1. CONTAINMENT CONTROL SYSTEMS

3. Containment control system
1.Leachate collection system
2.Gas collection systems
Liner and Cover
- Control movement of leachate & landfill gases

4. Engineered Containment

5. Steps for leachate control in landfills
Liner system:
-Prevent leachate migration from sides & bases to subsoil
-Control damage of liner system
-Minimization of leachate heads above liner system
Drainage
-Proper collection & removel of leachate

6. 2.Separate waste from animals, plants, insects, humans
COVER SYSTEMS
FUNCTIONS:
1.Control runoff
2.Separate waste from animals, plants, insects, humans
3. Prevent infiltration of precipitation entry into waste
4. Control release of gas from waste

7. A Typical Landfill Cap
Objective of final cover system is to improve surface drainage, minimize infiltration and support vegetation

8. Components of cover system

9. CONSTRUCTION MATERIAL: Top soil, cobbles
1. SURFACE LAYER ( 40 to 100 cm)
FUNCTION:
Vegetation growth
Evapotranspiration
Prevent erosion
CONSTRUCTION MATERIAL:
Top soil, cobbles

10. Prevent intrusion by plants, animals etc
2. PROTECTION LAYER
FUNCTION:
Store water
Prevent intrusion by plants, animals etc
Protect barrier layer from freeze , thaw etc
CONSTRUCTION MATERIAL:
Mixed soil, cobbles

11. 3. DRAINAGE LAYER (100 to 150mm)
FUNCTION:
Drain away infiltrating water
CONSTRUCTION MATERIAL:
Sand,
Gravel,
Geotextiles,
Geonets,
Geocomposites

12. 4. BARRIER LAYER( 200 to 300 mm) FUNCTION:
Prevent infiltration of water into waste
Escape of gas out of waste
CONSTRUCTION MATERIAL:
Clay liners
Geomembranes
Geosynthetic clay liners
Bentonite mix ovelain bt HDPE membrane

13. 5. GAS COLLECTION LAYER (150 t0 200 mm
FUNCTION:
Trasmit gas to collection points
CONSTRUCTION MATERIAL:
Sand
Geotextiles
Geonets

14. LINER SYSTEMS Leachate drainage, Collection layer, Barrier layer
Low permeability, durable, resistant to attack
Liner materials-
-natural clays,
-amended soil,
-geomembranes,
-geosynthetic clay liners

16. TYPES OF LINER SYSTEMS
SINGLE LAYER SYSTEMS
SINGLE COMPOSITE LINER SYSTEM
DOUBLE LINER SYSTEM

17. 1. SINGLE LAYER SYSTEMS
One layer of impermeable material – to control leachate flow
Lining material : clay/amended soil/geomembrane
Used for:
-Nonreactive, non hazardous, non biodegradable waste
- Water table is deep

18. 2. SINGLE COMPOSITE LINER SYSTEM
Two or more layers of impermeable materials
Suitable for muncipal solid waste

19. 3.DOUBLE LINER SYSTEM
Two liners provided one over the other with sand layer sandwiched in between
Sand layer provided with network of pipes –to collect leachate if any infiltrates into it from upper liner

20. Liner Requirements Hydraulic conductivity 10-7 cm/sec or less
Thickness 100cm or more
Adequate strength under compressive loads & along side slope
Absence of clay clods
Absence of shrinkage cracks

21. Liner Specifications Boynton & Daniel % fines ≥ 20-30%
Platicity index ≥ 7-10%
% gravel ≤ 30%
Max particle size 20-50mm
Bagchi
% fines 40-50%
Platicity index 10-30%
Liquid limit 25-30%
Clay content 18-25%
DOE
Plasticity 10-30%
Activity ≥ 0.3

22. Liner Design Aspects
Identification of borrow area & source of materials
For in situ soil- Conduct field permeability tests
Liner materials- Lab study
Source of additive materials
Additive mixes- Lab tests
Field trial test on test pads – to find compaction parameters

23. LANDFILL LINERS
Rigid liners
Flexible liners

24. 1. RIGID LINERS Cement Grout Cement Concrete Soil cement
Bituminous concrete
Bitumen Panels

25. a. Cement Grout
Cement: sand 1:4
W/c
Sides & bottom grouted

26. b. Cement Concrete Grout
Cement + sand + Coarse aggregate
Reinforced with wire mesh or reinforced bars

