Management and Rehabilitation of dump sites

• Landfill sites have the potential to pollute the surrounding environment (soil, water, air)
• It is imperative that landfill sites are developed and managed effectively to prevent pollution
• Waste is received daily and compacted to reduce the volume
• At the end of each day, the waste is covered with soil in order to avoid further contact with air, keeping it dry and keeping pests away
• Landfill sites normally accept harmless (general) waste only; hazardous waste is taken to special sites that are equipped to handle it
• Rain water that filters through the landfill accumulates in pipes at the base of the landfill
• This leached water is tested regularly. If the levels of chemical becomes unacceptably high, it is treated to prevent contamination
• Toxins are rendered harmless through chemical reactions
• As waste decomposes, methane gas is released
• Methane gas is extracted and piped away via the pipes embedded in the fill and burned or used as an energy source
• The base of a well-developed landfill site consists of a clay layer lined with plastic to prevent contamination
• Groundwater in the vicinity of the landfill site is monitored to ensure that there is no leaking of leached water, which could cause pollution.
• When a landfill site is full, it is covered with a plastic cover and then with soil
• Plants are planted to bind the soil and this prevent wind and water erosion. This is a closed landfill site
• Groundwater and gas emissions are still regularly monitored at a closed landfill site to ensure that it remains stable and does not pollute the environment
• A less invasive, cost effective method of rehabilitating a landfill to prevent or counteract pollution is phytoremediation
• Phytoremediation is the use of green plants to remove toxic substances from the soil, water, sediment and air, or to render them harmless
• Specially selected or genetically modified plants are used for phytoremediation
• The plants cultivated in the contaminated area absorb and store toxins and convert them into less harmful substances. (e.g gases that are released into the air)
• After some time, the plants are removed and replaced to prevent the toxins accumulating in food chains
• Rehabilitated landfill sites are often developed as recreation areas, such as sports fields, golf courses or parks