7-_Design_Narrative.pdf

Repair C17 Landing Zone JBC Project No. SBML 11-1056

North Auxiliary Airfield Final Design Narrative

ADC Project No. 14178 Page 1 May 8, 2015

TABLE OF CONTENTS

Page

I. PROJECT INFORMATION, DESCRIPTION AND LOCATION

A. Design Team B. Description of Work C. Airfield Description D. Project Information E. Project Site Features F. Site Information

II. SITE DEMOLITION

A. Site Demolition Description

III. SITE AND LAYOUT DESIGN

A. Airfield Geometric Layout B. Pavement Markings C. Criteria / Regulations D. Summary of Design Requirements and Results

IV. PAVEMENT DESIGN

A. Existing Pavement Composition and Condition B. Pavement Design Description

V. ELECTRICAL DESIGN

A. General B. Lighting Layout C. Taxiway Edge Lights D. Airfield Signage E. Cable F. Counterpoise G. Grounding H. Airfield Duct/Conduit System I. Base Cans J. Lighting Circuits

VI. STORM DRAINAGE SYSTEM DESIGN

A. Storm Drainage System Description B. Quantitative Storm Drainage System Description C. Criteria / Regulations D. Summary of Design Requirements and Results E. Pre-Development Hydrology Narrative F. Post-Development Hydrology Narrative G. Hydrology Analysis Summary H. Calculation Basis

VII. SEDIMENTATION & EROSION CONTROL / SWPPP

A. Sedimentation/Erosion Control System Description / SWPPP B. Criteria / Regulations C. Summary of Design Requirements and Results

APPENDIX A – SITE MAPS

APPENDIX B – PAVEMENT CALCULATIONS

APPENDIX C – STORM DRAINAGE CALCULATIONS

APPENDIX D – STORM WATER POLLUTION PREVENTION PLAN (SWPPP)

APPENDIX E – EROSION CONTROL CALCULATIONS

APPENDIX F – JET BLAST EROSION

ADC Project No. 14178 Page 2 May 8, 2015

I. PROJECT INFORMATION, DESCRIPTION AND LOCATION

Glick/Boehm & Associates, Inc. and ADC Engineering, Inc. have been commissioned by Joint Base

Charleston – Air Base Civil Engineering Squadron for design services associated with the Repair C17

Landing Zone – NAAF project as described in the Design Work Order dated July 7, 2014.

A. Design Team

Civil Engineer: ---------- ADC Engineering, Inc. – Hanahan, South Carolina

Lighting: ------------------ Atkins – Raleigh, North Carolina

Surveying: --------------- Forsberg Engineering & Surveying, Inc. – Charleston, South Carolina

Geotechnical: ----------- S&ME, Inc. – Mount Pleasant, South Carolina

B. Description of Work

This project consists of the complete reconstruction of the approximately 3,500 foot long Assault

Landing Zone located at North Auxiliary Air Field. The reconstructed landing zone will be comprised of a new 90 foot wide Portland cement concrete section, asphalt shoulder pavement and asphalt over-run pavement. New airfield lighting and signage, pavement markings, sodding and grassing will also be included in the project.

C. Airfield Description

North Air Force Auxiliary Airfield is located in North, South Carolina and is used primarily for C-17

Globemaster III training by the 628 ABW and its Air Force Reserve units, the 315th Airlift Wing, at

Joint Base Charleston. The airfield consists of two runways: the main runway, Runway 6-24, and a landing zone, Runway 5-23.

D. Project Information

Location: .................................................. North Auxiliary Airfield

North, South Carolina – Orangeburg County

Latitude: .................................................. 3336’39” N

Longitude: ............................................... 8104’24” W

E. Project Site Features

1. Quad Map

This project is located in the USGS North, SC Quadrangle Map.

2. FEMA Information

This site is located in Flood Zone X, as depicted on FEMA Community Panel 45075 C0130C, dated January 16, 2014.

F. Site Information

1. Geotechnical Exploration

The geotechnical explorations conducted for North Air Force Auxiliary Airfield have been utilized for this project. A copy of that report is included as a separately bound document and in the specifications.

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II. SITE DEMOLITION

A. Site Demolition Description

This project includes the demolition of the existing airfield pavement, airfield lighting and a RCP pipe that crosses underneath the landing zone.

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III. SITE AND LAYOUT DESIGN

A. Airfield Geometric Layout

The geometric layout for this project was designed in accordance with UFC 3-260-01 Airfield and

Heliport Planning and Design for a C-17 Globemaster III aircraft type.

