Marathon Major Civil Revamp


Cajun was contracted to perform civil concrete and underground piping construction for the Marathon Garyville Major Civil Revamp Project. The contracted scope included construction of new refinery units U27, U359, and U126; Upgrades to units U55, U214, U243, and U247; and modification upgrades/enhancements to pipe rack units U63, U263, and U59.

U27 Alky

  • Hogout excavation within the limits of the existing operating Alky and CAT units
  • Re-route of existing operational carbon steel and ductile iron firewater pipe systems, installation of new carbon steel oily water pipe system, and installation of new PVC acid pipe system
  • Installation of new foundations and area paving, including 1,266 CY acid settler foundation (79’ x 86’-6” x 5’ thick)


  • Hogout excavation including 200 wall feet of sheet piles along adjacent unit limits
  • Re-route of existing stormwater pipe, manholes, and catch basins for pile installation
  • Installation of new HDPE firewater pipe system and carbon steel oily water pipe system
  • Installation of new foundations, sump, and area paving

U359 Flare Gas Recovery

  • Hogout excavation
  • Installation of new stormwater pipe, manholes and catch basins, new firewater pipe system, and an oily water pipe system
  • Installation of new foundations and area paving

U55 Gasoline Desulfurization

  • Demo of existing paving and foundations for pile installation
  • Re-route of existing stormwater and firewater pipe systems for pile installation
  • Installation of new oily water pipe system
  • Installation of new foundations and area paving

U63 Alky Sphere

  • Installation of new foundations to support piping associated with new storage sphere being constructed

U214 KHT Flare Gas Recovery, U243 Utilities Flare Gas Recovery, U247 ARU Flare Gas Recovery

  • Demo of existing paving and re-route of oily water pipe system for pile installation
  • Installation of new foundations and area paving

U63, U263, and U59 Piperack Modifications

  • Drilling of approximately 15,000 holes ranging from 9” – 37” deep, both horizontally and vertically, to install rebar dowels for new retro-fit foundation upgrades and modifications


  • 20 month duration
  • 602,187 man-hours
  • 375 peak manpower

Work Performed

  • Installation of 1,200 CY helical pile grout
  • Installation of 964 tons rebar
  • Installation of 12,850 CY structural concrete
  • Installation of 57,620 CY sand backfill
  • Installation of 18,090 tons stone backfill
  • Installation of 3,400 CY seal slab and flowfill backfill
  • Installation of 11,210 LF underground piping


  • Despite the issues, delays, challenges, and the evolving growth of the project scope as engineered packages continued to be issued, Cajun completed our scope while maintaining a performance factor of .91 overall for the project.
  • All areas met or exceeded critical vessel and equipment delivery dates. Due to the value engineering and innovative planning that Cajun provided to the project, all areas mechanical scopes began with little to no delays and were on schedule to meet upcoming turnaround dates.
  • After all civil construction packages were issued, plans and schedules developed, and the needs of each Marathon management group established, Cajun’s manpower peaked at over 375 employees spread among 36 separate crews that completed 50 individual work packages.