0105_CobleCDLF_RevisedFacility&CCP&CQArpt_FID1427892_20200724

1
Chao, Ming-tai
From:Kemppinen, Hannu <[e-mail]>
Sent:Friday, July 24, 2020 11:14 AM
To:Chao, Ming-tai; Stanley, Sherri
Cc:Deanna Martin ([e-mail]); Joyce, Leonard; Davis, Amy; Bertolet, Larry
Subject:RE: [External] Comment_ 0105-CDFL-1998, 2020619 Phase 3A Partial closure Report
Attachments:01-05-CDLF_20200724 3A RTC.pdf
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Hi Ming:
On behalf of Coble’s CDLF, LaBella has prepared responses to the Phase 3A partial closure report received on June
24, 2020. The attached document includes revisions to the 3A closure report, Facility Plan and Closure & Post
Closure Care Plan. We understand Coble will provide the financial assurance mechanism based on the revised
closure and post-closure care plans thru their bonding company.

We hope these prepared documents combined in this submittal will provide all the information to the Section to
accept the 3A partial closure and prepare permit to continue operate the CDLF landfill. Thank you for your
assistance in the preparation of these documents.

Hannu Kemppinen, PG
LaBella Associates | Senior Project Manager

336-790-2252 direct
336-323-0092 office
336-209-7156 mobile

From: Chao, Ming‐tai <[e-mail]>  
Sent: Monday, July 20, 2020 12:41 
To: Kemppinen, Hannu <[e-mail]> 
Cc: Deanna Martin ([e-mail]) <[e-mail]>; Joyce, Leonard <[e-mail]>; 
Davis, Amy <[e-mail]>; Bertolet, Larry <[e-mail]>; Stanley, Sherri 
<[e-mail]> 
Subject: RE: [External] Comment_ 0105‐CDFL‐1998, 2020619 Phase 3A Partial closure Report 

Hi Hannu:

I knew that Coble closed out some Phase 3A landfill area as shown on the closure CQA report dated June
2020. But the Phase 3 permit application including Facility and C&PC Plans must reflect the latest changes
which, as the basis, will be incorporated into the new permit conditions. Attached is the latest Closure and Post-
closure Plan (C&PC Plan) dated December 2019 and prepared by LaBella, and you can see the inconsistent info
existing in the plan.

I received a bond rider/FA amount effective 11/05/2019 which must be the same as the amounts in cost
estimates in C/PC & PACA. Please let me know if you have any further questions of the requests.

2

From: Kemppinen, Hannu <[e-mail]>  
Sent: Monday, July 20, 2020 12:02 PM 
To: Chao, Ming‐tai <[e-mail]> 
Cc: Deanna Martin ([e-mail]) <[e-mail]>; Joyce, Leonard <[e-mail]>; 
Davis, Amy <[e-mail]>; Bertolet, Larry <[e-mail]> 
Subject: [External] Comment_ 0105‐CDFL‐1998, 2020619 Phase 3A Partial closure Report 

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[e-mail] 

Ming,
While we are finalizing the Coble 3A closure submittal, and reviewing your (below) introduction paragraph, we have
questions needing clarification regarding “revised permit renewal application and financial assurance mechanism.”

Responses to the permit renewal comments was submitted to the Section in November 1, 2019 and the attached
response was received on January 2020 stating “two major issues prevent permit being issued.”
1. Property deed information and financial assurance.
Coble provided the deed map on January 17, 2020, and it was acceptable to the Section.
2. Financial assurance was said to be pending the Phase 3A partial closure until the work would be
completed, and then the FA would be revised.
We have revised closure and post closure plans to be submitted with the 3A Closure report response letter
submittal.

I had talked about the FA revision with Sarah Rice in March 2020 and it was our understanding that the
closure & post-closure plans and FA will be finalized after the phase 3A closure was completed. Coble plans
to continue the same financial mechanism as in past with revised acreages closed and active operation.

Your advise will be much appreciated,

Hannu Kemppinen, PG
LaBella Associates | Senior Project Manager

336-790-2252 direct
336-323-0092 office
336-209-7156 mobile

From: Chao, Ming‐tai <[e-mail]>  
Sent: Wednesday, June 24, 2020 14:43 
To: Deanna Coble Martin <[e-mail]> 
Cc: Kirchner, Chuck <[e-mail]>; Stanley, Sherri <[e-mail]>; Kemppinen, Hannu 
 Ming‐Tai, Chao, P.E. 
Environmental Engineer, Solid Waste Section 
Division of Waste Management 
North Carolina Department of Environmental Quality 
919.707‐8251 (Office) 
[e-mail] 
3
<[e-mail]>; Joyce, Leonard <[e-mail]>; Davis, Amy <[e-mail]> 
Subject: Comment_ 0105‐CDFL‐1998, 2020619 Phase 3A Partial closure Report 

Dear Deanna:
FID 1416315
After completing a review of the June 2020 CQA report (FID 1416315) for a partial closure of the Coble’s
C&DLF, Permit No. 0105-CDLF-1998, the Solid Waste Section has several comments below. Please
respond the comments in writing and submit a final CQA report for this 5.6-acre partial closure activity and
the revised permit renewal application for Phase 1 thru 3 of the C&DLF including and the rule-required
financial assurance mechanism before July 24, 2020. If you have any problem to produce the requested
documents by the date of July 24, 2020 for a reasonable cause please contact myself for a new submittal
date within five (5) working days (by June 30, 2020) after receiving this e-mail message. The existing
permit (DIN 25405) for operating Coble’s C&DLF expired on September 02, 2019, and the Solid Waste
Section will revoke the permit and enforce the site closure on September 02, 2020 if the requested
documents/applications are not submitted in time for approval. This permit decision was originally sent to
your attention via an e-mail message on January 08, 2020 (FID 1387209).

The comments on the 5.6 acre partial closure CQA Report are:
1. (Sections 1 & 2.2.4) The partial closure report (DIN 24357) and the Phase 3 renewal application dated
December 2019 (FID 1378626) stated that the disposal area of 9.13 acres was partially closed, not 9.8
acres. The total acreage of partial closure areas of the C&DLF shall be 14.73 acres (= 9.13+5.6). Please
provide the correct closure acreage.

2. (Section 2.2) This Section states that “the surveyor verified the existing intermediate cover thickness to
be a minimum of 12 inches prior to Coble commencing the construction of low permeability infiltration
soil layer.” There are no survey data in Appendix 3 to confirm that the thicknesses of intermediate
cover over the 5.6-acre closure area meet the specified requirement. Please provide survey data.

3. (Section 2.2.1) According to the CQA plan (including Table 1) and Technical Specifications of the
approved Phase 3 PTC application dated March 2008 (DIN 4862), the report does not include the
following testing results:
i. Construction and QA/QC testing results associated with the test pad of the 18-inch-thick
infiltration layer [Sections 02218 & 02229 of the approved Technical Specifications (DIN
4862)].
ii. Please explain the discrepancy of number of tests described in Section 2.2.1 and those shown in
Appendices 1 & 2.
Test item Section 2.2.1 Appendices 1 & 2
K, from Shelby tube 18 18
K, from remold sample 2 1
PI NA 1
Standard Proctor NA one point method - 1
In-place density & moisture
content (nuclear gauge)
30 106 tested and 96 passed
In-place density & moisture
content (drive cylinder)
18 21 tested and 19 passed
4
iii. The Engineering Plan and Technical Specification Sections 02224 & 02227 and Table 1 (DIN
4862) require the final soil cover system pertaining a minimum friction angle of 26.6 degree by
ASTM D4767. Please provide the testing result in the CQA report.

4. (Section 2.2.2) The results of testing, per requirement listed in Table 1(DIN 4862), on the protective soil
layer/erosion layer are not available in the CQA report. Please provide the test results.

5. (Section 2.2.3)
i. The gas well diameter and the depth deviate from the approved ones (DIN 17384). Please
explain who approves the deviation and why the approval is acceptable by the Solid Waste
Section.
ii. This Section states that “for the Phase 3A closure, Coble installed six passive gas vents in a C&D
landfill, excavated pits thru the cover and infiltration layers to place perforated PVC pipes in
the top layer of the waste.” Additionally, the photos in Appendix 2 clearly show that areas for
installing gas vent were excavated after the final soil cover was completed installed. The gas
vent construction destroys the constructed soil cover; therefore, the soil testing (including, but
not limited to in-pace density & moisture content and hydraulic conductivity) on each lift per
layer must be properly conducted to demonstrate the final cover is successfully restored.

6. (Appendix 1, page 9 of 207)
i. The maximum dry density for soil sample CL-1 (Lab ID 2020-019-001-001) is 95.6 pcf. Please
correct the typo in the summary table including the % of the compaction effort.
ii. According to Table 1 (DIN 4862), the following soil testing at the frequency of one test per
10,000 CY is required, but the Lab testing results are not available in the CQA report. The
required tests are:
Particle size (ASTM D422 & D1140), soil classification (ASTM D 2487), moisture content
(ASTM D2216), PI (ASTM D4318), Standard Proctor (ASTM D698).

7. (Appendix 2, page 137 of 207) The in-place density test results at the Acre 13 (lift 1) & Acre 12 (Lift 3)
that are summarized in Field Daily Report dated 11/26/14 failed to meet the specified compaction effort
- 95% maximum dry density.

8. (Appendix 2, page 150-151)
i. The in-place density test results at the Acre 13 (lift 3) are failed to meet the specified compaction
effort - 95% maximum dry density.
ii. The density results of sample DC-1 showed on the summary table are inconsistent to those in lab
report on page 151.

9. (Appendix 3)
i. The survey points to measure the thickness of each layer of the final cover are not available on
the attached drawing sheets.
ii. The partial closure activities were not completed until March 09, 2020 (Referring Section 2.2),
but the as-built survey was certified by the licensed survey dated October 10, 2019. Why the as-
built survey is permissible?

Please contact me if you have any question of the comments.
5

From: Chao, Ming‐tai  
Sent: Friday, June 19, 2020 2:57 PM 
To: Deanna Coble Martin <[e-mail]> 
Cc: Kirchner, Chuck <[e-mail]>; Stanley, Sherri <[e-mail]>; Kemppinen, Hannu 
<[e-mail]> 
Subject: RE: [External] 0105‐CDFL‐1998 2020619 Phase 3A Partial closure Report 

Dear Mrs. Martin:

The Solid Waste Section receives the electronic copy of the CQA report for Phase 3A partial closure; this report
is uploaded to Laserfiche with a FID 1416315. Have a wonderful day.

From: Kemppinen, Hannu <[e-mail]>  
Sent: Friday, June 19, 2020 1:25 PM 
To: Chao, Ming‐tai <[e-mail]> 
Cc: Deanna Martin ([e-mail]) <[e-mail]>; [e-mail]; Joyce, Leonard 
<[e-mail]> 
Subject: [External] 0105‐CDFL‐1998 2020619 Phase 3A Partial closure Report 

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[e-mail] 

Ming,
6
On behalf Coble’s CDLF, LaBella has prepared the attached Phase 3A partial closure report for the Solid Waste
Section review. Following the partial closure certification by the Section, we will update the landfill closure and post-
closure care plans, and financial assurance. To prepare these proposed updates, we have asked Coble to prepare
the annual Solid Waste Report 2020 with annual tonnage data and updated survey. These data will be incorporated
to update the closure and post-closure care plans and the annual financial assurance in accordance with 13B
.0546.

