Most Polluted States in America

Which states produce the most pollution? The answer depends on how you measure it — total chemical releases, number of contaminated sites, or enforcement actions — and each tells a different story. A state with massive mining operations may top the release charts while having few Superfund sites, while a densely populated industrial state may have more cleanup sites but lower raw tonnage.

The rankings below use EPA's Toxic Release Inventory (TRI), which tracks annual chemical releases from industrial facilities. TRI captures a specific slice of pollution — chemicals released by facilities above reporting thresholds — not all environmental contamination. States with large mining, chemical manufacturing, or petroleum refining sectors tend to dominate because those industries handle the largest volumes of TRI-listed chemicals.

We also include Superfund site counts and total EPA penalties to give a fuller picture. Superfund sites represent the worst historical contamination — places where cleanup is federally managed. Penalty totals reflect recent enforcement activity, which correlates with both violation severity and EPA regional office priorities.