1. Paved Runways for C-17 Landing Zones

Item Requirement

Length 3500 feet

Width 90 feet

Width of Shoulders 10 feet

Longitudinal Grades of Runway & Shoulders Maximum 3%

Longitudinal Runway Grade Change Maximum 1.5% per 200 feet

Transverse Grade of Runway 0.5% Minimum, 3.0% Maximum

Transverse Grade of Runway Shoulders 1.5% Minimum, 5.0% Maximum

Width of Graded Area 35 feet

Transverse Grade of Graded Area 2.0% Minimum, 5.0% Maximum

Width of Maintained Area 70 feet

Maintained Area: Transverse Grade Maximum Range: +10.0% to -20.0%

2. Paved Overruns for C-17 Landing Zones

Item Requirement

Overrun Length 300 feet

Overrun Width 90 feet

Longitudinal Grade of Overruns Maximum 3%

Transverse Grade of Overruns 0.5% Minimum, 3.0% Maximum

Width of Overrun Shoulder 10 feet

Transverse Grade of Overrun Shoulders 1.5% Minimum, 5.0% Maximum

3. Paved Runway End Clear Zone for C-17 Landing Zones

Item Requirement

Length 500 feet

Width at Inner Edge 320 feet

Width at Outer Edge 500 feet

Longitudinal & Transverse Grade of Surface Maximum 5.0%

4. Paved Imaginary Surfaces for C-17 Landing Zones

Item Requirement

Primary Surface Length Runway Length plus 1,000 feet

Primary Surface Width 180 feet

Approach-Departure Clearance Surface –

Inner Edge 500 feet

Width at Inner Edge 500 feet

Slope 20H:1V

Slope Length 10,500 feet

Width at Outer Edge 2,500 feet at 10,500 feet from inner edge

ADC Project No. 14178 Page 5 May 8, 2015

B. Pavement Markings

The airfield marking layout was designed in accordance with ETL 09-6 C-130 and C-17 Landing

Zone (LZ) Dimensional, Marking, and Lighting Criteria. The markings include LZ edge markings, touchdown box, threshold bar, taxiway centerline, closed pavement marking and hold bar.

C. Criteria / Regulations

Criteria and regulations utilized in development of the design include but are not limited to:

UFC 3-230-06A Subsurface Drainage

UFC 3-260-01 Airfield and Heliport Planning and Design

UFC 3-260-02 Pavement Design for Airfields

ETL 09-6 C-130 and C-17 Landing Zone (LZ) Dimensional, Marking, and Lighting Criteria

D. Summary of Design Requirements and Results

The primary intent of the site design is to develop the project site to satisfy the owner/user needs and to comply with the various applicable criteria and regulations established by agencies governing development at the project location. The results of the design are primarily depicted on the project drawings and in the project specifications. The discussions contained below highlight special project requirements, approved variances, special exceptions or deviations and decisions that are not reflected elsewhere.

1. UFC Variances – Not Applicable

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IV. PAVEMENT DESIGN

A. Existing Pavement Composition and Condition

The typical existing pavement compositions vary as shown in the Pavement Evaluation excerpts provided in Appendix B.

B. Pavement Design Description

The airfield pavement design was completed in accordance with UFC 3-260-02 Pavement Design for

Airfields, UFC 3-230-06A Subsurface Drainage and PCASE (v.2.09.02) software with the following inputs:

1. Landing Zone

a. Option 2: Base Course

Pavement Type = Rigid

Traffic Pattern = C-17 Assault Landing Zone

Traffic Area = Area A

Modulus of Subgrade Reaction (K) = 100 pci

Pavement Section Thickness = 15 inch PCC / 6 inch Base Course

2. Landing Zone Shoulder

Pavement Type = Flexible

Traffic Pattern = Wheel

California Bearing Ratio (CBR) = 6

Pavement Section Thickness = 2 inch Asphalt / 8 inch Base Course

3. Taxiway

Pavement Type = Flexible

Traffic Pattern = Air Force Medium

Traffic Area = Area A

California Bearing Ratio (CBR) = 10

Pavement Section Thickness = 5 inch Asphalt / 14 inch Base

Course

It is noted from California Bearing Ratio (CBR) tests conducted during the geotechnical exploration that a CBR value of 6 percent was recommended to be used in the pavement design.