Thank you for your assistance with the Coble’s CD landfill operations and finalizing the permit renewal process that
has been underway for quite some time. Should you have questions regarding the submitted report, we are available
to help and provide clarification.

Thank you and have a great summer weekend.

Hannu Kemppinen, PG
LaBella Associates | Senior Project Manager
336-790-2252 direct
336-323-0092 office
336-209-7156 mobile
2211 West Meadowview Road, Suite 101
Greensboro, NC 27407
labellapc.com [labellapc.com] 

July 24, 2020
Ming-Tai Chao, P.E.
Permitting Branch, Solid Waste Section
Division of Waste Management
North Carolina Department of Environmental Quality
1646 Mail Service Center
Raleigh, NC 27699-1646

RE: Construction Quality Assurance Certification of Closure
Phase 3A Partial Closure
Coble’s C&D Landfill
Permit No. 01-05-CDLF-1998
5833 Foster Store Road
Liberty, NC 27298
Project No. 2191087 Phase 02

Dear Ming:

This letter is to certify that the revisions to the construction quality assurance (CQA) report and related
comments dated June 24, 2020 have been addressed for the recently completed Phase 3A Partial
Closure of the Coble’s C&D Landfill. In my professional opinion, the construction meets the applicable
requirements of the North Carolina Solid Waste Management Rules 15A NCAC 13B .0541, and was
completed in accordance with the approved closure plans and specifications. As used herein, the word
certify shall mean an expression of the undersigned engineer’s professional opinion to the best of their
knowledge, information, and belief, and does not constitute a warranty or guarantee.

The enclosed CQA record documentation report represents an accumulation of field, laboratory, and
other CQA data compiled in accordance with 15A NCAC 13B .0541 and the conditions of Permit No.
01-05-CDLF-1998, DIN 25405.

On behalf of Coble’s C&D Landfill, we would like to thank you in advance for reviewing the enclosed
report, conducting a site inspection, and issuing a certificate of partial closure. Please contact me at
[phone] if you have any questions or comments.

Respectfully submitted,
LaBella Associates
Amy Davis, P.E.
Regional Manager, Waste & Recycling Division

Enclosure
Copy: Mr. Kent Coble

July 24, 2020
Ming-Tai Chao, P.E.
Environmental Engineer, Solid Waste Section
Division of Waste Management
North Carolina Department of Environmental Quality
Raleigh, NC

RE: 01-05-CDLF-1998 Phase 3A Partial Closure

LaBella Associates (LaBella) submitted on June 19, 2020 Phase 3A partial closure report for the
Solid Waste Section review on behalf of Coble’s C&DLF. The Section informed the Cobles via e-mail
message dated June 24, 2020 with comments listed below. Section comments are repeated as they
appeared on the June 24, 2020 email, and our responses to the comments are in bold font for
clarity and ease of reading.
After completing a review of the June 2020 CQA report (FID 1416315) for a partial closure of the
Coble’s C&DLF, Permit No. 0105-CDLF-1998, the Solid Waste Section has several comments
below. Please respond the comments in writing and submit a final CQA report for this 5.6-acre
partial closure activity and the revised permit renewal application for Phase 1 thru 3 of the C&DLF
including and the rule-required financial assurance mechanism before July 24, 2020. If you have any
problem to produce the requested documents by the date of July 24, 2020 for a reasonable cause please contact myself for a new submittal date within five (5) working days (by June 30, 2020) after
receiving this e-mail message. The existing permit (DIN 25405) for operating Coble’s C&DLF
expired on September 02, 2019, and the Solid Waste Section will revoke the permit and enforce the
site closure on September 02, 2020 if the requested documents/applications are not submitted in time for approval. This permit decision was originally sent to your attention via an e-mail message on
January 08, 2020 (FID 1387209).
The comments on the 5.6 acre partial closure CQA Report are:
1. (Sections 1 & 2.2.4) The partial closure report (DIN 24357) and the Phase 3 renewal application
dated December 2019 (FID 1378626) stated that the disposal area of 9.13 acres was partially closed, not 9.8 acres. The total acreage of partial closure areas of the C&DLF shall be 14.73
acres (= 9.13+5.6). Please provide the correct closure acreage.
Phase Permitted Revised
Footprint Closed Open
1 7 6.5(1) 4.2 2.3
2A 1 0.9(1) 0.9 0
2B 4.8 4.6(1) 3.9 0.7
3A 6.3 6.3 5.6 0.7
1-3A 19.13 18.3 14.73 3.6

2
Sections 1 and 2.2.4 have been corrected as noted. Note in the permit modified the waste
footprints of Phase 1, 2A and 2B. The perimeter road is constructed in the approved waste footprint
of Phases 1 (0.5 acres), 2A (0.1 acres), and 2B (0.2 acres). Since no waste has ever been disposed
underneath the perimeter road, the areas occupied by the road (approximately 0.8 acres in total) are
excluded from the originally approved waste footprint of 66.8 acres (DIN 24357).

2. (Section 2.2) This Section states that “the surveyor verified the existing intermediate
cover thickness to be a minimum of 12 inches prior to Coble commencing the
construction of low permeability infiltration soil layer.” There are no survey data in
Appendix 3 to confirm that the thicknesses of intermediate cover over the 5.6-acre
closure area meet the specified requirement. Please provide survey data.

Paragraph 2.2 has been revised to state the intermediate layer is part of the operational
cover and in order to ensure adequate thickness of the closure cap, Coble constructed the
infiltration and cover soil layers thicker than required. The existing intermediate cover
thickness was verified and surface was surveyed to establish base grade for the infiltration
layer construction.

3. (Section 2.2.1) According to the CQA plan (including Table 1) and Technical
Specifications of the approved Phase 3 PTC application dated March 2008 (DIN 4862),
the report does not include the following testing results:
i. Construction and QA/QC testing results associated with the test pad of the 18-
inch-thick infiltration layer [Sections 02218 & 02229 of the approved Technical
Specifications (DIN 4862)].

Phase 3A partial closure continued the partial closure of the C&D LF, and Coble
continued in 3A closure using the same soil material as in Phases 1 and 2 closure.
As a practical matter, each acre first lift meeting permeability requirement was
treated as test pad.

ii. Please explain the discrepancy of number of tests described in Section 2.2.1 and
those shown in Appendices 1 & 2.

Test item Section 2.2.1 Appendices 1 & 2
K, from Shelby tube 18 18
K, from remold sample 2 1
PI NA 1
Standard Proctor NA one point method - 1
In-place density & moisture
content (nuclear gauge)
30 106 tested and 96 passed
In-place density & moisture
content (drive cylinder)
18 21 tested and 19 passed

3
Paragraph 2.2.1 has been revised to eliminate discrepancy in testing

iii. The Engineering Plan and Technical Specification Sections 02224 & 02227 and
Table 1 (DIN 4862) require the final soil cover system pertaining a minimum friction angle of 26.6 degree by ASTM D4767. Please provide the testing result
in the CQA report.

March 2008 CQA Plan, Table 1 ASTM 4767 one/material for cap construction, unless
otherwise approved by engineer. Phase 3A partial closure continued the partial
closure of the C&D LF Phases 1 and 2, and Coble continued using the same soil
material for the 3A closure. The CQA engineer accepts test results of previously
approved material for the subsequent sections continuing closure work.

4. (Section 2.2.2) The results of testing, per requirement listed in Table 1(DIN 4862), on the
protective soil layer/erosion layer are not available in the CQA report. Please provide the
test results.

The infiltration layer testing is required, but protective cover layer field-testing is not required
in Table 1. The protective cover soil was spread in two lifts and tracked up and down the
slope with the dozer and compactor to achieve a nominal compaction, so that vegetation can
develop a proper root system deep in the soil, as stated in the Section B. Engineering Plan,
Final Cover System - c. Protective / Erosion Layer.

5. (Section 2.2.3)
i. The gas well diameter and the depth deviate from the approved ones (DIN
17384). Please explain who approves the deviation and why the approval is
acceptable by the Solid Waste Section.

The gas vents were installed according to the 2012 approved method by excavation.
When DIN 17384 was approved, Coble having larger pipe on hand asked permission
to use larger vent pipe, but this time for 3A closure Coble installed the six-inch vent
pipes to comply with the Section approved standard pipe size for LFG vents.

ii. This Section states that “for the Phase 3A closure, Coble installed six passive gas
vents in a C&D landfill, excavated pits thru the cover and infiltration layers to
place perforated PVC pipes in the top layer of the waste.” Additionally, the
photos in Appendix 2 clearly show that areas for installing gas vent were
excavated after the final soil cover was completed installed. The gas vent
construction destroys the constructed soil cover; therefore, the soil testing
(including, but not limited to in-pace density & moisture content and hydraulic
conductivity) on each lift per layer must be properly conducted to demonstrate the
final cover is successfully restored.

The excavated infiltration soil was replaced in the pit around the gas vent and
compacted with the backhoe bucket. Cover soil was graded and tracked with dozer to
restore the closure surface. By restoring the infiltration and protective cover with the

4
excavated material additional soil testing is not necessary in restoring the small area
around the vent pipe.

6. (Appendix 1, page 9 of 207)
i. The maximum dry density for soil sample CL-1 (Lab ID 2020-019-001-001) is
95.6 pcf. Please correct the typo in the summary table including the % of the
compaction effort.

Requested correction made in the lab testing summary table.

ii. According to Table 1 (DIN 4862), the following soil testing at the frequency of
one test per 10,000 CY is required, but the Lab testing results are not available in
the CQA report. The required tests are:
Particle size (ASTM D422 & D1140), soil classification (ASTM D 2487),
moisture content (ASTM D2216), PI (ASTM D4318), Standard Proctor (ASTM
D698).

During the infiltration layer construction field-testing results are continuously
compared to existing Proctor data, moisture content, and visual classification.
Particle size and plastic index are closely related with permeability results. Due to
material consistency and satisfactory permeability testing results of the infiltration
layer construction, the referenced verification testing the CQA engineer considered
redundant.

7. (Appendix 2, page 137 of 207) The in-place density test results at the Acre 13 (lift 1) &
Acre 12 (Lift 3) that are summarized in Field Daily Report dated 11/26/14 failed to meet
the specified compaction effort - 95% maximum dry density.

The referenced testing satisfied permeability requirement thus the engineer accepted the
field compaction result below 95%.

8. (Appendix 2, page 150-151)
i. The in-place density test results at the Acre 13 (lift 3) are failed to meet the
specified compaction effort - 95% maximum dry density.

The referenced testing satisfied permeability requirement thus the engineer
accepted the field compaction result below 95%.

ii. The density results of sample DC-1 showed on the summary table are inconsistent
to those in lab report on page 151.

Requested correction has been made in the lab testing summary table.

9. (Appendix 3)
i. The survey points to measure the thickness of each layer of the final cover are not
available on the attached drawing sheets.

5

Surveyor revised drawings as requested.

ii. The partial closure activities were not completed until March 09, 2020 (Referring Section 2.2), but the as-built survey was certified by the licensed survey dated
October 10, 2019. Why the as-built survey is permissible?

Surveyor revised the date as requested.

