Black Hills Corp - Neil Simpson Complex – Emissions Trend

Gillette, WY · 2019–2023 · Parent: Black Hills Corp

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Black Hills Corp - Neil Simpson Complex, 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 1.9M in 2019 and closed at 1.5M in 2023 – a decrease of 18.7% 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 And Barium Compounds at 3.7M, followed by Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) at 2.9M.

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 (-18.7%)
2019 Total
1.9M lbs
2023 Total
1.5M lbs

Total Releases by Category

Air
Water
Land
Offsite Transfer
0379.4K758.8K1.1M1.5M1.9M 20192020202120222023 Pounds Released

Year-over-Year Comparison

Year Total Chemicals YoY Change
2019 1.9M lbs 11 -
2020 1.8M lbs 11 -2.4%
2021 1.6M lbs 11 -14.8%
2022 1.9M lbs 11 +21.6%
2023 1.5M lbs 11 -19.6%

Top Chemicals by Year

Chemical 20192020202120222023 Total
Barium And Barium Compounds - - 1.2M 1.5M 1.1M 3.7M
Barium compounds (except for barium sulfate (CAS No. 7727-43-7)) 1.5M 1.4M - - - 2.9M
Manganese 97.9K 102.4K 91.3K 98.4K 92.9K 482.9K
Copper 69.6K 76.0K 70.7K 76.9K 79.5K 372.7K
Vanadium (except when contained in an alloy) 77.2K 77.9K 71.4K 71.6K 72.7K 370.7K
Zinc (fume or dust) 56.2K 44.2K 40.9K 67.3K 48.2K 256.8K
Chromium 31.8K 34.1K 31.2K 41.4K 38.0K 176.4K
Nickel 31.3K 30.4K 29.3K 32.4K 30.9K 154.3K
Ammonia 30.1K 30.5K 27.2K 31.2K 31.0K 149.9K
Lead 19.4K 20.1K 19.7K 22.3K 22.0K 103.4K
Mercury 755 692 686 675 680 3.5K
Dioxin and dioxin-like compounds 1 1 1 0 0 4

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 Black Hills Corp - Neil Simpson Complex getting cleaner or dirtier?
Based on EPA TRI data from 2019–2023, Black Hills Corp - Neil Simpson Complex's total toxic releases have decreased by approximately 19%.
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.