MGP Site In Situ Stabilization

Site Overview

The former Manufactured Gas Plant (MGP) site operated from the late 1800s into the 1950s in an urban-industrial area. Envirocon performed pilot-scale testing for mix designs, full-scale bucket mixing in situ stabilization (ISS), and site restoration services to address volatile organic compounds (VOCs), benzene, heavy metals, coal tar, and DNAPL contamination at the site.

Project Highlights

• Conducted a 1,000 cubic yard pilot-scale test to revise and confirm mix design performance for the full-scale project
• Stabilized 29,000 cubic yards of contaminated soils using bucket mixing methodologies and GPS-equipped excavators to increase mixing precision
• Stabilized material using two excavators operating in 15-foot square grids to depths up to 30 feet
• Performed real-time monitoring of personnel and soil and identified elevated benzene levels in certain treatment areas that required an increase in personal protective equipment (PPE) for personnel
• Accomplished challenging logistical and site scheduling restraints by carefully planning work sequencing, traffic control, and resource utilization to meet milestone objectives

Value Delivered

Envirocon recommended the use of recycled granulated blast furnace slag as an alternative reagent for soil stabilization. This material is traditionally considered a waste product, but our technical team’s recommendation, based on successful use on other projects, saved the client $200,000 in material costs while meeting project objectives for stabilization criteria.