2 |
| Arizona | 4 | 0% | 1 |
| South Dakota | 3 | 0% | 0 |
| Virginia | 3 | 0% | 0 |
| North Dakota | 2 | 1% | 0 |
| Wisconsin | 2 | 0% | 0 |
| Indiana | 1 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
| Ohio | 1 | 0% | 0 |
| South Carolina | 1 | 0% | 0 |
| Tennessee | 1 | 0% | 0 |
Largest water systems with a Polychlorinated Biphenyls (PCBs) 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 | |
|
Corona, City of Corona · Riverside County |
169,380 | 6 | 0 | |
|
Joliet Joliet · Will County |
160,000 | 4 | 0 | |
|
City of Sunnyvale Sunnyvale · Santa Clara County |
157,566 | 5 | 0 | |
|
Inima USA / Aquaria LLC Dighton · Bristol County |
105,643 | 1 | 0 | |
|
Lehi City Utah County |
93,446 | 2 | 0 | |
|
South Huntington Water District Huntington (t) · Suffolk County |
81,760 | 1 | 0 | |
|
Kiryas Joel Kiryas Joel (v) · Orange County |
51,623 | 3 | 0 | |
|
Foley, Utilities Board of the City of Foley · Baldwin County |
50,919 | 1 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Polychlorinated Biphenyls (PCBs), including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Polychlorinated Biphenyls (PCBs) 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.