Date August 20, 2015

Project Solutions

RECON performed the building demolition, soil excavation, transportation and disposal, injection piping installation, and backfill and compaction activities at a former gas station within a residential and multi-family housing neighborhood in Newton, Iowa. RECON was contracted on the project because previous removal actions at the site failed to address all of the petroleum contaminated soils.

Work began with the demolition of a small building used as the service station office. Work included disconnection of utilities (water, gas and electric) and demolition of the building using an excavator equipped with a hydraulic thumb. Work also involved the excavation and off-site disposal of 3,700 cubic yards of petroleum contaminated soils. Due to poor quality backfill from previous excavation resulting in slope instability during excavation, RECON had to change from benching the excavation to establishing a one-to-one (1:1) slope in the fill area. In addition, RECON incrementally backfilled areas to maintain slope stability while working. To minimize the tracking of soil onto the city streets, RECON re-sequenced some of the work area to keep the concrete entrance intact as long as possible as a way to keep the city streets clean.

Installation of the injection piping involved placement of perforated PVC piping in the western portion of the open excavation, bedding the piping in pea gravel and installing flush-mounted manholes at ground surface.

Challenges

The site was located in a residential area which required RECON to be sensitive to the neighbors in terms of noise, dust, and odors. Since the site was located in a residential area, there was a concern with children and neighborhood residents entering the construction site. In addition to the installation of a chain link fence to preclude access to the site, RECON contracted additional site security during non-working hours to preclude unauthorized personnel from entering the work area.