Respectfully submitted,
LaBella Associates

Hannu Kemppinen
Senior Project Consultant

Prepared For:
COBLE’S SANDROCK, INC.
5833 FOSTER STORE ROAD
LIBERTY, NC 27298

Submitted by:
LaBella Associates
2211 West Meadowview Rd.
Suite 101
Greensboro, NC 27407
[phone]

PHASE 3A PARTIAL CLOSURE CQA REPORT
COBLE’S SANDROCK
CONSTRUCTION & DEMOLITION DEBRIS LANDFILL
PERMIT NO. 01-05-CDLF-1998
June 2020, Revised July 2020
Project no. 2191087

Cobles Sandrock, Inc. TOC LaBella Associates
C&D LF Partial Closure June 2020
CQA Certification Report

TABLE OF CONTENTS

Page

1.0 INTRODUCTION 1

2.0 CONSTRUCTION QUALITY ASSURANCE PROGRAM
2.1 Roles and Responsibilities 1
2.2. Earthwork 1
2.2.1 Infiltration Layer Testing and Results 2
2.2.2 Protective Cover – Erosion Layer 3
2.2.3 Passive Gas Vents 3
2.2.4 Construction Survey 3

Appendix 1: Laboratory Testing Results

Appendix 2: Daily Field Reports

Appendix 3: Record Survey Drawings

Cobles Sandrock, Inc. Page 1 LaBella Associates
C&D LF Partial Closure July 2020
CQA Certification Report
1.0 INTRODUCTION

This report, prepared by LaBella Associates (LaBella) on behalf of Cobles Sandrock,
Inc. (Cobles) addresses the quality assurance procedures and activities conducted during
partial closure construction of the Phase 3A at the Cobles C&D landfill in Alamance County,
North Carolina. The documents comprising this report were compiled for the C&D landfill
closure construction with North Carolina Solid Waste Management Regulations, 15A NCAC
13B and the Phase 3 Permit to Construct # 01-05.

Landfill partial closure report submitted to the Solid Waste Section by Joyce
Engineering, Inc. (now LaBella Associates) in August 2013 included 11 areas of the landfill
Phases 1 and 2 in total area of 9.8 acres. Parts of Phase 1 and 2 west side toe area were
subtracted from closure in 2014 to reduce the closure to 9.13 acres. This report covers the
continuing closure construction Coble has completed in areas 12 thru 17 of the Phase 3A
during 2014, 2016, 2019, and 2020. This report covers 5.6 acres of closure.

Cobles acted as the General Contractor and performed all closure construction
earthwork during the period from 2014 through 2020.

LaBella provided third party construction quality assurance program services.
Geotechnics assisted LaBella in the field soil testing and collected samples for soil materials
laboratory testing. The soils laboratory testing was conducted at Geotechnics, Inc. in
Raleigh, NC.

Allred Land Surveying of Snow Camp, NC provided survey for the Phase 3A partial
closure.

2.0 CONSTRUCTION QUALITY ASSURANCE PROGRAM

2.1 Roles and Responsibilities

Cobles retained LaBella to provide construction quality assurance during the Phase
3A landfill partial closure construction. As an independent consultant from the
Owner/Contractor, LaBella, along with the construction field representative Geotechnics
provided documentation of the infiltration layer construction. A representative of
Geotechnics visited the site to follow the closure work progression by testing each acre-lift in
the field compaction and collecting soil samples for laboratory permeability testing. Coble
retained a surveyor to provide periodic survey of the work to establish and maintain lines
and grades.

2.2 Earthwork

Coble continued the landfill partial closure construction in April 2014 by grading Area
12 on north side of the landfill Phase 3A to prepare for closure. The existing intermediate
cover surface was surveyed to establish base grades prior to Coble commencing the

Cobles Sandrock, Inc. Page 2 LaBella Associates
C&D LF Partial Closure July 2020
CQA Certification Report
construction of low permeability infiltration soil layer. The surveyor verified the intermediate
cover layer thickness in random locations presented in the drawing titled “Intermediate
Layer Boring Checks.” The intermediate layer is part of the operational cover and in order to
ensure adequate thickness of the closure cap, Coble constructed the infiltration and cover
soil layers thicker than required. The total section thickness of the infiltration and vegetative
layer section is a minimum of three feet.

Following the grading and survey of the intermediate cover, Coble proceeded with low
permeability soil infiltration layer construction. Area 12 closure construction was finalized in
November 2014. Area 13 closure work began in October 2016 and the work was
completed in December 2016. Coble continued Areas 14, 15 and 16 closure as part of the
Phase 3A partial closure in 2019. In 2020 Coble finished the 3A partial closure work
completing the area 17. Total of the areas 12 thru 17 closure is 5.6 acres.

The work was conducted utilizing the landfill heavy equipment; excavator, track
loader, compactor, and truck or a pan to deliver the soil to each area under closure
construction.

2.2.1 Infiltration Layer Testing and Results

Construction soil samples were collected and submitted to laboratory testing for
identifying index properties of the soil proposed for the landfill partial closure work in 2013.
The laboratory testing results are compiled in Appendix 1.

The field-testing of each lift included moisture and density testing with nuclear
methods, and a drive cylinder test to verify the nuclear gauge readings. Two Shelby tubes
were pushed into the soil to collect undisturbed soil samples of the low-permeability
material for laboratory testing.

At the beginning of each closure area, Coble constructed the first lift and treated it as
a test pad. With satisfactory permeability results, the closure could proceed to the next lift
construction. The infiltration layer was constructed in three lifts, each a minimum of six
inches in compacted thickness. The field testing records of the infiltration layer construction
including nuclear gauge testing, drive cylinder, undisturbed permeability sample (Shelby
tube), and daily field reports are included in Appendix 2.

Soil infiltration layer construction CQA testing included in-place wet density, moisture
content by nuclear method (ASTM D6938), calculated dry density and percent compaction
with a Troxler Model 3440 portable nuclear gauge. A density of soil in place by drive cylinder
method (ASTM D 2937) was used to collect a sample of soil to verify the nuclear gauge test
results for each acre lift. If the nuclear gauge moisture readings were found to deviate
significantly from the moisture percentage by direct heating method, the dry density and in-
place compaction percentage were re-calculated to verify compaction of the soil. If the
placed soils were found not to meet the specification in a given area, Coble was informed of
the test results and asked to re-work the soil. Following the soil re-work, the area was
subjected to CQA testing verification. With satisfactory nuclear gauge readings at the
randomly selected test locations the CQA field personnel pushed a drive cylinder to collect

Cobles Sandrock, Inc. Page 3 LaBella Associates
C&D LF Partial Closure July 2020
CQA Certification Report
the moisture-density verification sample and a Shelby tube to collect the undisturbed
sample for laboratory hydraulic conductivity test (ASTM D5084).

The partial closure construction was divided into areas each approximately one acre
in size to track the construction and field-testing. The field and laboratory testing included
3-acre lifts. Each lift was tested at a minimum of five randomly selected locations by nuclear
method, one drive cylinder, and one Shelby tube. The infiltration layer testing results met the
moisture-compaction with the permeability requirement. Appendix 1 includes laboratory
testing results and summary table.

2.2.2 Protective Cover – Erosion Layer

An 18-inch thick protective cover soil layer was placed over the completed infiltration
layer. The soil was spread in two lifts and tracked up and down the slope with the dozer and
compactor to achieve a nominal compaction so that vegetation can develop a proper root
system deep in the soil. Following placement of the erosion layer, the closed side slopes
were seeded to establish a vegetative cover during 2020 growing season.

2.2.3 Passive Gas Vents

Due to C&D LF waste content, drilling using traditional bucket auger methods for the
construction of passive gas vents is impossible. This installation modification to the landfill
gas vents was submitted October 1, 2012 to the SWS for review and approval (Section
authorization was given on October 9, 2012, Doc. ID 17384).

For the Phase 3A closure, Coble installed six passive gas vents in the C&D landfill,
excavated pits thru the cover and infiltration layers to place perforated PVC pipes in the top
layer of the waste. The 6-inch perforated segment of the vent pipes were installed in waste
to a minimum depth of 6 feet below the infiltration cap. Coble used for the excavation a
backhoe, and filling it with #57 stone. The excavated low-permeability soil was then
replaced back in the pit and compacted tamping with the excavator bucket to close the
infiltration layer. Protective soil was replaced and graded over the worked area to provide a
continuous layer of the closure cover.

2.2.4 Construction Survey

Coble retained Jeff Allred Land Surveying of Snow Camp, NC to provide survey for the
landfill partial closure work. After grading the intermediate cover, the prepared surface was
surveyed. The surveyor verified the intermediate cover layer thickness in random locations
presented in the drawing titled “Intermediate Layer Boring Checks.” The top of intermediate
cover thus served as base grades for the infiltration layer construction. At the completion of
the three lifts of infiltration layer a minimum of 18-inches in thickness, the surface was then
graded and surveyed. Protective cover a minimum of 18-inches in thickness was placed
over the infiltration layer. Once again, Coble graded the surface to final grades and the
surface was surveyed. The three surveys and the survey data point records are included in
Appendix 3.

Cobles Sandrock, Inc. Page 4 LaBella Associates
C&D LF Partial Closure July 2020
CQA Certification Report
The infiltration layer thickness meets or exceeds the minimum required thickness of
1.5 feet. In order to ensure adequate thickness of the infiltration layer and closure cap,
some areas were constructed thicker than required. The total section thickness of the
infiltration and protective cover soil layer section is a minimum of three feet. Coble used the
same soil material for both layers and this report reflects our acceptance of the extra clay
layer thickness replacing possible shortage of erosion layer in certain areas. In LaBella’s
professional opinion, this condition will not compromise the performance of the cap in any
way nor be detrimental to the establishment of grass or long-term maintenance of the cover.
The closure of areas 12, 13, 14, 15, 16 and 17 construction was conducted on
assumed acre basis on 6 acres. The closure construction survey encompasses total area of
5.6 acres.
The C&D landfill partial closure report for phases 1 and 2 August 2013 included 11
areas equaling 9.13 acres. This report covers partial closure of the Phase 3A C&D landfill of
6 areas equaling 5.6 acres.
Total areas closed to date encompasses 9.13 + 5.6 = 14.73 acres based on the
combined closure surveys. Financial assurance will be revised based on the reported
acreage of closure and remaining active area.

