America's Biggest Polluters: Top TRI Facilities by Total Releases
Which US industrial facilities report the highest toxic chemical releases? What chemicals they release, where they're located, and why volume alone doesn't tell the full story.
Key Takeaway
The top TRI reporters by volume are overwhelmingly mining operations, whose releases (primarily to land) dwarf manufacturing and energy facilities. When you filter for air releases, the pathway most directly affecting nearby communities, the rankings shift dramatically toward fossil fuel combustion, chemical manufacturing, and steel production. Understanding the pathway matters as much as the volume.
How the TRI Ranking Works
The EPA's Toxics Release Inventory requires 21,800+ industrial facilities to report annual releases of 770+ toxic chemicals. Releases are tracked through four pathways: air emissions, water discharges, land disposal, and off-site transfers. When rankings are compiled by total pounds released across all pathways, mining operations consistently dominate because of the enormous volumes of chemically-laden waste rock and tailings they generate.
This is important context: 100 million pounds of nitrate compounds disposed in a lined tailings pond in rural Nevada is a very different situation than 100,000 pounds of benzene emitted to the air in a Houston residential neighborhood. Both appear in TRI data, but they carry very different community health implications.
Browse the full list of TRI-reporting facilities or drill down by state to find the largest polluters in your region.
Top 12 TRI Facilities by Total Release Volume
The following table is generated live from PlainEnviro's EPA TRI database, ranked by each facility's most recent reported total release volume across all pathways. Visit each facility's page for the full multi-year chemical breakdown.
| # | Facility | Total Releases |
|---|---|---|
| 1 | RED DOG OPERATIONS Metal Mining | 3,344,259,312 lbs |
| 2 | NEVADA GOLD MINES LLC - GOLDSTRIKE MINES INC Metal Mining | 930,798,828 lbs |
| 3 | KENNECOTT UTAH COPPER MINE CONCENTRATORS & POWER PLANT Metal Mining | 781,364,122 lbs |
| 4 | HECLA GREENS CREEK MINING CO Metal Mining | 375,528,326 lbs |
| 5 | NEVADA GOLD MINES LLC - CARLIN SOUTH AREA Metal Mining | 216,700,413 lbs |
| 6 | MONTANA RESOURCES LLC Metal Mining | 215,159,829 lbs |
| 7 | NEVADA GOLD MINES LLC - TURQUOISE RIDGE Metal Mining | 180,790,314 lbs |
| 8 | BASIN ELECTRIC ANTELOPE VALLEY STATION Electric Utilities | 167,796,431 lbs |
| 9 | NEVADA GOLD MINES LLC-CORTEZ DISTRICT Metal Mining | 146,612,756 lbs |
| 10 | KENNECOTT UTAH COPPER SMELTER & REFINERY Primary Metals | 135,309,695 lbs |
| 11 | DARK HORSE TREATING FACILITY Natural Gas Processing | 131,329,964 lbs |
| 12 | FREEPORT-MCMORAN MIAMI INC Primary Metals | 129,290,398 lbs |
Source: EPA Toxics Release Inventory EPA Toxics Release Inventory Ranked live from PlainEnviro's EPA TRI database by each facility's most recent reported total release volume across all pathways (air, water, land, off-site transfer).
Mining vs. Manufacturing: A Tale of Two Release Types
The dominance of mining in TRI volume rankings reflects a structural feature of how mining waste is classified. When copper ore is processed, the leftover crushed rock (tailings) contains trace amounts of chemicals that must be reported under TRI. A large copper mine can generate 500M+ pounds of reportable chemicals annually, almost entirely to land disposal in engineered tailings impoundments.
Contrast this with a chemical plant or coal power facility that might release "only" 5-50 million pounds per year, but through air stack emissions that disperse directly into communities. Research on community health impacts consistently finds air emissions more strongly associated with local health outcomes than equivalent land disposal volumes.
Key sectors to watch for air releases specifically:
- Coal power plants: Hydrochloric acid, sulfuric acid, hydrogen fluoride, mercury, arsenic
- Chemical manufacturers: Benzene, toluene, ethylene, formaldehyde, chlorine
- Steel mills (EAF): Manganese, lead, chromium compounds from steel scrap
- Petroleum refineries: Benzene, hydrogen sulfide, particulate matter
- Cement kilns: Mercury, dioxins/furans, heavy metals (often co-process hazardous waste)
The Chemicals That Matter Most
Volume rankings tell one story. Toxicity-weighted rankings tell another. These chemicals draw the most regulatory and health scrutiny regardless of their total TRI volume:
- Dioxins and furans: Released in tiny quantities (grams, not pounds) but among the most toxic compounds known. Major sources include municipal waste incinerators, medical waste incinerators, and chlorine-bleached paper mills.
- Ethylene oxide: A known carcinogen used in hospital sterilization. Even small releases near dense populations have been the subject of enforcement actions and community protests.
- Lead compounds: No safe level of exposure. Battery manufacturers, recyclers, and smelters are the major TRI reporters. Lead is also a legacy contaminant in soil and paint not captured by TRI.
