MGP Site Remediation – Chicago, IL

RW Collins completed excavation and backfill activities in a 7.2-acre site of a former natural gas manufacturing plant in Chicago, IL. The MGP site contained active overhead transmission lines and 138kV pipe type underground cables positioned directly over a 450,000 cu. ft. former gas holder.

Remediation tasks

  • Removal of the contents and gas holder walls and floors
  • Backfill to subgrade with compacted limestone
  • Apply odor and dust cover measures

Other tasks:

  • Excavation to a depth of approximately 30 ft. below ground surface
  • Extreme care taken to perform work safety beneath steel truss system
  • Supported the installation of six steel sheet pile cofferdams
  • Excavation of coal tar impacted soil
  • Placement/compaction of limestone backfill was complete in each 30-ft. deep cell under the Confined Space Entry procedures

Project Facts

  • 2-year project
  • Excavating and loading more than 500,000 tons of coal tar impacted soil
  • Placement and compaction of 500,000 tons of limestone aggregate backfill
  • Pumping, onsite treatment and discharge of 3 million gallons of impacted water
  • Compete removals of 290,000 and 200,000 cu. ft. gas holders
  • Removal of two tar wells