Please join us on Tuesday, May 18 on Zoom! We will be hosting the national AEG President William H. Godwin from the San Francisco Bay Area Chapter of AEG who will be giving a presentation titled Lessons Learned from the Baker Beach Landfill Removal Project.
Lessons Learned from the Baker Beach Landfill Removal Project
William H. Godwin, PG, CEG
National Association of Engineering and Environmental Geologists (AEG) President and San Francisco Bay Area Chapter Member
After a three-year planning, site investigation and design process, two Army-era landfills were removed from the steep 270 foot (80 meter) high bluffs above Baker Beach in the Presidio of San Francisco in 2007. The landfills had been created over a 50-year period during the last century by dumping of waste soil, construction debris and incinerator ash over the steep cliffs. High-value serpentine habitat and historic artillery batteries and earthworks surrounding the landfills, as well as locally unstable slopes prevented the construction of access roads to simplify the removal process.
Despite extensive pre-removal site exploration and analyses, once excavation and removal began the landfills were found to contain nearly double the amount of waste that had been anticipated, resulting in a significant increase in project cost. By using a combination of paddle conveyors, “spyder “walking excavators, off-road dump trucks and a bucket-brigade of long-reach hydraulic excavators the contractor was able to remove the waste soil and debris and adhere to the original project schedule.
A project post-mortem indicated that additional drilling and sampling during the site investigation phase would have likely revealed the presence of thicker fill deposits, allowing a more accurate estimate of the eventual waste tonnage and better estimates of the project’s final cost, albeit at a significant increase in the cost of the investigation.
This presentation was given at the 2007 AEG Annual Meeting in Los Angeles and the 2010 IAEG Congress in Auckland, New Zealand. Portions of this presentation have been updated.
William H. Godwin is a member of the San Francisco Bay Area Chapter of the Association of Environmental and Engineering Geologists (AEG) and is the current 2020-21 National President. He has been a practicing geologist for over 40 years and has been working as an independent geologic consultant since 2014 and as an on-call employee for several large geotechnical consulting firms. Mr. Godwin earned a Bachelor of Science degree in Geology from the University of Redlands, in Southern California. He is a licensed Professional Geologist (PG) and Certified Engineering Geologist (CEG) in California. He lives in Pacific Grove California.