What criteria must be met for encapsulation of hazardous materials?

The correct choice focuses on the necessity for employing methods to contain and control hazardous substances, which is a fundamental requirement in the management of hazardous materials. Encapsulation serves as a critical strategy to ensure that these materials are isolated from the environment in a way that prevents them from leaching into soil, groundwater, or surface water, thus safeguarding public health and the ecosystem.

This strategy involves the use of physical barriers such as barriers or containment structures that can prevent the escape of hazardous materials and limit exposure. Additionally, it often encompasses the use of engineered solutions that monitor and maintain the site over time, ensuring that any potential risks are effectively managed.

When considering the other options, absorption of chemicals into the ground does not protect the environment or population; instead, it may worsen pollution. Simple disposal into landfills can lead to contamination of land and water resources, undermining efforts to manage hazardous materials responsibly. Completely removing materials from the site might seem favorable but can be impractical or pose new risks during transport, making containment a more viable and safer approach in many scenarios.