Tesoro Corp

2 facilities · 2 states · 5.5M lbs total releases

According to the EPA Toxics Release Inventory, Tesoro Corp is the reported parent of 2 Form R facilities across 2 states, disclosing 5.5M lbs of toxic releases. 14 of 77 reported chemicals carry a carcinogen classification in the TRI extract. The heaviest-reporting state by release volume is California (4.8M lbs). Those TRI figures remain self-reported disclosure pounds for Tesoro Corp, including carcinogen-flagged substances, not a measured public-health risk score.

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Release-over-release change

What changed for Tesoro Corp: EPA TRI 2023 reporting year

2022 → 2023

Same facilities, both years

-19.9%

2 facilities that filed in 2022 and 2023

Whole inventory

-19.9%

1.4 million lb → 1.1 million lb, every facility that filed

  • Tesoro Corp's total reported releases fell from 1.4 million lb in 2022 to 1.1 million lb in 2023, based on EPA TRI filings.
  • Tesoro Corp's water releases rose from 179 lb in 2022 to 602 lb in 2023, based on EPA TRI filings.
  • Tesoro Corp's land releases fell from 599 lb in 2022 to 401 lb in 2023, based on EPA TRI filings.
  • Tesoro Corp's air releases fell from 1.2 million lb in 2022 to 943.4 thousand lb in 2023, based on EPA TRI filings.

TRI parent disclosure trail

Read Tesoro Corp from filing to facility

Largest Form R sites under this parent: Tesoro Los Angeles Refinery-Carson Operations; Tesoro Refining & Marketing Company LLC - Slc. Neighbor parents on the disclosure ladder: Clean Harbors Inc; Waste Management Inc; Quikrete Holdings; Valero Energy Corp. Largest disclosed chemicals by pounds: Ammonia; Methanol; Toluene; Zinc compounds; n-Hexane. Heaviest-reporting states in this extract: California; Utah. Industry labels on the parent rollup: Petroleum. Start from those named sites and neighbors rather than a generic parent blurb; pounds stay disclosure, not risk.

Source: U.S. Environmental Protection Agency, TRI Basic Data Files Toxics Release Inventory (TRI) · August 2026

Total Releases
5.5M lbs
Facilities
2
Chemicals
77
Carcinogens
14

Largest Form R sites under this parent: Tesoro Los Angeles Refinery-Carson Operations; Tesoro Refining & Marketing Company LLC - Slc. Neighbor parents on the disclosure ladder: Clean Harbors Inc; Waste Management Inc; Quikrete Holdings; Valero Energy Corp. Largest disclosed chemicals by pounds: Ammonia; Methanol; Toluene; Zinc compounds; n-Hexane. Heaviest-reporting states in this extract: California; Utah. Industry labels on the parent rollup: Petroleum.

Tesoro Corp ranks #248 of 4,988 slug-merged TRI parents by disclosed release pounds, mid-to-upper among parents, not a top-25 volume name. Tesoro Corp files across 2 states, a regional parent portfolio rather than a single-state discloser. Releases are facility-concentrated: Tesoro Los Angeles Refinery-Carson Operations accounts for most of Tesoro Corp's disclosed pounds, so peer comparisons should weight that site, not an even portfolio average.

Parent aggregation for Tesoro Corp follows facility-reported names. Compare the named neighbors (Clean Harbors Inc; Waste Management Inc; Quikrete Holdings) before treating rank as a hazard score; TRI stays self-reported and unweighted by toxicity.

Where Tesoro Corp sits among TRI parents

Tesoro Corp sits on a disclosure ladder beside Clean Harbors Inc and Waste Management Inc and Quikrete Holdings and Valero Energy Corp. Open those parents for a different facility count, state span, and chemical mix.

Higher disclosed volume

Lower disclosed volume

Largest chemicals disclosed by Tesoro Corp

Ammonia; Methanol; Toluene; Zinc compounds; n-Hexane lead the Form R pound rollup for this parent, including filings such as Tesoro Los Angeles Refinery-Carson Operations. Pound totals, not toxicity-weighted risk.