END OF REPORT
Project 2191087.00.02
LaBella Associates, P.C.
Perm (K)
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)Fines LL PL PI
2012-656-01-01 Lowperm R2 ML 18.2%105.6 20.5%2.3%104.3 98.8%1.1E-06 66.7%37 30 7
2012-656-01-02 Intermed CL 15.1%112.8 17.6%2.5%106.2 94.1%4.7E-07 56.0%39 25 14
2012-656-12-01 P-1 ML 16.0%107.1 17.9%1.9%102.2 95.4%4.7E-06 66.7%39 30 9
12-02 P-2 ML 17.6%106.5 18.7%1.1%102.3 96.1%1.1E-06 56.0%41 27 14
12-03 P-3 ML 16.8%108.8 18.9%2.1%103.4 95.0%4.6E-06 56.0%38 28 10
Perm (K)
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)
2014-677-01-01 A12 L1 ML 18.2%105.6 26.5%8.3%95.6 90.5%1.5E-07
2014-677-02-01 A12 L2 ML 18.2%105.6 18.4%0.2%104.1 98.6%1.2E-07
*2014-677-03-01 A12 L3 CL 15.1%113.9 20.8%5.7%106.2 93.2%3.9E-08
Perm (K)
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)
2016-803-01-01 A13 L1 CL 15.1%113.9 11.5%-3.6%109.9 96.5%1.2E-06
2016-803-02-01 A13 L2 CL 15.1%113.9 10.8%-4.3%109.2 95.9%3.8E-06
2016-803-03-01 A13 L3 CL 15.1%113.9 9.5%-5.6%103.7 91.0%6.9E-06
Perm (K)
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)
2019-195-001-01 A14 L1 CL 15.1%113.9 12.5%-2.6%111.4 97.8%2.0E-06
2019-195-002-01 A14 L2 CL 15.1%113.9 7.1%-8.0%116.6 102.4%1.2E-07
2019-195-003-02 A14 L3 CL 15.1%113.9 14.6%-0.5%111.2 97.6%2.7E-07
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)2019-195-001-02 A15 L1 CL 15.1%113.9 14.6%-0.5%110.0 96.6%1.0E-062019-195-002-02 A15 L2 CL 15.1%113.9 10.2%-4.9%112.6 98.9%5.1E-072019-195-003-01 A15 L3 CL 15.1%113.9 13.5%-1.6%119.8 105.2%1.6E-07
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)2019-195-004-01 A16 L1 CL 15.1%113.9 8.9%-6.2%113.8 99.9%2.0E-062019-195-005-01 A16 L2 CL 15.1%113.9 13.9%-1.2%114.3 100.4%2.5E-062019-195-006-01 A16 L3 CL 15.1%113.9 9.6%-5.5%110.0 96.6%7.4E-07
Perm (K)
Lab ID Sample USCS OMC MDD MC OMC-MC DD DD/MDD (cm/sec)Fines LL PL PI2020-019-001-001 CL-1 MH 25.3%95.6 25.3%0.0%91.4 95.6%2.5E-06 70.2%56 40 162020-019-002-01 A17 L1 MH 25.3%95.6 16.7%-8.6%95.7 100.1%2.0E-062020-019-003-01 A17 L2 MH 25.3%95.6 29.2%3.9%91.9 96.1%2.1E-072020-019-003-02 A17 L3 MH 25.3%95.6 22.0%-3.3%95.2 99.6%2.5E-06
2020 Closure Construction Standard
Proctor Shelby Tube Samples
2016 Closure Construction Standard
Proctor Shelby Tube Samples
2019 Closure Construction Standard Proctor Shelby Tube Samples
2014 Closure Construction
Atterberg Limits
Standard
Proctor Shelby Tube Samples
Standard
Proctor Remolded Lab Samples2012 - Closure Construction
Atterberg Limits
COBLE'S SANDROCK CDLF PHASE 3A CLOSURE CONSTRUCTION 2014-2020
90
95
100
105
110
115
120
125
0%5%10%15%20%25%30%35%DRY DENSITY, PCFMOISTURE CONTENT %
MOISTURE-DENSITY RESULTS OF CLAY SOIL SAMPLESPERMEABILITY LESS THAN 1.0E-05 CM/SEC Saturation Line SpecificGravity = 2.80
Lower Bound ofAcceptance Zone
Remolded Samples
Partial Closure Acre-Lifts
A12
A13
A14
A15
A16
A17
SURVEY POINT INTERM.
COVER ELEV.
LAYER
THICKNESS
(Ft.)
INFILTRATION
CLAY SOIL ELEV.
LAYER
THICKNESS
(Ft.)
FINAL COVER
ELEV.
TOTAL
THICKNESS SURVEY POINT INTERM.
COVER ELEV.
LAYER
THICKNESS
(Ft.)
INFILTRATION
CLAY SOIL ELEV.
LAYER
THICKNESS
(Ft.)
FINAL COVER
ELEV.
TOTAL
THICKNESS
10213 619.11 2.20 621.31 1.61 622.92 3.81 11455 603.55 1.56 605.11 1.74 606.85 3.30
10729 621.31 11548
10861 622.92 11612
10198 612.95 1.73 614.68 3.87 618.55 5.60 11431 632.48 2.43 634.91 1.76 636.67 4.19
10731 614.68 11529
10898 618.55 11596
10185 602.29 1.50 603.79 3.74 607.53 5.24 11417 646.74 1.55 648.29 1.66 649.95 3.21
10733 603.79 11513
10900 607.53 11579
10215 622.33 1.50 623.83 3.53 627.36 5.03 11428 644.41 1.77 646.18 1.84 648.02 3.61
10744 623.83 11526
10859 627.36 11590
10200 612.74 1.88 614.62 2.64 617.26 4.52 11432 629.57 2.53 632.10 2.07 634.17 4.60
10770 614.62 11530
10929 617.26 11594
10202 616.43 1.50 617.93 1.52 619.45 3.02 11449 611.54 1.87 613.41 1.51 614.92 3.38
10773 617.93 11542
10933 619.45 11606
10158 585.17 3.34 588.51 1.98 590.49 5.32 11456 601.42 2.91 604.33 2.15 606.48 5.06
10754 588.51 11549
10911 590.49 11613
11459 600.25 2.58 602.83 1.64 604.47 4.22
11116 616.43 1.63 618.06 1.74 619.80 3.37 11616
11116STK1 618.06 11448 608.72 1.63 610.35 2.27 612.62 3.90
11116STK2 619.80 11541
11117 614.10 1.75 615.85 1.72 617.57 3.47 11605
11117STK1 615.85 11433 627.19 1.81 629.00 1.69 630.69 3.50
11117STK2 617.57 11531
11118 615.59 1.68 617.26 1.93 619.19 3.61 11595
11118STK1 617.26 11427 640.75 2.25 643.00 1.60 644.60 3.85
11118STK2 619.19 11525
11119 612.68 1.87 614.56 1.67 616.22 3.54 11589
11119STK1 614.56 11426 636.73 2.03 638.76 1.82 640.58 3.85
11119STK2 616.22 11524
11120 611.47 1.60 613.06 1.75 614.82 3.35 11588
11120STK1 613.06 11447 608.57 1.59 610.16 1.99 612.15 3.58
11120STK2 614.82 11540
11122 610.38 1.74 612.11 1.61 613.72 3.34 11604
11122STK1 612.11 11460 598.45 2.19 600.64 1.78 602.42 3.97
11122STK2 613.72 11553
11123 607.43 1.74 609.18 2.04 611.22 3.79 11617
11123_STK 609.18 11463 599.80 1.62 601.42 2.25 603.67 3.87
11123STK1 611.22 11556
11126 605.60 1.53 607.14 1.69 608.82 3.22 11620
11126STK1 607.14 11446 613.34 1.69 615.03 1.62 616.65 3.31
11126STK2 608.82 11539
11127 602.95 1.83 604.78 1.85 606.63 3.68 11603
11127STK1 604.78 11434 626.37 2.26 628.63 1.90 630.53 4.16
11127STK2 606.63 11532
11129 600.44 1.66 602.11 1.51 603.61 3.17 11596
11129STK1 602.11 11425 634.14 2.28 636.42 1.57 637.99 3.85
11129STK2 603.61 11523
11130 598.99 1.68 600.67 1.54 602.21 3.22 11587
11130STK1 600.67 11420 639.21 1.68 640.89 1.51 642.40 3.19
11130STK2 602.21 11516
11132 592.82 1.69 594.51 1.86 596.37 3.55 11582
11132STK1 594.51 11421 631.96 2.25 634.21 1.50 635.71 3.75
11132STK2 596.37 11517
11133 591.69 1.62 593.31 1.54 594.84 3.16 11583
11133STK1 593.31 11424 628.91 1.60 630.51 1.65 632.16 3.25
11133STK2 594.84 11522
11136 595.59 1.87 597.46 1.63 599.09 3.50 11586
11136STK1 597.46 11435 621.89 1.60 623.49 1.75 625.24 3.35
11136STK2 599.09 11533
11139 603.60 1.52 605.12 1.88 607.00 3.40 11597
11139STK1 605.12 11445 613.33 1.77 615.10 1.95 617.05 3.72
11139STK2 607.00 11538
11141 604.96 1.52 606.48 2.33 608.81 3.85 11602
11141_STK 606.48 11464 599.96 1.57 601.53 1.74 603.27 3.31
11141STK1 608.81 11557
11143 608.32 1.59 609.91 1.66 611.57 3.25 11621
11143_STK 609.91 11468 592.84 2.50 595.34 4.26 599.60 6.76
11143STK1 611.57 11561
11144 605.66 1.59 607.26 1.52 608.78 3.12 11623
11144STK1 607.26 11444 608.87 2.00 610.87 1.62 612.49 3.62
11144STK2 608.78 11537
11145 606.42 1.64 608.07 1.97 610.04 3.62 11601
11145STK1 608.07 11436 616.76 1.91 618.67 1.63 620.30 3.54
11145STK2 610.04 11534
11147 609.86 1.69 611.55 1.55 613.10 3.24 11598
11147_STK 611.55 11469 593.13 1.78 594.91 1.55 596.46 3.33
11147STK1 613.10 11562
11150 610.71 2.17 612.88 1.67 614.55 3.83 11629
11150_STK 612.88
11150STK1 614.55 11641 617.16 1.72 618.88 1.50 620.38 3.22
11151 612.75 1.75 614.50 2.28 616.78 4.03 11641_STK 618.88
11151_STK 614.50 11641STKA 620.38
11151STK1 616.78 11642 617.29 1.55 618.84 1.52 620.36 3.07
11154 608.12 1.68 609.80 2.91 612.71 4.59 11642_STK 618.84
11154STK1 609.80 11642STKA 620.36
11154STK2 612.71 11643 615.76 1.52 617.28 2.72 620.00 4.24
11155 612.55 1.96 614.51 1.98 616.50 3.95 11643_STK 617.28
11155_STK 614.51 11643STKA 620.00
11155STK1 616.50 11644 617.44 3.70 621.14 2.34 623.48 6.04
11156 614.94 2.00 616.94 2.09 619.03 4.09 11644_STK 621.14
11156_STK 616.94 11644STKA 623.48
11156STK1 619.03 11645 633.04 4.70 637.74 1.42 639.16 6.12
11157 613.77 1.59 615.35 1.59 616.95 3.18 11645_STK 637.74
AREA 12
AREA 13
AREA 14 and 15
AREA 16
COBLE SANDROCK C&D LANDFILL PHASE 3A PARTIAL CLOSURE
SURVEY POINT INTERM.
COVER ELEV.
LAYER
THICKNESS
(Ft.)
INFILTRATION
CLAY SOIL ELEV.
LAYER
THICKNESS
(Ft.)
FINAL COVER
ELEV.
TOTAL
THICKNESS SURVEY POINT INTERM.
COVER ELEV.
LAYER
THICKNESS
(Ft.)
INFILTRATION
CLAY SOIL ELEV.
LAYER
THICKNESS
(Ft.)
FINAL COVER
ELEV.
TOTAL
THICKNESS
11157STK1 615.35 11645STKA 639.16
11157STK2 616.95 11646 635.03 2.55 637.58 1.67 639.25 4.22
11158 617.93 1.58 619.51 1.70 621.21 3.28 11646_STK 637.58
11158STK1 619.51 11646STKA 639.25
11158STK2 621.21 11647 634.00 1.50 635.50 1.50 637.00 3.00
11160 621.65 1.85 623.50 1.57 625.06 3.41 11647_STK 635.50
11160STK1 623.50 11647STKA 637.00
11160STK2 625.06 11648 632.25 2.03 634.28 1.50 635.78 3.53
11161 621.81 1.94 623.75 1.59 625.34 3.53 11648_STK 634.28
11161STK1 623.75 11648STKA 635.78
11161STK2 625.34 11650 644.14 1.89 646.03 1.51 647.54 3.40
11163 624.29 1.91 626.19 2.78 628.97 4.69 11650_STK 646.03
11163STK1 626.19 11650STKA 647.54
11163STK2 628.97 11651 646.92 1.51 648.43 1.50 649.93 3.01
11172 624.54 1.90 626.44 2.65 629.09 4.55 11651_STK 648.43
11172_STK 626.44 11651STKA 649.93
11172STK1 629.09 11652 645.58 2.53 648.11 1.51 649.62 4.04
11173 624.23 1.73 625.96 2.39 628.36 4.13 11652_STK 648.11
11173_STK 625.96 11652STKA 649.62
11173STK1 628.36 11653 641.21 2.07 643.28 1.99 645.27 4.06
11175 620.54 1.68 622.22 1.56 623.78 3.24 11653_STK 643.28
11175_STK 622.22 11653STKA 645.27
11175STK1 623.78
11176 618.02 1.55 619.57 1.55 621.12 3.10 11664 614.64 1.53 616.17 1.52 617.69 3.05
11176_STK 619.57 11664_18 616.17
11176STK1 621.12 11664_36 617.69
11177 616.80 1.60 618.40 1.76 620.16 3.36 11665 616.58 1.60 618.18 1.86 620.04 3.46
11177_STK 618.40 11665_18 618.18
11177STK1 620.16 11665_36 620.04
11178 615.25 1.66 616.91 1.54 618.45 3.20 11666 612.27 1.57 613.84 1.52 615.36 3.09
11178STK1 616.91 11666_18 613.84
11178STK2 618.45 11666_36 615.36
11180 612.97 1.50 614.47 1.73 616.20 3.24 11669 627.37 1.66 629.03 2.07 631.10 3.73
11180STK1 614.47 11669_18 629.03
11180STK2 616.20 11669_36 631.10
11181 611.68 1.57 613.26 1.65 614.91 3.22 11670 633.33 1.53 634.86 1.58 636.44 3.11
11181_STK 613.26 11670_18 634.86
11181STK1 614.91 11670_36 636.44
11184 609.66 1.54 611.20 1.55 612.75 3.09 11671 626.37 1.53 627.90 2.11 630.01 3.64
11184_STK 611.20 11671_18 627.90
11184STK1 612.75 11671_36 630.01
11185 605.72 1.64 607.36 1.71 609.08 3.36 11674 627.93 1.60 629.53 1.57 631.10 3.17
11185STK1 607.36 11674_18 629.53
11185STK2 609.08 11674_36 631.10
11186 601.10 1.61 602.70 2.14 604.85 3.75 11675 638.80 1.56 640.36 2.11 642.47 3.67
11186_STK 602.70 11675_18 640.36
11186STK1 604.85 11675_36 642.47
11187 600.97 1.88 602.85 3.02 605.87 4.90 11676 645.58 1.51 647.09 1.57 648.66 3.08
11187_STK 602.85 11676_18 647.09
11187STK1 605.87 11676_36 648.66
11188 596.35 1.56 597.90 1.72 599.62 3.27 11679 653.64 1.70 655.34 2.06 657.40 3.76
11188_STK 597.90 11679_18 655.34
11188STK1 599.62 11679_36 657.40
11189 595.00 1.62 596.62 1.51 598.13 3.13 11680 647.00 1.56 648.56 1.53 650.09 3.09
11189STK1 596.62 11680_18 648.56
11189STK2 598.13 11680_36 650.09
11190 592.01 1.55 593.56 1.50 595.06 3.05 11681 632.60 1.53 634.13 2.15 636.28 3.68
11190STK1 593.56 11681_18 634.13
11190STK2 595.06 11681_36 636.28
11193 599.29 1.64 600.93 2.00 602.93 3.64 11682 620.71 1.62 622.33 1.50 623.83 3.12
11193_STK 600.93 11682_18 622.33
11193STK1 602.93 11682_36 623.83
11196 591.38 1.66 593.04 1.51 594.55 3.18 11684 626.38 1.52 627.90 1.50 629.40 3.02
11196STK1 593.04 11684_18 627.90
11196STK2 594.55 11684_36 629.40
11199 591.98 1.71 593.69 2.13 595.82 3.84
11199_STK 593.69
11199STK1 595.82
11200 599.91 1.59 601.51 1.97 603.48 3.56
11200_STK 601.51
11200STK1 603.48
11201 600.36 1.51 601.87 1.70 603.56 3.20
11201_STK 601.87
11201STK1 603.56
11202 592.77 2.62 595.40 2.47 597.86 5.09
11202_STK 595.40
11202STK1 597.86
11205 592.06 2.59 594.65 2.24 596.89 4.83
11205_STK 594.65
11205STK1 596.89
11206 599.17 1.56 600.73 1.53 602.26 3.09
11206_STK 600.73 Jeff Allred, PLS
11206STK1 602.26 Allred Land Surveying, PLLC
11207 598.64 1.62 600.25 1.71 601.96 3.32 Office Address:
11207_STK 600.25 814 D Knox Road McLeansville, NC 27301
11207STK1 601.96 Mailing Address:
11208 595.85 1.55 597.40 1.66 599.05 3.21 8065 Coble Mill Road Snow Camp, NC 27349
11208_STK 597.40 Phone:
11208STK1 599.05 336-684-8202
11209 592.18 1.54 593.72 2.20 595.93 3.75 [e-mail]
11209_STK 593.72
11209STK1 595.93
11216 592.27 2.36 594.63 1.51 596.14 3.87
11216_STK 594.63
11216STK1 596.14
AREA 17
Prepared For:
COBLE’S SANDROCK, INC.
5833 FOSTER STORE ROAD
LIBERTY, NORTH CAROLINA 27298

