7302_DukeRoxboro_VegetationMaintenance_DIN27726_20170324

3191 Pine Hall Road
Walnut Cove, North Carolina 27009
336-215-4576

Page 1 of 1
March 24, 2017 North Carolina Department of Environmental Quality
Division of Waste Management Solid Waste Section
1646 Mail Service Center
Raleigh, North Carolina 27699
Attn: Ms. Shannon Aufman (submitted electronically)
Re: Roxboro Vegetation Maintenance
Permit No. 7302-INDUS-1988 Roxboro Steam Electric Plant 1700 Dunnaway Road
Semora, North Carolina 27343
Dear Ms Aufman,
Duke Energy is submitting the attached Vegetation Maintenance and Implementation Plan for Clearing Projects at the Roxboro Steam Electric Plant Landfill (Permit No. 7302-INDUS). This work is to assist
with routine visual inspection procedures and is intended to occur predominately on the lower portion of the east slope of the landfill.

If you need additional information in regards to this submittal please do not hesitate to call me at 336-215-4576 or email [e-mail].

Regards,
Kimberlee Witt, PE
Environmental Services
Attachments: Roxboro Vegetation Maintenance and Implementation Plan for Clearing Projects
cc: Elizabeth Werner - NCDEQ Ed Mussler - NCDEQ
Evan Andrews - Duke Energy Robert Howard – Duke Energy
Robert Miller – Duke Energy
Ed Sullivan – Duke Energy
Vegetation Maintenance and
Implementation Plan for
Clearing Projects
Roxboro Industrial Landfill
Duke Energy Progress – Roxboro Steam Station
Person County, North Carolina
Amec Foster Wheeler Project No. 7810170864
To: Duke Energy Progress
Date 03/24/2017
From: Amec Foster Wheeler
Vegetation Maintenance and Implementation Plan Duke Energy – Roxboro Steam Station
Roxboro Industrial Landfill Person County, North Carolina
Amec Foster Wheeler Project No. 7810170864 TOC 03/24/2017
Table of Contents
1 BACKGROUND ..................................................................................................................................... 1
1.1 Facility Description ........................................................................................................................ 1
1.2 Scope of Plan ................................................................................................................................ 1
2 MANAGEMENT OF LANDFILL VEGETATION ..................................................................................... 1
2.1 Existing Conditions ........................................................................................................................ 1
2.2 Chemical Vegetation Control ........................................................................................................ 1
2.3 Brush ............................................................................................................................................. 2
2.4 Trees 2-Inches or Less (DBH) ...................................................................................................... 2
2.5 Trees 2-Inches or Greater (DBH) .................................................................................................. 2
2.6 Phasing of the Clearing Operations .............................................................................................. 3
3 INTERIM COVER MAINTENANCE ....................................................................................................... 3
3.1 Inspection ...................................................................................................................................... 3
3.2 Erosion .......................................................................................................................................... 3
3.3 Earthen Cover ............................................................................................................................... 3
FIGURES
Figure 1 Existing Conditions
ENGINEER’S STATEMENT
The procedures in this plan are consistent with the goal of clearing and maintaining portions of the landfill
to facilitate visual inspection and to improve the integrity of the soil cover by removal of woody material as
described herein.
Vegetation Maintenance and Implementation Plan Duke Energy – Roxboro Steam Station
Roxboro Industrial Landfill Person County, North Carolina
Amec Foster Wheeler Project No. 781010864 Page 1 of 3 03/24/2017
1 Background
1.1 Facility Description
The Roxboro Steam Station is located at 1700 Dunnaway Road in Semora, Person County, North
Carolina. The Roxboro Industrial Landfill (referred to as the landfill) is located predominantly within the
footprint of the filled East Ash Basin (EAB), which was constructed to receive sluiced ash from the
Roxboro plant. When the plant converted to dry fly ash handling, an unlined industrial landfill was
permitted in the East Ash Basin area. In 1988 the North Carolina Department of Environment and Natural
Resources (now Department of Environmental Quality, NCDEQ) issued Solid Waste Permit No. 7302 for
the unlined industrial landfill. The approximate limits of the unlined landfill are shown on Figure 1.
In 2001, a plan for a lined industrial landfill was developed. The limits of lined landfill Phases 1 through 6,
also permitted under Solid Waste Permit No. 7302, are shown on Figure 1.
