Landfill Engineer

Imagine you are crouching over a smelly pit of garbage, with seagulls circling the trash and bulldozers moving piles behind you. You are a landfill engineer and you are here talking to the city's sanitation department about a new project to deal with the problem of growing garbage production and too little space to put it. The city isn't interested in building another dump, which is just an open hole, but instead has asked you to design a landfill. It will be your job to design a landfill facility at this location that can be isolated from the surrounding air, soil, and groundwater, thereby protecting the environment while holding the city's trash for decades to come.

As a landfill engineer, you must factor a number of considerations into your design. You have already been involved in the project for more than a year, working with hydrogeologists, city planners, biologists, and other scientists and engineers, conducting an environmental assessment of the proposed site. Once the necessary studies have been completed and proper approvals granted, you and your team decide what kind of liner system to use to keep waste from coming into contact with the soil and to keep leachate, liquids that have come in contact with the waste, from seeping into the groundwater.

In this case, you will use a double liner system: one-liner layer will be compacted clay and the other will be a plastic-like geosynthetic liner. Above the liners, you will build a leachate collection system that will minimize the leachate levels within the waste by draining or pumping it out of the site for treatment. Next, you will design a storm water drainage system to keep rain and other moisture out of the landfill to reduce the amount of leachate generated. The storm water drainage system will consist of a system of ditches that will collect and drain water away from the site. You will also have to consider whether to collect landfill gases produced by the breakdown of garbage. The landfill will produce carbon dioxide and methane, both of which are greenhouse gases.

On top of that, methane is explosive, so safeguards must be put in place to minimize the potential for explosions or landfill fires. You might build a flare to burn off the methane or collect it for use in generating power for the city. Finally, you must also consider public health concerns and operational constraints in your design, including noise, dust, odour, litter, traffic, and visual impacts. It's a complicated process, but your design will produce a safe and effective way of storing the city's waste.