Tesoro Refining & Marketing Co LLC – Emissions Trend

Anacortes, WA · 2019–2023 · Parent: Marathon Petroleum Corp

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Tesoro Refining & Marketing Co LLC, 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 176.1K in 2019 and closed at 121.9K in 2023 – a decrease of 30.8% 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 274.5K, followed by Toluene at 60.2K.

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.

Overall Trend
↓ Decreasing (-30.8%)
2019 Total
176.1K lbs
2023 Total
121.9K lbs

Total Releases by Category

Air
Water
Land
Offsite Transfer
035.2K70.4K105.6K140.8K176.1K 20192020202120222023 Pounds Released

Year-over-Year Comparison

Year Total Chemicals YoY Change
2019 176.1K lbs 31 -
2020 138.9K lbs 34 -21.1%
2021 152.3K lbs 31 +9.6%
2022 135.3K lbs 30 -11.1%
2023 121.9K lbs 30 -9.9%

Top Chemicals by Year

Chemical 20192020202120222023 Total
Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) 56.1K 43.9K 60.8K 64.1K 49.7K 274.5K
Toluene 16.1K 12.7K 9.1K 10.1K 12.2K 60.2K
Xylene (mixed isomers) 12.2K 16.1K 13.4K 7.5K 8.1K 57.4K
Hydrogen sulfide 7.7K 4.6K 11.0K 10.9K 7.6K 41.7K
n-Hexane 9.4K 7.4K 7.6K 11.3K 5.3K 41.0K
Ammonia 7.6K 6.3K 6.7K 6.7K 7.3K 34.6K
Cyclohexane 8.3K 6.4K 5.2K 4.8K 6.8K 31.6K
Hydrogen cyanide 6.0K 5.6K 6.0K 6.0K 5.3K 28.9K
Benzene 8.0K 8.1K 4.1K 4.0K 4.2K 28.4K
Copper 20.1K - - - - 20.1K
Copper compounds - - 16.9K - - 16.9K
Phenol 2.7K 2.6K 2.6K 2.6K 2.6K 13.2K
1,2,4-Trimethylbenzene 4.6K 5.2K 732 326 2.1K 12.9K
Ethylbenzene 3.1K 2.5K 2.5K 2.2K 2.1K 12.5K
Nickel compounds 10.7K - - - - 10.7K

About This Data

Trend data is sourced from the EPA Toxic Release Inventory (TRI). Facilities report annually. Release quantities are self-reported estimates. Year-over-year changes may reflect changes in production, pollution control measures, reporting methodology, or chemical thresholds.

A decrease in reported releases does not necessarily indicate improved environmental performance, as it may reflect production cutbacks, facility closures, or changes in reporting requirements. Similarly, increases may reflect expanded production rather than degraded environmental practices.

Frequently Asked Questions

Is Tesoro Refining & Marketing Co LLC getting cleaner or dirtier?
Based on EPA TRI data from 2019–2023, Tesoro Refining & Marketing Co LLC's total toxic releases have decreased by approximately 31%.
What time period does this trend data cover?
This page shows 5 years of EPA Toxic Release Inventory data from 2019–2023. Release quantities are self-reported estimates filed annually by the facility.