Timothy Reed, P.E., Senior Project Manager, Sanborn, Head & Associates, Inc.
With each lateral expansion of a landfill, a corresponding gas collection and conveyance system (GCCS) is typically permitted and constructed. The system for the new cell relies on the GCCS that was installed in the previous cell. Unfortunately, systems typically aren't installed exactly as designed and as-built surveys are sometimes overlooked or misplaced. Even when systems are installed as designed, facility operators may not have the sophisticated survey equipment needed to verify that collectors and pipes are installed at the correct elevations and slopes, condensate traps have sufficient elevation difference to overcome the vacuum provided by the blowers, and so on.
A landfill "master plan" provides a progressive filling and GCCS development plan that allows a landfill manager to think through the development of their landfill, identify issues with access and stormwater management, and most importantly, plan for the incremental expansion of the GCCS.
This SWANA Webinar reviews the GCCS design, layout, construction, and post-construction techniques used at the Juniper Ridge Landfill in Old Town, Maine, to expand and maintain their GCCS in accordance with the landfill's master plan. Over the past several years, procedures at the Juniper Ridge Landfill have evolved from frequent straying from the master plan, requiring the expense and frustration associated with repeated redesigns, to a well-oiled machine that produces well-installed, effective, LFG collection infrastructure.
Construction drawings with horizontal and vertical coordinates are provided electronically to operations staff. Infrastructure is installed and surveyed using the facility's GPS equipment, and as-built information is returned to the designer and integrated into the facility as-built drawings. With each precisely installed GCCS expansion, subsequent GCCS expansions can be designed and constructed more efficiently. The GCCS development at the Juniper Ridge Landfill is a model for facilities everywhere to follow.
The master plan is a powerful tool, but more often than not, facilities don't have one, or they stray from the master plan. Once you stray from the master plan, it's hard to get back on track.
Using computer aided design (CAD) and global positioning system (GPS) technology, GCCS designers and facility operators have the tools needed to simplify GCCS construction, keep construction on track with the master plan, maintain an as-built drawing database, and allow systems to perform better and last longer.