Groundwater protection and monitoring are integral parts of construction and operations. Future areas to be developed will use a composite liner system consisting of compacted clay soil and a high-density polyethylene plastic liner.
Groundwater monitoring wells located around the perimeter of the site are sampled and analyzed on a scheduled basis by groundwater monitoring technicians. The groundwater quality data are evaluated by independent professionals and submitted to TCEQ for the agency's review.
A leachate collection and extraction system is placed over the liner system. (Leachate is the liquid generated by rainfall and the natural decomposition of waste.) Leachate is collected in sumps and automatically pumped to an onsite holding tank for storage. The stored leachate is disposed of under state regulations.
To manage storm water runoff, the Hillside Landfill uses sedimentation ponds, silt fences, rock dams, erosion control mats, and other best management practices under the Texas Pollution Discharge Elimination System (TPDES) as well as the site's municipal solid waste permit.
The landfill employs an active collection and recovery system to control landfill gas, which is formed by the decomposition of deposited solid waste. Landfill gas extraction wells installed to remove the gas are connected to a central, high-temperature flare that safely destroys the collected gas.
The TCEQ inspects the facility on a regular basis. These inspections include a review of the facility's operational and record-keeping requirements.