Landfill Runoff Issues

Landfill runoff is water from precipitation that passes over or accumulates in a landfill site and is later pumped out of the site, usually into a body of water or the local storm drain. While landfill regulation is very strict with regard to the disposal of solid waste, regulation regarding runoff tends to be more lax, left up to state authorities in the United States. Public health and environmental experts, however, have identified a number of serious risks and issues with landfill runoff.

Mercury and Persistance

• The chemicals found in landfill runoff can be as varied as the contents of a landfill -- everything from common household waste to hazardous wastes like mercury from electronics and medical supplies. Landfill runoff is usually pumped off the landfill site, filtering out most of the large pieces of waste, but still leaving potentially high concentrations of dangerous pathogens and chemicals found in solid waste. In the case of mercury, the U.S. EPA considers landfill runoff a leading source of the chemical, a deadly toxin that can cause kidney damage, neurological disorders and can even be deadly in humans. Mercury, moreover, cannot be digested by most organisms, leaving it to accumulate in tissues and build-up over years (bio-accumulate).

Styrene and Exposure Amounts

• Runoff is of particular concern during storm surges, when greater precipitation increases the likelihood and amount of water collecting in a landfill site. In order to deal with these unforeseen volumes of water, landfills usually evacuate the runoff waters directly into the local storm drain or in a nearby body of water, meaning that, unlike the gradual process of leaching, landfill runoff tends to be a drastic event involving large volumes of contaminants. Even relatively harmless chemicals can be very problematic in the large amounts found in storm surge runoff. Styrene, a chemical generated by the production or decomposition of rubber and plastics, is one such example. Only mildly toxic in small amounts, causing skin, eye and upper respiratory tract irritation, chronic or highly acute exposures to styrene can cause severe gastrointestinal disorders, central nervous system symptoms and can potentially increase the risk of cancer.

Benzene and Instability

• Benzene, an organic pollutant found in crude oil and petroleum products, is one of the most concerning chemicals found in landfill runoff. Even in small amounts, benzene can cause serious irritation and inflammation of organic tissues and mucus membranes. In large or sustained doses, benzene can cause serious circulatory conditions, like decreased blood pressure or anemia, and is a known carcinogen. In addition, benzene is a highly unstable compound and evaporates at room temperature, contaminating the air around landfill runoff. Although landfill runoff tends to principally contaminate water resources, the presence of chemicals like benzene that quickly and easily pass into the air and soil makes the risks of landfill runoff broader. The diversity of contaminants present in landfill runoff creates a general risk of soil, air and water pollution, posing a large potential risk to both wildlife and human populations.

PCBs and Historical Pollutants

• One of the particular risks of landfill contamination is the age of many of the pollutants found in a landfill. Materials like polychlorinated biphenyls (PCBs), banned in the United States in 1979 and internationally by the Stockholm Convention of 2001, can still be found in materials produced and land-filled before the pollutant was strictly regulated. Landfills are something of a museum of human waste and, sadly, much of the historical collection of waste contains materials now known to be extremely dangerous and have since been banned. Landfill runoff, however, can continue to provide new sources of old pollutants. In the case of PCBs, the organic compounds are extremely toxic, linked to everything from central nervous system damage to reproductive disorders and cancer.