Submitted By:
LaBella Associates
2211 West Meadowview Rd.
Suite 101
Greensboro, NC 27407
336-323-0092
NC License No. C-0430

FACILITY PLAN
COBLE’S SANDROCK
CONSTRUCTION & DEMOLITION DEBRIS LANDFILL
PERMIT NO. 01-05
august 2019, rev. october 2019. Rev. July 2020
Project no. 2191087
II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
1
TABLE OF CONTENTS

FACILITY PLAN .................................................................................................................................1
1. Waste Stream ......................................................................................................................2
2. Landfill Capacity ..................................................................................................................3
3. Special Engineering Features ............................................................................................6
4. Partial Closure of the Landfill .............................................................................................7

FIGURES Site Location Map Partial Closure Survey Maps TABLES Table 1 Future Tonnage Projection DRAWINGS

Drawing FP-01 Facility Plan – Site Development
Drawing FP-02 Facility Plan – Proposed Final Contours
Drawing FP-03 Facility Plan – Facility Boundary Plat

APPENDICES
Appendix 1 Franchise Agreement
Appendix 2 Slope Stability

FACILITY PLAN

This facility plan defines the development of the Coble’s Sandrock C&D landfill property and
describes the permit of an existing facility. This plan includes drawings, which present the
long-term, general design concepts related to construction, operation, and closure of the
C&DLF unit(s). Additional solid waste management activities located at the C&DLF facility
are identified in the plan to meet the requirements of the SWMP .0537 Subchapter. The
facility plan defines the waste stream proposed for management at the C&DLF facility,
different types of landfill units or non-disposal activities included in the facility design, and
describe general waste acceptance procedures.

The facility will accept construction and demolition (C&D) debris, and other wastes similar to
those typically found in the accepted waste streams such as roofing shingle waste from the
manufacturer, waste building materials from mobile home manufacturers and wooden
pallets for disposal. No municipal solid waste, hazardous waste, industrial waste, liquid
waste, or waste not characterized as LCID or C&D, shall be accepted for disposal.

II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
2

The areal limits of the C&DLF unit(s), total capacity of the C&DLF unit(s), and the proposed
waste stream must be consistent with the Division's approval set forth in accordance with
Rule .0536 (a)(1). Revised Facility and Engineering Plans Drawings (FP-01, FP-02 and EP-
04, EP-05) provide the information required in Section .0537(d).

1. Waste Stream

Types of Waste Specified for Disposal: Only construction/demolition debris will be accepted
at the C&D landfill. Construction and demolition debris defined in NC General Statutes is
waste or debris resulting solely from construction, remodeling, repair, or the demolition of
pavement, buildings, or other structures.

Service Area: The Alamance County Franchise Agreement, provided in Appendix 1, limits the
service area to be served by the Coble’s Sandrock Landfill to customers within 25 miles
from the site. Existing customers outside the 25-mile service limitation are grandfathered
under the Franchise Agreement and Coble's Sandrock may continue to accept wastes from
these customers. Coble's Sandrock may also accept waste from new customers outside the
25-mile service area to replace existing customers outside the service area; however, first
priority in terms of disposal capacity is to be given to waste generated within Alamance
County.

The Counties from which the facility has previously taken waste include Alamance, Cabarrus,
Caswell, Chatham, Davidson, Forsyth, Green, Guilford, Lee, Orange, Randolph, Rockingham,
and Wake. Alamance County recognizes that the Coble Sandrock C&D landfill currently
accepts waste from customers outside the 25-mile radius, and these existing customers are
grandfathered under the Franchise Agreement. New customers outside the 25-mile radius
may be accepted to replace the existing customers in accordance with Section 4 of the
Franchise Agreement.

Segregation Management Procedures: Recyclable material will be segregated from the
waste stream and temporarily stored in containers or stockpiles prior to removal from the
site. Recyclable material may include wood, metals, concrete, plastic, cardboard, and other
materials with appropriate recycling markets. Scrap metal is removed from the site
frequently and taken to a metal recycling facility. Cardboard is stored in a 40-yard container
that is removed from the site by various vendors when full. Coble’s Sandrock deconstructs
mobile trailer homes at the working face of the C&D landfill. Identified C&D waste material
removed from the deconstruction process is placed into the landfill. The franchise
agreement requires monitoring waste and to reject any significant levels of asbestos.

The locations of the mobile trailer home deconstruction area and the recyclables storage
areas follow the location of the working face as it progresses across the landfill.

II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
3
Equipment: Coble Sandrock proposes to operate the following equipment at the C&D
landfill:
CAT 330 CL
CAT 973 Loader
CAT D8 Dozer
CAT Rubber Tire Loader
TREX off-road Truck
TREX Pan
TREMAC Shear Muncher
Precision Husky Tub Grinder
Power Screen Screener
Fuel Truck
Link Belt Trackhoe

Equipment may be added or deleted, depending condition to upgrade and on the volume of
waste accepted.

2. Landfill Capacity

Overall Facility Life
The available airspace for waste, operational cover soil and intermediate cover material for
the entire facility is 6,935,903 cy. Assuming that 10% of that volume will be soil, 6,242,313
cy are available for waste material. Utilizing in-place waste density of 1050 lbs/cy, the
remaining tonnage capacity of the landfill is 3,277,214 tons. The in-place waste density
stated above is within the typical range of densities measured for C&D debris.

