6512_Duke_Sutton_Cell6SubgradeCertification_DIN28212_20170713

1300 Mint Street, Suite 300 Charlotte, North Carolina 28203 PH 704.227.0840 www.geosyntec.com
GC6198/Subgrade Certification - Cell 6

11 July 2017
Mr. Stephen Williams Duke Energy Corporation 801 Sutton Steam Plant Road Wilmington, NC 28401

Subject: Subgrade Certification Letter Sutton CCR Landfill - Cell 6 Wilmington, North Carolina
Dear Mr. Williams:
Geosyntec Consultants of North Carolina, P.C. (Geosyntec) prepared this letter to comply with
Condition No. 9 found in Attachment 2 of the Permit to Construct No. 6512-INDUS-2016 for the
Sutton CCR Landfill located in Wilmington, North Carolina.
Condition No. 9 states, “A licensed geologist must report any pertinent geological feature(s)
exposed during phase or cell excavation. Prior to placing any landfill liner, the geologist must
submit to the Section Hydrogeologist a written report that includes an accurate description of
the exposed geological feature(s) and effect of the geological feature(s) on the design,
construction, and operation of the cell, phase, or unit.”
OVERVIEW OF CONSTRUCTION OBSERVATION
The earthworks construction activities were performed by Glover Construction (Glover) starting
on 3 March 2017 and were substantially completed on 26 June 2017. Mr. John Carruth of
Geosyntec served as the designated representative and was on site to observe the construction
activities under the direction of the undersigned.
CERTIFICATION
Surficial sands and the Cretaceous Peedee Formation form part of the borrow pit at the ST
Wooten Property, which is adjacent to landfill area, and are very similar in nature. There are no
significant confining units between the two formational units in this area. Fill material was
excavated from the borrow pit at the ST Wooten Property to bring the Cell 6 area up in elevation
from between six and ten feet; no excavation occurred in the Cell 6 area.
Mr. Stephen Williams 11 July 2017
Page 2

GC6198/Subgrade Certification - Cell 6
As expected, the soils excavated in the borrow pit to obtain structural fill for placement in Cell 6
corresponded to a light brown to tan, fine to medium sand. The observed geological features will
not have any adverse effect on the design, construction, and operation of Cell 6.
If you have any questions or require additional information, please do not hesitate to contact the
undersigned.
Sincerely,

Beau Hodge, P.G.
Principal Geologist
NC License No. 1243

C. Fabian Benavente, P.E.
Senior Engineer