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V. ELECTRICAL DESIGN

A. General

Modifications to the airfield lighting will be required within the project limits for the repair of the C-17

Landing Zone. Modifications will include the demolition of existing landing zone lighting and associated electrical duct/conduit and the installation of new landing zone lighting, marker panels, 5 kV cable, grounding, counterpoise and electrical duct/conduit. The modifications and overall design of the electrical system will meet the current requirements of the following criteria:

AFI 13-217 Drop Zones and Landing Zone Operations

ETL 09-6 (Change 1) C-130 and C-17 Landing Zone (LZ) Dimensional, Marking, and Lighting

Criteria

UFC 3-535-01 Visual Air Navigation Facilities

UFC 3-535-02 Design Drawings for Visual Air Navigational Facilities

UFC 3-260-01 Airfield and Heliport Planning and Design

B. Lighting Layout

For Runways 05 and 23, this project will provide lighting for AMP-1, AMP-3 and AMP-3 Covert configurations. The existing Airfield Lighting Control System will allow any one of the three configurations to operate on either Runway.

AMP-1 Intermediate Steady Burn Edge Lights will be FAA L-850A type, bi-directional white, quartz fixtures installed on an L-868C base can with properly sized isolation transformer and

BRITE remote.

They will be installed at 500 foot minimum / 1,000 foot maximum spacing along the runway.

They will be installed 5 feet from the edge of the full strength runway.

AMP-1 Edge Light with Split Green/Red Lens will be FAA L-850A type, bi-directional green/red, quartz fixtures installed on an L-868C base can with properly sized isolation transformer and BRITE remote.

They will be installed at the threshold and 5 feet from the edge of runway pavement.

AMP-1 Synchronized Flashing Strobe Lights will be FAA-E-2952 type, uni-directional white, halogen fixtures installed on an L-868C base can with properly sized isolation transformer and

BRITE remote.

They will be installed at the threshold and 1 foot, 10 inches from the edge of pavement.

AMP-3 Steady Burn Edge Lights will be FAA L-850A type, bi-directional white, quartz fixtures installed on an L-868C base can with properly sized isolation transformer and BRITE remote.

They will be installed from the threshold at 500 foot spacing and will be installed 5 feet from the edge of the full strength runway.

AMP-3 Covert Infrared Edge Lights will be FAA L-850A type, uni-directional, quartz fixtures installed on an L-868C base can with properly sized isolation transformer and BRITE remote.

They will be installed from the threshold at 500 foot spacing and will be installed 5 feet from the edge of the full strength runway.

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AMP-3 Flashing Strobe Lights will be FAA-E-2952 type, uni-directional white, halogen fixtures installed on an L-868C base can with properly sized isolation transformer and BRITE remote.

They will be located 2.5 feet from Runway 23 end centerline and 2.5 feet from the threshold to match existing light location on Runway 05 end.

AMP-3 Covert Infrared Flashing Strobe Lights will be FAA-E-2952 type, bi-directional, halogen fixtures installed on an L-868C base can with properly sized isolation transformer and

BRITE remote.

They will be located 2.5 feet from Runway 23 end centerline and 2.5 feet from the threshold to match existing light location on Runway 05 end.

AMP-1/AMP-3 Marker Orange Panels will be FAA L-858 300 mph type signs, without electronics, installed on a concrete base. They will be installed at the threshold and 20 feet from the operational runway edge.

AMP-1 Marker Cerise Panels will be FAA L-858 300 mph type signs, without electronics, installed on a concrete base. They will be located 500 feet minimum / 1,000 feet maximum spacing along the runway. They will be installed 20 feet from the operational edge of the runway.

AMP-3 Marker Cerise Panels will be FAA L-858 300 mph type signs, without electronics, installed on a concrete base. They will be located 500 feet from the departure end threshold and 300 feet from the end of the opposite overrun end.

C. Taxiway Edge Lights

The new taxiway edge lights for Taxiways A and B will be mounted on new L-868B load-bearing base cans. New taxiway edge lights located along taxiway fillets will be semi-flush LED, L-852T (L).

The taxiway edge lights will be installed 5 feet from the theoretical edge of the full strength pavement. Taxiway edge lights will be omni-directional blue. None of the new taxiway edge lights will be equipped with an internal heater. The existing taxiway edge lights within project limits that are removed during demolition will be turned over to the Government or legally disposed of as requested during construction.

D. Airfield Signage

An existing abandoned airfield sign concrete foundation located at the old mandatory hold position marking on Taxiway B will be removed. A new airfield sign unit will installed at the relocated mandatory hold position marking. The sign unit shall be LED, Style 3, Class 2 (low temperature rating) and Mode 3 (300 mph wind loading). The sign unit will be installed on a new concrete sign base with the sign reference point located at a perpendicular distance of 55 feet from the theoretical edge of full strength pavement. The 55 foot distance is to the front edge of the sign unit.

