Advancements in Municipal Solid Waste Landfill Cover System: A Review

Abstract

Municipal solid waste (MSW) landfill cover systems have
evolved from being merely a soil cap to a multicomponent, nearly impermeable
systems providing better control over infiltration and landfill gas
(LFG) emissions. Recently, there has been a widespread development
of alternative cover systems which addresses the shortcomings of conventional
cover systems such as high construction and maintenance
costs, susceptibility to damage due to desiccation cracking and freezing,
and ineffective control of LFG emissions. Landfills are regarded as
the third largest source of anthropogenic methane (
CH4) emissions in the
United States. Apart from CH4,
landfills are a significant source of various
other gasses such as carbon dioxide, hydrogen sulfide and several
other odorous and non-methanogenic organic compounds. The modern
engineered landfills typically install gas collection systems in addition to
the conventional soil cover to mitigate LFG emissions. However, these
systems are not always 100% efficient in capturing all the emissions.
Moreover, at the older landfills where installing gas collection systems
is not economical and practically feasible, the fugitive LFG emissions is
a persistent problem. In this regard, alternative cover systems with wide
range of cover materials have been explored to address the fugitive LFG
emissions. This paper summarizes the advancements in the MSW landfill
cover systems over the years, along with the core mechanisms underlying
their function. Then, advancements in the alternative cover systems,
including their advantages, are discussed. Finally, the research challenges/
opportunities in the field of exploring alternate landfill cover systems
are presented.