27. c. Soil Cement
Cheap, naturally available
Cement + aggregate blended in dry condition
Water plant or after dry mix spread on prepared surface

28. Chemical compatibility b/w landfill contents & bituminous material
d. Bituminous Concrete
Thickness 4cm to 15cm
Chemical compatibility b/w landfill contents & bituminous material

29. Effective seepage control system Disadv - Low strength
5. Bitumen Panel
Effective seepage control system
Disadv
- Low strength
-High deformation characteristics

30. 2. FLEXIBLE LINERS
Natural Liners
Compacted clay
Chemically treated/amendedsoil
Bentonite clay
b. Composite liners
c. Synthetic liners

31. a. Natural Liners- Compacted soil Liners
Natural clay- liner material
If clay not available- Soil + bentonite
( amended soil)- used
Synthetic geomembranes
Flexible membrane with amended soil
Geosynthetic clay liner
Natural clay excavated or recompacted
If clay brought from nearby areas- spread in layers & compacted

32. Construction aspects Clear borrow area- removal of shrubs etc
Adjust w.c in borrow area
Sprinkling/irrigating- increase w.c
Ripping/areation- Lower w.c
Excavation of materials
Transportation- Haulers/ conveyor systems
Spreading & levelling in thin layers

33. Final wc adjustment by spraying & mixing water
Compaction using rollers
Quality testing
Placement of next lift & process continued
Lift thickness of clay liners 25-30cm
Sheep foot rollers for compacting lifts
Lift placed in horizontal layers
Lift placed parallel to slope (Side slope 2.5 H to 1 V)

34. b. Amended soil liners Low permeability clay not available-
In situ clay + bentonite ( medium –high plasticity)-
achieve low hydraulic conductivity
High permeability clay + sodium bentonite- Hydraulic conductivity less than 1x10-7cm/s
Well graded soil 5-10% by weight of bentonite
Uniformly graded soil 10-15% bentonite

35. Construction Similar to compacted clay liner
After excavation stage, additive is introduced into the soil
Additives like bentonite introduced in 2 ways:
In plant Mixing
Central plant mixing

36. In central plant method,
-Soil & additive mixed in pugmill/ central mixing plant
-Water added along with bentonite or seperately
After compaction of lift, covered with plastic sheet- to protect from dessication which results in cracking

37. Contaminant transport-Transportation by advection/diffusion- studies need to be carried out
Chemical compatibility test need to be conducted

38. 3. Synthetic Flexible Liners
Polymeric Materials produced in sheets
Thinner, light weight, good quality control, ease of installation, Cost effectiveness
Types of geosynthetics used:
Geotextiles,geomats,geospace,Geogrids,
geonets, geocell, bonded geogrid, geocomposite

39. 1.PHYSICAL PROPERTIES
Thickness mm
Specific gravity
Weight
Water vapour transmisson
1-10g/cm2 in 24 hrs
2.CHEMICAL PROPERTIES
Ozone resistance
U-V resistance
Chemical Compatibility
3. THERMAL PROPERTY
Durability in hot & cold climate

40. Ground modification techniques
Mechanical modification
Chemical Modification
Hydraulic modification

42. Liner systems other than Basal lining
1.Side lining system
Similar to basal lining system
Due to steepness of slope, prefabricated products like geomembrane /geocomposite clay liners used

43. 2.Draiange Blanket Thickness 0.3-0.5m, @ Bottom 16-32mm gravel
Serves as leakage collection system
Maintain proper hydraulic head above liner
Divert leachate to collection pipes
Bottom provided with gently sloped gravel trenches

44. 3.Surface lining or top capping
-Proper cover
-prevent infiltration
-Prevent intrusion of vegetation/animals
-Resistant to external forces

47. Two Types of Solar Caps Flexible solar panels Rigid panels
Low power production efficiency ca. 6%
Higher power production efficiency > 13%
Light
Heavier (steel frame, glass)
Flexible, unbreakable
Stiff frame
Works well with diffuse light
Less efficient with diffuse light
Works well with temperatures above 40°C
Less efficient with temperatures above 40°C

48. Rigid Panels

49. Flexible Panels

50. Tessman Rd. Landfill, Houston Tx
Winner of the 2010 SWANA Gold Excellence Award for Landfill Secondary Use

52. Questions