E. Cable

Cable will be No. 6 AWG, 5kV, L-824, type C for airfield series circuits. Amerace Super Connector splice kits, or approved equal, will be used in lieu of heat shrink connections, per AMC preferences.

The 5kV cables routed will be equipped with stainless cable tags for circuit identification.

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F. Counterpoise

Counterpoise will be No. 4 AWG bare, solid copper. The system will not be attached to airfield lighting cans, fixtures, signs, or handholes. The system will be installed ½ the depth of the conduit and ½ the distance from the conduit and edge of full strength pavement for conduit parallel to pavement. A ¾-inch x 10-foot ground rod will be installed every 1,000-feet, staggered 500-feet with ground rods installed with the grounding system, to the extent possible. Counterpoise will stop 2-feet from base cans, base can plazas, and signs.

G. Grounding

Grounding will be accomplished via No. 6 AWG XHHW bare solid copper green ground wire installed in the conduit system and attached to internal ground lugs on base cans and ground lugs on fixtures.

A ¾-inch x 10-foot ground rod will be installed every 1,000-feet, staggered 500-feet with ground rods installed with the counterpoise system, to the extent possible. All metallic parts in handhole will be grounded.

H. Airfield Duct/Conduit System

New duct/conduit will be installed to interconnect the base cans for each new fixture to be installed.

The duct/conduit will be concrete encased under full strength pavement, shoulder pavement and turf areas. Conduits shall be of the size and configuration as indicated in the plans.

I. Base Cans

Base cans will be cast-in-place, galvanized steel with flared threaded hubs. All cans will be drained to the under drain or storm drain system, to the extent possible. Each can that houses an L-830 isolation transformer will include a transformer stand. Grounding from the fixture to the internal ground lug will be accomplished via a 6-foot flexible flat tinned copper braided ground strap.

Exothermic welding to ground rods in base cans will be via a “one-shot” weld. All base can mounting bolts will be bright orange, ceramic-metallic/fluoropolymer coated bolts.

J. Lighting Circuits

Existing homerun for C-17 landing zone will be removed and replaced with new homerun cables that will terminate at lighting vault. Also, existing circuits feeding Taxiway Charlie will be removed and replaced to the extent possible.

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VI. STORM DRAINAGE SYSTEM DESIGN

A. Storm Drainage System Description

A single subdrain line will run parallel to the LZ on each side. The subdrain line will drain light cans along the new LZ and outfall to an existing ditch. The location of the outfall is the south side of the

LZ where it transitions to Taxiway Delta.

B. Quantitative Storm Drainage System Description

The following is an approximate summary of storm drainage system features associated with this project:

275 lf +/- new non-perforated subdrain pipe

6,650 lf +/- new 4” non-perforated subdrain pipe

1 ea new headwall

C. Criteria / Regulations

Criteria and regulations utilized in development of the design include but are not limited to:

American Association of State Highway and Transportation Officials (AASHTO) Standard

Specifications for Highway Bridges

American Concrete Pipe Association (ACPA) Concrete Pipe Design Manual

ASTM C 76 Standard Specification for Reinforced Concrete Culvert, Storm Drain and Sewer

Pipe

UFC 3-230-15FA Surface Drainage Facilities for Airfields and Heliports

UFC 3-230-16FA Drainage and Erosion Control Structures for Airfields and Heliports

UFC 3-320-05A Structural Design Criteria for Structures Other Than Buildings

SCDHEC Standard for Stormwater Management and Sediment Reduction R72-300 thru 72-316

(June 2002)

SC Stormwater Management and Sediment Control Handbook for Land Disturbance Activities

(September 2005)

South Carolina General Permit for Stormwater Discharges from Large and Small Construction

Activities SCR 100000 (August 2006)

MS4 Operator (Joint Base Charleston)

D. Summary of Design Requirements and Results

1. Storm Drainage Design

The primary storm drainage design is to comply with the quantitative and qualitative requirements of SCDHEC, the governing municipality, the governing department of transportation, owner and to protect adjacent properties as well as the surrounding environment.

The specific objectives for this project are described in the Post-Development Hydrology

Narrative.

2. Lighting System Drainage Design

The primary intent of the lighting system drainage design is to promote the drainage of the LZ light base cans, handholes and other new electrical features. New lighting features will connect to 4 inch diameter PVC collector pipes located in the paved shoulder. Cleanouts will be provided at critical points to allow access to collector pipes. Elevations permit outfall to an existing ditch on the south side of the LZ where it transitions to Taxiway Delta.

