Challenge
GZA was retained by Tully Construction (Tully), the firm implementing the closure of this 285-acre landfill, to complete all design phases of the project and procedure contract phases. To reduce the time and cost of construction, Tully enlisted GZA to review the contract documents and evaluate potential alternative closure options.
The Fresh Kills Landfill facility is owned and operated by New York City Department of Sanitation (NYCDOS). The Section 6/7 project was contracted as a design-build delivery system. The preliminary cap design, permit phase work, and construction management were provided by URS Corporation (URS). GZA worked closely with URS on all design, construction, and submittal issues. The changes were presented through a project submitted process. The submittals were reviewed and approved by NYCDOS, URS, and Show Environmental (gas system operator). GZA served as On-site System Designer responsible for monitoring the system installation and making decisions regarding field modifications.
Solution
GZA’s first task was to develop a comprehensive cap system design in conformance with the permit phase design and NYCRR Part 360. This design includes cap structure, cap structure drainage system, surface water collection and conveyance system. A design report and project design drawings were prepared; the design was reviewed and accepted by URS, NYCDOS, and NYDEC. Subsequently, GZA prepared and submitted design enhancements on behalf of Tully, resulting in a more efficient design and cost savings. GZA’s design enhancements also streamlined construction efforts and schedule. During the design process GZA identified gas system design changes that resulted in a more effective overall system while minimizing maintenance requirements, including switch over procedures, well head components and configuration, condensation, collection and disposal, and conveyance piping layouts.
The landfill geometry consisted of long, shallow sloping landfill surfaces with short, steeply pitched perimeter slopes. The original design included the use of costly landfill gas control and steep slope drainage geosynthetic materials. GZA reevaluated the preliminary designs for the surface water drainage systems and cap drainage systems, making changes to the surface water configuration and above liner cap systems that were accepted and incorporated into an approved final design
Benefit
Fresh Kills Landfilll is now referred to as Freshkills Park and is enjoyed by local residents and visitors in Staten Island and throughout New York City.
