Gas emission from landfill is related to both site conditions and envi
ronmental changes, yet almost no data are being gathered in the field
to describe this linkage adequately. In this paper the results of a re
view of selected sites in the UK and Germany are presented: they illus
trate how even continuous recording proves insufficient for the purpos
e of explaining gas emissions from site. Site stratigraphy must be kno
wn in some detail if either continuous or frequent recording is to be
used meaningfully, because site stratigraphy largely governs the pathw
ays available for gas migration. As shown in the example presented her
e, it is also necessary to add a record of site history to that of sit
e stratigraphy and environmental change if records of gas emission wit
h time are to be properly interpreted. (C) 1997 ISWA.