EPA TRI Facility · Metal Mining
Stillwater Mining Co East Boulder Mine
Big Timber, MT
- Total releases
- 2.0M lbs
- Chemicals reported
- 14
- Carcinogens
- 3
- Primary pathway
- Land Disposal
Stillwater Mining Co East Boulder Mine has reported 2.0M lbs of toxic releases across 14 chemicals to the EPA Toxic Release Inventory, based on annual facility disclosures from 2019 through 2023. Of the chemicals reported, 3 are classified as carcinogens, representing 21% of the facility's chemical profile. The facility operates in the Metal Mining sector. The primary release pathway is land disposal, accounting for 100% of total releases. All release data shown below is self-reported to the EPA under the Emergency Planning and Community Right-to-Know Act (EPCRA) Section 313.
Stillwater Mining Co East Boulder Mine files annual Form R disclosures to the EPA Toxics Release Inventory under EPCRA Section 313, classified under NAICS 212299 (Metal Mining). Across 5 years of records spanning 2019–2023, the site has disclosed 2.0M lbs in cumulative toxic releases across 14 distinct chemicals, 3 of which (21%) carry a carcinogenic classification.
The dominant release pathway is land disposal at 2.0M lbs (99.7% of total volume), followed by air releases at 0.3%. Between 2019 and 2023, reported totals held roughly flat - from 410.7K lbs to 409.5K lbs.
TRI Form R values are self-reported estimates, not measured stack emissions, and treat every pound of reported chemical equally regardless of toxicity. Inclusion in the TRI database does not establish a health risk to nearby residents; it documents the annual reporting record that Stillwater Mining Co East Boulder Mine has filed with the EPA under federal community right-to-know requirements.
Quick Facts
Compare this facility
See how Stillwater Mining Co East Boulder Mine stacks up against nearby facilities and the typical reporter.
99% less than the comparison
17% more than the comparison
Comparison reflects reported pounds and chemical counts, not toxicity or health risk. Averages cover facilities reporting any release.
How does this facility release toxic chemicals?
How Stillwater Mining Co East Boulder Mine releases toxic chemicals into the environment. Total: 2.0M lbs.
Emissions Trend Summary
From 2019 to 2023, total releases held roughly flat (410.7K lbs to 409.5K lbs).
Reported total releases by year
Stillwater Mining Co East Boulder Mine - annual TRI totals
- 2019 0
2019
0 million lbs
- 2020 0
2020
0 million lbs
- 2021 0
2021
0 million lbs
- 2022 0
2022
0 million lbs
- 2023 0
2023
0 million lbs
What this shows Year-over-year reported totals. TRI figures are self-reported estimates and can swing with production levels, waste-rock handling and reporting changes, not only with emissions controls.
| Year | Total | Chemicals |
|---|---|---|
| 2019 | 410.7K lbs | 8 |
| 2020 | 416.8K lbs | 8 |
| 2021 | 447.5K lbs | 6 |
| 2022 | 285.5K lbs | 9 |
| 2023 | 409.5K lbs | 8 |
Chemical Releases
Aggregated across all reporting years (2019–2023). 3 of 14 chemicals are carcinogens. Sorted by total release volume.
| Chemical | Total | Flags |
|---|---|---|
| Nickel compounds | 696.2K lbs | Carcinogen |
| Nickel And Nickel Compounds | 446.1K lbs | Carcinogen |
| Methanol | 297.4K lbs | - |
| Chromium and Chromium Compounds(except for chromite ore mined in the Transvaal Region) | 268.1K lbs | - |
| Copper And Copper Compounds | 113.7K lbs | - |
| Copper compounds | 86.5K lbs | - |
| Chromium compounds (except for chromite ore mined in the Transvaal Region) | 48.0K lbs | - |
| Lead And Lead Compounds | 4.4K lbs | - |
| Propylene | 4.2K lbs | - |
| Lead compounds | 2.7K lbs | - |
| Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 2.5K lbs | - |
| Mercury And Mercury Compounds | 50 lbs | - |
| Mercury compounds | 45 lbs | - |
| Styrene | 0 lbs | Carcinogen |
Location
Other Facilities in Montana
About TRI Data
Data as of 2023 reporting year. Source: U.S. Environmental Protection Agency (EPA) Toxic Release Inventory.
Data comes from the EPA Toxic Release Inventory (TRI) program. Facilities that manufacture, process, or otherwise use listed toxic chemicals above threshold amounts are required to report annually to the EPA.
Release quantities are self-reported by the facility and may represent estimates rather than exact measurements. "Total releases" includes releases to air, water, land, and off-site transfers for disposal. Quantities shown here are aggregated across all available reporting years.
PlainEnviro presents this data without advocacy framing. The presence of a facility in the TRI database does not by itself indicate a health risk. For site-specific health questions, consult your local environmental or health agency.
Frequently Asked Questions
What chemicals does Stillwater Mining Co East Boulder Mine release? ▼
What industry is Stillwater Mining Co East Boulder Mine in? ▼
How long has Stillwater Mining Co East Boulder Mine reported to the TRI? ▼
How does Stillwater Mining Co East Boulder Mine release toxic chemicals? ▼
Are emissions from Stillwater Mining Co East Boulder Mine increasing or decreasing? ▼
Is Stillwater Mining Co East Boulder Mine a health risk? ▼
Does Stillwater Mining Co East Boulder Mine release carcinogens? ▼
Explore More Data for Montana
What to do with this facility's data
Use this facility profile as a starting point, then check how it compares.
- See whether releases reported by Stillwater Mining Co East Boulder Mine are rising or falling over time. View trends
- This facility ranks #869 of 25,902 TRI facilities nationwide by total reported releases - among the top 3.4% of reporting sites by volume. Ranking reflects reported pounds, not toxicity or health risk. See the full rankings
- Check Montana's statewide profile for the full picture: total facilities, water systems, and Superfund sites. View Montana profile
TRI release totals are self-reported estimates submitted to the EPA, not independently measured stack emissions; a high rank reflects reported volume, not necessarily local health risk.
Read our methodology - how this data is sourced, computed, and verified.
Related
Sources & how this page was built
Every figure on this page traces to public, federal-government data on Stillwater Mining Co East Boulder Mine. The records below are the primary sources; our methodology explains how they are joined, computed, and verified.
- EPA Toxics Release Inventory (TRI) Basic Data Files - annual self-reported chemical-release filings. epa.gov
- EPA TRI Program, chemical & reporting reference - what each chemical is and how releases are counted. epa.gov
- EPA Facility Registry Service (FRS) - authoritative facility location and identity. epa.gov
- EPA Enforcement & Compliance History Online (ECHO) - regulatory and compliance context. echo.epa.gov
- EPA Envirofacts - the EPA data warehouse that exposes these datasets. enviro.epa.gov
Retrieved and formatted by PlainEnviro Editorial. TRI release totals are self-reported estimates, not measured stack emissions.
According to the U.S. Environmental Protection Agency, the Toxics Release Inventory has required annual industrial disclosure since its creation under the Emergency Planning and Community Right-to-Know Act in October 1986, and this facility's record is drawn from PlainEnviro's database of more than 25,000 EPA-tracked facilities through the 2023 reporting year; see our methodology for full source citations and refresh cadence.