Springerville Generating Station – Emissions Trend

Springerville, AZ · 2019–2023 · Parent: Uns Energy Corp

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Springerville 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 3.0M in 2019 and closed at 2.5M in 2023 – a decrease of 18.5% 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 9.3M, followed by Manganese compounds at 1.3M.

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
↓ Decreasing (-18.5%)
2019 Total
3.0M lbs
2023 Total
2.5M lbs

Total Releases by Category

Air
Water
Land
Offsite Transfer
0601.3K1.2M1.8M2.4M3.0M 20192020202120222023 Pounds Released

Year-over-Year Comparison

Year Total Chemicals YoY Change
2019 3.0M lbs 16 -
2020 2.8M lbs 16 -6.2%
2021 2.7M lbs 16 -6.0%
2022 2.7M lbs 16 +3.0%
2023 2.5M lbs 16 -10.3%

Top Chemicals by Year

Chemical 20192020202120222023 Total
Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) 2.1M 1.9M 1.8M 1.9M 1.7M 9.3M
Manganese compounds 303.9K 261.0K 254.6K 251.1K 237.4K 1.3M
Ammonia 110.8K 118.1K 141.8K 122.3K 115.3K 608.4K
Vanadium compounds 132.6K 131.2K 126.8K 111.6K 105.5K 607.7K
Zinc compounds 84.0K 86.6K 82.4K 72.8K 73.7K 399.4K
Copper compounds 80.5K 81.0K 82.6K 80.1K 74.8K 399.0K
Chromium compounds (except for chromite ore mined in the Transvaal Region) 59.4K 57.8K 53.7K 49.6K 48.3K 268.8K
Nickel compounds 41.2K 42.5K 37.8K 34.0K 36.5K 192.0K
Hydrogen fluoride 34.4K 41.6K 30.0K 26.5K 27.3K 159.9K
Lead compounds - 44.6K 40.5K 37.2K 35.3K 157.5K
Arsenic compounds 38.5K 31.0K 30.5K 25.0K 26.2K 151.1K
Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) 9.9K 9.8K 10.7K 9.6K 9.3K 49.3K
Lead And Lead Compounds 46.5K - - - - 46.5K
Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size) 1.5K 1.4K 1.2K 1.1K 1.1K 6.2K
Mercury compounds - 704 649 615 599 2.6K

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 Springerville Generating Station getting cleaner or dirtier?
Based on EPA TRI data from 2019–2023, Springerville Generating Station's total toxic releases have decreased by approximately 18%.
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.