Based on excerpt from the historical record (Table 1), Coble’s C&D landfilled an average of
14,004.85 tons/year during the previous five-year period 2016-2020; cumulative in-place
waste volume as of July 2020 is 719,433 tons or 1,131,537 cy. Using the recent five-year
landfilled average, the remaining capacity calculates approximately 124,426 cy until 2024
in the permitted Phases 1-3A (1,255,963 cy). Subsequently, when permitted to operate,
Phase 3B added capacity 349,213 cy, the full date for Phases 1-3B is estimated until 2037
(1,605,176 cy).
Permitted capacities are shown in the below:

II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
4
Phase Acres Acres
(Revised)
Gross
Capacity (CY)
1 7.0 6.5 365,301
2 5.8 5.5 320,000
3A 6.3 6.3 570,662
3B 5.8 349,213
4 8.2 1,043,245
5 7.0 890,575
6 8.0 1,017,800
7 6.9 877,852
8 11.8 1,501,255
Totals 66.8 18.3 6,935,903
Permitted Capacity for each Phase
Permit Status
Approved for
development,
requires submittal
of PTC/PTO
PTO (9/30/1998)
PTO (5/20/2003)
PTO (4/29/2011)
PTC (1/30/2009)

Note in the permit that modified the waste footprints of Phase 1, 2A and 2B. The perimeter
road is constructed in the approved waste footprint of Phases 1 (0.5 acres), 2A (0.1 acres),
and 2B (0.2 acres). Since no waste has ever been disposed underneath the perimeter road,
the areas occupied by the road (approximately 0.8 acres in total) are excluded from the
originally approved waste footprint of 66.8 acres (DIN 24357). The gross capacities were
not reduced from the originally permitted volumes.

On the next page Table 1. Future Tonnage Projections are based on recent five-year average
tonnage landfilled.

II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
5
COBLE SANDROCK C&D LF
Annual
Report
Tons
Received
Waste in Place
(tons)
Air Space
Consumed
Annual (CY)
Air Space
Consumed
Cumulative
(CY)
Survey
Date
UF
(tn/cy)
Density
(lbs/cy)
Remaining
Capacity
each Phase
(CY)
Remaining
Capcity
Entire
Facility (CY)
Facility
Cumulative
(CY)
TABLE 1 - FUTURE TONNAGE PROJECTION
2014 11,046.38 639,454.44 16,558 958,539 6/13/2014 0.67 1334 297,424 5,977,364
2015 9,954.39 649,408.83 15,201 991,714 7/15/2015 0.65 1310 264,249 5,944,189
2016 14,891.36 664,300.19 30,281 1,021,995 6/28/2016 0.49 984 233,968 5,913,908
2017 13,539.15 677,839.34 30,316 1,052,311 7/25/2017 0.45 893 203,652 5,883,592
2018 12,411.09 690,250.43 23,640 1,075,951 6/21/2018 0.53 1050 180,012 5,859,952
2019 16,262.60 706,513.03 30,976 1,106,928 0.53 1050 149,035 5,828,975
2020 12,920.07 719,433.10 24,610 1,131,537 0.53 1050 124,426 5,804,366
2021 14,004.85 733,437.95 26,676 1,158,213 0.53 1050 446,963 5,777,690
2022 14,004.85 747,442.81 26,676 1,184,889 0.53 1050 420,287 5,751,014
2023 14,004.85 761,447.66 26,676 1,211,565 0.53 1050 393,611 5,724,338
2024 14,004.85 775,452.52 26,676 1,238,241 0.53 1050 366,935 5,697,662 Phase 3A
2025 14,004.85 789,457.37 26,676 1,264,917 0.53 1050 340,259 5,670,986 1,255,963
2026 14,004.85 803,462.22 26,676 1,291,593 0.53 1050 313,583 5,644,310
2027 14,004.85 817,467.08 26,676 1,318,269 0.53 1050 1,330,152 5,617,634
2028 14,004.85 831,471.93 26,676 1,344,945 0.53 1050 1,303,476 5,590,958
2029 14,004.85 845,476.79 26,676 1,371,620 0.53 1050 1,276,801 5,564,283
2030 14,004.85 859,481.64 26,676 1,398,296 0.53 1050 1,250,125 5,537,607
2031 14,004.85 873,486.49 26,676 1,424,972 0.53 1050 1,223,449 5,510,931
2032 14,004.85 887,491.35 26,676 1,451,648 0.53 1050 1,196,773 5,484,255
2033 14,004.85 901,496.20 26,676 1,478,324 0.53 1050 1,170,097 5,457,579
2034 14,004.85 915,501.06 26,676 1,505,000 0.53 1050 1,143,421 5,430,903
2035 14,004.85 929,505.91 26,676 1,531,676 0.53 1050 1,116,745 5,404,227
2036 14,004.85 943,510.76 26,676 1,558,352 0.53 1050 1,090,069 5,377,551
2037 14,004.85 957,515.62 26,676 1,585,028 0.53 1050 1,063,393 5,350,875 Phase 3B
2038 14,004.85 971,520.47 26,676 1,611,704 0.53 1050 1,036,717 5,324,199 1,605,176
Note:Table is based on annual average tonnage of 14,004.85 landfilled from 2016 thru 2020.
Cumulative volume includes weekly cover soil.
Utilization factor 0.53 is representative for the industry .

Future phases 4-8 approved for development require permits to construct and operate.

Overall Facility Soil Balance
The base grading plan, including access roads, for the entire remaining facility yields a net
1,537,784 cy of cut. Approximately 325,871 cy of soil will be needed for final cap (3 feet
thick) construction. Assuming 10% of the permitted landfill volume 693,590 cy of soil will
be needed for cover soil material. Subtracting the estimated soil requirements from the
calculated available material leaves an excess of 518,323 cy of soil.

Phase 3B
To evaluate the air space requirement for a 5-year phase, assuming an average annual
tonnage of 14,004.85 tons/year, the projected total tonnage for the next 5-year phase is
70,024 tons. Assuming an average (UF 0.53 tn/cy) annual consumed air space of 37,112
cy/year, the projected annual volume for next 5-year phase would be 185,564 cy. Closure
II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
6
cap soil volume for 3B is estimated 28,072 cy. Phase 3B permitted gross capacity is
349,213 cu. Assuming the waste disposal at the recent five-year average rate, the capacity
would be reached some time during 2037 as shown in the Table 1.

Phase 3B has been under construction and the grading was completed in June 2019. In
order to keep active working face under 4 acres in accordance with the Permit to Operate,
Coble postpones the Phase 3B application of 5.8 acre footprint until later date. At that time
the 3B Construction report will be submitted to the Section for review and issuance for
Permit to Operate.

3. Special Engineering Features

Containment and Environmental Control Systems

Cap System:

The cap system is described from bottom to top in the following paragraphs.

Infiltration Barrier: The infiltration barrier is proposed to consist of either (1) 18 inches of
compacted soil with a permeability no greater than 1x10-5 cm/sec; or (2) a geosynthetic clay
liner. The low-permeability soil barrier, or the GCL, will lie directly above an intermediate soil
cover layer of at least 12 inches in thickness. GCL stability analysis and specifications are
included in Appendix 2 of this Plan.

Erosion Control Components (Protective Layer and Erosion Layer): A protective layer
consisting of at least 12 inches of local soil will be placed on top of the infiltration barrier.
The erosion and protective layers will not be heavily compacted to promote vegetative
growth.

Vegetative Cover: After placement of the protective layer, the area that has been closed will
be seeded with a grass mixture. Mulch and erosion control matting will be used as needed
to further minimize erosion and promote vegetative growth.

Leachate Management Systems:

Leachate collection and management systems are not designed or permitted for this
construction and demolition unlined waste disposal facility.

Base Liner Systems:

The base of the landfill is excavated to designed base grades and remaining native soil will
serve as the base of the landfill, with the condition that the upper two feet of the base soils
consist of the following soil types: SC, SM, ML, CL, MH, or CH (according to Unified Soil
Classification System).

II - Facility Plan Labella Associates, PC.
C&D LF 5-Year Permit Renewal/LOS August, 2019
Coble Sandrock, North Carolina Revised July 2020
7

Gas Management System:

Passive gas vents will be installed to a minimum depth of 10-feet below surface in the waste
mass at a frequency of one vent per acre.

4. Partial Closure of the Landfill

The west side of the landfill Phases 1 and 2 Coble closed in 2012-2013 and the CQA report
was submitted to the Section in August 2013. Coble continued the partial closure of Phase
3A in the areas 14 thru 17 since 2014 and completed the work in 2020. At completion of
the closure efforts, the partial closure CQA report includes the areas 12-17. Partial closure
surveys are included in the Figures attachment of this Plan. The financial assurance for the
C&D landfill will be revised in accordance with rule .01628.

