3606_Gaston_MSWLF_LFGExtractWells_DIN27578_20170403

“Satisfying Our Clients with
Dedicated People Committed to Total Quality”
8720 Red Oak Boulevard, Suite 505, Charlotte, NC 28217-4938
T 704.527.3227  F 704.527.3228  www.chacompanies.com

March 31, 2017

Mr. Larry Frost
NCDEQ - Asheville Regional Office Solid Waste Section
2090 U.S. Highway 70 Swannanoa, NC 28778
Re: Unit 2, Phase 1 – Gas Extraction Well Additions
Gaston County Landfill Gaston County, North Carolina
CHA Project Number 21420
Dear Mr. Frost:
Please find attached for approval the proposed layout and technical specification for additional gas wells to be installed in the Phase 1 MSWLF unit. The technical specification (Section 02610 “Landfill Gas Wells –
PVC”) describes the installation procedures and construction quality control measures. The proposed wells
are part of the previously approved landfill gas utilization plan for the site.

If you have any comments or questions, please contact me.

Sincerely,

Robert C. Sallach, PE
Senior Vice President
RCS/der
Attachments: SCS Drawings (Sheets 1 through 5)
Specification Section 02610 “Landfill Gas Wells – PVC”
cc: Marcie Smith, Gaston County Ed Shuffler, HDR

21420 GASTON COUNTY MARCH 2017 GASTON COUNTY LANDFILL - UNIT II - PHASE 1 - LFG COLLECTION SYSTEM EXPANSION
02611
SECTION 02611

LANDFILL GAS WELLS - PVC

TABLE OF CONTENTS

ARTICLE TITLE PAGE

1.1 SCOPE OF APPLICATION 1
1.2 REFERENCES 1
1.3 SUBMITTALS 1
1.4 SITE CONDITIONS 1
2.1 AGGREGATE 2
2.2 SOLID WALL PIPE 2
2.3 SLOTTED PIPE 2
2.4 BACKFILL 2
3.1 DRILLING 2
3.2 BACKFILLING 3
3.3 DISPOSAL 3
3.4 ABANDONMENT OF BORE HOLE 3
3.5 FINAL SURVEY AND BORING (WELL) LOGS 3

