Mp Mine Operations LLC
Total reported releases 1.6M lb rose meaningfully year over year (+16%). Total releases concentrations are up 16% since 2023.
67750 BAILEY RD, Mountain Pass, California · 212290 · Metal Mining
Notable Signals
No notable signals at this facility for the current reporting year. See chemicals and equity context below for the full picture.
What This Facility Releases
Lead And Lead Compounds
Lead And Lead Compounds concentrations are up 16% since 2023.
Ammonia
Ammonia concentrations are up 58% since 2023.
Propylene
Propylene concentrations have more than halved since 2011.
Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)
Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) concentrations have more than halved since 2013.
Chlorine
Chlorine concentrations have fallen 29% since 2010.
Mercury And Mercury Compounds
Mercury And Mercury Compounds concentrations are up 16% since 2023.
Who Lives Next To This Facility
San Bernardino County County, CA (no Census block groups within 3 miles — falling back to containing county): a population of 2,180,563. Why we surface this →
Low-income
People of color
Under age 5
Over age 64
Source: Census ACS 2018-2022 (5-year), county-level fallback. Indicator-level percentile and EJ-disparity scores are surfaced on the county page and the state page — they describe wider regional exposure burdens, not effects attributable to a single facility.
Source. EPA Toxics Release Inventory · retrieved 2026-05-07. Reporting year 2024. TRI is a federal public-domain dataset under 17 USC §105.
What this is not. TRI quantifies releases reported by the facility under EPCRA §313 — not ambient air or water concentrations measured at receptors. We do not attribute individual health outcomes to specific facilities; that exceeds what the data can support.