What is the most common way to dispose of hazardous waste in the United States? What are the two dangers of this method of disposal?

The most common way to dispose of hazardous waste in the United States is land-filling. Although land-filling is a highly regulated disposal method, environmental problems stemming from chemical contaminants still persist, threatening the health and safety of the larger public.

Two of the problems of land-filling are hydrological and atmospheric in character. The atmospheric effects largely stem from the production of methane gas. Methane is considered to be twenty times more effective in trapping solar heat than carbon dioxide and can further exacerbate the greenhouse effect. Furthermore, landfills also introduce other toxic gases, dust, and chemical contaminants into the atmosphere, and this contributes to the deterioration of air quality in and around landfills.

The second danger of landfills is hydrological in character: despite EPA (Environmental Protection Agency) regulations requiring landfills to include clay liners, groundwater barriers, and monitoring wells on location, toxic chemicals still leach into groundwater. These leachates pollute a wide variety of drinking water sources that the general public relies on. Wildlife in surrounding areas are also endangered by these drinking water sources, as the presence of TCE (trichloroethylene), a carcinogen, is a commonly reported substance in contaminated groundwater. As an example of its toxicity, just four drops in a twenty thousand gallon pool can prove fatal to humans and animals. TCE is mostly removed through evaporation in the atmosphere; however, when present in groundwater, evaporation becomes nearly impossible.