21420 GASTON COUNTY MARCH 2017 GASTON COUNTY LANDFILL - UNIT II - PHASE 1 - LFG COLLECTION SYSTEM EXPANSION
02611 — 1
SECTION 02611 1
LANDFILL GAS WELLS - PVC 2
PART 1 — GENERAL 3
1.1 SCOPE OF APPLICATION 4
A. Supply all equipment, materials, and labor needed to install Unit II, Phase 1 landfill gas (LFG) 5
extraction wells as specified herein and as indicated on the attached Drawings. 6
1.2 REFERENCES 7
A. American Society for Testing and Materials (ASTM): 8
1. ASTM C136 - Standard Method for Sieve Analysis of Fine and Coarse Aggregates. 9
2. ASTM C702 - Standard Practice for Reducing Field Samples of Aggregate to Testing Size. 10
3. ASTM D1557 - Standard Test Method of Moisture-Density Relations of Soils and Soil Aggregate 11
Mixtures Using 10 lb (4.54 kg) Rammer and 18-in. (457 mm) Drop. 12
4. ASTM D2487 - Standard Test Method for Classification of Soils for Engineering Purposes. 13
5. ASTM D2488 - Standard Practice for Description of Soils (Visual-Manual Procedure). 14
6. ASTM D2922 - Standard Test Methods for Density of Soil and Soil-Aggregate In-Place by 15
Nuclear Methods (Shallow Depth). 16
7. ASTM 4318 - Standard Test Method for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. 17
8. C1147, Standard Practice for Determining the Short-Term Tensile Weld Strength of Chemical-18
Resistant Thermoplastics. 19
9. D1238, Standard Test Method for Melt Rates of Thermoplastics by Extrusion Plastometer. 20
10. D1248: Specification for Polyethylene Plastics Molding and Extrusion Materials. 21
11. D1505, Standard Test Method for Density of Plastics by the Density Gradient Technique. 22
12. D2321, Standard Practice for Underground Installation of Thermoplastic Pipe for Sewers and 23
Other Gravity Flow Application. 24
13. D2513: Standard Specification for Thermoplastic Gas Pressure Pipe, Tubing, and Fittings. 25
14. D2657, Standard Practice of Heat Fusion Joining of Polyethylene Pipe and Fittings. 26
15. D3261: Standard Specification for Butt Heat Fusion Polyethylene (PE) Plastic Fittings for 27
Polyethylene (PE) Plastic Pipe and Tubing. 28
16. D3350, Standard Specification for Polyethylene Plastics, Pipe, and Fittings. 29
17. D3350: Standard Specification for Polyethylene Plastics Pipe and Fittings Materials. 30
18. F1473, Standard Test Method for Notch Tensile Test to Measure the Resistance to Slow Crack 31
Growth of Polyethylene Pipes and Resins. 32
19. F894, Standard Specifications for Polyethylene (PE) Large Diameter Profile Wall Sewer and 33
Drain Pipe. 34
1.3 SUBMITTALS 35
A. Submit to the Engineer Certificates of Compliance on materials furnished, and manufacturer's 36
brochures containing complete information and instructions pertaining to the storage, handling, 37
installation, and inspection of pipe and appurtenances furnished. 38
B. The Contractor shall submit to the Engineer upon request, samples of all well backfill materials 39
furnished. 40
C. The Contractor will provide the Engineer detailed well logs and construction diagrams for all wells 41
drilled, including the total depth of the well, the static water level, depth, thickness, and 42
description of soil or waste strata, (including dates from any readable material), and the 43
occurrence of any water bearing zones. 44
1.4 SITE CONDITIONS 45
A. Obstructions and saturated conditions are sometimes encountered when drilling in a landfill, 46
many of which can be drilled through. The Contractor is expected to make reasonable effort to 47
drill through obstructions and saturated conditions and will be paid for offset redrilliing and 48
boring abandonment only with prior approval in writing by Engineer. Contractor will be paid for 49
abandonment of abandoned hole and for well installation at new location. 50

21420 GASTON COUNTY MARCH 2017 GASTON COUNTY LANDFILL - UNIT II - PHASE 1 - LFG COLLECTION SYSTEM EXPANSION
02611 — 2
B. Contractor shall develop Health and Safety Plan as required for all drilling and pipe installation 1
per OSHA. 2
PART 2 — PRODUCTS 3
2.1 AGGREGATE 4
A. Gravel pack shall be a non-calcareous washed stone of a 1-IN to 2-IN diameter size so as not to 5
impair flow to pipe perforations/slots. 6
2.2 SOLID WALL PIPE 7
A. All pipe and fittings shall be rigid Schedule 80 PVC. 8
2.3 SLOTTED PIPE 9
A. Refer to Drawings for detail. 10
2.4 BACKFILL 11
A. Contractor shall provide suitable soil backfill materials as required for use in the construction of 12
the proposed gas wells from on-site excavation. Backfill materials shall be hauled to the work 13
area by the Owner and stockpiled at a location designated by the Contractor. Select backfill 14
material shall be on-site clay material. 15
PART 3 — EXECUTION 16
3.1 DRILLING 17
A. Prior to the commencement of boring operations, all safety equipment as required by the 18
Contractor’s Health and Safety (H&S) Plan shall be provided and maintained in good working order 19
and be available throughout the duration of the project. The Contractor shall implement and 20
follow all safety precautions and procedures outlined under the H&S Plan to protect personnel, 21
monitor the work area environment, and secure bore hole during construction. 22
B. Well boreholes shall be 36 IN in diameter, drilled to the approximate depth shown on the 23
Drawings or directed by Engineer. No boring shall be advanced below the boring depths shown on 24
Drawings unless approved by Engineer. Contractor must use dry drilling equipment; wet rotary 25
drilling equipment may not be used. All borings shall be made with bucket type augers and 26
extended through waste. 27
C. The boring depths and locations shown on the Drawings are estimated and may be adjusted in the 28
field by the Engineer as follows: 29
1. If water is encountered in a boring, the Contractor may be directed to drill beyond the point 30
at which it was encountered. If wet conditions remain, the boring may be terminated and 31
the length of perforated pipe adjusted by the Engineer, or the well may be relocated. If wet 32
conditions cease (e.g., due to trapped water layer), then drilling will continue to the design 33
depth. 34
2. The Gaston County’s Unit II, Phase 1 Landfill is a Subtitle D facility with a composite bottom 35
liner system. As such, the Contractor must ensure that the liner is not breached or 36
penetrated during drilling operations. 37
3. The Contractor shall be responsible to provide all required survey and control (horizontal and 38
vertical elevation control) to accurately monitor and record boring depths during drilling 39
operations. 40
4. All borings shall be terminated at least 15 FT above the top of liner (sand drainage layer). 41
D. The bore for the well shall be straight and the well casing pipe shall be installed in the center of 42
the bore hole. The Contractor will take all tension off of the pipe by mechanical means and 43
center the pipe in the middle of the borehole before starting the placement of backfill. 44
E. PVC well pipe shall have solvent glue joints. Below grade joints shall also have stainless steel lag 45
screws at 180 degrees. 46

