The key environmental problem we face as a result of landfills is groundwater pollution from leachates (the liquid that drains or 'leaches' from a landfill). Although they intended to protect human beings from toxins, due to natural deterioration the protective barriers only delay the inevitable. When a new municipal landfill is proposed, advocates of the project always emphasize that “no hazardous wastes will enter the landfill”. However several studies have shown that even though municipal landfills may not legally receive “hazardous” wastes, the leachate they produce is as dangerous as leachate from hazardous waste landfills.
The major issue caused with landfill leachates is the leakage of a large number of toxins into fresh water waterways, which ultimately end up in our homes as drinking water or water for everyday use. Since landfills are most often located in and around large bodies of fresh water or in swamps, the pollution often goes undetected. The compounds submerge to the ground, to the ground water, and inevitably to our dinner tables. The pollution is also severely harmful to animal and plant life.
Groundwater contamination may result from leakage of very small amounts of leachate. TCE is a carcinogen typically found in landfill leachate. It would take less than 4 drops of TCE mixed with the water in an average swimming pool (20,000 gallons) to render the water undrinkable. Some surveys conducted have shown that 82% of the landfills have leaks and up to 41% of the landfills had a leak area of more than one square foot. EPA sponsored research shows that burying household garbage in the ground poisoned the ground water. The EPA has stressed that, even with the double liner landfills, the probability of leaking is very high.