20231114_Narrative

UU11nn
Materials Company
November 14, 2023
Mr.Adam Parr, PE
N. C. Department of Environmental Quality
Division of Land Resources
Land Quality Section
1612 Mail Service Center
Raleigh, North Carolina 27699-1612
RE: Enka Quarry
Mining Permit No. 11-03
Permit Modification including Property Addition
Dear Parr:
Please find enclosed an original and four copies of the Operations Plan, Reclamation Plan,
and Mining Permit Application for Permit Modification.A check is enclosed in the amount
of$7S0.00 for payment of the required processing fee. This operation will not invoke any of
the seven denial criteria listed under G.S. 74-S1.
The modification includes the following:
• Quarry pit expansion into currently permitted Overburden Storage Areas,
• New areas are being proposed for disturbance within the 12.7 acres to be
added.
• Drainage from expansion will flow to a new and existing erosion and
sediment control structures,
• Updated Operations Plan,
• Updated Reclamation Plan,
• Includes the Approved Quarry Pit Limit from May 23, 2017, this pit limit was
inadvertently omitted from the last permit modification in 2022.
Sincerely,
Tony Johnson
Environmental Engineer
cc: David Cade
CHARLOTTE REGIONAL OFFICE—VULCAN CONSTRUCTION MATERIALS,L.L.C.
11020 David Taylor Drive,SUITE 400,CHARLOTTE,NC 28262,TELEPHONE [phone], FAX [phone]

Enka Quarry•Mining Permit No. 11-03
Vulcan Construction Materials,LLC
Mining Permit Modification November 14,2023
Introduction
Vulcan Construction Materials, LLC ("Vulcan") operates the Enka Quarry, Permit No. 11-03, in
Buncombe County, North Carolina. The site is located on the south side of US Rt 19/23, at
1186 Smokey Park Highway, Candler,NC 28715.
This mining permit modification provides an overview of the existing conditions of the quarry
and a detailed plan for the proposed site improvements. The proposed activities include adding a
12.7-acre tract to the permit boundary for overburden storage. The purpose of this modification is
to install additional erosion and sediment control measures to utilize the new area for overburden
storage.
Existing Conditions
Property and Permit Boundary
The existing permitted property at Enka Quarry consists of 288.00 acres of land owned
by Vulcan Lands, Inc. This permitted area is shown on Operations Plan.
Landuse
Within the 1,249.23-acre permitted area, Vulcan currently has approximately 580.6 acres
for quarry related activities including: approximately 0.60 acre for tailings / settling pond
area, 19.4 acres for stockpiles, 48.40 acres for overburden storage area, 25.10 acres
for processing/haul roads area, and 143.10 acres for mine excavation area. The remaining
areas are used for buffers and wildlife enhancement.
Wetlands and Streams
The area included in this permit modification request has been investigated for the presence
of Waters of the U.S. (wetlands and streams). Any such areas have been verified and
delineated using appropriate protocol and their locations surveyed. No impacts to Waters
of the US are proposed by this modification request.

Rockingham Quarry•Mining Permit No. 77-01
Vulcan Construction Materials,LLC
Mining Permit Modification November 18,2021
Proposed Land Disturbance Boundary
This mine permit modification adds 12.70 acres to thew west side of the approved mine permit
boundary. The purpose of this modification is to install erosion and sediment control measures to
utilize this additional tract for overburden storage.
All storm water runoff from the proposed modification area will be controlled by existing
Outfall 107-011 and proposed Outfall 107-011. Included with this modification are the
design drawings and computations for these outfall structures.
Construction Sequence
1. Enter the area of existing Outfall 107-012 to remove any trees and brush in and around the
basin, plus remove any sediment within the basin to maximize the sediment trapping
capacity.
2. Install silt fence as shown on the site plan.
3. Construct Sediment Basin with Rock Dam 107-011 as per the design plan and computations.
4. Install the 5' high rock dam in the existing conveyance channel to provide internal sediment
storage capacity.
5. Commence excavation overburden from the existing overburden pile and place it directly
above the new basin 107-011. A temporary 24" diameter culvert will be placed in the
existing conveyance channel to provide access for construction equipment to traverse for
the existing overburden pile to this new storage area. Continue filling in this area above
basin 107-001 until the grades for Temporary Sediment Trap—Thrash Property are achieved
along with the access road and roadside channel from the "Drainage Break"to the sediment
trap.
6. Surface water discharging from the temporary sediment trap will flow into the existing
conveyance channel, then pass through existing Rock Dam Outfall 107-012.
7. Vegetate disturbed areas in progression as soon as final grades are achieved in an area.
8. As part of the plan for removing the existing overburden storage pile, a drainage path will
be excavated from the existing quarry pit side to the existing conveyance channel, as shown
on the site plan, to turn the drainage from the existing conveyance channel and Outfall 107-
012 back to the quarry pit.
9. Continue filling and vegetating the proposed overburden storage area to the grades shown
on the site plan.