END
57057
0
580
590
60
0
58
0
580
5805706106306006106206206306406506406
5
0
6
6
0 60061062063065
0
6
4
0610620630
6406406306506406306206406306
40
650640650640640
640 570570610640570
580630
640630640590600FOSTER STORE ROAD
FOSTER STORE ROA
D
200' PROPERTY
BUFFER (TYP.)
50' STREAM BUFFER
PRIVATE
DWELLING
PRIVATE
DWELLING
PRIVATE
DWELLING
PRIVATE
DWELLING
PHASE 1
(7.0 AC)
PHASE 2B
(4.76 AC)
PHASE 2A
(1.1 AC)
WASTE LIMITS
500'
BUFFER
FROM
RESIDENCE
50'
STREAM
BUFFER
100 YEAR FLOOD
PLAIN LIMITS
PHASE 3A
(6.36 AC)PHASE 3B
(5.87 AC)
SCALE HOUSE
ABANDONED
RESIDENCE 640640
650
640
620
61
0
6206
4
0660
620
61
0
600
610SURVEY WITHIN BOUNDARY DATED
MAY 22,2019. SURVEY OUTSIDE
BOUNDARY DATED JANUARY 24, 2005
569.37
P-23
P-25
MW-10S
MW-10D
MW-8
PZ-19S
PZ-19D
MW-4
MW-2
MW-7
MW-5
P-24
MW-11
MW-6
FACILITY BOUNDARY
(154.20 ACRES)
50' STREAM
BUFFER
50' STREAM
BUFFER
SHINGLE
STOCKPILE
TDD
S
S
ARE
A
APPROXIMATE LIMITS OF
APPROVED CLOSURE
APPROXIMATE LIMITS OF
CLOSURE TO BE SUBMITTED
FOR APPROVAL
CLOSED LCID
DISPOSAL AREA
PERMIT NO.01-05
CLOSED LCID
DISPOSAL AREA
PERMIT NO.
ALAMA-2002-028
PHASE 4
(8.2 AC)
0
(FEET)
GRAPHIC SCALE
600300150
Revisions
NO:DATE:DESCRIPTION:
1 08/27/19 PERMIT RENEWAL RTC
2 12/9/19 RESPONSE DEQ COMMENTS RECIEVED 11/1/19
3 07/21/2020 REVISED PER DEQ COMMENTS
EP-01
ENGINEERING PLAN:
EXISTING CONDITIONS
RH
HK
DRAWING NAME:6/3/2010 8:47:56 AMDRAWING NUMBER:
DATE:
ISSUED FOR:
DRAWN BY:
REVIEWED BY:
PROJECT NUMBER:
© 2019 LaBella Associates
1604 Ownby Lane
Richmond, VA 23220
804-355-4520
labellapc.com
Coble's Sandrock Inc.
Alamance County, North Carolina
2191087.00
PERMIT RENEWAL
08/27/2007
L:\Coble Sandrock\dwg\2019 RENEWAL\Engineering Plan\Plot Sheets\e_EP-01- EXIST COND RTC 12_19.dwg Layout=Layout1NOT F
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COBLE SANDROCK C&D LF
Annual
Report Tons Received Waste in Place
(tons)
Air Space
Consumed
Annual (CY)
Air Space
Consumed
Cumulative
(CY)
Survey Date UF
(tn/cy)
Density
(lbs/cy)
Remaining
Capacity each
Phase (CY)
Remaining
Capcity Entire
Facility (CY)
Facility
Cumulative
(CY)
1998
1999 14,111.32 14,111.32
2000 40,488.38 54,599.70
2001 99,225.55 153,825.25
2002 79,035.85 232,861.10
2003 78,328.36 311,189.46
2004 57,962.06 369,151.52
2005 57,855.27 427,006.79
2006 55,849.02 482,855.81
2007 49,981.45 532,837.26
2008 40,428.22 573,265.48 51,905 736,000 5/30/2008 0.78 1558 6,199,903
2009 14,488.29 587,753.77 844,632 6,091,271
2010 12,769.32 600,523.09 18,156 853,861 6/8/2010 0.70 1407 6,082,042
2011 10,104.71 610,627.80
2012 8,428.04 619,055.84
2013 9,352.22 628,408.06
2014 11,046.38 639,454.44 16,558 958,539 6/13/2014 0.67 1334 297,424 5,977,364
2015 9,954.39 649,408.83 15,201 991,714 7/15/2015 0.65 1310 264,249 5,944,189
2016 14,891.36 664,300.19 30,281 1,021,995 6/28/2016 0.49 984 233,968 5,913,908
2017 13,539.15 677,839.34 30,316 1,052,311 7/25/2017 0.45 893 203,652 5,883,592
2018 12,411.09 690,250.43 23,640 1,075,951 6/21/2018 0.53 1050 180,012 5,859,952
2019 16,262.60 706,513.03 30,976 1,106,928 0.53 1050 149,035 5,828,975
2020 12,920.07 719,433.10 24,610 1,131,537 0.53 1050 124,426 5,804,366
2021 14,004.85 733,437.95 26,676 1,158,213 0.53 1050 446,963 5,777,690
2022 14,004.85 747,442.81 26,676 1,184,889 0.53 1050 420,287 5,751,014
2023 14,004.85 761,447.66 26,676 1,211,565 0.53 1050 393,611 5,724,338
2024 14,004.85 775,452.52 26,676 1,238,241 0.53 1050 366,935 5,697,662 Phase 3A
2025 14,004.85 789,457.37 26,676 1,264,917 0.53 1050 340,259 5,670,986 1,255,963
2026 14,004.85 803,462.22 26,676 1,291,593 0.53 1050 313,583 5,644,310
2027 14,004.85 817,467.08 26,676 1,318,269 0.53 1050 1,330,152 5,617,634
TABLE 1 - FUTURE TONNAGE PROJECTION
Annual
Report Tons Received Waste in Place
(tons)
Air Space
Consumed
Annual (CY)
Air Space
Consumed
Cumulative
(CY)
Survey Date UF
(tn/cy)
Density
(lbs/cy)
Remaining
Capacity each
Phase (CY)
Remaining
Capcity Entire
Facility (CY)
Facility
Cumulative
(CY)
2028 14,004.85 831,471.93 26,676 1,344,945 0.53 1050 1,303,476 5,590,958
2029 14,004.85 845,476.79 26,676 1,371,620 0.53 1050 1,276,801 5,564,283
2030 14,004.85 859,481.64 26,676 1,398,296 0.53 1050 1,250,125 5,537,607
2031 14,004.85 873,486.49 26,676 1,424,972 0.53 1050 1,223,449 5,510,931
2032 14,004.85 887,491.35 26,676 1,451,648 0.53 1050 1,196,773 5,484,255
2033 14,004.85 901,496.20 26,676 1,478,324 0.53 1050 1,170,097 5,457,579
2034 14,004.85 915,501.06 26,676 1,505,000 0.53 1050 1,143,421 5,430,903
2035 14,004.85 929,505.91 26,676 1,531,676 0.53 1050 1,116,745 5,404,227
2036 14,004.85 943,510.76 26,676 1,558,352 0.53 1050 1,090,069 5,377,551
2037 14,004.85 957,515.62 26,676 1,585,028 0.53 1050 1,063,393 5,350,875 Phase 3B
2038 14,004.85 971,520.47 26,676 1,611,704 0.53 1050 1,036,717 5,324,199 1,605,176
Note:Table is based on annual average tonnage of 14,004.85 landfilled from 2016 thru 2020.
Cumulative volume includes weekly cover soil.
Utilization factor 0.53 is representative for the industry .
Prepared For:
COBLE’S SANDROCK, INC.
5833 FOSTER STORE ROAD
LIBERTY, NORTH CAROLINA 27298

Submitted By:
LaBella Associates
2211 West Meadowview Rd.
Suite 101
Greensboro, NC 27407
336-323-0092
NC License No. C-0430

CLOSURE & POST-CLOSURE CARE PLAN
COBLE’S SANDROCK
CONSTRUCTION & DEMOLITION DEBRIS LANDFILL
PERMIT NO. 01-05
august 2019, Rev. october 2019, Rev. July 2020
Project no. 2191087
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 1 August 2019
Coble’s Sandrock, North Carolina Revised July 2020

Contents

CLOSURE & POST-CLOSURE CARE PLAN .................................................................................................................... 2
CLOSURE ....................................................................................................................................................................... 2
1. Description of Cap System: ............................................................................................................................. 2
2. Closure Area ..................................................................................................................................................... 2
3. Waste Inventory ............................................................................................................................................... 3
4. Schedule .......................................................................................................................................................... 3
5. Cost Estimate for Closure................................................................................................................................ 4
6. Closure Certification ........................................................................................................................................ 4
7. Deed Recordation ............................................................................................................................................ 5
POST CLOSURE ......................................................................................................................................................... 5
1. Contact ............................................................................................................................................................. 5
2. Security ............................................................................................................................................................ 5
3. Post-Closure Maintenance .............................................................................................................................. 5
4. Inspection Plan ................................................................................................................................................ 6
5. Post-Closure Land Use .................................................................................................................................... 7
6. Post-Closure Cost Estimate .............................................................................................................................. 7

APPENDICES
APPENDIX A GROUNDWATER MONITORING WELL MAINTENANCE RECORD
APPENDIX B POST-CLOSURE INSPECTION RECORD
APPENDIX C METHANE MONITORNG TEST RECORD
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 2 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
CLOSURE & POST-CLOSURE CARE PLAN

CLOSURE

1. Description of Cap System:
The cap system to be used is designed to minimize infiltration and erosion. The cap system
will consist of:
• A low-permeability infiltration layer of at least 18 inches with a permeability not
greater than 1.0 x 10-5 cm/sec; or geosynthetic clay liner (GCL);
• An erosion layer that contains a minimum of 12 inches of earthen material that is
capable of sustaining native plant growth. Approved Alternate Cover Material (ACM)
mulch/soil mixture in accordance Operations Plan Section 4 Cover Materials
Requirements.

Construction of the cap system was prepared in accordance with Rule .0540 of this Section
and the following requirements:
(A) post-settlement surface slopes will be a minimum of five percent and a
maximum of 33 percent; and
(B) a gas venting or collection system will be installed below the low-
permeability barrier to minimize pressures exerted on the barrier.

The construction of the closure cap will be in accordance with the Volume 2 Application for
Permit to Construct Phase 3 and the specifications provided in Appendix IV. The Application
to Construct Phase 3 was approved by the SWS on 2/19/2009.

Procedures for Cap Installation
The construction of the cap will be in accordance with the specifications provided in
Appendix IV.

2. Closure Area

Portions of Phases 1, 2A/B and 3A are active for landfill operations. Summary table below
shows current status of the landfill phases open and closed acreages. Active landfill closure
applies to the top area of Phases 1 and 2A/B piggyback and 3A.

C&D LF Closure vs. Open Area Summary

Phase Permitted Revised
Footprint
Closed Open
1 7 6.5(1) 4.2 2.3
2A 1 0.9(1) 0.9 0
2B 4.8 4.6(1) 3.9 0.7
3A 6.3 6.3 5.6 0.7
1-3A 19.13 18.3 14.73 3.6

V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 3 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
Note in the permit modified the waste footprints of Phase 1, 2A and 2B. The perimeter road
is constructed in the approved waste footprint of Phases 1 (0.5 acres), 2A (0.1 acres), and
2B (0.2 acres). Since no waste has ever been disposed underneath the perimeter road, the
areas occupied by the road (approximately 0.8 acres in total) are excluded from the
originally approved waste footprint of 66.8 acres (DIN 24357).

3. Waste Inventory

As of July 2020 annual facility reporting, the cumulative tonnage received and landfilled was
719,433 tons since the beginning of operations (1999). At an average density of 1050
pounds/cubic yard, this equates to approximately 1,131,537 cubic yards of consumed
airspace.

4. Schedule

The Phases 1, 2 and 3A permitted capacity is 1,255,963 cy. Subtracting current
approximately consumed 1,131,537 cy of airspace, the balance is estimated 124,426 cubic
yards. The three-foot thick closure cap is expected to consume 4,840 cy/acre. Following
landfill Phase 1 and 2 closure of 9.13 acres and Phase 3A closure of 5.6 acres, the
remaining active area shown in the above table is approximately 3.7 acres. The remaining
area to be closed is expected to take 17,910 cy reducing landfilling airspace (124,426 –
17,910) to 106,516 cubic yards. Based on the recent five-year landfilled average of 26,676
cu/year the remaining airspace is estimated 4 years or some time in 2024.

Prior to beginning final closure, Coble’s Sandrock must notify the Division that a Notice of
Intent to close the facility has been placed in the operating record.

Phase 3B is pending completion and permit to operate (PTO). Phases 4 through 8 approved
for future development require submittals of PTC/PTO applications.

The permitted C&DLF gross capacity of Phases 1-8 is 6,935,903 cy. As of July 2020 the
estimated consumed air space is 1,131,537 cy. The remaining gross balance leaves
5,804,366 cy for waste, weekly cover, and final cap.

Closure activities are proposed to begin within 30 days of final receipt of waste.
Construction of the closure cap is to be completed within 180 days following the initiation of
closure activities. The total length of the proposed closure period is 210 days following the
final receipt of waste.

Proposed Closure Milestones and Schedule
Milestone Proposed Schedule from the Date of
Final Receipt of Waste Testing of borrow sources Within 6 months prior to closure Grading of intermediate cover Within 30 to 60 days Placement of soil cap 30 to 150 days
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 4 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
Milestone Proposed Schedule from the Date of
Final Receipt of Waste Final inspection of cap by P.E. 150 to 180 days Construction of stormwater
controls
90 to 180 days
Seeding and mulching 150 to 180 days Preparation of survey plat 180 to 210 days Submittal of closure certification 180 to 210 days

5. Cost Estimate for Closure
Closure Cost Estimate for 3.7 Acres

6. Closure Certification

A professional engineer, registered in the State of North Carolina, will verify that the closure
has been completed in accordance with the Closure Plan. The contents of the signed
Certification Report will be as described below.

