Waste containment systems final cover system

Final cover systems are another important component of waste containment systems used at landfills. While liner systems are installed beneath the waste, final cover (or closure) systems are installed over the completed solid waste mass. For hazardous waste landfills, 40 CFR 264 requires that the landfill be closed with a final cover system that meets certain performance criteria, most notably, that they have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present. U.S. EPA guidance documents517 recommend that final cover systems for hazardous waste landfills consist of at least the following, from top to bottom ... 

Modern landfill facilities, waste lagoons, and leachate ponds use geotextiles in their key designed systems to contain wastes within the facility. The main designed systems are groundwater and gas collection systems underneath the base liner system, typically consisting of a leak detection system and a leachate collection and removal system, and within the final cover system to collect gas and water below and above the barrier system, respectively. 

Figure 19.2 Final cover system of a modem waste containment facility typically containing a geomembrane barrier layer.

Section 3). The second group covers some basic technical criteria related to the waste, the repository and the environment (Section 4). Two further criteria are concerned with assurance of compliance of the disposal systems with the safety objectives (Section S). The final sections contain a discussion of the long time-scale aspects of high level waste disposal (Section 6) and a bibliography of important reports in the subject area. The order of presentation of the principles and criteria within the text does not indicate their relative importance. 

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