EPA TRI Facility · Metal Mining

Mp Mine Operations LLC

Mountain Pass, CA

Total releases
1.4M lbs
Chemicals reported
6
Latest report
2023
Primary pathway
Land Disposal

LAND Form-R mix

Mp Mine Operations LLC: how the 1.4M lbs splits

1.4M lbs across all reported pathways

  • Land Disposal 1.4M lbs 99.0%
  • Air Releases 14.2K lbs 1.0%
  • Off-site Transfers 50 lbs <0.1%
  • Water Discharges 1 lbs <0.1%

Mp Mine Operations LLC's 1.4M lbs Form-R total is LAND - land disposal is 99.0% of the bar. Next segment: air releases at 1.0%. Leading chemical by pounds: Lead And Lead Compounds.

HEAVY volume LAND pathway CLEAN

Mp Mine Operations LLC is an EPA Toxics Release Inventory reporter in Mountain Pass, CA, in the metal mining sector. It reported 1.4M lbs of releases across 6 chemicals in 2023. That ranks 1,070 of 25,986 TRI facilities nationwide by cumulative reported pounds, counting each facility over however many years it has filed. In California's 1,149 reporting TRI sites, pounds #1 is not chemical-count #1. Mp Mine Operations LLC is pounds #19 and chemical-count #158 at 1.4M lbs. Clean Harbors Buttonwillow LLC leads reported pounds (50.4M lbs) at 45 chemicals (chemical-count #2). Chevron Products Co Richmond Refinery leads chemical count at 46 chemicals (3.0M lbs, pounds #13). Pounds reported are not a measure of toxicity or health risk. Nearest other TRI reporters: Equinox Gold Corp Castle Mountain Venture Castle Mountain; US Army Fort Irwin National Training Center; U.S. Marine Corps Twentynine Palms Air Ground Combat Center; U.S. Marine Corps Logistics Base Barstow Nebo Range. Similar-scale Metal Mining peers outside California: Chemours - Starke Facility; Georgia Mineral Operations; Eagle Mine; Missouri Cobalt. Largest disclosed chemicals by pounds: Lead And Lead Compounds; Ammonia; Propylene; Chlorine.

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Mp Mine Operations LLC stamps HEAVY volume with a dominant LAND pathway (99.0% land disposal) across 6 chemicals. Cumulative Form-R extract: 1.4M lbs (2023–2023). All figures are self-reported EPCRA §313 estimates, not measured stack emissions or a health-risk score. Scale peers include Chemours - Starke Facility and Georgia Mineral Operations.

#1,070 of 25,986 TRI facilities nationwide by total reported releases - among the top 4.1% of reporting sites by volume. Ranking reflects reported pounds, not toxicity or health risk.

Mp Mine Operations LLC vs. every reporting TRI facility

Cumulative reported release pounds, with this facility marked in the national distribution

1.4M lbs Top 4% higher than 96% of 25,986 reporting TRI facilities

This facility 0 lbs 20M+ lbs every reporting TRI facility, bucketed by value

Each bar is a $1M-wide band; taller bars hold more reporting TRI facilities. The dashed line and filled bar mark this facility. Hover, focus, or tap a bar for its full count, share, and position.

Source U.S. Environmental Protection Agency, Toxics Release Inventory · 2023 reporting year

Mp Mine Operations LLC: Lead And Lead Compounds-led volume

Among the 103 Metal Mining facilities in this database, Mp Mine Operations LLC reports the 59th-largest volume (1.4M lbs). Its reported volume is concentrated rather than spread: Lead And Lead Compounds alone is 99.0% of the total. Scale peers outside California include Chemours - Starke Facility and Georgia Mineral Operations.

Concentrated means ≥60% of Mp Mine Operations LLC's pounds in one chemical - here Lead And Lead Compounds at 99.0%. Not a toxicity score.

