Final answer:
The purpose of a liner in a sanitary landfill is to prevent the leakage of harmful substances into the environment.
Step-by-step explanation:
The purpose of a liner in a sanitary landfill is to prevent the leakage of harmful substances into the environment. Liners are typically made of a combination of clay, plastic, and other materials that create a barrier between the waste and the underlying soil and groundwater. This helps to protect the environment and prevent contamination of nearby water sources.
For example, a clay liner can absorb and retain liquids, preventing them from seeping into the ground. A plastic liner, on the other hand, acts as a physical barrier, preventing the waste from coming into direct contact with the soil and groundwater. Together, these liners help to ensure that the waste remains contained within the landfill and does not pose a threat to the surrounding ecosystem.