Clean Air Act stationary source · ICIS-AIR OK0000004003900020
MARKWEST OKLAHOMA GAS CO LLC / BUTLER ARAPAHO GAS PLANT, Butler, OK: Clean Air Act compliance record, inspections, violations, penalties
- OperatingOperating status
- Major sourceEmissions classification
- Unaddressed-StateCurrent violation status, as filed
- 42Compliance evaluations since January 1, 2017
- 1High-priority violations since January 1, 2017
- 2Formal enforcement actions since January 1, 2017
MARKWEST OKLAHOMA GAS CO LLC / BUTLER ARAPAHO GAS PLANT, at 0.2 MI S OF N2120 AND E0870 RD, Butler in Custer County, Oklahoma, is an operating major source of air pollution on EPA’s ICIS-AIR register. EPA’s file records its current violation status (ICIS-AIR’s high-priority violation field) as “Unaddressed-State”. The status and classification are as EPA’s facility file stood when Velarion loaded it (September 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the source’s current standing, quarter by quarter.
Identity
| Facility as filed | MARKWEST OKLAHOMA GAS CO LLC / BUTLER ARAPAHO GAS PLANT |
|---|---|
| ICIS-AIR ID | OK0000004003900020 |
| EPA facility registry ID | 110007386998 |
| Operating status | Operating |
| Emissions classification | Major source |
| Current violation status (ICIS-AIR high-priority violation field) | Unaddressed-State |
| Address | 0.2 MI S OF N2120 AND E0870 RD, Butler, OK 73625 |
| County | Custer County |
| In a nonattainment county | No (EPA Green Book) |
| Industry (NAICS) | Oil and gas extraction (NAICS 2111) |
| SIC code | 1321 |
| EPA region | 06 |
Cited to the EPA ICIS-AIR facility file (ECHO download).
Programs and pollutants
Velarion’s copy of EPA’s ICIS-AIR download does not include its program, pollutant and Title V certification files, so this page does not list the Clean Air Act programs MARKWEST OKLAHOMA GAS CO LLC / BUTLER ARAPAHO GAS PLANT is under or the pollutants it is permitted for. The programs each evaluation and violation below was recorded under are shown with it. EPA’s free Detailed Facility Report lists both.
Compliance evaluations
- 42Evaluations since January 1, 2017
- 5Full compliance evaluations
| Date | What EPA recorded | Agency | Programs |
|---|---|---|---|
| March 4, 2026 | FCE On-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 31, 2024 | FCE On-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| February 22, 2023 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| February 7, 2023 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| February 7, 2023 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 24, 2023 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 10, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 4, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 4, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| July 28, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| July 28, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| April 18, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| April 18, 2022 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| March 31, 2022 | FCE On-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 18, 2021 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| June 25, 2021 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| April 29, 2021 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| February 19, 2021 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 20, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 7, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 4, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| June 30, 2020 | FCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| May 26, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| April 29, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| March 9, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| February 3, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 28, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 27, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 23, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 7, 2020 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| October 29, 2019 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| September 11, 2019 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 22, 2019 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| July 26, 2019 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| February 13, 2019 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| January 15, 2019 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 20, 2018 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| May 16, 2018 | FCE On-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| March 2, 2018 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| August 2, 2017 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| July 26, 2017 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
| March 1, 2017 | PCE Off-Site | State | 40 CFR Part 63 Area Sources; MACT Standards (40 CFR Part 63); New Source Performance Standards; State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards; Title V Permits |
Violations
- 4Violation determinations since January 1, 2017
- 1Of them high-priority
A high-priority violation (HPV) is the most serious class of Clean Air Act non-compliance an agency records; a federally reportable violation (FRV) is the next step down. Each row is one determination as EPA’s violation history files it.
| Date | What EPA recorded | Agency | Programs |
|---|---|---|---|
| May 8, 2026 | HPV day-zero determination | State | MACT Standards (40 CFR Part 63); New Source Performance Standards; Title V Permits |
| April 30, 2024 | Earliest FRV determination | State | MACT Standards (40 CFR Part 63); New Source Performance Standards; Title V Permits |
| June 29, 2022 | Earliest FRV determination | State | MACT Standards (40 CFR Part 63); New Source Performance Standards; Title V Permits |
| September 28, 2020 | Earliest FRV determination | State | MACT Standards (40 CFR Part 63) |
Enforcement and penalties
2 formal enforcement actions since January 1, 2017, 2 of them with a penalty filed above zero. Each penalty is shown as EPA’s formal action file states it; “Not stated” means the file gives no figure, and $0 is a disclosed zero.
| Date | What EPA recorded | Agency | Penalty, as filed |
|---|---|---|---|
| December 17, 2024 | Administrative Order | State | $4,725 |
| January 8, 2019 | Civil Judicial Action | U.S. EPA | $154,166 |
Informal enforcement
| Date | What EPA recorded | Agency |
|---|---|---|
| May 12, 2026 | Notice of Violation | State |
| June 7, 2024 | Notice of Violation | State |
| January 25, 2023 | Notice of Violation | State |
| November 30, 2021 | Notice of Violation | State |
Stack tests
- 31Stack tests since January 1, 2017
- 0Recorded as failed
| Date | What EPA recorded | Agency |
|---|---|---|
| September 11, 2025 | Pass | State |
| September 11, 2025 | Pass | State |
| July 31, 2025 | Pass | State |
| July 31, 2025 | Pass | State |
| July 31, 2025 | Pass | State |
| October 4, 2024 | Pass | State |
| October 4, 2024 | Pass | State |
| July 23, 2024 | Pass | State |
| February 28, 2023 | Pass | State |
| August 18, 2022 | Pass | State |
| August 17, 2022 | Pass | State |
| August 17, 2022 | Pass | State |
| September 9, 2021 | Pass | State |
| September 9, 2021 | Pass | State |
| September 9, 2021 | Pass | State |
| October 7, 2020 | Pass | State |
| October 7, 2020 | Pass | State |
| October 5, 2020 | Pass | State |
| March 6, 2020 | Pass | State |
| October 17, 2019 | Pass | State |
| October 17, 2019 | Pass | State |
| October 14, 2019 | Pass | State |
| October 23, 2018 | Pass | State |
| October 23, 2018 | Pass | State |
| October 22, 2018 | Pass | State |
| October 22, 2018 | Pass | State |
| October 22, 2018 | Pass | State |
| October 22, 2018 | Pass | State |
| October 25, 2017 | Pass | State |
| October 25, 2017 | Pass | State |
| October 25, 2017 | Pass | State |
Cited to the EPA ICIS-AIR evaluation, violation, stack test and enforcement files (ECHO download), events dated January 1, 2017 or later as loaded; up to 50 rows of each shown, newest first.
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How we handle your data → Privacy
EPA publishes a free Detailed Facility Report for every source on ECHO: its compliance status quarter by quarter, its evaluations, and its violations, enforcement actions and penalties. EPA also sends free notices of new inspections and enforcement actions through ECHO Notify; enter EPA facility registry ID 110007386998 there.
Nearby on the register
- Air-emissions sources in Custer County
- Every source record in Custer County, A to Z
- Air-emissions sources in Oklahoma
- Every source record in Oklahoma, A to Z
Figures from EPA’s ICIS-AIR download, loaded September 14, 2026.