AECOM / ComEd

O6 ENV completed demolition of a 3-story process building, a 2-story support building, a 1-story storage building and a pump house. The buildings were razed by excavator, the foundations were removed, and the debris was sized and segregated. Concrete and metal debris were recycled, and general debris was disposed of at an approved landfill. Additionally, 60,000 cubic yards of soil impacted with coal tar that was identified during construction activities at the plant. The source of the coal tar contamination was discovered to have originated from the gas holder tanks that remained in place from the former manufactured gas plant that operated on the site.

The impacted soil was excavated with an 80,000 lb. hydraulic excavator and loaded into end dump trailers and transported to Belleville, Michigan for disposal at a Sub-Title C Landfill. Source Material (Coal Tar) that was encountered and deemed not suitable for direct load was mixed with other non-impacted soil in order to pass paint filter and be suitable for transportation. The impacted soil was manifested as Non-RCRA Regulated Waste under 40 CFR Section 262.34(a) which provides an RCRA Exemption for certain wastes generated from former manufactured gas plant activities.

The excavations were backfilled using soil and gravel from an off-site borrow source. The borrow material was transported by tandem truck and placed with an excavator and compacted to the levels recommended in the scope of work.