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

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

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

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)

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

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

Liner Quality Control Plan Regulations 30 TAC §330.331: Design Criteria 30 TAC §330.333: Leachate Collection System 30 TAC §330.335: Alternative Liner Design 30 TAC §330.337: Special Liner Design Constraints 30 TAC §330.339: Liner Quality Control Plan 30 TAC §330.341: SLER & GLER

Landfill Liner Design Basic Requirements

Liner System Design

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

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

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

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

Compacted Clay Liner Installation & Testing

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

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

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

Soil Compaction Sheepsfoot Roller Tamping Foot Roller

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

Geomembrane Installation & Testing

HDPE Geomembrane HDPE: High Density Polyethylene Composition: 97% polyethylene resin 2 – 3% carbon black and additives Typically 60-mil Source: http://www.geosolutionsinc.com/products/liners-pvc-hdpe.html

Hot Wedge Welding Machine Hot Wedge Seaming Hot Wedge Welding Machine Hot Wedge Seaming

Extrusion Welding Machine Machine Cross Section

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

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

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

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: www.geosynthetic-institute.org/grispecs/gm19.pdf

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: www.geosynthetic-institute.org/grispecs/gm19.pdf

Shear Test GRI Testing Photos

Shear Test – Photo 1 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Shear Test – Photo 2 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Shear Test – Photo 3 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Shear Test – Photo 4 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Shear Test – Photo 5 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Peel Test GRI Testing Photos

Peel Test – Photo 1 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Peel Test – Photo 2 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Peel Test – Photo 3 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Peel Test – Photo 4 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Peel Test – Photo 5 Source: www.geosynthetic-institute.org/grispecs/gm19.pdf

Peel Test – GRI Testing Photos Source: www.geosynthetic-institute.org/grispecs/gm19.pdf Photo 1

Peel Test – GRI Testing Photos Source: www.geosynthetic-institute.org/grispecs/gm19.pdf Photo 2

Geosynthetic Clay Liner (GCL) Installation & Testing

GCL – Summary Bentonite layer supported by geotextiles and/or geomembranes Held together by needling, stitching, or chemical adhesives https://en.wikipedia.org/wiki/Geosynthetic_clay_liner

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

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

GCL - Sodium Bentonite sodium montmorillonite variety naturally occurring mineral found in Wyoming and North Dakota Properties: k ≈ 1 x 10-11 cm/sec w ≥ 100% self healing Source: http://www.mariopilato.com/sodium-bentonite.htm

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

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

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

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

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.)

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

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

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

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

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

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

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

Geocomposite Material Installation & Testing

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: www.gseworld.com

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

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

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

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

Conclusion Draft guidance has been posted online: http://www.tceq.texas.gov/permitting/waste_permi 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. 

Questions? How to contact us: Municipal Solid Waste Permits Section Texas Commission on Environmental Quality Municipal Solid Waste Permits Section P. O. Box 13087 MC-124 Austin, TX 78711-3087 Phone: 512-239-2335 Fax: 512-239-2007 E-Mail: mswper@tceq.texas.gov