Marathon Mandan Refinery – Emissions Trend

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Marathon Mandan Refinery, spanning 2019–2023. Each annual total aggregates on-site air emissions, surface-water discharges, land disposal, and off-site transfers reported by the facility under EPCRA Section 313, which requires disclosure whenever a listed chemical is manufactured, processed, or otherwise used above threshold quantities.

Reported releases opened at 352.9K in 2019 and closed at 377.8K in 2023 – a increase of 7.1% over the window. The chart below stacks the four TRI release media (air, water, land, off-site) and overlays the yearly total. The top contributor by cumulative mass is Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) at 814.3K, followed by Propylene at 284.0K.

Because TRI figures are estimated, not metered, year-over-year deltas can reflect methodology revisions, ownership changes, or shifts in what a facility classifies as reportable, not only physical emission changes. Treat the trajectory as a disclosure record, and cross-reference with the EPA Enforcement and Compliance History Online (ECHO) system for the fuller regulatory picture on this petroleum facility.