1. Liner Construction & Testing Guidance Overview
Ruben Meza, Jr., P.E. Waste Permits Division Municipal Solid Waste Permits Section
2017: TCEQ Environmental Trade Fair

2. Agenda Summary of Revised Guidance Document
Liner Design – Basic Requirements
Compacted Clay Liner
Geomembrane
Geosynthetic Clay Liner (GCL)
Geocomposite Material

3. Description of Revised Guidance
New Title: Guidance for Liner Construction & Testing for a MSW Landfill
Procedures for installation & testing of liner system
Complies with regulations in 30 TAC Chapter 330, Subchapter H: Liner System Design & Operation
Status: finalize by late summer 2017

4. Document History
September 1, 1993: QA-QC for Waste Containment Facilities
July 1, 1994: Liner & Construction Handbook
July 7, 2000: Final Cover Systems Cons & Testing (Draft)
November 1, 2001: Liner Construction & Testing (Draft)

5. Noted Revisions Flexibility for soil compaction
New section for protective cover
Low-ground-pressure equipment may travel on geomembrane
Revised geomembrane procedures:
manufacturing testing: GRI GM-13
seaming procedures: GRI GM-9
seam testing: GRI GM-19

6. Noted Revisions
Revised testing methods: clay liner, geomembrane, and GCL
Test Methods: geocomposite drainage layer
Flexibility for testing methods
Updated Glossary

7. Liner Quality Control Plan Regulations
30 TAC § : Design Criteria
30 TAC § : Leachate Collection System
30 TAC § : Alternative Liner Design
30 TAC § : Special Liner Design Constraints
30 TAC § : Liner Quality Control Plan
30 TAC § : SLER & GLER

8. Landfill Liner Design
Basic Requirements

9. Liner System Design

10. Type I Liner 2-ft Protective Cover Single / Double Sided Geocomposite
60-mil Smooth/Textured HDPE Geomembrane
2-ft Clay Liner

11. Type I Liner with GCL 2-ft Protective Cover
Single / Double Sided Geocomposite
60-mil Smooth / Textured HDPE Geomembrane
Unreinforced / Reinforced GCL

12. Class 1 Cell 2-ft Protective Cover Single / Double Sided Geocomposite
60-mil Smooth / Textured HDPE Geomembrane
3-ft Clay Liner

13. Type IV Liner Compacted Clay Liner In-Situ Liner 1-ft Protective Cover
3-ft Clay Liner
In-Situ Liner
4-ft In-Situ Liner
Top one foot for protective cover

14. Compacted Clay Liner
Installation & Testing

15. Compacted Clay Liner Requirements
Design Values
Plasticity Index ≥ 15
Liquid Limit ≥ 30
Percent Passing No. 200 Sieve ≥ 30%
Percent Passing one-inch sieve = 100%
Permeability ≤ 1 x 10-7 cm/sec

16. Soil Testing – Source Borrow Materials
Soil Classification
Moisture/Density Relationship
Sieve Analysis
Atterberg Limits
Coefficient of Permeability

17. Moisture / Density Relationship
Test: standard / modified proctor test
Results: max dry unit weight & optimum moisture content
Use parameters to compact liner
Source: EPA/600/R-93/182, September 1993

18. Soil Compaction
Sheepsfoot Roller
Tamping Foot Roller

19. Constructed Liner – Conformance Testing
Field Density
Atterberg Limits
Permeability
Thickness Verification

20. Geomembrane
Installation & Testing

21. HDPE Geomembrane HDPE: High Density Polyethylene Composition:
97% polyethylene resin
2 – 3% carbon black and additives
Typically 60-mil
Source:

22. Hot Wedge Welding Machine
Hot Wedge Seaming
Hot Wedge Welding Machine
Hot Wedge Seaming

23. Extrusion Welding Machine
Machine Cross Section

24. Geomembrane - Seams
Source: EPA/600/R-93/182, September 1993

25. Geomembrane Manufacturer Testing
Manufacturer Testing: GRI GM-13
Thickness • Carbon Black Content
Density • Carbon Black Dispersion
Tensile Properties • Oxidation Induction Time
Tear Resistance • Oven Aging
Puncture Resistance • UV Resistance
Stress Crack Resistance

26. Geomembrane Conformance Testing
Thickness
Density
Carbon Black Content & Dispersion
Tensile Properties
Destructive Testing
Shear
Peal
Non-destructive Testing
Air Pressure
Vacuum Box

27. Hot Wedge Seaming – Seam Strength
Seam Strength from GRI GM- 19 for 60 mil HDPE Geomembrane:
Shear Strength: 120 lb/in
Shear Elongation: 50%
Peel Strength: 91 lb/in
Peel Elongation: 25%
Source:

28. Extrusion Welding – Seam Strength
Seam Strength from GRI GM- 19 for 60 mil HDPE Geomembrane:
Shear Strength: 120 lb/in
Shear Elongation: 50%
Peel Strength: 78 lb/in
Peel Elongation: 25%
Source:

