Once we bring the waste elevation to permitted final grade, we place a final cover over the top to entomb the waste. This cover keeps liquids out and gases in and ensures the protection of the environment. The cap includes 18 inches of soil or clay, a low-density polyethylene liner, a geocomposite drainage layer, and 18 inches of topsoil and vegetation.
The system to collect liquid within the landfill includes perforated pipes placed above the liner system to collect any liquid that has touched waste. The liquid is then processed through our state-of-the-art Membrane Biological Reactor pretreatment plant and, once pretreated, discharges to a wastewater treatment plant for final processing.
Rainwater that does not touch any waste must also be managed appropriately. Stormwater runoff is collected and contained in permitted detention ponds, allowing soil particles to settle before the water is discharged. Visual inspections are conducted quarterly, and analysis is done annually. Ponds are routinely inspected during monthly TDEC site visits.
Groundwater monitoring wells around the site perimeter ensure that landfill operations are not impacting groundwater. Five wells and two springs are sampled semi-annually, and results are submitted to the state.
Steps are taken to control dust and litter. Periodic watering of access roads prevents dust from rising when trucks travel in and out of the landfill. A sweeper is used to keep nearby roadways clean. Litter is minimized by limiting the size of the active disposal area, applying daily cover and using fencing on windy days to catch blowing materials. Any litter that blows off-site is collected by landfill personnel.
Landfill gas and odors are controlled with good operational programs, such as waste compaction, applying daily cover per our permit, and the use of an effective landfill gas collection and control system. Landfill personnel conduct routine odor inspections to minimize odor and deal with odor as quickly as possible once detected. The landfill gas system is upgraded and expanded with regular frequency as the landfill grows. We install gas collection infrastructure much earlier than required by federal and state regulation. Additionally, we use a misting/odor-neutralization system to assist with odor control.