Chemical Disclosed lbs
Ammonia 3.6M lbs
Methanol 246.1K lbs
Toluene 184.0K lbs
Zinc compounds 150.1K lbs
n-Hexane 141.7K lbs

Where does this company operate?

State Facilities Total Releases
California 1 4.8M lbs
Utah 1 668.7K lbs

Facilities (2)

Facility Releases
Tesoro Los Angeles Refinery-Carson Operations Carson, CA 4.8M lbs
Tesoro Refining & Marketing Company LLC - Slc Salt Lake City, UT 668.7K lbs

Frequently Asked Questions

How much pollution does Tesoro Corp release?
Tesoro Corp discloses 5.5M lbs across 2 facilities. On the ladder it sits near Clean Harbors Inc and Waste Management Inc. Tesoro Corp ranks #248 of 4,988 slug-merged TRI parents by disclosed release pounds, mid-to-upper among parents, not a top-25 volume name.
How many facilities does Tesoro Corp operate?
Tesoro Corp maps to 2 facilities in California, Utah, including Tesoro Los Angeles Refinery-Carson Operations; Tesoro Refining & Marketing Company LLC - Slc. Releases are facility-concentrated: Tesoro Los Angeles Refinery-Carson Operations accounts for most of Tesoro Corp's disclosed pounds, so peer comparisons should weight that site, not an even portfolio average.
What industries and chemicals show up for Tesoro Corp?
Tesoro Corp's disclosed pounds sit inside a single reported industry label: Petroleum. Tesoro Corp's largest disclosed chemicals by pounds are Ammonia, Methanol, Toluene, Zinc compounds, n-Hexane (none of those top chemicals carry a carcinogen flag in this extract). Neighbor parents: Clean Harbors Inc; Waste Management Inc; Quikrete Holdings; Valero Energy Corp.
Does Tesoro Corp release carcinogens?
Yes - 14 carcinogen-flagged substances appear in the extract. Largest by pounds include Ammonia; Methanol; Toluene; Zinc compounds; n-Hexane.

Compare beyond the release ladder

Nationwide peers by disclosed pounds & facility count

Cross-portfolio TRI parents nearest Tesoro Corp on total disclosed release pounds (5.5M lbs) and reporting facility count (2). Release-volume peers include Energizer Holdings Inc, Green Bay Packaging Inc, American Cast Iron Pipe Co. Neighborhoods are forced disjoint so each axis surfaces a different set of parents.

About This Data

EPA TRI parent totals cover all media. This extract's heaviest states for the parent are California, Utah; facility-reported names can vary across subsidiaries.

Source: U.S. Environmental Protection Agency, TRI Basic Data Files

What to do with Tesoro Corp's TRI parent record

From Tesoro Corp, open Tesoro Los Angeles Refinery-Carson Operations or compare against Clean Harbors Inc rather than reading rank alone.

  • Open the largest Form R site for Tesoro Corp (Tesoro Los Angeles Refinery-Carson Operations in CA). Largest facility
  • Compare against Waste Management Inc, the next-higher disclosed-volume parent. Higher-volume parent
  • Browse the full parent release ranking to see where Tesoro Corp sits among all slug-merged TRI parents. All parent companies

Rank and peers (Clean Harbors Inc, Waste Management Inc) are disclosure volume only, not toxicity-weighted risk or enforcement status.

Use and verify this record

Tesoro Corp's record groups disclosed TRI parent-company filings so readers can compare reporting context without treating the total as a measure of risk.

Company release figures are computed directly from EPA Toxic Release Inventory data; source names and the record-linking method are documented in the methodology.

Primary sources

PlainEnviro renders public EPA records directly from its data pipeline; no figure on this page is typed in by an editor. See the editorial standards and corrections policy for how source changes and reported errors are handled.