EIA Studies of 3 Pre-Identified Hazardous Waste Disposal Sites in ...

Rapid EIA Studies of 3 Pre-identified Hazardous Waste Disposal Sites in NCT - Delhi
Page No.171
6.1.2 Landfill Liner System and Specifications
As the site falls in the region where subsoil is permeable and water table is 2.5
m beneath the base of the landfill ( 2 m of excavation bgl and groundwater
table is available at 4.5 m bgl), the liner system suggested is double composite
liner as per the minimum technical requirements as specified in "Criteria for
Hazardous Waste Landfills" published by Central Pollution Control Board
(Hazardous Waste Management, Series: HAZWAMS/17/2000-01).
Bottom liner system
The double composite liner (Refer Figure 6.2) includes the following
components:
(b)
(i)
(ii)
(d)
(i)
(ii)
(a) Primary leachate collection layer:
Thickness = 30 - 45 cm of gravel layer
Co-efficient of permeability = 10 -2 cm/sec (minimum).
Primary composite liner:
HDPE Geomembrane:
Thickness = 1.5 mm
Tensile Strength at yield: > 18 KN/m.
Tensile Strength at Break: > 30 KN/m.
Tear Resistance: > 150 N and
Puncture Resistance: > 250 N.
Compacted clay layer:
Thickness = 45 cm -60 cm
Co-efficient of permeability = 10 -7 cm/sec (maximum)
(c) Secondary leachate collection layer (leak detection layer) :
Thickness = 30 cm - 45 cm of gravel layer
Co-efficient of permeability = 10 -3 cm/sec (minimum)
Secondary composite liner:
HDPE Geomembrane:
Thickness = 1.5 mm
Tensile Strength at yield: > 18 KN/m.
Tensile Strength at Break: > 30 KN/m.
Tear Resistance: > 150 N and
Puncture Resistance: > 250 N.
Compacted clay layer
Thickness = 45 cm - 60 cm
Co-efficient of permeability = 10 -7 cm/sec (maximum).
Environment Division, National Productivity Council, New Delhi
7