Tesoro Alaska - Kenai Refinery – Emissions Trend

Kenai, AK · 2019–2023 · Parent: Marathon Petroleum Corp

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Tesoro Alaska - Kenai 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 53.3K in 2019 and closed at 45.1K in 2023 – a decrease of 15.3% 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 n-Hexane at 94.1K, followed by Toluene at 28.6K.

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 (-15.3%)
2019 Total
53.3K lbs
2023 Total
45.1K lbs

Total Releases by Category

Air
Water
Land
Offsite Transfer
011.7K23.4K35.2K46.9K58.6K 20192020202120222023 Pounds Released

Year-over-Year Comparison

Year Total Chemicals YoY Change
2019 53.3K lbs 19 -
2020 58.6K lbs 19 +10.0%
2021 40.5K lbs 17 -30.9%
2022 48.4K lbs 18 +19.5%
2023 45.1K lbs 19 -6.8%

Top Chemicals by Year

Chemical 20192020202120222023 Total
n-Hexane 19.8K 17.4K 17.3K 20.3K 19.2K 94.1K
Toluene 6.3K 7.5K 4.5K 5.5K 4.8K 28.6K
Xylene (mixed isomers) 3.7K 4.7K 4.5K 5.3K 4.3K 22.5K
Hydrogen sulfide 4.9K 6.1K 3.0K 4.0K 3.5K 21.4K
Benzene 2.9K 3.1K 2.9K 3.6K 3.9K 16.5K
Cyclohexane 3.6K 2.9K 2.6K 3.0K 2.6K 14.7K
Ammonia 2.9K 2.4K 2.5K 2.5K 2.2K 12.6K
Nickel compounds - 7.8K - - 198 8.0K
1,2,4-Trimethylbenzene 1.1K 1.1K 1.0K 1.2K 1.2K 5.6K
Ethylbenzene 702 866 789 960 1.3K 4.6K
Molybdenum trioxide - 3.3K - - 140 3.5K
Lead compounds 2.9K 16 8 8 7 2.9K
Carbonyl sulfide 562 440 620 570 570 2.8K
Mercury compounds 2.3K 17 15 27 24 2.4K
Methanol 145 220 120 630 360 1.5K

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 Alaska - Kenai Refinery getting cleaner or dirtier?
Based on EPA TRI data from 2019–2023, Tesoro Alaska - Kenai Refinery's total toxic releases have decreased by approximately 15%.
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.