The exposed portion of the unlined landfill has interim cover consisting of soil with stabilizing vegetation or
road surfacing material throughout. The surface of the lower portion of the eastern slope contains some
woody vegetation and trees. Duke Energy wishes to facilitate visual inspection of the surface of the
interim cover.
1.2 Scope of Plan
The intent of this Vegetation Maintenance and Implementation Plan (referred to as the Plan) is to outline
requirements for clearing and maintaining portions of the landfill to facilitate visual inspection of the area
and to improve the integrity of the soil cover by removal of woody material. Specifically, Duke Energy
intends to remove trees and woody vegetation from approximately 6 acres on the lower portion of the east
slope of the Landfill (referred to as “this project”). This project and any subsequent clearing projects will
involve the removal of all woody material. Trees 2-inches or less in diameter will be removed without
disturbing the subsoil and leaving roots and root balls in place. Trees 2-inches or greater in diameter will
be removed along with roots and root balls. Trees and debris from vegetation removal will be disposed of
at an offsite Land Clearing and Inert Debris (LCID) landfill, except as follows. For root balls containing
ash, the Owner will identify handling and disposal methods in accordance with station permits and waste
management regulations.
This Plan provides guidance on vegetation removal from brush to large trees with the intent of maintaining
the function of the landfill interim cover.Removal of trees will be completed under the direction of the
System Owner. Approved erosion and sedimentation control measures (which are not described in this
plan) will be implemented.
2 Management of Landfill Vegetation
2.1 Existing Conditions
The existing vegetation on the landfill is predominantly non-woody vegetation, but includes heavy brush
and trees on the lower portion of the east slope. It is the intent of Duke Energy to remove woody
vegetation to facilitate inspection of the east slope of the unlined landfill. The procedures used to remove
the existing woody vegetation will be different than the methods for routine upkeep. After the initial woody
vegetation removal, the need for any additional woody vegetation removal will be established by Duke
Energy personnel.
2.2 Chemical Vegetation Control
If there are areas of dense woody vegetation where access by mowers is limited, these areas may be
managed using herbicides. It is critical that chemical treatments be applied by qualified personnel in
accordance with manufacturer's directions, Duke Energy safety practices and the Roxboro Steam Station
NPDES and groundwater subject management expert. This document is not intended to serve as a guide
to chemical vegetation management. Refer to literature provided by Duke Energy, State of North Carolina
and Person County for guidance regarding chemical vegetation control, including the proper methods,
application rates, frequency and season of the year for applications.
Vegetation Maintenance and Implementation Plan Duke Energy – Roxboro Steam Station
Roxboro Industrial Landfill Person County, North Carolina
Amec Foster Wheeler Project No. 781010864 Page 2 of 3 03/24/2017
2.3 Brush
The lower portion of the east slope of the landfill is covered with dense brush. This obscures visual
inspection of the area and prevents walking or vehicle access. Where accessible, brush can be managed
using mechanical methods, such as mowers and hand held trimmers. For large areas, or areas where
access for conventional mowers or bush hogs is not available, specialized forestry management
equipment can be used to clear brush and trees. Such equipment must be operated by qualified
personnel subject to Duke Energy safety requirements.
Reconnaissance of ground surface conditions should be conducted prior to introduction of mowing
equipment. Brush covered areas adjacent to monitoring wells, culverts, and waste markers should be
managed using hand equipment. Brush from this project be ground or chipped on site and used as
appropriate temporary erosion control measure on this project.
2.4 Trees 2-Inches or Less (DBH)
Trees with a diameter of 2-inches or less (as measured at breast height, or "DBH") should be removed
and not allowed to be re-established on the landfill surface.This is best accomplished by routine mowing.
Potential for impact to the interim cover is low. In general, trees of this size should be managed the same
as brush as described above.
2.5 Trees 2-Inches or Greater (DBH)
Individual trees greater than 2-inches in diameter DBH that are identified for removal should be marked in
the field using surveyor ribbon or similar material. Removal of trees greater than 2-inches in diameter
shall be performed by cutting the trunk flush at the ground surface, removing the stump and root ball,
cleaning the root ball cavity, backfilling with compacted soil, installing erosion control matting, and
stabilizing with permanent vegetation. If practical, segregate and stockpile available topsoil for later reuse.
