Environmental Engineering Reference
In-Depth Information
[MCQ 99] rightly conclude that the application of a thorough and stringent quality
assurance program substantially reduces the frequency of holes in a geomembrane
liner. A similar conclusion has been reached by Rollin
et al
. [ROL 99] from their
work on French and Canadian landfills.
The variation in leak density per area of liner surveyed is plotted in Figure 16.26,
based on the data reported by Laine and Darilek [LAI 93], Colucci and Lavagnolo
[COL 95], McQuade and Needham [MCQ 99] and Rollin
et al
. [ROL 99]. It is
interesting to note that the density of leaks tends to decrease as the area surveyed
increases. No final conclusion can be drawn on this issue, however, due to the
uncertainty linked to the varying conditions encountered in different sites. Colucci
and Lavagnolo [COL 95] pointed out that larger installations tend to have better
construction quality programs, whereas smaller sites have proportionally more
complex features to deal with.
160
McQuade & Needham (1999)
Rollin et al. (1999)
Colucci & Lavagnolo (1995)
Laine & Darilek (1993)
140
120
100
80
60
40
20
0
100
1000
10000
100000
Area survey ed (m
2
)
Figure 16.26.
Variation of leak density versus area surveyed [BOU 02]
Many excellent attempts have been made to predict the rate of leakage through
composite liners using calculations based on the fundamental parameters that govern
the problem. Excellent summaries of the current methods for holes in direct contact
with the underlying mineral liner or GCL may be found in Rowe [ROW 98] and
Touze-Foltz
et al.
[TOU 99]. Another solution proposed by Rowe [ROW 98] takes
into account the presence of holes when in contact with a wrinkle in the
geomembrane. Touze-Foltz
et al
. [TOU 99, TOU 01] and Rowe and Booker [ROW
00] extended this solution to take into account non-uniform transmissivity and small
transmissivity, respectively, at the geomembrane/CCL or GCL interface and the
interaction of two wrinkles. The reader is referred to these sources for further
information.
