Hobbies And Interests
Landfills
Since 1991, the Environmental Protection Agency has required that landfills, especially those designated for potentially hazardous waste, contain liners or other protections designed to prevent leakage. Unfortunately, older landfills often used no such protections, allowing the waste built up over decades to leak toxins into the soil. Even the liners in modern landfills are vulnerable to damage over time due to shifting garbage or gas buildup, making any landfill a potential toxic threat to waterways in the region.
Leachate
Landfill leakage occurs when water passes through the layers of trash in a landfill, picking up contaminants along the way. The resulting liquid, called leachate, may sit for years at the bottom of the landfill until a breach in the liner allows it to escape into the environment. While much of the attention paid to landfill pollution focuses on toxic landfills, even normal garbage dumps can produce leachate containing bacteria, viruses, and high levels of ammonia with the potential to wipe out aquatic species and choke off the oxygen supply of rivers and streams. Many older landfills have installed drainage systems in an attempt to siphon off this dangerous waste, but these pipes are prone to clogging and breakage and represent only a partial solution.
Other Contaminants
Leachate becomes much more dangerous when it involves toxic wastes. Many different consumer goods involve heavy metals of one sort or another, from the mercury in compact fluorescent light bulbs to cadmium and other metals in electronic devices. If leachate picks up these substances, it can spread them into the water table, potentially raising the contaminant levels high enough to affect humans and cause neurological or genetic damage. In addition, carcinogens like trichloroethylene are common in landfill leachate, and can cause health problems at extremely low concentrations.
The Water Table
One of the biggest concerns about landfills and water pollution is the long-term nature of the problem. The water that passes into and through underground aquifers can take years or even decades to cycle through the water table before it returns to the surface. This means that contaminated water may affect a region̵7;s water table for an extended period, and contaminants that leak into the system now may not be evident until years after the leak occurs. As more and more contaminated water enters the system, it increases the potential threat to future generations.