Title: Using Soil-Cement Mixing for Soft Ground Improvement at a Landfill
Speakers: Todd Swackhamer, P.E. and Jon Whiting, E.I.T.
The Seneca Meadows Landfill in central New York is the largest municipal solid waste landfill in the
state. It is situated in extremely challenging soil conditions that have caused a history of stability
problems at the facility. Following two major slope failures during construction in the early 2000’s the
facility decided to try a different approach to develop stable landfill cells. Todd will discuss the site
history and geologic setting of the facility, and how his firm assembled a massive amount of data into a
model to characterize the subsurface conditions. He will describe how the model was used to design a
ground improvement program to allow for the berms and excavations to be constructed while meeting
the required factors of safety. Jon will conclude the discussion talking about the construction methods,
assessment techniques, and lessons learned from the last few years.
1 PDH Approved
Todd graduated from the University of Cincinnati in 1998 with his Bachelor of Science in Civil
Engineering and from the University of Michigan in 1999 with his Master of Science in Civil Engineering
with a geotechnical engineering focus. Following his graduation, he joined McMahon & Mann Consulting
Engineers, P.C. (MMCE), a geotechnical engineering consulting firm located in Buffalo. Todd became a
principal in the firm in 2014. He has worked on a wide variety of geo-design projects, mostly in the
Midwest and Northeast. His focus has been in slope stabilization, excavation support design, creek
stabilization, and dam engineering.
Jon graduated from the State University of New York at Buffalo (UB) in 2015
with Bachelors of Science in
Civil Engineering with a focus on geotechnical and structural engineering. He joined MMCE after
receiving his degree. His focus with MMCE has been on subsurface exploration and characterization,
geo-structural projects, construction monitoring, and slope stabilization. Prior to graduating from UB,
Jon spent 15 years working in construction related fields.