Landfills are specially constructed sites designed so waste can be safely and effectively disposed. North Carolina has the following types of landfills: municipal solid waste, industrial waste, construction and demolition, land clearing and inert debris. Municipal solid waste landfills accept waste commonly known as "garbage," among other items. They are not allowed to take liquids or hazardous waste. In 1993, North Carolina increased the standards for its landfills and closed all unlined MSWLF landfills by 1998. Now, only lined municipal solid waste landfills accept household waste. Here are some basic facts about MSW landfills. Why Have A Landfill At All? Recycling, reducing waste and reusing items can greatly reduce the amount of waste created, but people keep generating more and more. Composting can take care of some materials, but the remaining waste items need to be disposed of safely. Before waste was regulated, people routinely dumped trash into lakes, streams and ravines. This practice caused human sickness nearby and downstream. Proper waste disposal protects human health and the environment. What’s "municipal solid waste?" Garbage, household hazardous waste and a host of other items thrown out by people and corporations are called "municipal waste." MSW landfills are not allowed to take hazardous waste, liquids, tires or large appliances, which are also called "white goods." Don’t Landfills Breed Disease, Smell and Attract Rodents? If properly managed, modern landfills do none of the above. State regulations require waste to be covered daily with earth or an alternate cover. This daily cover deters rodents and greatly reduces the smell associated with natural decomposition. All landfills monitor methane levels and take steps to avoid hazardous buildups of this gas. Some landfills burn the methane produced by decomposing waste to produce energy. This keeps the methane, which is a greenhouse gas, from entering earth’s atmosphere. Methane produces half the energy of natural gas and it is a renewable energy source. North Carolina’s methane program is one of the best in the nation. Why Are MSW Landfills Lined? EPA found that most municipal landfills hold some type of polluting material that can contaminate groundwater. Many people drink groundwater (where well water comes from) so contamination can pose a health threat and harm the environment. Household hazardous waste (pesticides, cleaners, batteries, etc.), electronics (lead) and a number of other items put into MSW landfills could contaminate groundwater if the liners did not stop the contaminants. How Do Liners Prevent Groundwater Contamination? Imagine you are a raindrop that landed atop a landfill. After landing on a piece of waste, you trickle down through more waste, picking up contaminants along the way. Leachate is the term used to describe water that has passed through waste at a landfill. Unless a liner stops it, leachate can seep down through the soil until it joins and contaminates the local groundwater. Liners stop leachate before it can seep into the earth. Leachate collection pipes gather this contaminated water and send it to a central location. Leachate can be treated onsite or delivered to a wastewater treatment plant for treatment. North Carolina uses composite liners, which mean more than one material is used. First, a layer of soil is placed where the landfill will hold waste. Clay or some other earth that does not allow water to pass through easily is used for this layer. Next, a high density plastic liner is placed on top of the soil layer. A highly permeable layer of soil (that allows water to pass through easily) like sand or gravel is placed on top of the liner. Then, the leachate collection pipes are placed on top of the gravel. Who Picks Landfill Locations? Public Landfills The people in communities, cities or towns work with their elected leaders to select a site. Property ownership and local zoning considerations play an important role. Public meetings give the residents a chance to weigh in on the decision as well. Communities also get to choose who runs the landfill. Some choose to run their own facility (public) and other communities hire private companies to do this for them (private). Private Landfills Waste companies may select a site and approach the local government for its approval. As with the public landfills, the residents have a chance to comment on the decision. Once a site is selected, an application for a landfill permit is sent to the state’s solid waste section. The staff examine site suitability from a different perspective. Soil type, groundwater levels, and whether or not the site is in a floodplain are some things the state looks for, but they also check the site for historic or cultural value and endangered species. Since every site is a little different, the staff usually ask for additional information after they receive a permit. The state also holds public meetings so residents can comment on proposed landfills. What Happens When Landfills Close? Before a landfill permit is granted, the state requires landfill owners to prove they can afford to maintain, close, monitor and take corrective actions should groundwater contamination or methane buildups occur. Once the landfill is full, it is covered with another composite layer. This keeps rainwater from entering the landfill and greatly reduces the amount of leachate created. Systems that check the air, groundwater and surface water (lakes and streams) for contamination are installed. Then, the systems are maintained for 30 years.

NCDENR -  Division of Waste Management  401 Oberlin Road - Suite 150, Raleigh, NC 27605   (919) 508-8400 E-mail Us