Hae-Seung Lee* and Nobutoshi Tanaka*

* Department of Environmental and Sanitary Engineering, Faculty of Engineering, Hokkaido University

+ Correspondence should be addressed to Nobutoshi Tanaka:
(Kita 13 Nishi 8, Kita-ku, Sapporo 060 Japan)

Abstract

This study presents the three diagrams for the design of gas vents, in order to control gas flux through final cover soil, and the maximum pressure under final cover soil. Each of the three diagrams corresponds to one of the following cases; 1) a gas vent of independent vertical type, 2) a vertical gas vent connected to a leachate collection pipe network, and 3) the surface of a landfill site finally covered by impermeable geomembrance. By using the diagrams, Ks and Lx are designed when G, Lz and Kx was given as the landfill conditions and H[eta] and d[delta]Pmax as the control conditions, where, Ks = permeability of final cover soil[m2], Lx = half-distance between two vents[m], G[s-1] = gas generation rate, Lz = depth of refuse layer[m], Kx = permeability of refuse[m2], H[eta] = landfill gas collection efficiency[-], and d[delta]Pmax = the maximum pressure under final cover soil[Pa].

Key words: sanitary landfill site, design of gas vent, gas collection efficiency, gas pressure under cover soil