The entire stump and root ball should be removed, including roots in excess of 2-inches in diameter.This
may require excavation into CCR. If CCR is exposed and excavated, it should be managed separately
from cover soil and vegetation. At the discretion of the Duke Energy personnel, CCR removed from
excavations as part of interim cover maintenance can be placed back into the excavation providing the
original interim cover surface elevations are generally maintained. All such areas must be covered by a
minimum 2-foot thickness of interim cover soil. Alternately, CCR can be removed from the area and
disposed in the active area of the landfill.
Excavations through the interim cover should be prepared for interim cover placement by stepping or
benching the sides of the excavation to allow effective blending of the new and in-place interim cover
soils. Loose materials at the base of the excavation,including CCR should be graded and compacted as
needed before placement of the cover soil. Cover soil should be placed in thin lifts. Lift thickness is
dependent of the size of the repair area, the type of soil used for cover and the type of grading and
compaction equipment used. As a guideline, a maximum loose lift thickness of 8-inches is suitable for
lightweight compaction equipment. Lift thickness can be increased or decreased depending on the
equipment available and the geometry of the repair area.
Monitoring of the repair by a qualified engineer or technician is recommended.The following activities are
recommended:
x Documentation of the location of the repair, and the nature of the repair,
x Size and depth of the excavation,
x The presence of CCR in the excavation and the fate of any CCR removed from the excavation as
part of the repair,
x The conditions of the base and sides of the excavation prior to backfill (i.e., loose materials,
preparation of slopes by benching, etc.),
x Source and classification of interim cover soils used in the repair (include available field or
laboratory Proctor data, etc.),
Vegetation Maintenance and Implementation Plan Duke Energy – Roxboro Steam Station
Roxboro Industrial Landfill Person County, North Carolina
Amec Foster Wheeler Project No. 781010864 Page 3 of 3 03/24/2017
x Lift thickness, compaction methods and equipment, number of passes,
x Density testing (if completed),
x Surface restoration, including topsoil, mulching, seeding,
x The total thickness of the interim cover soil should be measured and recorded to document
compliance with regulatory criteria,
x Follow-up inspections to monitor establishment of vegetation, erosion, etc.
It is recommended that filling of excavations associated with root ball removal and other repair areas
where CCR is exposed be completed as quickly as possible after excavation.
Grade the surface of the repair into the adjacent interim cover areas in a way that does not result in
erosion or trapped surface water runoff. This may require placement of interim cover soils in areas
outside of the original repair area. If this is the case, it is recommended that the vegetation and topsoil be
removed before placement of the interim cover soil. Once repairs are completed, place topsoil (if
available) and erosion control matting. Establish vegetation in accordance with the solid waste permit
requirements.
Monitor repair areas and correct any deficiencies noted in the interim cover.
2.6 Phasing of the Clearing Operations
During any required clearing operations, removal of large trees and their stumps could be delayed until
safe effective access is established by removal of brush, etc. These operations could also be delayed
until a more favorable season of the year.It is not the intent of this document that all trees and brush must
be removed in a single operation. Duke Energy staff should phase the work as needed to most effectively
and safely manage the vegetation removal process.
3 Interim Cover Maintenance
3.1 Inspection
Inspections will be performed at a frequency in accordance with the solid waste permit for the landfill.
Inspection and maintenance of the interim cover are to be completed only when conditions are deemed
safe for personnel and for the operation of equipment.
It is recommended that annual inspections be conducted at the same time each year to best document
changed conditions between inspections, and to plan and monitor maintenance, etc. Inspection during the
winter months provides the best visibility of the cover surface since vegetation is generally dormant.
Inspection of vegetation should be completed during the summer months.
3.2 Erosion
Areas of erosion noted during inspections will be repaired as needed by methods including filling,
regrading, vegetating, and installing erosion control matting.
3.3 Earthen Cover
Maintenance of vegetation, repairs to or installation of ditches,or repairs to eroded areas require
placement of a minimum of a 2-foot thickness of compacted soil over the top of the CCR. For purposes of
this document, soils used for repairs of the unlined landfill should meet the following requirements:
x Soils consisting of clean natural soil classified as SM, SC, ML, or CL-ML, MH, CH using the
Unified Soil Classification System (USCS) containing no topsoil or other deleterious material,
x No particles exceeding 4 inches in size, and
x Compaction to at least 93% of the maximum dry density determined by test method ASTM D698.