TRI Reporter
Clean Air Act
Clean Water Act
RCRA
ROCKY MOUNTAIN POWER - HARDIN GENERATING STATION
Quick Summary
- •Released 9,724 lbs of toxic chemicals to the environment in the most recent TRI reporting year.
- •Assessed $0 in total penalties since records began.
- •Reports releases of chemicals classified as known or probable carcinogens.
- Address
-
643 INDUSTRIAL PARK RD
HARDIN, MT 59034
View on map ↗ - County
- BIG HORN County
- Industry
- Utilities
- NAICS (North American Industry Classification)
- 221112
- Inspections
- 3 · last Jun 2, 2025
- Total Penalties
- $0 · last Jan 16, 2013
- Registry ID
- 110038363623
How This Compares
#24
of 55 TRI reporters in MT
#412
of 584 TRI reporters in Utilities
Ranked by most recent year's total TRI releases.
TRI Toxic Chemical Releases
Annual pounds of each toxic chemical released to air, water, and land, as reported to the EPA Toxic Release Inventory. Carcinogen (♦) and PFAS designations are per EPA and IARC classifications.
Emissions Trend (2015–2024)
-3% overall
| Year | Total Releases (lbs) | vs Prior Year |
|---|---|---|
| 2015 | 33,226 | — |
| 2016 | 22,445 | -32% |
| 2017 | 9,724 | -57% |
| 2018 | 10,048 | +3% |
| 2019 | 9,178 | -9% |
| 2020 | 588 | -94% |
| 2021 | 36,518 | +6111% |
| 2022 | 38,231 | +5% |
| 2023 | 29,649 | -22% |
| 2024 | 32,245 | +9% |
2024
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 26,940 | 26,940 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 2,863 | 2,863 | — | — | 54,397 | |
| Manganese | 1,401 | 1,401 | — | — | 23,166 | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 321 | 321 | — | — | — | |
| Hydrogen fluoride | 321 | 321 | — | — | — | |
| Lead compounds | 208 | 208 | — | — | 996 | |
| Copper | 97 | 97 | — | — | 1,838 | |
| Zinc compounds | 92 | 92 | — | — | 1,743 | |
| Mercury compounds | 3 | 3 | — | — | 7 | |
| Dioxin and dioxin-like compounds | 1 | 1 | — | — | — | ♦ Carcinogen |
2023
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 24,299 | 24,299 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 3,016 | 3,016 | — | — | 57,301 | |
| Manganese | 1,386 | 1,386 | — | — | 23,226 | |
| Hydrogen fluoride | 289 | 289 | — | — | — | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 289 | 289 | — | — | — | |
| Lead compounds | 189 | 189 | — | — | 936 | |
| Copper | 91 | 91 | — | — | 1,726 | |
| Zinc compounds | 86 | 86 | — | — | 1,636 | |
| Mercury compounds | 3 | 3 | — | — | 6 | |
| Dioxin and dioxin-like compounds | 1 | 1 | — | — | — | ♦ Carcinogen |
2022
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 29,851 | 29,851 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 4,932 | 4,932 | — | — | 93,700 | |
| Manganese | 2,195 | 2,195 | — | — | 37,882 | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 355 | 355 | — | — | — | |
| Hydrogen fluoride | 355 | 355 | — | — | — | |
| Lead compounds | 252 | 252 | — | — | 1,522 | |
| Copper | 148 | 148 | — | — | 2,806 | |
| Zinc compounds | 140 | 140 | — | — | 2,659 | |
| Mercury compounds | 2 | 2 | — | — | 12 | |
| Dioxin and dioxin-like compounds | 1 | 1 | — | — | — | ♦ Carcinogen |
2021
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 27,020 | 27,020 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 5,752 | 5,752 | — | — | 109,287 | |
| Manganese | 2,513 | 2,513 | — | — | 44,297 | |
| Hydrogen fluoride | 322 | 322 | — | — | — | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 322 | 322 | — | — | — | |
| Lead compounds | 250 | 250 | — | — | 1,786 | |
| Copper | 173 | 173 | — | — | 3,298 | |
| Zinc compounds | 164 | 164 | — | — | 3,121 | |
| Mercury compounds | 1 | 1 | — | — | 12 | |
| Dioxin and dioxin-like compounds | 1 | 1 | — | — | — | ♦ Carcinogen |
2020
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 502 | 502 | — | — | 8,016 | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 33 | 33 | — | — | — | |
| Lead compounds | 32 | 32 | — | — | 128 | |
| Zinc compounds | 12 | 12 | — | — | 223 | |
| Arsenic compounds | 10 | 10 | — | — | 41 | ♦ Carcinogen |
| Mercury compounds | 0 | 0 | — | — | 1 |
2019
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 7,631 | 7,631 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 783 | 783 | — | — | 13,504 | |
| Manganese compounds | 431 | 431 | — | — | 6,997 | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 91 | 91 | — | — | — | |
| Hydrogen fluoride | 91 | 91 | — | — | — | |
| Lead compounds | 71 | 71 | — | — | 366 | |
| Copper compounds | 43 | 43 | — | — | 678 | |
| Zinc compounds | 34 | 34 | — | — | 641 | |
| Mercury compounds | 2 | 2 | — | — | 2 | |
| Dioxin and dioxin-like compounds | 0 | 0 | — | — | — | ♦ Carcinogen |
2018
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 8,072 | 8,072 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 1,074 | 1,074 | — | — | 19,843 | |
| Manganese compounds | 548 | 548 | — | — | 9,281 | |
