What is a common requirement for landfills to reduce environmental impact?

The correct response highlights that all listed practices are common requirements for landfills to mitigate their environmental impact.

Active monitoring systems are essential as they allow landfill operators to detect and address issues such as leachate leakage, gas emissions, and other potential environmental hazards. Continuous monitoring ensures compliance with regulations and aids in minimizing risks to surrounding ecosystems and communities.

Maintenance of cover systems is crucial as well. Cover systems help to contain waste, manage odours, and reduce the infiltration of rainwater, which can lead to leachate formation. A well-maintained cover system also minimizes pest attraction and helps manage potential health risks.

Placement of waste in layers is another vital practice that contributes to effective landfill operations. This approach aids in compaction, which maximizes space within the landfill, and it can assist in controlling methane production by managing the decomposition process through layers of cover material.

By combining these practices—active monitoring, maintaining cover systems, and layering waste—landfills can significantly reduce their environmental footprint and enhance waste management strategies. Therefore, all these requirements work together to ensure the sustainable operation of landfills.