chapter 4: temperature inside the landfill

suggested that interferences by ferrous materials were negligible when the moisture content in
the waste is below 20% for leachate or 40% for tap water.
2.4.4 Electrical resistivity tomography
Electrical Resistivity Tomography (ERT) consists of measuring the potential distribution
when electrical current is injected into the underground via galvanic or capacitive contact
(Imhoff et al, 2007). The galvanic contact requires direct contact of the electrode with the waste
while in capacitive contact, electrodes can be placed above a geomembrane. Changes in moisture
content are expressed by the resistivity variations that occur during liquid injection (Guerin et al,
2004).
Guerin et al (2004) performed experiments on a landfill in France using various
geophysical methods including electromagnetic slingram mapping and electrical 2D imaging.
Although a definitive relationship between resistivity and moisture content was not developed in
the study, it was concluded that ERT methods allow water to be located within a landfill. Also
the influence zone of the leachate recirculation system can be located using ERT methods.
2.4.5 Partitioning gas tracers
Two gas tracers are injected and then extracted under steady gas flow in Partitioning Gas
Tracers Tests (PGTT). One of tracers (the conservative tracer) is inert while the other tracer (the
water-partitioning tracer) being hydrophilic, partitions into and out of water while passing
through the solid waste inside the landfill (Imhoff et al., 2007). The parameter used to estimate
moisture content is the difference in the arrival times of the two tracers at a gas collection well or
an intermediate sampling well. The arrival times of the tracers are measured by gas
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