Certification Reports:

The CQA report will contain the results of the construction quality assurance and
construction quality control testing results, descriptions of procedures, and results of
retesting. The CQA report will contain as-built drawings noting any deviation from the
approved engineering plans and will also contain a narrative including, but not limited to,
CQA daily reports with photographs of major project features, and documentation of
proceedings of all progress and troubleshooting meetings. The CQA report will be submitted
after completion of construction of the cap system in accordance with the requirements of
Rule .0543. The CQA report must bear the seal of the project engineer and a certification
that construction was completed in accordance with the CQA Plan and acceptable
engineering practices.

COMPONENT ACRES CY UNITS UNIT COST ($)TOTAL ($)
Mobilization 1 $5,000 $5,000
18" Clay (10E-5 cm/sec)3.6 8,639 CY $3.50 $30,238
18" Field & Lab testing 3.6 TM $2,294 $8,190
18" Vegetative Soil 3.6 8,639 CY $3.50 $30,238
Seeding/Revegetation 3.6 AC $1,500 $5,355
Survey 3.6 1 $1,500 $5,355
Subtotal:$84,376
Engineering/CQA (~5%)1 $4,219
Contingency (~5%)1 $4,219
FA 2020 TOTAL $92,814
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 5 August 2019
Coble’s Sandrock, North Carolina Revised July 2020

7. Deed Recordation

Following closure, the owner or operator will record a notation on the deed to the landfill
facility property at the local county Register of Deeds office, or some other instrument that is
normally examined during title search, and notify the Division that the notation has been
recorded and a copy has been placed in the operating record. The notation on the deed
shall in perpetuity notify any potential purchaser of the property that the land has been used
as a C&D landfill unit or facility and its use is restricted under the closure plan approved by
the Division.

POST CLOSURE

Post-closure activities must be conducted at the landfill for a period of 30 years following
closure of the landfill. However, the length of the period can be increased or decreased in
accordance with Division directives.

1. Contact

Coble’s Sandrock, Inc. will handle questions and/or problems, which might occur during the
post-closure care period.

CONTACT PERSON: Mr. Kent Coble
OWNER: Mr. Kent Coble
ADDRESS: 5833 Foster Store Road
Liberty, North Carolina 27298
PHONE NUMBER: [phone]
FAX: [phone]

2. Security

Control access to the site by the use of barriers and gates at roadway entrances. Maintain
these control devices throughout the post-closure care period, and inspected as part of the
monthly inspection program. Mark all barriers and gates clearly with signs stating the name
and nature of the facility and the person to contact in case of emergency or breach of
security.

3. Post-Closure Maintenance

Post-closure maintenance and monitoring will be conducted at the landfill for a period of 30
years after final closure. The Division may decrease the length of the post-closure period if
the owner or operator demonstrates that the reduced period is sufficient to protect human
health and the environment, and the Division approves this demonstration. The period
might be increased by the Division if the Division determines that the lengthened period is
necessary to protect human health and the environment.

V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 6 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
Monitoring will include semi-annual sampling of groundwater and surface water, quarterly
gas monitoring, and quarterly inspection of the final cover and monitoring and control
systems. Maintenance needs identified through the monitoring program must be initiated
no later than 60 days after the discovery, and within 24 hours if a danger or eminent threat
to human health or the environment is indicated. Minor cap maintenance may be deferred
until there is a sufficient amount of work to justify the mobilization of equipment and
personnel.

Add soil to the cap as necessary to correct the effects of settlement and subsidence of the
landfill and to prevent run-on and run-off from eroding the final cap.

Protect and maintain stormwater control devices, surveyed benchmarks, groundwater
monitoring wells, surface water monitoring/sampling gauges and LFG wells.

If seeps are discovered, an investigation of why there is a seep and if the cap integrity has
been compromised shall be performed. If the clay cap has released leachate the cap will be
repaired and recompacted to closure CQA required levels and the vegetative layer will be
reestablished.

Mow vegetation twice per year. Cost for routine maintenance assumes 10% of the cap area
will require reseeding and fertilizing each year.

Maintain and repair security fencing, gates, and access roads as necessary.

4. Inspection Plan

Routine inspections will be conducted throughout the post-closure care period. These
inspections will be carried out quarterly unless problems are detected that indicate that
more frequent visits are warranted. Potential impacts to the public and environment will be
considered in determining the inspection frequency. Items to be included in the monthly
inspection will be as follows:

• Access and security control,
• Stormwater management,
• Erosion and sediment control,
• Edge markers of the landfill waste footprint/disposal boundary,
• Gas management,
• Groundwater and landfill gas monitoring systems, and
• Vector control.

The quarterly inspections will be carried out by someone properly trained and
knowledgeable about landfills, such as the landfill owner, operator or engineering
consultant. The results of the inspections will be documented in Post Closure Inspection
Form. If inspections indicate that repairs are necessary, repairs will be initiated as soon as
practicable.

If a leachate seep or outbreak is observed in the routine inspection tasks as noted in
Appendix B, a verbal notice to the SWS within 24 hours and within 15 days a written
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 7 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
notification with the assessment sampling plan must be submitted to the SWS. The
leachate releases assessment/sampling guidance that can be found in the following web
link should be appended to the plan:
https://edocs.deq.nc/gov/WasteManagement/0/edoc/1319075/MSW%20Leachate_Relea
ses_Sampling_Guide.pdf?searchid=22b91c58-be48-4f48-97ecae3766e88565

In addition to the routine quarterly inspections, special inspections will be performed and
documented after events, which may cause damage to the integrity of the landfill cover,
such as heavy rainfall. Inspection may also be necessary following written or verbal
complaints, vandalism or fires. Following special inspections, any necessary repairs will be
initiated as soon as practicable.

Maintain records of all inspections in the operating record.

5. Post-Closure Land Use

The primary land use for the site after closure of the landfill will be open dormant green
space. No raising of animals shall be allowed after final closure per Rule 15A NCAC 13B
.0543(f)(3) without written approval of DEQ.

6. Post-Closure Cost Estimate Update for 2020 (Table on next page)

V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 8 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
Post-Closure Cost Estimate Update for 2020

Notes:
1. All costs include labor by third party.
2. Water quality monitoring costs are estimated from 2019-2020 budgets.
3. Cost for groundwater wells assumes maintenance of each well every other year.
4. Cost for the gas probes assumes maintenance of each probe every other year.
5. Cost for routine maintenance assumes 1/10 of the cap area will require reseeding
and fertilizing each year.
6. Post Closure Care includes all permitted Phases 1, 2, 3A.
7. Future Phases issued PTO will be added to the closure & Post Closure Care Plans.

END

ITEM UNIT QUANTITY UNIT COST ANNUAL COST
INSPECTIONS/ RECORD KEEPING per trip 4 500.00$ 2,000.00$
MONITORING
Explosive gases (quarterly)per trip 4 400.00$ 1,600.00$
Groundwater/Surfacewater (semi-annually)
Sampling per trip 2 3,000.00$ 6,000.00$
Analysis per trip 2 3,000.00$ 6,000.00$
Reporting per trip 2 2,700.00$ 5,400.00$
Subtotal 19,000.00$
ROUTINE MAINTENANCE (third party)
Mowing ($35/acre) 2 times a year acre 36.6 1,281.00$ 46,884.60$
Reseeding & Fertilize(5)acre 1.8 1,500.00$ 2,700.00$
Vector and Rodent Control acre 18.3 25.00$ 457.50$
Subtotal 50,042.10$
WELL MAINTENANCE
Groundwater Wells lump sum 1 500.00$ 500.00$
Gas Detection Probes lump sum 1 250.00$ 250.00$
Subtotal 750.00$
CAP REPAIR lump sum 1 5,000.00$ 5,000.00$
TOTAL OF ABOVE ITEMS 76,792.10$
ENGINEERING --3%2,303.76$
CONTINGENCY --5%3,839.61$
Annual inflation factor
TOTAL ANNUAL POST-CLOSURE COST (IN 2019 DOLLARS)82,935.47$
TOTAL ANNUAL POST-CLOSURE COST (IN 2020 DOLLARS)1.017 84,345.37$
TOTAL 30 YEAR POST-CLOSURE COST (IN 2020 DOLLARS)2,530,361.13$
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 9 August 2019
Coble’s Sandrock, North Carolina Revised July 2020
APPENDIX A

GROUNDWATER MONITORING WELL MAINTENANCE RECORD

FACILITY: WELL #:

LOCATION: DATE:

INSPECTOR: COMPANY:

1. Is surface water diverted away from the wellhead?

2. Is the concrete pad still intact and free of cracks?

3. Has surface water runoff undercut the concrete pad?

4. Is the outer casing still secure and locked?

5. Is the well identification tag present and is it legible?

a. Does the well identification tag provide the following information:

 The well identification number?
 Drilling contractor name and registration number?
 Total depth of well?
 Depth to screen?
 A warning that the well is not for water supply and that the ground water
may contain hazardous materials.

6. Is the grout between the inner and outer well casings all the way to the ground surface?

7. Is the inner casing firmly grouted in place?

8. Are the inner and outer casings upright and unobstructed?

9. Is water collecting in the outer casing? Does a weep hole need to be bored in the outer
casing to provide drainage?

10. Is the monitoring well accessible by a four-wheel drive vehicle?

11. Have brush and weeds been trimmed so that the well is easy to locate and access?

12. Does the inner well casing have a vented cap?

13. Is the monitoring well visible and adequately protected from moving equipment?
V – Closure & Post-Closure Care Plan Labella Associates, PC C&D LF 5-Year Permit Renewal/LOS 10 August 2019
Coble’s Sandrock, North Carolina

APPENDIX B

POST-CLOSURE INSPECTION RECORD

FACILITY: WELL #:
LOCATION: DATE:

INSPECTOR: COMPANY:

1. Access and Security Control
o Is a notice prohibiting the further disposal of waste materials clearly visible at
the entrance to the facility? o Is the site adequately secured by means of gates, chains, berms, fences or
other security measures to prevent unauthorized entry? o Are the access roads to and within the site maintained to provide access to the
closed disposal area and to all monitoring points?

2. Erosion and Sediment Control
o Is the vegetation adequate to stabilize the site and prevent erosion?
o Are the erosion control measures adequate to prevent silt from leaving the site
and to prevent excessive on-site erosion?
o Do the sediment basins require cleaning out, as indicted by the level of
sediment buildup?

3. Drainage Control Requirements
o Are all areas adequately sloped to promote surface water runoff in a controlled
manner? o Are there areas of observed settlement, subsidence, and/or displacement of
the closure cap? o Are all drainage channels free of accumulated sediment?

4. Uncontrolled Escape of Leachate or Landfill Gas
o Are there any leachate seeps observed? o Are there any signs of uncontrolled releases of landfill gas?

5. Environmental Monitoring Systems
o Are all monitoring wells (gas and groundwater) properly maintained? (Note:
Complete the Groundwater Monitoring Well Maintenance Record during
semiannual sampling events.)

6. Miscellaneous
o Are all site benchmarks marked and evident? o Do vector control measures appear adequate?
V – Closure & Post-Closure Care Plan Labella Associates, PC
C&D LF 5-Year Permit Renewal/LOS 11 August 2019 Coble’s Sandrock, North Carolina

APPENDIX C

LANDFILLGAS MONITORING TEST REPORT

Facility:
Location:
Date of Test:
Weather Condition:
Temperature: Barometric Pressure:
Sampling Personnel:

Monitoring Point Description/Location Time
CH4 / H2S
Concentration
(% of LEL)