Percolate collection layers and blind drains are built between the primary and the
secondary barrier systems to collect and drain the percolate leaked from the primary
barrier system. The secondary collection layer uses the composite geotechnical
drainage net, and the main blind drains are installed with perforated pipes. The
percolate collected by the main and secondary percolate collection layers and blind
drains is gathered to the collecting well, lifted to the percolate regulating tank by the
inclined tube lift pump, and finally transported to the sewage treatment plant for
treatment. One percolate collecting well is built in each landfill area, and installed
with one primary and one secondary percolate lifting inclined tube pumps.
The percolate lifting pump shall have a capacity such that the percolate from the
operating units will be emptied in 24 h during the days with the maximum rainfall
to ensure the smooth performance of landfill operation. The construction of the
seepage prevention works and discharge guiding pipes at the bottom of the landfill
is shown in Fig. 5.101; the construction of the slope seepage prevention system is
illustrated in Fig. 5.102; and the construction of the percolate collection system is
shown in Fig. 5.103.
The slope seepage prevention of the project is mainly stepped up by careful
design, the adoption of anti-seepage materials and other measures. The following
anti-seepage actions are taken in the design:
Initial fill layer
Hazardous wastes after pretreatment
Protective layer
Bagged soil
Filter layer
600 g/m
2 non-woven geotextiles
Primary barrier system
2.0 mm thick HDPE geomembrane
Enhanced barrier system
4,800 g/m
2 GCL bentonite cushion
Primary percolate collection layer 6.3 mm thick HDPE drainage grid
Secondary barrier system
1.0 mm thick HDPE geomembrane
Basal layer
Finished slope.
40-60mm pebbles (percolate discharge guiding system)
600g/m 2 anti-aging non-woven geotextiles (in double layers)
2.0mm HDPE geomembrane
6.3mm geocomposite drainage grid
1.5mm HDPE geomembrane
1000mm compacted clay
600g/m 2 non-woven geotextile
Groundwater discharge guiding system
Typical sectional view of slope and bottom barrier structure of current design
Fig. 5.101 Anti-seepage and discharge guiding pipes at the landfill bottom of the project
5.6 East China
355
secondary barrier systems to collect and drain the percolate leaked from the primary
barrier system. The secondary collection layer uses the composite geotechnical
drainage net, and the main blind drains are installed with perforated pipes. The
percolate collected by the main and secondary percolate collection layers and blind
drains is gathered to the collecting well, lifted to the percolate regulating tank by the
inclined tube lift pump, and finally transported to the sewage treatment plant for
treatment. One percolate collecting well is built in each landfill area, and installed
with one primary and one secondary percolate lifting inclined tube pumps.
The percolate lifting pump shall have a capacity such that the percolate from the
operating units will be emptied in 24 h during the days with the maximum rainfall
to ensure the smooth performance of landfill operation. The construction of the
seepage prevention works and discharge guiding pipes at the bottom of the landfill
is shown in Fig. 5.101; the construction of the slope seepage prevention system is
illustrated in Fig. 5.102; and the construction of the percolate collection system is
shown in Fig. 5.103.
The slope seepage prevention of the project is mainly stepped up by careful
design, the adoption of anti-seepage materials and other measures. The following
anti-seepage actions are taken in the design:
Initial fill layer
Hazardous wastes after pretreatment
Protective layer
Bagged soil
Filter layer
600 g/m
2 non-woven geotextiles
Primary barrier system
2.0 mm thick HDPE geomembrane
Enhanced barrier system
4,800 g/m
2 GCL bentonite cushion
Primary percolate collection layer 6.3 mm thick HDPE drainage grid
Secondary barrier system
1.0 mm thick HDPE geomembrane
Basal layer
Finished slope.
40-60mm pebbles (percolate discharge guiding system)
600g/m 2 anti-aging non-woven geotextiles (in double layers)
2.0mm HDPE geomembrane
6.3mm geocomposite drainage grid
1.5mm HDPE geomembrane
1000mm compacted clay
600g/m 2 non-woven geotextile
Groundwater discharge guiding system
Typical sectional view of slope and bottom barrier structure of current design
Fig. 5.101 Anti-seepage and discharge guiding pipes at the landfill bottom of the project
5.6 East China
355