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E. Pre-Development Hydrology Narrative

The pre-development analysis for this project required and includes the analysis of a 526 acre contributory basin. This basin discharges to three separate outfalls defined as the Northwest

Boundary, East Boundary and South Boundary.

The Pre-Development contributory area and outfalls are as follows:

Northwest Boundary = 146 acres (piped outfall via 4-36 inch RCP)

East Boundary = 20 acres (outfall via sheet flow)

South Boundary = 360 acres (piped outfall via 2-48 inch RCP)

Total = 526 acres

The Northwest Boundary sub basins and outfalls are as follows:

NW-1A 4.75 acres (sheet flow to existing drainage structure and outfall to NW boundary)

NW-1B 34.25 acres (sheet flow to RCP and outfall to NW-1A)

NW-2 22 acres (sheet flow to existing drainage structure and outfall to NW boundary)

NW-3 85 acres (sheet flow to existing drainage structure and outfall to NW boundary)

The East Boundary sub basins and outfalls are as follows:

E-1 20.1 acres (sheet flow to East boundary)

The South Boundary sub basins and outfalls are as follows:

S-1A 170 acres (sheet flow to South boundary)

S-1B 48 acres (sheet flow to horizontal elliptical pipe to S-1A)

SE-1A 77 acres (sheet flow to existing ditch and outfall to South Boundary)

SE-1B 65 acres (sheet flow to existing ditch and outfall to SE-1A)

Refer to the attached Pre-Development Basin Map, spreadsheet titled ‘Drainage Area/Curve

Numbers/Time of Concentration – Pre-Developed Conditions’ and ICPR input/output for pre-developed conditions.

F. Post-Development Hydrology Narrative

This project is required by SCDHEC Standard for Stormwater Management and Sediment Reduction

72-300 through 72-316 to meet pre-developed peak discharge rates for the 2- and 10-year storm events. The post-development analysis presented herein has been prepared based on the changes associated with the reconstruction of the C-17 Landing Zone.

The post-development analysis for this project studied the same 526 acre contributory area as the pre-development analysis.

The Post-Development contributory area and outfalls are as follows:

Northwest Boundary = 146 acres (piped outfall via 4-36 inch RCP)

East Boundary = 20 acres (outfall via sheet flow)

South Boundary = 360 acres (piped outfall via 2-48 inch RCP)

Total = 526 acres

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The Northwest Boundary sub basins and outfalls are as follows:

NW-1A 4.75 acres (sheet flow to existing drainage structure and outfall to NW boundary)

NW-1B 34.25 acres (sheet flow to RCP and outfall to NW-1A)

NW-2 22 acres (sheet flow to existing drainage structure and outfall to NW boundary)

NW-3 85 acres (sheet flow to existing drainage structure and outfall to NW boundary)

The East Boundary sub basins and outfalls are as follows:

E-1 20.1 acres (sheet flow to East boundary)

The South Boundary sub basins and outfalls are as follows:

S-1A 170 acres (sheet flow to South boundary)

S-1B 48 acres (sheet flow to horizontal elliptical pipe to S-1A)

SE-1A 77 acres (sheet flow to existing ditch and outfall to South Boundary)

SE-1B 65 acres (sheet flow to existing ditch and outfall to SE-1A)

Refer to the attached Post-Development Basin Map and spreadsheet titled ‘Drainage Area/Curve

Numbers/Time of Concentration – Post-Developed Conditions’ for post-developed conditions.

A summary of impervious surface changes from pre-development conditions to post-development conditions are as follows:

Impervious Surface Change Result

Addition of paved shoulders to Landing strip and removal of abandoned PCC apron Decrease impervious surface 0.20 acres

Net Impact Decrease Impervious Area 0.20 acres

The entire affiliated 526 acre basin has been analyzed to determine the impact of the project on storm water runoff. Due to the removal of existing abandoned and excess pavement, the project results in a decrease in impervious area by 0.2 acres.

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G. Hydrology Analysis Summary

The table below provides a summary of the Basin Data, Pre-Development and Post-Development discharges for this project.

