- COVER VEGETATION
- As portions of the landfill are completed,native grasses and shrubs are plantedand the areas are maintained as openspaces. The vegetation is visually pleasing and prevents erosion of the underlying soils.
- Top Soil
- Helps to support and maintain the growth of vegetation by retaining moisture and providing nutrients.
- PROTECTIVE COVER SOIL
- Protects the landfill cap system and provides additional moisture retention to help support the cover vegetation.
- Drainage Layer
- A laryer of sand or gravel or a thick plastic mesh called a geonet drains excess precipitation from the protective cover soil to enhance stability&help prevent infiltration of water through the landfill cap system. A geotextile fabric, similar in appearance to felt, amy be located on top of the drainage layer to provide separation of solid particles from liquid. This prevents clogging of the drainage layer.
- Geomembrane
- A thick plastic layer forms a cap that prevents excess precipitation from entering the landfill and forming leachate. This layer also helps to prevent the escape of landfill gas, thereby reducing odors.
- Compacted Clay
- Is placed over the waste to form a cap when the landfill reaches the permitted height. This layer prevents excess precipitation from entering the landfill&forming leachate&helps to prevent the escape of landfill gas, thereby reducing odors.
- Daily Cover
- At the end of each working period, waste is covered with six to twelve inches of soil or other approved material. Daily cover reduces odors, keeps litter from scattering and helps deter scavengers.
- Waste
- As waste arrives, it is compacted in layers within a small area to reduce the volume consumed within the landfill. This practice also helps to reduce odors, keeps litter from scattering and deters scavengers.
- Leachate Collection Layer
- A layer of sand or gravel or a thick plastic mesh called a geonet collects leachate and allows it to drain by gravity to the leachate collection pipe system.
- Filter Geotextile
- A geotextile fabric, similar in appearance to felt, may be located on top of the leachate collection pipe system to provide separation of solid particles from liquid. This prevents clogging of the pipe system.
- Leachate Collection Pipe System
- Perforated pipes, surrounded by a bed of gravel, transport collected leachate to specially designed low points called sumps. Pumps, located within the sumps, automatically remove the leachate management facilities for treatment or another proper method of disposal.
- Geomembrane
- A thick plastic layer forms a liner that prevents leachate from leaving the landfill&entering the environment. This geomembrane in typically constructed of a special type or HDPE. HDPE is tough, impermeable and extremely resistant to attack by the compounds that might be in the leachate. This layer also helps to prevent the escape of landfill gas.
- Compacted Clay
- Is located directly below the geomembrane and forms an additional barrier to prevent leachate from leaving the landfill and entering the envirnment. This layer also helps to prevent the escape to landfill gas.
- Prepared Subgrade
- The native soils beneath the landfill are prepared as needed prior to beginning landfill construction.