What are the basic characteristics of a modern landfill site. List any three and also mention the reasons for their use.

Explanation

### Step-by-Step Solution:

1. **Definition of Modern Landfill Sites**:
Modern landfill sites are designated areas where waste is disposed of in a controlled manner. They are engineered to minimize environmental impact and manage waste effectively.

2. **Characteristic 1: Leachate Management**:
- **Description**: Modern landfills are equipped with a leachate management system, which often includes a lining made of clay or plastic. This lining prevents leachate (the liquid that drains or 'leaches' from a landfill) from contaminating the surrounding soil and groundwater.
- **Reason for Use**: This characteristic is crucial for protecting the environment and preventing contamination of agricultural lands and water supplies, which can pose health risks to humans and wildlife.
...