Basin Data Storm Data Pre-Development

Conditions Post-Development

Conditions

Northwest Boundary

Impervious Area 44.45 ac 44.45 ac

Pervious Area 101.55 ac 101.55 ac

Total Area 146 ac 146 ac

Composite C 0.41 0.41

Cumulative CN 72 72

Tc (min) 57 57

I – 2 year (in/hr) 2.64 2.64

I – 10 year (in/hr) 3.25 3.25

2 yr runoff (cfs) 156.95 cfs 156.95 cfs

10 yr runoff (cfs) 193.48 cfs 193.48 cfs

East Boundary

Impervious Area 3.1 ac 3.3 ac

Pervious Area 17 ac 16.8 ac

Total Area 20.1 ac 20.1 ac

Composite C 0.29 0.30

Cumulative CN 67 67

Tc (min) 29 29

I – 2 year (in/hr) 3.86 3.86

I – 10 year (in/hr) 4.78 4.78

2 yr runoff (cfs) 22.43 cfs 23.11 cfs

10 yr runoff (cfs) 27.90 cfs 28.64 cfs

South Boundary

Impervious Area 34.2 ac 33.8 ac

Pervious Area 325.8 ac 326.2 ac

Total Area 360 ac 360 ac

Composite C 0.24 0.24

Cumulative CN 65 64

Tc (min) 135 135

I – 2 year (in/hr) 1.40 1.40

I – 10 year (in/hr) 1.71 1.71

2 yr runoff (cfs) 122.70 cfs 122.26 cfs

10 yr runoff (cfs) 150.63 cfs 150.09 cfs

Overall, this project decreases impervious area for the entire parcel by 0.2 acres. However, the East

Boundary outfall has a slight increase in impervious area, thus a slight increase in runoff. Given the nature of the project and the fact that the increase in impervious area is not appreciable, this project will not result in significant adverse impacts on the receiving waterway. Therefore, a waiver of stormwater management for quantitative control of the State Stormwater Management and Sediment

Reduction Act is requested. The project meets the criteria set out in R72-302.B.

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H. Calculation Basis

1. Basin Analysis

Basin analysis is performed to determine the characteristics of the basins (Pre-development and

Post-development) that will influence the amount of runoff that can be anticipated for a given basin.

Areas – Within the project boundaries, areas are measured directly from the drawings. For off-site contributory basins, areas are measured from available sources such as USGS

Quadrangle Maps, other surveys or designs, FEMA panels, and as-built drawings. Areas are expressed in acres.

Runoff Coefficients – Runoff coefficients area calculated for both the Rational Formula (‘C’ values) and the SCS TR 55 (‘CN’ Curve Numbers). Curve Numbers are determined using the tables in the SCS TR 55 manual and are based on ground cover and the hydrologic soils group. The runoff coefficients used are as follows:

Curve Number Runoff Coefficient “C”

Paved 98 0.90

Grassed 61 0.17

Times of Concentration (Tc) – Times of concentration are calculated from formulas for sheet flow, shallow concentrated flow and open channels, published in SCS TR-55. The minimum time of concentration used, as allowed by SCDHEC, is 0.10 hours (6 minutes).

2. Hydraulic Calculations

a. Subarea Flow Analysis – Using the information calculated as indicated above, the individual sub-basins are analyzed to determine the contributory flow to each inlet. These calculations are done using the Rational Formula (Q=CIA).

Q = CIA

Q = peak rate of runoff in cubic feet per second (cfs)

C = runoff coefficient (see above)

I = average intensity of rainfall in inches per hour (in/hr)

A = drainage area in acres (ac) (see above)

The intensity of rainfall has been calculated based on values used by the South Carolina

Department of Transportation:

I = a/(b+tc)^c a, b, c = coefficients tc = time of concentration (min) (see attached spreadsheet)

SCDOT 2-Yr Event Coefficients SCDOT 10-Yr Event Coefficients

A 257.70309 279.2215

B 32.87932 29.67198

C 1.0185 0.99788

This analysis results in an Inlet Q.

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VII. SEDIMENTATION & EROSION CONTROL / SWPPP

A. Sedimentation/Erosion Control System Description / SWPPP

This project proposes to replace an existing LZ with a new pavement section at North Auxiliary

Airfield. Land disturbance will be involved for construction of the LZ pavement section and regarding of the LZ maintained area.

B. Criteria / Regulations

Criteria and regulations utilized in development of the design include but are not limited to:

SCDHEC Standard for Stormwater Management and Sediment Reduction R72-300 thru 72-316

(June 2002)

SC Stormwater Management and Sediment Control Handbook for Land Disturbance Activities

(September 2005)

South Carolina General Permit for Stormwater Discharges from Large and Small Construction

Activities SCR 100000 (August 2006)

MS4 Operator (City of North Charleston)

C. Summary of Design Requirements and Results

The Storm Water Pollution Prevention and Sedimentation and Erosion Control measures included in this project have been designed to satisfy the requirements of the SCDHEC Standards for

Stormwater Management and Sediment Reduction as well NPDES Construction General Permit.