21420 GASTON COUNTY MARCH 2017 GASTON COUNTY LANDFILL - UNIT II - PHASE 1 - LFG COLLECTION SYSTEM EXPANSION
02611 — 3
3.2 BACKFILLING 1
A. Backfilling of the well shall commence immediately after well drilling is completed and the well 2
piping has been installed in the borehole. Backfill materials shall be installed as indicated on the 3
Drawings and as approved by the Engineer. 4
B. Gravel pack shall be placed using a tremie method at a rate that will not damage the integrity of 5
the well pipe. 6
C. Soil backfill shall be placed in 12-IN lifts and rodded in the boring to provide even distribution and 7
compaction. 8
D. If well construction is not completed by the end of the workday, the borehole shall be covered 9
with a plate of sufficient size and overlap to prevent access to the hole. The plate shall be 10
covered with earth and be capable of supporting the loading (earth depth) required to prevent 11
the escape of landfill gas. 12
3.3 DISPOSAL 13
A. Waste excavated from the well borehole shall be disposed at the existing working face. 14
Contractor shall have waste to working face. 15
3.4 ABANDONMENT OF BORE HOLE 16
A. If the Contractor is required to abandon a borehole for any reason, the hole shall be backfilled 17
with the excavated materials to a depth of 4 FT below ground surface in lifts not to exceed 2 FT. 18
The backfill materials shall be compacted to the in-situ densities of the existing fill by rodding. 19
The top 4 FT of the hole shall be backfilled with a cohesive material and compacted to the 20
density required to meet a 10-5 cm/sec permeability. 21
3.5 FINAL SURVEY AND BORING (WELL) LOGS 22
A. The Contractor shall provide a field survey map prepared by a North Carolina registered land 23
surveyor showing the as-built location of each gas well installed (and abandoned). The survey 24
shall be accurate to within 0.1 FT horizontally and vertically and shall be based on the existing 25
site survey control coordinate system. The survey will document the northing, easting, and 26
elevation of each well at the existing grade and at the top of the casing pipe. 27
B. Contractor shall provide a certified boring log for each well recording existing ground surface at 28
well prior to boring, final drilling depth and total boring length. 29
1. The same data shall be recorded for any abandoned bore hole. 30
2. The boring logs shall be certified by driller. 31
3. The certified boring logs shall be provided to Engineer prior to the Contractor requesting final 32
payment. 33
34
END OF SECTION 35
36