The primary goal of landfill closure is to prevent the release of contaminants, such as leachate and landfill gas, into the environment. This is achieved through a combination of engineering and institutional controls.

All of the above are common methods of landfill closure. Capping involves placing a layer of impermeable material over the landfill to prevent the infiltration of water. Leachate collection and treatment involves collecting and treating the liquid that seeps from the landfill. Gas collection and flaring involves collecting and burning the methane gas that is produced by the decomposition of organic waste in the landfill.

The purpose of post-closure care for landfills is to monitor the landfill for potential problems, maintain the integrity of the landfill cap, and prevent the release of contaminants into the environment.

Post-closure care for landfills typically lasts in perpetuity, meaning that it continues indefinitely. This is because the potential for contamination from a landfill can persist for many years after it is closed.

Vegetation plays an important role in landfill closure and post-closure care. It helps to stabilize the landfill cap, reduce erosion, and improve the appearance of the landfill.

Leachate is liquid that seeps from a landfill. It can contain a variety of contaminants, including heavy metals, organic compounds, and nutrients. Leachate is collected and treated before being discharged to prevent contamination of groundwater.

The purpose of a landfill gas collection system is to collect and flare methane gas, reduce greenhouse gas emissions, and prevent explosions.

Financial assurance is a mechanism to ensure that funds are available for landfill closure and post-closure care. It is required by regulations in many jurisdictions and can be provided through a variety of mechanisms, such as bonds, letters of credit, and trust funds.

Community involvement in landfill closure and post-closure care is important to ensure that the community's concerns are addressed, build trust between the community and the landfill operator, and promote transparency and accountability.

Landfill closure and post-closure care can be challenging due to a variety of factors, including technical challenges, such as managing leachate and landfill gas, financial challenges, such as securing funding for closure and post-closure care, and regulatory challenges, such as complying with complex regulations.

Best practices for landfill closure and post-closure care include using a multi-barrier approach to prevent contamination, implementing a comprehensive monitoring program, and engaging the community in the closure and post-closure care process.

Emerging technologies for landfill closure and post-closure care include bioreactor landfills, phytoremediation, and geosynthetic clay liners.

Trends in landfill closure and post-closure care include an increasing focus on sustainability, use of innovative technologies, and greater community involvement.

Challenges facing the landfill industry in terms of closure and post-closure care include increasing regulatory requirements, rising costs of closure and post-closure care, and public opposition to landfills.