The contents of the design include:

Storm Water Pollution Prevention Plan

Protection from Sedimentation/Erosion During Construction

Protection from Sedimentation/Erosion After Construction

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APPENDIX A – SITE MAPS

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APPENDIX B – PAVEMENT CALCULATIONS

Pavement Thickness Report U.S. Army Corps of Engineers

PCASE Version 2.09.02 Date : 10/13/2014Design Name : LZ-BASE

Design Type : Airfield Pavement Type : Rigid

Traffic Area : Area A Analysis Type : K

Depth of Frost (in) : 0 Wander Width (in) : 70

% Load Transfer : 25 Effective K (pci) : 149

Reduced Sub Effective K (pci) : 0 Layers Count : 3 Joint Spacing : 15 to 20 ft

Dowel Spacing : 15.00 in Dowel Length : 20.00 in

Dowel Diameter: 1.00 to 1.25 in

Layer Information

Layer Type Material Type Frost Code Flexural Strength

(psi) % Steel Analysis

Non frost Design

Thickness (in)

Reduced Subgrade Strength

(in)

Limited Subgrade

Penetration (in)

K Strength

(pci)

PCC N/A NFS 650 0 Compute 15.02 0 0 0 Base bound Crushed Sto NFS 0 0 Manual 6 0 0 0

Natural Subgrade Cohesive Cut NFS 0 0 Manual 0 0 0 100

Traffic Information

Pattern Name :

AIR FORCE

ASSAULT

LANDING ZONE

(C-17) PAVED

COPY-1

Vehicles Weight (lb)

Traffic Area A, B Weight (lb)

Traffic Area C, D

ACN

Passes Traffic

Area A, B, C

Passes Traffic Area D

Equivalent Passes

C-17A GLOBEMASTER III 502000 376500 45 100000 1000 100000

PCASE Version 2.09.02 Date : 10/13/2014Design Name : SHOULDER

Design Type : Airfield Pavement Type : Flex Shoulder

Traffic Area :

Analysis Type : CBR

Depth of Frost (in) : 0 Wander Width (in) : 0

Layer Information

Layer Type Material Type Frost Code Analysis

Non frost Design

Thickness (in)

Reduced Subgrade Strength

(in)

Limited Subgrade Penetratio n (in)

CBR

Strength

Asphalt Asphalt NFS Manual 2 0 0 0

Base Unbound

Crushed Stone NFS Compute 8.06 0 0 100

Natural Subgrade Cohesive Cut NFS Manual 0 0 0 6

Traffic Information Pattern Name : WHEEL

Vehicles Weight (lb)

Traffic Area A, B Weight (lb)

Traffic Area C, D

ACN

Passes Traffic Area

A, B, C

Passes Traffic Area

D 10000 7500 0 5000 50

PCASE Version 2.09.02 Date : 12/12/2014Design Name : TWY-MEDIUM

Design Type : Airfield Pavement Type : Flexible

Traffic Area : Area A Analysis Type : CBR

Depth of Frost (in) : 0 Wander Width (in) : 70

Layer Information

Layer Type Material Type Frost Code Analysis

Non frost Design

Thickness (in)

Reduced Subgrade Strength

(in)

Limited Subgrade Penetratio n (in)

CBR

Strength

Asphalt Asphalt NFS Manual 5 0 0 0

Base Unbound

Crushed Stone NFS Compute 13.27 0 0 100

Natural Subgrade Cohesive Cut NFS Manual 0 0 0 10

Traffic Information

Pattern Name :

AIR FORCE

MEDIUM

COPY-1

Vehicles Weight (lb)

Traffic Area A, B Weight (lb)

Traffic Area C, D

ACN

Passes Traffic Area

A, B, C

Passes Traffic Area

D

Equivalent Passes

B-52H

STRATOFORTRESS

400000 300000 61 400 4 4182

C-17A GLOBEMASTER III 585000 438750 45 400000 4000 400000

F-15E EAGLE 81000 60750 33 100000 1000 7

BACKGROUND INFORMATION

Location

North Field is located 3 miles east of North, South Carolina, 65 miles northwest of Charleston Air Force Base, and 45 miles southeast of the state capital of Columbia. The land area of the base is 2,300 acres, of which 1,150 acres are undeveloped.

