Five to six pollution diffusion monitoring wells are deployed in the T shape
(Fig. 2.5) or in the + shape (Fig. 2.6). Linear-shaped monitoring wells are equally
spaced (50–80 m) in the mountainous areas in the direction of groundwater flow.
Downstream springs, if any, can be used for monitoring pollution diffusion.
(b) Non-standard MSWLFs
• Pore water in plains and gentle plateaus
A site background monitoring well is set in the upstream, 30–50 m from the
landfill;
Among the six pollution diffusion monitoring wells, one is installed 30–50 m
from landfill boundary on each of the two sides, in the direction perpendicular to
groundwater flow. Four are installed in the downstream, in a diamond shape with a
diagonal length of 50–100 m in the direction perpendicular to groundwater flow,
including one 5–10 m away, one 30–50 m away for landfills with an age of less
than 10a, and one 50–80 m away for landfills with an age of more than 10a, as
shown in Fig. 2.7.
Fig. 2.5 Schematic diagram of the T-shaped layout in a standard MSWLF site
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2 Environmental Background Investigation of Groundwater …