29. Shear Test
GRI Testing Photos

30. Shear Test – Photo 1
Source:

31. Shear Test – Photo 2
Source:

32. Shear Test – Photo 3
Source:

33. Shear Test – Photo 4
Source:

34. Shear Test – Photo 5
Source:

35. Peel Test
GRI Testing Photos

36. Peel Test – Photo 1
Source:

37. Peel Test – Photo 2
Source:

38. Peel Test – Photo 3
Source:

39. Peel Test – Photo 4
Source:

40. Peel Test – Photo 5
Source:

41. Peel Test – GRI Testing Photos
Source:
Photo 1

42. Peel Test – GRI Testing Photos
Source:
Photo 2

43. Geosynthetic Clay Liner (GCL)
Installation & Testing

44. GCL – Summary
Bentonite layer supported by geotextiles and/or geomembranes
Held together by needling, stitching, or chemical adhesives

45. GCL: Non-reinforced
Source: Designing with Geosynthetics 6th ed.

46. GCL: Internally Reinforced
Source: Designing with Geosynthetics 6th ed.

47. GCL - Sodium Bentonite sodium montmorillonite variety
naturally occurring mineral found in Wyoming and North Dakota
Properties:
k ≈ 1 x cm/sec
w ≥ 100%
self healing
Source:

48. Geotextiles - Overview
Made from polymeric fibers
Fibers are made from polypropylene, carbon black, and additives
Once fibers are manufactured they are joined together to make a fabric or geotextile
Geotextiles are classified as woven and nonwoven

49. Woven Geotextile at 24X Magnification
Source: EPA/600/R-93/182, September 1993

50. Nonwoven Needle Punched Geotextile
Nonwoven Needle Punched Geotextile at 24X Magnification
Source: EPA/600/R-93/182, September 1993

51. Nonwoven Heat Bonded Geotextile
Nonwoven Heat Bonded Geotextile at 24X Magnification
Source: EPA/600/R-93/182, September 1993

52. GCL – Installation
Subgrade preparation similar to procedures in geomembrane section
Joining GCLs is done by overlapping without sewing or other mechanical connections
Overlap distances should be marked on GCL by manufacturer (typically 6 – 12 in.)

53. GCL - Installation
GCL with needle punched nonwoven geotextiles require bentonite in the overlap regions
Minimum Bentonite Required: 0.25-lb dry bentonite per linear foot of lap joint
Bentonite in lap-joint must be the same type used in the manufacture of the GCL

54. GCL – Manufacturer Testing
Bentonite
Free Swell
Fluid Loss
Geotextile
Mass / unit area
Grab Tensile Strength
Geomembrane
Mass / Unit Area
Thickness
Tensile Properties
GCL Product
Bentonite – mass / unit area
Bentonite – moisture content
Tensile strength
Grab tensile strength
Permeability
Lap Joint Permeability

55. GCL – Conformance Testing
GCL Product
Bentonite mass / unit area
Permeability
Direct shear

56. Direct Shear Device - GCL
Source: Shear Strength of GCL’s, 2002

57. Direct Shear - GCL
Source: Shear Strength of GCL’s, 2002

58. Interface Shear Testing GCL / Geomembrane
Source: Shear Strength of GCL’s, 2002

59. Failure Envelope 𝜏 𝑓 = 𝑐 𝐴 + 𝜎 tan 𝛿
Source: Shear Strength of GCL’s, 2002

60. Geocomposite Material
Installation & Testing

61. Geocomposite Material
Composition: geonet with a geotextile or geomembrane heat bonded on 1 or both sides
Geocomposite drainage layer has replaced granular drainage layer
Fluid flows within the geonet
Source:

62. Geonets - Summary Manufactured similar to geomembrane Composition:
97% polyethylene;
2 – 3% carbon black and additives
Typically covered with a geomembrane or geotextile
Source:

63. Geocomposite - Installation
Material is positioned and unrolled over substrate material (typically geomembrane)
The material is either overlapped or sewn together
In any case, follow manufacturers directions for installation and connections

64. Geocomposite – Manufacturer Testing
(Resin) Geonet
Density
Melt Flow Index
Geonet
Mass / Area
Thickness
Compression
Transmissivity
Geotextile
Mass / Area
Grab Tensile Strength
Trapezoidal Tear Strength
Burst Strength
Puncture Strength
Thickness
Apparent Opening Size
Permitivity

65. Geocomposite – Conformance Testing
GCL Product
Transmissivity
Interface Shear or Ply Adhesion

66. Conclusion
Draft guidance has been posted online: ts/msw_permits/msw_liners_covers.html
We are accepting stakeholder comments until May 31, 2017. 
We plan to have this document finalized by late summer 2017. 

67. Questions? How to contact us: Municipal Solid Waste Permits Section
Texas Commission on Environmental Quality
Municipal Solid Waste Permits Section
P. O. Box MC-124
Austin, TX
Phone:
Fax: