Geotechnical Modeling of Landfill Expansion Stability

To evaluate the feasibility of a landfill expansion, geotechnical investigations, engineering analyses and stability modeling using finite element methods were performed as part of conceptual design efforts. Providing a practical waste management option to serve the future needs of Baltimore City, Maryland requires increasing the capacity of the existing Quarantine Road Landfill to encompass the former Millennium Landfill located within the Hawkins Point industrial area at the city outskirts. The proposed expansion will increase waste heights 145 feet above the existing waste to achieve maximum heights of up to 215 feet covering a 160-acre footprint. Geotechnical and Hydrogeological studies were performed to support the landfill expansion concept design and permitting to satisfy Code of Maryland Regulations Phase II and the Maryland Department of the Environment regulatory requirements. This paper primarily discusses the geotechnical investigations and modeling, including long-term settlements and stability, and the implications for the leachate collection systems design.