20240123_ADI_Received

Martin
Marietta
Charlotte Quarry 2023 Mine Permit
ADI Resubmittal — January 20, 2024
• ADI Resubmittal Cover Letter
• Revised Mine Plan & Erosion Control Detail
Engineering Calculations JAii 2 311114
• Revised Culvert Calculations `';'ivWG PROG1?AM
• Revised Culvert Rip Rap Calculations
Martin Marietta Materials, Inc.
8701 Red Oak Blvd. Suite 540
Charlotte, NC 28217
704-407-1475

/AMartin lay Nivens
Mcirlettc Regional Manager Environmental Services
East Division
January 20, 2024 FedEx Delivery
Mr.Adam Parr, P.E.
State Mining Engineer
NC DEQ Division of Energy, Mining and Land Resources
512 North Salisbury Street
Raleigh, NC 27699-1612
RE: Martin Marietta Charlotte Quarry—Mine Permit#60-02 Modification Resubmittal
Dear Mr. Parr:
This letter is providing additional information as requested in the letter received from your office
dated January 10,2024,for the modification of the mine permit#60-02 for the Charlotte Quarry.
The following items have been addressed:
• There is a haul road on the east side of the operation that is drawn across an existing berm.
Please clarify the use or proposed construction of this haul road.
• This approved, proposed road has been removed.
• The north arrow on the Erosion and Sediment Control(E&SC) map is not correct. Please
correct the direction of the north arrow.
• The north arrow orientation has been corrected.
• The name of the skimmer basin appears as Skimmer Basin #I on the E&SC map and
Skimmer Basin #2 on the mine map and in the E&SC Calculation document. Please clarify
the name ofthe skimmer basin and correctly label the basin on all maps.
• The proposed skimmer basin will be Skimmer Basin#2. This has been reflected
on all sheets.
• The name of the culvert and apron in the E&SC calculations appears as "Culvert A"in the
title and "Culvert#2" in the table. Please clam the name of the culvert. Please clearly
identify and label on the map the location of this culvert.
• The label had been corrected and shown as Pipe#2 on all information.
• The mine map shows a pipe named "Pipe #2"under the proposed berm; however, this pipe
does not appear on the E&SC map. Please clarify the purpose of this pipe and clearly
indicate and label the pipe on the E&SC map. Please provide construction and maintenance
details for this pipe.
• Pipe #2 will be installed after initial erosion control measures are installed and
prior to developing the proposed overburden berm south across the existing
Carolina Regional Office
8701 Red Oak Blvd.Suite 540,Charlotte,NC 28217
t.[phone] m.[phone] [e-mail]
w .martinmarietta.com

May 14, 2020
Page 2
drainage divide. This pipe is provided to prevent stormwater runoff from pending
on the west side of the overburden berm. This pipe will be installed with a rock
pipe inlet protection(Std. 6.55)on the inlet side of the pipe to prevent sediment
from accumulating within the pipe. This pipe has been added to the S&EC plan
for clarification.
• There are concerns that the proposed silt fencing down slope of the new proposed skimmer
basin along the creek buffer may notfunction as required. Please verb that additional rows
or alternate siltfencing will be installed as needed.
• The current proposed silt fence is specified as silt fencing with wire fence
supporting the fabric installed with steel posts per NC SECDM Std. 6.62. An
additional row of silt fence has been provided along the stream buffer to provide
extra protection.
Should you have any questions or need any additional information, please contact me at 704-409-
1475 or via e-mail at iay.nivens(&martinmarietta.com
Sincerely,

Engineering Calculations
• Culvert Calculations
• Culvert Rip Rap Calculations

/A Martin
Marietta
Culvert Sizing Calculations
Date: January 15,2024
Drainage Area Runoff 25 Year Proposed Required Provided Pipe Outlet Velocity
Structure (acres) Coefficient Intensity Q25 Pipe Slope Pipe Size Size (fps)
Pipe#2 9.5 0.3 645 18.3825 MOO 13,98 18 8
Culvert Rip Rap Apron Sizing Calculations
NC Sediment and Erosion Control Manual NYDOT Method (Appendix 8.06.5)
Outlet Rip Rap Minimum Minimum
Structure Pi Size(in) Val city
(fps) Zone Stone Size De th Length ft Width(ft
Pipe#2 1 18 8 1 6" 12" 6 4.5