Answer:
Bottom liner system
Explanation:
Bottom liner system is the component of the MSW landfill that tests and ensures that groundwater is not contaminated.
This is evident in the fact that the Bottom liner system helps to remove wastés and ensuing léachàté from groundwater. Therefore, it ensures that the trash does not come in contact with the outside soil, most specifically the groundwater.
Hence, in this case, the correct answer is "BOTTOM LINER SYSTEM"
