Give the landfill design consideration in details.
Answers
Landfill Design
The Simi Valley Landfill is designed to dispose of non-hazardous solid wastes. All disposal areas are constructed with a composite liner system and leachate collection system. The leachate collection system gathers wastewater that is generated by the overlying municipal solid waste.
The primary liner consists of a synthetic 60-mil-thick high-density polyethylene (HDPE). Under the primary liner is 2-ft of low permeability soil, or equivalent material. Together, these two components of the liner system prevent contaminants from penetrating the surrounding environment.
The leachate collection system consists of synthetic drainage material called geocomposite. The geocomposite is comprised of high-density polyethylene channels manufactured to rapidly convey liquids such as leachate. It is considered to be an acceptable equivalent to one-foot of granular drainage material. A non-woven filter geotextile is attached to prevent infiltration of soil that will clog the geocomposite. Base grades are sloped to a central collection sump which is designed for subsequent removal of leachate to an onsite storage tank.
All areas of the liner system are protected by a 1.5 ft thick soil layer. The soil layer prevents the overlying waste from penetrating and damaging the liner system.
Open refuse is minimized by the construction of daily work areas sized to handle only each day's volume, and subsequently covered and sealed with soil at the end of each day.
What is a landfill?
A landfill is a carefully designed structure built into or on top of the ground, in which trash is separated from the area around it.
Why are landfills important?
Landfills contain garbage and serve to prevent contamination between the waste and the surrounding environment, especially groundwater.
What happens to the trash in a landfill?
Landfills are not designed to break down trash, merely to bury it. That’s because they contain minimal amounts of oxygen and moisture, which prevents trash from breaking down rapidly. So landfills are carefully filled, monitored and maintained while they are active and for up to 30 years after they are closed.
What is the difference between a dump and a landfill?
A dump is an open hole in the ground where trash is buried and where animals often swarm. Dumps offer no environmental protection and are not regulated.
A landfill is a carefully designed and monitored structure that isolates trash from the surrounding environment (e.g., groundwater, air, rain). This isolation is accomplished with the use of a bottom liner and daily covering of soil.