Pioneer Crossing Temporary Capping
Pioneer Crossing Landfill has completed 41.5-acres of temporary capping in 2021, primarily at the top of the landfill and upper southeastern slopes.
Landfill slopes that have not reached final grades and will receive waste in the distant future have maintenance challenges. Remedial work is required routinely to prevent negative outcomes of exposed slopes and environmental elements continually affect surface conditions. A geomembrane temporary cap addresses these maintenance issues and provides a real benefit to the operation as well as the surrounding environment and community.
The following are some of the operational and environmental benefits of the temp cap:
• Less leachate generation from the capped area (56 million less gallons of rainfall will need to be stored, transported, and treated at the POTW over the 41.5 acre cap area annually).
• Barrier to control landfill odors
• No more leachate seeps
• No soil washouts
• Can easily place gas lines above the geomembrane
Temporary caps potentially reduce routine maintenance work, leaving operation staff available for other tasks. The cap provides peace of mind that slopes remain in compliance and regulators don’t need to report non-compliance conditions of exposed slopes during inspection events. The possibility of odors to the surrounding community following storm events is less likely. The landfill gas capture rate increases which reduces the possibility of fugitive methane emissions released to the atmosphere.
Also, ballasting the geomembrane and using the right materials for ballasting is important since there is no soil cover system above the temporary cap. Pioneer uses a ballast system utilizing bags filled with rock and tied together with UV resistant rope tied at an approximate 10-ft x 10-ft grid. This is commonly used by landfills with temporary caps to prevent wind from damaging the cap system or aiding in gas pushing up against the cap. Pioneer Crossing also utilizes gas wells installed throughout the temp cap system to control these issues.