The objective in designing lining systems for the containment of the l
eachate generated within a landfill is the prevention of contamination
of groundwater and surface waters. The technology involving the desig
n of these systems has progressed to a point that the integrity of the
containment can be relied on over the long term. Double-lined systems
provide the additional benefit of being able to quantify the performa
nce of the lining system through the detection of leakage through the
upper liner. The difficulty, however, lies with the qualitative evalua
tion of the system. This paper addresses this issue and offers a pract
ical approach for the design and evaluation of double-lined systems an
d the leakage that is detected.