City: Quincy
State: Illinois
Owner: Ameren Services
General Contractor: Ameren Services

Project Description:
Schnabel was contracted to design and construct an excavation support system and groundwater cut off wall to allow the removal of contaminated soils from a former Manufactured Gas Plant in Quincy, Illinois.  Over 650 secant piles were designed and installed to rock in order to facilitate this remediation project.  Internal bracing was used to laterally support the secant walls.

The 25-foot deep excavation was excavated and backfilled in quadrants over the course of a year.  A carefully monitored tent was placed over the site to contain any potential contamination and to keep the weather out.  The secant piles were installed into rock to prevent groundwater from entering the site.