MarkWest Energy Partners, L.P. – Gas Processing, Fractionation, and Pipeline Development Services


MarkWest Energy Partners, L.P.


Ohio, Pennsylvania, and West Virginia

CEC Services

  • Site Selection Services
  • Unmanned Aerial Services
  • Civil Engineering
  • Geotechnical Engineering
  • Structural Engineering
  • Ecological Permitting
  • Archeological Investigations
  • Construction Document Preparation
  • Site Construction Bid Services
  • Construction Management Services
  • CQA
  • Survey/GPS/GIS Services
  • Landscape Architecture/Land Planning
  • Site Grading/Earthwork Analysis
  • Erosion & Sedimentation Control/NPDES Permitting
  • Stormwater Management/BMP Design
  • Wetlands and Waters Delineations
  • Phase I & II Assessments
  • Flood Routing and FEMA Map Revisions
  • Threatened & Endangered Species
  • Surveys/Wildlife Surveys
  • Air Compliance and Permitting
  • Auditing and Compliance Plans
  • Slope Stability/Retaining Structure Design
  • Site Characterization
  • ALTA NSPS Land Title Surveys


Owner Objective

MarkWest Energy Partners, L.P. (MarkWest) provides fully integrated natural gas midstream services in the liquids-rich areas of the Marcellus and Utica Shale. MarkWest is the largest processor of natural gas in Marcellus, with fully integrated processing, fractionation, storage, and marketing operations.

CEC Approach

Since 2010, CEC has developed a partnership with MarkWest through work on several gas processing and fractionation facilities as well as NGL pipelines in Ohio, Pennsylvania, and West Virginia. CEC and MarkWest teamed up early to evaluate potential sites for development of processing facilities and to evaluate potential pipeline routes.

CEC’s experts researched potential sites and right-of-ways (ROW) to identify stream and wetlands impacts, geologic hazards (landslide prone soils, rock outcrops, etc.), prepared preliminary layout and grading plans, completed estimates of earthwork volumes, plotted utility locations, and prepared permitting and constructability reviews to aid MarkWest in site and ROW selections. To date, CEC has collaborated with Markwest to complete engineering and permitting designs for ten MarkWest gas processing and fractionation facilities and over 600 miles of NGL and natrual gas pipelines.

Areas of Operation

  • Ohio, Southwest and Northwest Pennsylvania, and Northern West Virginia
  • Gathering
  • 1.2 Bcf/d gathering capacity
  • Processing
  • 4.5 Bcf/d total cryogenic processing capacity
  • NGL Pipelines
  • NGL pipelines connecting Sherwood, Mobley, Majorsville, and Houston complexes
  • Purity ethane pipeline connecting Keystone complex to Mariner West project



  • Bluestone Plant, Approx. 120-acre site, Jackson Township, Butler County, PA
    • 5 cryogenic gas processing plants (2 operational, 3 under construction), future de-ethanizer facility, rail yard facility and future rail yard expansion, storage tank facilities
  • Houston Plant, Approx. 180-acre site, Houston, Washington County, PA
    • 4 cryogenic gas processing plants (3 operational, 1 under construction), De-Ethanizer, rail facility with 2,500 feet of track, 10 track rail yard with about 4.5 miles of rail, 80’ diameter propane storage tank
  • Harmon Creek (under construction), Approx. 125-acre site in Washington County, PA
    • Full build out to include 2 de-ethanizer plants and up to 4 cryogenic processing plants

West Virginia

  • Majorsville Plant, Approx. 110-acre site, Ohio County, WV
    • 10 cryogenic gas processing plants planned (5 operational, 1 under construction), 2 De-ethanizer plants planned (1 operational)
  • Mobley Plant, Approx. 100-acre site, Wetzel County, WV
    • 4 cryogenic gas processing plants each with a capacity of 200 million cubic ft. per day, a 5th cryogenic plant and De-Ethanizer under construction
  • Sherwood Plant, Approx. 97-acre site, Doddridge County, WV
    • 13 cryogenic gas processing plants planned (9 operational, 1 under construction), 3 De-Ethanizer Plants planned (1 operational, 1 under construction)
  • Smithburg (currently in permitting), Approx. 220-acre site, West Union, WV
    • Full build out to include 2 de-ethanizer plants and up to 8 cryogenic processing plants.


  • Cadiz Condensate Plant and Truck Loading Facility, Approx. 34-acre site, Harrison County, OH
    • Project facility is comprised of a condensate stabilization processing plant and 20-stall truck loading/unloading area, with various appurtenances (storage tanks, pig launchers, paraffin catcher, etc.) used to support gas processing activities.
  • Hopedale, 180,000 Bbl/d of shared C3+ fractionation, Jewell, OH
    • Seneca, 400 MMcf/d capacity cryogenic processing plant, Noble County, OH