Clean Air Act stationary source · ICIS-AIR PA000772757
MARKWEST LIBERTY MIDSTREAM/ CARPENTER COMP STA, West Alexandria, PA: Clean Air Act compliance record, inspections, violations, penalties
- OperatingOperating status
- Synthetic minor sourceEmissions classification
- No Violation IdentifiedCurrent violation status, as filed
- 15Compliance evaluations since January 1, 2017
- 0High-priority violations since January 1, 2017
- 1Formal enforcement actions since January 1, 2017
MARKWEST LIBERTY MIDSTREAM/ CARPENTER COMP STA, at 265 OLD NATIONAL PIKE, West Alexandria in Washington County, Pennsylvania, is an operating synthetic minor 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 “No Violation Identified”. Washington County is on EPA’s Green Book list of areas that do not meet a national air quality standard. 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 LIBERTY MIDSTREAM/ CARPENTER COMP STA |
|---|---|
| ICIS-AIR ID | PA000772757 |
| EPA facility registry ID | 110063587355 |
| Operating status | Operating |
| Emissions classification | Synthetic minor source |
| Current violation status (ICIS-AIR high-priority violation field) | No Violation Identified |
| Address | 265 OLD NATIONAL PIKE, West Alexandria, PA 15376 |
| County | Washington County |
| In a nonattainment county | Yes (EPA Green Book) |
| Industry (NAICS) | Oil and gas extraction (NAICS 2111) |
| SIC code | 1311 |
| EPA region | 03 |
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 LIBERTY MIDSTREAM/ CARPENTER COMP STA 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
- 15Evaluations since January 1, 2017
- 3Full compliance evaluations
| Date | What EPA recorded | Agency | Programs |
|---|---|---|---|
| June 18, 2025 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| May 16, 2025 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| June 20, 2024 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| March 28, 2024 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| August 31, 2023 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| March 10, 2022 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| February 17, 2022 | FCE On-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| March 24, 2021 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| March 16, 2021 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| August 13, 2020 | FCE On-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| April 20, 2020 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| June 6, 2019 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| April 25, 2018 | FCE On-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| March 29, 2018 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
| April 21, 2017 | PCE Off-Site | State | State Implementation Plan for National Primary and Secondary Ambient Air Quality Standards |
Violations
- 0Violation determinations since January 1, 2017
- 0Of 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.
EPA’s violation history file holds no violation for ICIS-AIR PA000772757 since January 1, 2017.
Enforcement and penalties
1 formal enforcement actions since January 1, 2017, 1 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 |
|---|---|---|---|
| July 9, 2018 | Civil Judicial Action | U.S. EPA | $385,000 |
Informal enforcement
EPA’s informal action file holds no notice or warning for ICIS-AIR PA000772757 since January 1, 2017.
Stack tests
- 19Stack tests since January 1, 2017
- 0Recorded as failed
| Date | What EPA recorded | Agency |
|---|---|---|
| April 28, 2026 | Pass | State |
| April 29, 2025 | Pass | State |
| July 17, 2024 | Pass | State |
| April 30, 2024 | Pass | State |
| July 20, 2023 | Pass | State |
| June 5, 2023 | Pass | State |
| May 4, 2023 | Pass | State |
| August 23, 2022 | Pass | State |
| May 5, 2022 | Pass | State |
| September 3, 2021 | Pass | State |
| May 7, 2021 | Pass | State |
| August 25, 2020 | Pass | State |
| May 5, 2020 | Pass | State |
| August 27, 2019 | Pass | State |
| May 7, 2019 | Pass | State |
| August 28, 2018 | Pass | State |
| May 10, 2018 | Pass | State |
| September 6, 2017 | Pass | State |
| May 11, 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 110063587355 there.
Nearby on the register
- Air-emissions sources in Washington County
- Every source record in Washington County, A to Z
- Air-emissions sources in Pennsylvania
- Every source record in Pennsylvania, A to Z
Figures from EPA’s ICIS-AIR download, loaded September 14, 2026.