Waste Management

Concept: In waste management, leachate refers to the contaminated liquid that forms when water (often rainwater) passes through waste materials in landfills. As the water moves through the waste, it dissolves and carries various chemical substances, organic matter, and pollutants. Leachate may contain:

• Organic compounds
• Heavy metals
• Toxic chemicals
• Microorganisms

Because of these dissolved contaminants, leachate can pose serious risks to soil and groundwater quality if it is not properly managed.
Step 1: Understanding how leachate forms.
When precipitation or surface water infiltrates a landfill, it percolates through the layers of waste and dissolves soluble materials. This process produces a polluted liquid known as leachate.
Step 2: Environmental significance.
Leachate is a major environmental concern in landfill management because it can contaminate nearby groundwater and surface water bodies if not properly collected and treated.
Step 3: Eliminating other options.

• Gas released from decomposing waste refers to landfill gas (mainly methane and carbon dioxide).
• Solid residue after incineration is known as ash.
• Recycled organic compost material refers to compost.

Therefore, leachate is the liquid that drains through waste and carries dissolved contaminants.