Landfill Cap
The landfill Cap which is the sealing layer over a landfill is usually done to:* Reduce exposure on the surface of the waste facility.
* Inhibit vertical infiltration of water into wastes that would create contaminated leachate.
* Manage gas emissions from underlying garbage.
* Produce a ground surface so as to maintain foliage and/or exist for additional purposes.
The plan of landfill cap depends on the environment and the objectives of the landfill cap. A landfill Cap can range from a one-layer system of vegetated soil to a multifaceted multi-layer technique of soils and geosynthetics. In general, less involved systems are necessary in arid climates and more complex systems are required in wet weather climates. The material used in the building of a landfill cap includes low-permeability and high-permeability soils and geosynthetics. The low-permeability materials redirect water and preclude its path into the trash. The high permeability materials move water away that percolates into the landfill cap.
The most crucial components of a landfill cap are the barrier layer and the drainage layer. The barrier layer can be low-permeability soil (clay) and/or geosynthetic clay liners (GCLs) or stabilized local soils. Often times the local soil is disregarded as usable simply due to the fact that it will not meet the permeability requirements. SCI is able to take the "un-suitable" soils and modify them to exceed the requirements for a landfill cap. SCI has been enhancing soils to meet permeability requirements for years. A typical soil can be enhanced to exceed the 1 x 10-6 cm/sec requirements of the average landfill cap.
For more information on our programs please download the following document regarding our landfill products and refer also to our section on permeability reduction.
SCI landfill cap information PDF
Articles of interest
How to construct a Landfill Cap
Videos about Landfills and the landfill cap
