EPA Outlines Areas of Concern at a Pennsylvania Shale Plant

 September 17, 2012 - In response to an article written in February describing a, EPA Clean Air Act inspection at a MarkWest plant in southwestern Pennsylvania, the Clean Air Council submitted a Freedom of Information Act request to EPA. The Council requested all documents associated with the inspection which occurred in November and December 2011. The Council received an Air Compliance Inspection Report as well as MarkWest's follow-up responses to the Areas of Concern which were identified in the report. Both documents are attached below.

The areas of EPA's concern are outlined below with MarkWest's responses:

  • There have been at least three flaring events at the Houston Processing Plant since September 2011.
    • The flaring events were a result of upset conditions
  • EPA detected 5 leaking valves with a leak rate of 4.1%. They also found a leaking pump. There were several components missing tags. There were also several open ended lines at the gas inlet lines which were leaking.
    • In October MarkWest found 46 leaking valves but they were only leaking at a rate of 1.17%. A subsequent review found that a suction flange, which does not require monitoring, rather than a pump was leaking. Tags have been placed on all components that require them. The open lines were repaired
  • EPA identified monitoring inconsistencies.
    • MarkWest ensures that the proper methodology has been and continues to be used
  • There were more than 1800 instances where valves were not re-monitored within 120 days of their previous monitoring events as required.
    • MarkWest states that many of these valves were shutdown when they were not being monitored and a small number of valves were in service but not accessible to the monitoring technician because of construction at the site.
  • MarkWest is shipping liquid wastewater off-site but have not sampled the waste stream to determine the VOC/HAP content.
    • MarkWest has process knowledge of the waste stream and is confident that it should not be characterized as hazardous waste. They attached the latest sample results from the third party disposal company.
  • MarkWest has not determined that the closed drain system is not subject to the leak detection requirements of new source performance standards under section KKK.
    • Because the drain system is not greater than 10% VOC it is not subject to KKK but a sample of the liquids have been ordered for analysis.
  • MarkWest is not conducting daily visible emissions monitoring as required.
    • The operators have been trained accordingly.


MW FOIA Compliance Inspection Report.pdf1003.42 KB
MW FOIA Compliance Inspection Response.pdf1.21 MB