Mp Mine Operations LLC Form-R facts

Sector
Metal Mining
HEAVY volume
1.4M lbs
LAND pathway
Land Disposal
CLEAN chem count
6
Lead chemical
Lead And Lead Compounds

Compare this facility

See how Mp Mine Operations LLC stacks up against nearby facilities and the typical reporter.

Total reported releases
Mp Mine Operations LLC
1.4M lbs
Equinox Gold Corp Castle Mountain Venture Castle Mountain
206.6K lbs

6.8× more than the comparison

Chemicals reported
Mp Mine Operations LLC
6
Equinox Gold Corp Castle Mountain Venture Castle Mountain
12

50% less 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 Mp Mine Operations LLC releases toxic chemicals into the environment. Total: 1.4M lbs.

Land Disposal 1.4M lbs (99.0%)
Air Releases 14.2K lbs (1.0%)
Off-site Transfers 50 lbs (<0.1%)
Water Discharges 1 lbs (<0.1%)

Chemical Releases

Aggregated across all reporting years (2023–2023). Sorted by total release volume.

Chemical Total Flags
Lead And Lead Compounds 1.4M lbs -
Ammonia 7.2K lbs -
Propylene 2.2K lbs -
Chlorine 2.1K lbs -
Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) 1.8K lbs -
Mercury And Mercury Compounds 471 lbs -

Mp Mine Operations LLC · LAND-pathway site

Mountain Pass, CA
35.4734, -115.5285
County TRI context
San Bernardino · 20.0% of county pounds
EPA Facility ID
92366MLYCRI15AN

Compare beyond California

Nationwide peers by reported pounds & chemical count

Cross-state TRI reporters nearest Mp Mine Operations LLC on cumulative reported pounds (1.4M lbs) and distinct chemical count (6). Release-pound peers include Composite Technology Assemblies LLC, Charter Next Generation - Lexington, Ag Processing Inc. Chemical-count peers include Eaton Intelligent Power Ltd, Leoni Wire Inc, Turf Care Supply-Hatfield Plant. Neighborhoods are forced disjoint so each axis surfaces a different set of sites.

About TRI Data

Data as of 2023 reporting year. Source: U.S. Environmental Protection Agency (EPA) Toxic Release Inventory.

On this page the largest disclosed chemicals include Lead And Lead Compounds, Ammonia, Propylene, Chlorine; nearby reporters include Equinox Gold Corp Castle Mountain Venture Castle Mountain. Mp Mine Operations LLC stamps HEAVY volume · LAND pathway · CLEAN carcinogen-lbs on this Form-R extract. Totals are self-reported estimates under EPCRA §313, not measured stack emissions or a health-risk score.

Use and verify this record

This Mp Mine Operations LLC TRI extract (HEAVY · LAND · CLEAN · lead Lead And Lead Compounds) joins EPA Form-R filings with facility identity - reported pounds, not a health-risk rating.

Mp Mine Operations LLC totals are self-reported EPCRA §313 estimates for Mountain Pass, CA, latest year 2023. NAICS 212290 · Metal Mining. 20.0% of San Bernardino TRI pounds in this extract. Nearest ABS peer: Composite Technology Assemblies LLC (Δ 1.5K lbs). Pounds ≠ exposure.

Mp Mine Operations LLC stamps HEAVY volume · LAND pathway · CLEAN · lead Lead And Lead Compounds. PlainEnviro renders this EPA Form-R extract from its pipeline; no figure is typed in by an editor. Corrections: editorial policy.

All federal data sources used on this page
  • EPA Toxics Release Inventory (TRI) Basic Data Files - annual self-reported chemical-release filings. epa.gov
  • EPA TRI Program reference - how chemicals and reported releases are counted. epa.gov
  • EPA Facility Registry Service - facility location and identity. epa.gov
  • EPA ECHO - regulatory and compliance context. epa.gov
  • EPA Envirofacts - the EPA data warehouse exposing these datasets. epa.gov