Coronado Generating Station – Emissions Trend

Saint Johns, AZ · 2019–2023 · Parent: Salt River Project Ai&pd

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Coronado Generating Station, 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 264.5K in 2019 and closed at 408.1K in 2023 – a increase of 54.3% 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 Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) at 905.9K, followed by Barium And Barium Compounds at 665.8K.

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 electric utilities facility.

Overall Trend
↑ Increasing (+54.3%)
2019 Total
264.5K lbs
2023 Total
408.1K lbs

Total Releases by Category

Air
Water
Land
Offsite Transfer
090.9K181.8K272.8K363.7K454.6K 20192020202120222023 Pounds Released

Year-over-Year Comparison

Year Total Chemicals YoY Change
2019 264.5K lbs 12 -
2020 350.7K lbs 14 +32.6%
2021 454.6K lbs 15 +29.6%
2022 386.9K lbs 14 -14.9%
2023 408.1K lbs 14 +5.5%

Top Chemicals by Year

Chemical 20192020202120222023 Total
Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) 228.7K 295.5K 381.7K - - 905.9K
Barium And Barium Compounds - - - 332.3K 333.6K 665.8K
Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) 11.7K 16.3K 12.6K 11.0K 25.0K 76.6K
Vanadium compounds 7.5K 7.9K 10.0K 9.3K 10.0K 44.7K
Zinc compounds 7.3K 5.5K 6.5K 6.3K 7.0K 32.6K
Hydrogen fluoride 4.1K 4.3K 5.4K 5.1K 6.0K 25.0K
Manganese And Manganese Compounds - - - 11.9K 13.0K 24.9K
Ammonia 4.5K 4.9K 4.5K 4.3K 6.1K 24.3K
Manganese compounds - 9.8K 13.4K - - 23.1K
Chromium compounds (except for chromite ore mined in the Transvaal Region) - - 12.5K - - 12.5K
Copper compounds - 5.5K 6.8K - - 12.3K
Copper And Copper Compounds - - - 5.8K 6.2K 12.0K
Lead compounds 628 996 1.2K - - 2.8K
Lead And Lead Compounds - - - 1.0K 1.1K 2.1K
Mercury compounds 23 30 36 - - 89

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 Coronado Generating Station getting cleaner or dirtier?
Based on EPA TRI data from 2019–2023, Coronado Generating Station's total toxic releases have increased by approximately 54%.
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.