Principles and Practice of Engineering (PE) Environmental Practice Exam 2025 – The All-in-One Guide to Master Your PE Exam!

The purpose of a landfill's flexible membrane liners is to prevent leachate migration. Leachate is the liquid that percolates through waste material and can carry harmful substances into the surrounding environment, potentially contaminating groundwater and soil. The flexible membrane liner acts as a barrier, specifically designed to contain leachate within the landfill, thereby protecting the surrounding environment from potential contamination.

These liners are crafted from durable materials that ensure a low permeability, which is critical in environmental protection efforts. By preventing the escape of potentially toxic leachate, the membrane liners play a vital role in maintaining the integrity of both the landfill and the surrounding ecosystems. This containment is essential in regulatory compliance and in minimizing the environmental impact of landfills.

The other options, while related to landfill design and management, do not specifically address the primary role of flexible membrane liners in leachate control. Enhanced air circulation, increased waste compaction, and drainage are important aspects of landfill operation but are not the primary function of flexible membrane liners.