| Hydrogen fluoride | 96 | 96 | — | — | — | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 96 | 96 | — | — | — | |
| Lead compounds | 73 | 73 | — | — | 443 | |
| Copper compounds | 46 | 46 | — | — | 819 | |
| Zinc compounds | 41 | 41 | — | — | 776 | |
| Mercury compounds | 1 | 1 | — | — | 3 | |
| Dioxin and dioxin-like compounds | 0 | 0 | — | — | — | ♦ Carcinogen |
2017
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 6,100 | 6,100 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 1,987 | 1,987 | — | — | 32,028 | |
| Manganese compounds | 1,154 | 1,154 | — | — | 21,032 | |
| Copper compounds | 119 | 119 | — | — | 2,190 | |
| Zinc compounds | 109 | 109 | — | — | 2,070 | |
| Lead compounds | 102 | 102 | — | — | 1,180 | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 73 | 73 | — | — | — | |
| Hydrogen fluoride | 73 | 73 | — | — | — | |
| Mercury compounds | 7 | 7 | — | — | 8 | |
| Dioxin and dioxin-like compounds | 0 | 0 | — | — | — | ♦ Carcinogen |
2016
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Ammonia | — | — | — | — | — | |
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 17,857 | 17,857 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 2,304 | 2,304 | — | — | 43,784 | |
| Manganese compounds | 1,417 | 1,417 | — | — | 24,644 | |
| Hydrogen fluoride | 213 | 213 | — | — | — | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 213 | 213 | — | — | — | |
| Lead compounds | 176 | 176 | — | — | 1,374 | |
| Copper compounds | 134 | 134 | — | — | 2,549 | |
| Zinc compounds | 127 | 127 | — | — | 2,410 | |
| Mercury compounds | 4 | 4 | — | — | 9 | |
| Dioxin and dioxin-like compounds | 0 | 0 | — | — | — | ♦ Carcinogen |
2015
| Chemical | Total (lbs) | Air | Water | Land | Off-Site | |
|---|---|---|---|---|---|---|
| Ammonia | — | — | — | — | — | |
| Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 26,342 | 26,342 | — | — | — | |
| Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 3,462 | 3,462 | — | — | 65,779 | |
| Manganese compounds | 2,134 | 2,134 | — | — | 37,170 | |
| Hydrogen fluoride | 314 | 314 | — | — | — | |
| Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) | 314 | 314 | — | — | — | |
| Lead compounds | 261 | 261 | — | — | 2,077 | |
| Copper compounds | 203 | 203 | — | — | 3,856 | |
| Zinc compounds | 192 | 192 | — | — | 3,645 | |
| Mercury compounds | 4 | 4 | — | — | 14 | |
| Dioxin and dioxin-like compounds | 1 | 1 | — | — | — | ♦ Carcinogen |
Waste Management & Recycling
How this facility manages toxic chemicals beyond direct releases — through recycling, energy recovery, and on-site or off-site treatment. Data from the most recent TRI reporting year. Quantities in pounds.
| Chemical | Released | Recycled | Energy Recovery | Treated |
|---|
Off-Site Transfer Destinations
Facilities to which toxic chemicals were transferred for disposal, recycling, energy recovery, or treatment during the most recent TRI reporting year. Quantities in pounds.
| Destination | Chemical | Disposal | Recycling | Energy Rec. | Treatment |
|---|---|---|---|---|---|
|
BIG HORN COUNTY LANDFILL
HARDIN, MT
|
Copper | 1,838 | — | — | — |
|
BIG HORN COUNTY LANDFILL
HARDIN, MT
|
Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) | 54,397 | — | — | — |
|
BIG HORN COUNTY LANDFILL
HARDIN, MT
|
Lead compounds | 996 | — | — | — |
|
BIG HORN COUNTY LANDFILL
HARDIN, MT
|
Manganese | 23,166 | — | — | — |
|
BIG HORN COUNTY LANDFILL
HARDIN, MT
|
Mercury compounds | 7 | — | — | — |
|
BIG HORN COUNTY LANDFILL
HARDIN, MT
|
Zinc compounds | 1,743 | — | — | — |
Compliance Violations
Individual permit violations recorded by the EPA across air, water, and hazardous waste programs. Open violations are unresolved as of the most recent ECHO data update.
| Program | Type | Violation Date | Return to Compliance | Status |
|---|---|---|---|---|
| caa | FRV | Jan 30, 2023 | — | Open |
| caa | FRV | Nov 28, 2018 | — | Open |
| caa | FRV | Oct 30, 2018 | — | Open |
| caa | HPV | Jun 10, 2016 | Jun 10, 2016 | Resolved |
Enforcement Actions
Formal enforcement cases brought by the EPA or state agencies, including administrative orders and civil penalties assessed. Penalty amounts reflect what was formally assessed, not necessarily what was collected.
Notice of Violation
Clean Air Act
· Case 3603670374 · Feb 24, 2023
Warning Letter
Clean Air Act
· Case 3601783433 · Mar 11, 2019
Warning Letter
Clean Air Act
· Case 3601732316 · Jan 16, 2019
Notice of Violation
Clean Air Act
· Case 3600740786 · Jun 10, 2016
Other facilities in BIG HORN County, MT
ROCKY MOUNTAIN OPERATING CO
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HARDIN WWTP UPGRADES
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WYOLA LAGOON
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FARMERS UNION OIL COMPANY
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· Retail Trade
WARREN TRANSPORT - HARDIN
HARDIN, MT