The Engineering Behind Landfills

People view landfills as one giant trash can. Landfills are a lot more complicated than this simple view point. Landfills are used to contain garbage. The important aspect of landfills is that they keep the garbage separate from the environment such as groundwater. Because landfills contain little to no oxygen or moisture, they are not meant to break down the garbage but simply to bury the trash. As a result, landfills need to be thoughtfully filled, monitored, and analyzed while they are active and many years after they are closed. 

There are many parts to a landfill. A landfill has seven total parts to it. The first one is the bottom liner. The objective of the bottom liner is to prevent the trash from mixing with soil or groundwater. Once waste has been approved, it is sent to the next part known as cells. Cells collect the disposal of waste and then compact and tear apart the trash using machinery. The leachate collection system, also known as a sump, is a low point at the bottom of the landfill. The purpose of the sump is to collect liquids so that it can be drained out of the landfill. Engineers build a storm water drainage system into the landfills for protection against storms and other weather conditions. Landfills produce a lot of methane gas that is unhealthy for the environment. To combat this as much as possible, a methane collection system is built to gather the methane gas which can sometimes be used as a source of energy. Each cell needs a cover. Covers can be made from soil, foam, or other materials. When a landfill is completely full or done being used a permanent cover must be placed on all the cells. Groundwater monitoring stations are put in place to test the quality of groundwater and make sure other parts of the landfill are doing their job. All of these parts, come together to help collect garbage and keep the trash away from the surrounding environment.

One of the largest landfills is in the ocean. It is known as the Great Pacific Garbage Patch. It is located in the middle of the Pacific Ocean. It is about the size of Texas. The largest patch is located between Hawaii and California.

Landfills are a not simple to understand. A lot of science goes into the construction of a landfill. The important factor about landfills is that it is not a black hole. The earth has limited space and we need to do our part to ensure we make it as sustainable as possible.