4117_A1SandrockCDLF_Phase3A_finalCQARpt_FID1318857_20190405

Wood Environment & Infrastructure Solutions, Inc. Page 1 Tel – [phone]
4021 Stirrup Creek Drive, Suite 100 Fax – [phone]
Durham, North Carolina 27703 www.woodplc.com
Licensure: NC Engineering F-1253; NC Geology C-247

April 4, 2019

Ms. Sherri Stanley, PE, Branch Head
NCDENR Division of Waste Management
Solid Waste Section Permitting Branch
1646 Mail Service Center
Raleigh, NC 27699-1646

Subject: Construction Quality Assurance Documentation
A-1 Sandrock CDLF Phase 3A
Greensboro, North Carolina (Guilford County)
Solid Waste Permit 4117-CDLF-2008

Dear Ms. Stanley:

Wood Environment & Infrastructure Solutions, Inc. (Wood) is pleased to present this report on
behalf of A-1 Sandrock, Inc., documenting the completion of Phase 3A of the approved CDLF
expansion. This work was completed in pursuit of a Permit to Operate (PTO) from the Solid Waste
Section (SWS). Within this report, please find documentation for construction of Phase 3A,
including the certification of subgrade conditions and adherence to the approved construction
plan. At present, A-1 Sandrock seeks the Section’s approval of the construction and the issuance
of a Permit to Operate (PTO).

This report is organized into the following sections.

1. Letter Report
2. Attachments
A. As-built construction drawings
B. Test pits to confirm ground water separation and bedrock
C. Laboratory Test Results
D. Photographic documentation

CQA Documentation Report Permit 4117-CDLF-2008
A-1 Sandrock, Inc. Phase 3A Guilford County, North Carolina

2 www.woodplc.com

OVERVIEW

This report is intended to satisfy the requirements of 15A NCAC 13B .0540 for documentation of
Construction Quality Assurance (CQA) for Phase 3A at A-1 Sandrock CDLF. Phase 3 is a contiguous
footprint covering approximately 7.6 acres. Construction was divided into two equal sub-phases:
Phase 3A (newly constructed within the higher elevations to the northeast side of Phase 3) and
Phase 3B (not constructed because of a temporary soil stockpile relict of Phase 2 construction in
the lower elevations to the southwest side of Phase 3).

Phase 3A exists within an excavated section with base grades approved under the earlier PTC. The
upper 24 inches of the soil consists of USCS classifications ML and SM. Visual soil classification
was performed via 17 tests pits dug across Phase 3A by A-1 Sandrock under the supervision of
Wood personnel. Laboratory soil confirmation was performed on bulk samples collected from 4
of the 16 test pits as outlined in the Phase 3 PTC.

The test pits indicated two small areas where the separation to rock-like materials that could not
be easily excavated was encountered at depths of 36 and 42 inches (Test Pits 2 and 6, respectively).
At these locations, appropriate amounts of soil fill were placed to provide the required 48 inches
of separation. The base grades were surveyed by a licensed surveyor after the test pit
investigation.

Wood personnel observed that the composition and relative density of soils within Phase 3A are
consistent with those observed in Phase 1 and Phase 2. The behavior of the soils under load were
confirmed via proof rolling to evaluate the soil density; a large track excavator (CAT 335 or
equivalent) moved across the site with no indications of soft or pumping soil conditions. These
methods are used extensively in the construction industry and are appropriate for this site.

Major aspects of the new construction included:

1. Establishment of layout and grade control by a third-party licensed surveyor.

2. Verification of base grading consistency with approved plans (See Attachment A).

3. Verification of minimum 4-foot base grade separation to ground water and bedrock
(See Attachment B).

CQA Documentation Report Permit 4117-CDLF-2008
A-1 Sandrock, Inc. Phase 3A Guilford County, North Carolina

3 www.woodplc.com

4. Adjusting base grades as needed to meet the four feet of separation requirement by
placing additional soil fill and confirming fill placement with additional test pits.

5. Verification that soils within the upper 24 inches of finished base grades meets NC
DEQ Solid Waste Section requirements for soil type (See Attachment B).

6. Performing confirmation laboratory testing to verify soil type (See Attachment C).

7. Installing permanent marker posts at the perimeter of the waste footprint.

RESPONSIBILITIES AND DOCUMENTATION

The Facility served as its own contractor (facility manager Ronnie Petty supervising) using in house
staff and equipment, local surveying support (Allied Professional Services, PLLC, Clint Osborn, PLS
surveyor), and field engineering support and CQA oversight (Wood E&IS, Pablo Rios-Maldonado,
Senior CMT Technician supervising). Documentation of the work consists of field notes and "as-
built" construction plans, plus a series of photographs, presented in separate sections of this
report (See Attachments).

While inspecting the test pits and capturing photographs of the phase, it was apparent that two
locations (Test Pit 2 and 6) in the Phase 3A footprint did not meet the requirements of separation
with the current base grades established. These areas were noted, and the facility owner was
notified that additional material was required in these areas. Soil was added, and grades were
transitioned into surrounding grades. A bulk sample of the fill material was collected to confirm
the material met soil-type requirements in the upper 24 inches. After additional fill material was
placed, confirmation test pits were performed at the previously identified locations (Test Pit 2 and
6). It was confirmed the required separation was met with respects to ground water and bed rock
elevations.

The project engineer was able to confirm that the base grade construction for Phase 3A meets
the regulatory requirements based on visual observations and laboratory test results. The visual
soil classifications were confirmed with laboratory testing in accordance with ASTM D4318 and
D7928. All soils tested passed the visual and laboratory evaluation criteria.

CQA Documentation Report Permit 4117-CDLF-2008
A-1 Sandrock, Inc. Phase 3A Guilford County, North Carolina
4 www.woodplc.com
CERTIFICATION
This is to certify that construction of Phase 3A of the A-1 Sandrock CDLF was completed in
substantial compliance with the (1) approved CQA Plan, (2) conditions of the Permit to Construct,
(3) Solid Waste Management Rules, and (4) approved grades, as depicted on the “as-built” plans.
Said plans were prepared based on a topographic survey by a licensed surveyor. Subgrade soil
types meet the current regulatory requirements based on visual inspection. No ground water,
detrimental soils, or bedrock were encountered at or above the approved subgrade elevations.
Please contact us if you have any questions or comments.
Cordially yours,
Wood Environment & Infrastructure Solutions, Inc.
Michael C. Raup, P.E. G. David Garrett, P.G., P.E.
Geotechnical Engineer Senior Engineer
NC – PE 45271 NC – PG 0983
NC – PE 25462
3-19-19

CQA Documentation Report Permit 4117-CDLF-2008
A-1 Sandrock, Inc. Phase 3A Guilford County, North Carolina

www.woodplc.com

Attachment A
As-Built Construction Drawing