What is a Sanitary Landfill?
A sanitary landfill is a waste disposal facility where layers of compacted garbage are covered with layers of earth. When the facility reaches capacity, a cap is applied to close the site. Sanitary landfills are one of the most popular methods for disposing of waste, although they have some distinct drawbacks. This technique for waste management was developed in the 1930s, in response to growing pressures created by a growing population.
The site for a sanitary landfill needs to be selected with care. Ideally, it should be located above the water table, in an area which is not geologically active. Other considerations may have to do with aesthetics; because landfills can be odorous at times, they are generally not located in immediate proximity to residential communities. The land also must be inexpensive to make the cost of operating the landfill worth it, and it must be accessible to roads so that garbage can be easily delivered.
Preparation of the site begins with establishing liners. It is common to start with a compacted clay base, followed by synthetic liners, with pipelines to trap and carry materials which leach from the landfill, including fluids and gases. Then, deposition of garbage can begin. At any given time, the landfill has a small exposed working area, with the rest of the site being covered. Maintaining a working area at a sanitary landfill minimizes pests such as rodents and insects. This can be costly, and at landfills that lack funds, exposed garbage can create a serious health hazard.
One of the biggest problems with a sanitary landfill is the environmental hazard. As materials inside the layers of compacted garbage break down, they generate gases, including methane, which are flammable. Some landfills simply vent these gases, while others actively trap them, using them as fuel. Landfills also generate leachates, materials which could damage the natural environment if they end up in the water table, making control of leaching critical.
Once a sanitary landfill is closed, the work does not stop. The site needs to be maintained and monitored. Often, landfills are reclaimed once they are full, with the area on top being used to make sports fields, parks, office parks, and so forth. These uses can only be approved when it is clear that the site has been well secured, and when there are systems in place to handle methane gas and other materials which may leach or vent from the landfill.
@allenJo - I have a great idea for future waste management projects.
Send it all into outer space. The universe is very, very big and no one will complain about its effect on our environment. The stuff can be packaged, compacted and sealed just as it is now, and we can have scheduled launches of thousands of mini rockets that propel the stuff into space.
Or better yet, send it aloft on a space elevator. Scientists are already toying with the idea of space elevator technology so it’s quite possible that we could use these machines to hoist away stuff we no longer need on Earth.
I know that it sounds far-fetched, but I don’t know think we should be limited to Earth-bound solutions to these problems.
@hamje32 - That’s a very good question, and the answer is something that waste management folks and environmentalists have been advocating for some time: recycling.
Just think about the different materials that you use each day which can be recycled: plastic, glass, cardboard, steel and paper. Each of these materials, when recycled, will reduce the amount of landfill needed for the real waste and will also reduce energy costs, as it takes energy to dump waste products into landfills.
Each one of us should do our part to recycle everything that we can. I think we still have time before we hit that ceiling where there is no more landfill within which to dump our waste, so we should start recycling now before it's too late. It’s the environmentally smart thing to do.
I’ve always thought that this was the way waste was disposed of, but I have always been bothered by one simple question: what happens when we use up all the land for the sanitary landfill sites? How will we dispose of our waste then?
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