City of St. Peters Central Materials Recovery & Transfer Station

After all the cells in a landfill are used and are full, then we start the process of reclaiming. The idea is that the space on top of the landfill can be used for other purposes. Whatever is the type of landfill, the space on top of it is covered by layers of dirt, to recreate reusable soil. The space is compacted, and it is made sure to be leakproof so that there is no spillage onto the environment.

There are specific laws that regulate the use of landfills after being full and there are specific measures to be taken and to assure compliance. For chemical and garbage that is hazardous, there is a synthetic material that covers it. There is an intricate drainage system. For general garbage, there is a liner system at the bottom area of the cells. The top is covered by topsoil, clay, and synthetic materials.

After this has been done, the space on top of the landfill can support various uses. It can be used to create parks, As of right now, there are more than 1000 parks in the USA that originated from landfill places. The area on top can be used to generate electricity and attach solar panels. This idea is a bit dangerous as the ground below can shift during the years. The area on top of a landfill can even support wildlife habitats, as the layers of clay and dirt that cover the landfill can support and grow trees.

A landfill has very detailed business operations. The waste arrives at the facility in garbage trucks on a section called the Cell. The cell is made of an isolated layer, that prevents any waste or liquids from leaking. In the cell, the waste is sorted out. This unit is enclosed, as the sun and the atmospheric conditions can interact with the waste. Afterward, the garbage is compressed in the smallest volume possible. The cell will accept new waste until it is full. When it reaches, it is further reinforced on top with various materials and dirt. The idea is that the area on top of the cell is reused and to support vegetation.

The important part of this process is the base of the cell. It must prevent liquids and other pollutants from reaching the soil. For this reason, the cell is isolated below with layers of plastic and clay, to create a strong isolation system.

Regarding liquids, they are collected onto a unit called the sump. In this unit, the liquids are processed, and when they are cleaned on pollutants, they are reintroduced onto the environment. Each landfill has groundwater monitoring, which means they collect the quality of groundwater before it reaches the landfill and afterward it exits the landfill. Regarding gasses generated by the waste, they are collected via a special system that ends up reusing the methane generated and the gases to produce energy.

When a landfill reaches the point that all the cells are full, then the landfill stops operations. This doesn’t mean that the owners of the landfill have no responsibilities. They must be monitored for 30 years after closure, and that means assuring the quality of groundwater and preventing leakage to the soil of any type of waste.

There is an interesting type of landfill, inert landfills. This type of landfill receives sand, concrete, and other waste related to construction. This type of waste does not have any biohazards nor decomposes, or it does so very slowly. These types of waste neither produce liquid waste. In this category, we mostly have asphalt, rocks, bricks, yard leaves. In this category, we do not include demolition waste.

Chemical landfills are a variation of sanitary landfills. Chemical landfills are made to secure and hazardous waste. This type of landfill is made on top of a nonporous bedrock. The idea is to create a place that is specialized to reduce the likelihood of hazardous waste reaching the environment. This type of landfill has a pit with a heavily protected bottom that does not allow hazardous materials to reach the soil. These landfills are operated by specialized personnel, and they have strong monitoring systems. To deposit materials in a chemical landfill, it is mandatory to research the local applicable laws and any federal laws that pertain to the type of waste that you intend to dispose of.

There is a lot of waste generated in the USA. In 2018, there were 292 million tons of waste generated. Averagely that is 4.9 Lb. of waste per person. The waste from municipalities is recycled the most. The data says that in 2018, there was a recycling rate of 32%. Some of the waste is reprocessed not other means such as bio-chemical management.The largest categories of waste pertain to paper, food plastics, yard trims, and metals. Food, plastics, and paper make are the main resources for energy production from waste.