- Mercury: Coal power plants are the largest industrial mercury emitters; releases have declined substantially due to the Mercury and Air Toxics Standards (MATS) since 2015.
- Chromium compounds: Hexavalent chromium (Cr-VI) is a potent carcinogen. Steel manufacturing, chrome plating, and leather tanning are major sources.
Trends: Are Releases Going Up or Down?
The overall trend in TRI releases has been downward since the program began in 1988, though with important nuances:
- Air releases have declined significantly, driven by Clean Air Act regulations, MATS for power plants, and technology improvements in manufacturing.
- Water discharges have also declined, reflecting Clean Water Act permit requirements and industrial wastewater treatment investment.
- Land disposal has fluctuated based on mining activity levels, commodity prices, and regulatory requirements for tailings management.
- Off-site transfers have increased as facilities shift from on-site disposal to off-site treatment and recycling, which may represent actual progress or just geographic relocation of the problem.
PlainEnviro shows 5-year trends for every facility, making it easy to see whether a specific facility is improving or worsening over time. Look for facilities with consistently increasing air releases as a potential flag for community concern.
How to Use This Data
When investigating industrial pollution in any area, follow this analytical framework:
- Start with your state: Browse state pages to see the top releasers in your state by total volume and by air releases specifically.
- Filter by pathway: Sort by air emissions for community health relevance; sort by water discharges for watershed concerns.
- Check chemical toxicity: Look up specific chemicals in PlainEnviro's chemical directory to understand carcinogen status, persistence, and health effects.
- Look at trends: A facility with declining releases over 5 years is behaving differently from one with increasing releases, even if current volumes are similar.
- Cross-reference enforcement: EPA's ECHO database shows inspection and enforcement history for each facility, available via the facility's EPA registration number.
Frequently Asked Questions
Which industries release the most toxic chemicals in the US?
Metal mining is by far the largest TRI release sector by volume, accounting for over 70% of total on-site releases in many years due to waste rock and tailings. Electric power generation (especially coal), chemical manufacturing, primary metals (steel, aluminum smelting), and paper manufacturing follow. However, volume alone doesn't reflect health risk, mining releases are often to land in remote areas, while chemical plant air emissions may pose higher community risk at lower volumes.
Does being on the TRI list mean a facility is illegal or dangerous?
No. TRI reporting is a transparency requirement, not a violation indicator. Facilities can legally release certain amounts of chemicals under their EPA or state permits. The TRI data shows what is released, not whether those releases exceed legal limits. High volumes warrant attention and investigation, but they don't automatically indicate illegal activity or imminent health risk.
Why do some mining facilities release hundreds of millions of pounds?
Hard rock mining generates enormous volumes of waste rock and tailings (crushed rock after ore extraction) that contain naturally occurring trace metals like copper, lead, zinc, arsenic, and nitrate compounds. These are reported under TRI because they contain listed chemicals. A copper mine releasing 500M pounds of nitrate compounds in tailings is a very different situation from a chemical plant releasing 10,000 pounds of benzene into the air, but both appear in TRI totals.
How is TRI data collected?
Facilities that manufacture, process, or use more than threshold quantities of any of the 770+ listed chemicals must file annual Form R or Form A reports with the EPA by July 1 for the prior calendar year. The EPA compiles and publishes the data typically 9-12 months later. Reporting is self-certified; EPA conducts audits and can penalize facilities for underreporting, but doesn't independently measure emissions at every facility.
What chemicals pose the greatest health risk in TRI releases?
Volume and health risk often diverge. Chemicals of particular health concern include: lead and lead compounds (neurotoxin, no safe level), mercury (nervous system damage, bioaccumulates in fish), benzene (known carcinogen, leukemia risk), ethylene oxide (carcinogen, used in sterilization), dioxins and furans (highly toxic even in tiny amounts, released by incinerators and chlorine bleaching), and PFAS compounds (persistent "forever chemicals"). The EPA maintains priority chemical lists for regulatory focus.
Can I find facilities near me in this data?
Yes. PlainEnviro lets you browse facilities by state and county, with full TRI release data for each reporting facility. Each facility page shows annual release volumes, chemical breakdowns, release pathways (air, water, land), and 5-year trends. Use the state pages to find the largest polluters in your area by total release volume.
Sources
- U.S. Environmental Protection Agency, Toxics Release Inventory (TRI), 2019–2023
- EPA TRI National Analysis, published annually
- EPA ECHO, Enforcement and Compliance History Online
- EPA, Mercury and Air Toxics Standards (MATS) implementation data
- EPA, NATA (National Air Toxics Assessment) modeled risk estimates
This content is for informational purposes only. TRI data is self-reported by facilities and reflects legal releases under permits, not violations. Release volumes do not directly translate to health risk. Always consult primary EPA sources and relevant state environmental agencies for definitive information.
Every figure on PlainEnviro is rendered directly from EPA environmental compliance data, no number is typed in by an editor. This guide draws directly on EPA data. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.