Sediment Basin with Rock Dam - 107-011
Enka Quarry
Watershed Characteristics
Total Drainage Area - 7.5 Acres
Disturbed Drainage Area - 2.5 Acres
Runoff Coefficient- 0.50
Time of Concentration - 10 Min
2 Year 10 Year 25 Year 100 Year
Rainfall Intensity (in/hr) - 4.16 5.65 6.44 7.69
Runoff V (cfs) - 15.6 21.2 24.2 28.8
Basin Characteristics
Basin -Top El. 2140.0
Top Useable El - 2138.0
Top Dimensions- 50 x 60
Bottom El - 2132.0
Bottom Dimensions - 24 x 38
Shape - Rectangular
Top Width - 20 FT
Design Computations
Required Storage Volume - 9,000 cu ft = 333 cu yd = 0.21 ac-ft
Available Storage Volume - 9,928 cu ft Storage Avail > Storage Rqrd by- 10 %
Water Surface Area (sq ft) - 3,000
Q2 = 44 %
Trapping Efficiency Q10 = 33 %
Q25 = 29 %
Rock Check Dam Spillway 11
Spillway Invert Elevation 2138.0
Freeboard Depth - 1 ft
Flow Depth - 1 ft
Total Depth - 2 ft
Bottom Width - 20 ft
Left Side Slope - 5 :1
Right Side Slope - 5 :1
Total Spillway Capacity- 153 cfs
25 Year Storm Flow Depth - 0.7 ft
100 Year Storm Flow Depth - 0.8 ft

Temporary Sediment Trap -Thrash Property
Enka Quarry
Watershed Characteristics
Total Drainage Area - 1.2 Acres
Disturbed Drainage Area - 1.2 Acres
Runoff Coefficient- 0.50
Time of Concentration - 10 Min
2 Year 10 Year 25 Year 100 Year
Rainfall Intensity (in/hr) - 4.16 5.65 6.44 7.69
Runoff 'Q' (cfs) - 2.5 3.4 3.9 4.6
Basin Characteristics
Basin -Top El. 2198.0
Top Useable El - 2196.0
Top Dimensions- 33 x 77 Triangle
Bottom El - 2190.0
Bottom Dimensions - 9 x 53 Triangle
Shape - Triangle
Top Width - 20 FT
Design Computations
Required Storage Volume - 4,320 cu Eft 160 cu yd = 0.10 ac-ft
Available Storage Volume - 4,500 cu ft Storage Avail > Storage Rqrd by- 4 %
Water Surface Area (sq ft) - 1,690
Q2 = 155 %
Trapping Efficiency Q10 = 114 %
Q25 = 100 %
Rock Check Dam Spillway 11
Spillway Invert Elevation 2196.0
Freeboard Depth - 1 ft
Flow Depth - 1 ft
Total Depth - 2 ft
Bottom Width - 8 ft
Left Side Slope - 2 :1
Right Side Slope - 2 :1
Total Spillway Capacity- 71 cfs
25 Year Storm Flow Depth - 0.5 ft
100 Year Storm Flow Depth - 0.5 ft

Roadside Ditch
Enka Quarry
Watershed Characteristics
Total Drainage Area - 2 Acres
Disturbed Drainage Area - 2 Acres
Runoff Coefficient- 0.50
Time of Concentration - 10 Min
2 Year 10 Yea 25 Year 100 Year
Rainfall Intensity (in/hr) - 4.16 5.65 1 6.44 7.69
Runoff V (cfs) - 4.2 5.7 1 6.4 7.7
Channel Characteristics
Depth - 2 ft
Bottom Width - 2 ft
Left Side Slope - 2 :1
Right Side Slope - 2 :1
Channel Slope - 2 %
Design Computations -11
d (ft) A (sq ft) R (ft) n V (fps) V*R Q(cfs) Comments
Retardance Class 'D' 0.82 2.98 0.53 0.052 2.6 1.4 7.9 V—VP & Q>Q25
Retardance Class 'C' 1.01 4.06 0.62 0.080 1.9 1.2 7.8 V--VP & Q>Q25
Temporary Lining Design 0.56 1.75 0.39 0.025 4.5 1.7 7.8 Q>Q2
Shear Stress-Td for Q2= 0.7 Use Synthetic Mat -SC 150