Construction History

The airfield at North Field consists of an 8,000-foot-long by 150-foot-wide primary runway, a 3,500-foot-long by 90-foot-wide assault strip, a single parallel taxiway, two ladder taxiways, and two connecting taxiways. There are two apron areas no longer used as airfield pavement not included in this report. Overruns for Runway 06/24 can be used by aircraft when exiting onto either Taxiways Bravo or Echo.

Most recently, Taxiway Alpha underwent a 3-inch mill and overlay in 2011, and at the same time, Taxiway Charlie was completely reconstructed.

A detailed construction history listed by airfield feature is in Appendix C.

Soil Conditions

In 1988, the USDA Soil Conservation Service (SCS) published a soil survey of Orangeburg County that includes relatively detailed mapping of the soil classifications for the soils found on the airfield. The natural subgrade soils are primarily beach sand and contain shell fragments. The soil survey lists the natural soils for North Field as a patchwork of sands (often poorly graded), clays (high and low plasticity), and silts. Both visual field classifications and formal laboratory classifications of subgrade soils were consistent with the SCS mapping.

Results of laboratory testing are included in the Summary of Physical Properties in Appendix C for all soil layers encountered beneath the pavement.

Climate

North Field is located 100 miles from the Atlantic Ocean in the southeast portion of the United States. Due to its proximity to the ocean, the climate at North Field is characterized by high humidity with temperatures rarely dropping below freezing. The average annual precipitation is approximately 47 inches, with July and August being the wettest months. The late summer and early fall months have higher rainfall rates than other months, with 4 to 5 inches per month in June through September. Figures 1 and 2 give temperature and average annual rainfall summaries; more detailed engineering weather data (EWD) can be obtained from the 14th Weather Squadron website at https://notus2.afccc.af.mil/SCIS/. The climate at North Field does not warrant a frost evaluation or thaw-weakened AGLs to be produced since there are 28 freeze-thaw cycles with a frost depth of 0 inches on a 50-year recurrence.

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THICK

(in)

DESCRP

FLEX

(psi)

THICK

(in)

DESCRP

FLEX

(psi)

THICK

(in)

DESCRP K/CBR

THICK

(in)

DESCRP K/CBR DESCRP K/CBR

A01B1 PARKING APRON A - NE - - - - - - - -

A01B2 PARKING APRON A - NE - - - - - - - -

O01C

SAF RUNWAY

OVERRUN

29,775 GOOD - - - 15.00 PCC 555 4.00 STAB

5.00

WELL

GRADED

SAND

W/GRAVEL

- SP-SM 8

O02C

SAF RUNWAY

OVERRUN

33,050 GOOD - - - 5.25 AC - 5.00

WELL

GRADED

SAND

W/GRAVEL

4.00

CLAYEY

SAND

POORLY

GRADED

SAND (12"

DRY)

65/14

R01A RUNWAY 06/24 75,125 FAIR 15.75 AC - 6.50 PCC 755 - -

6.00 8.00

SM 7

SM 7

SC 7

R02A RUNWAY 06/24 75,375 GOOD

5.00 9

6.75 9

AC

BB

2.00 9

6.00 9

AC

PCC

NT

- 12.00 7 SM 7

50 6

SC 7

12 6

R03A RUNWAY 06/24 450,000 GOOD 14.75 AC - 6.25 PCC 800 - -

8.00 SM 7

40 SC 7

R04A RUNWAY 06/24 445,000 GOOD

4.75 7.50

AC

BB

2.00 7.00

AC

PCC

7.00 SM 7

75 SC 7

R05A RUNWAY 06/24 75,000 FAIR 15.75 AC - 6.25 PCC 705 - -

11.00 SM 7

75 SC 7

R06A RUNWAY 06/24 74,150 GOOD

4.50 8.25

AC

BB

2.00 6.00

AC

PCC

8.00 SM 7

75 SC 7

R07A RUNWAY 05/23 317,575 FAIR - - - 5.00 AC - 11.00

WELL

GRADED

SAND

W/GRAVEL

10.00

CLAYEY

SAND

40 SP-SM 7

T01A TAXIWAY ECHO 35,000 GOOD

15.75 1.75

PCC

AC

7.00 PCC 735 - -

9.00 SM 7

- SC 7

T02A TAXIWAY ECHO 40,000 GOOD

15.00 1.50

PCC

AC

6.00 PCC 700 - -

12.00 SM 7

- SC 7

T03A TAXIWAY ECHO 75,300 GOOD

13.75 1.50

PCC

AC

6.00 PCC 700 - -

11.00 SM 7

- SC 7

T04A TAXIWAY BRAVO 35,000 GOOD

15.00 1.00

PCC

AC

6.75 PCC 680 - -

6.50 SM 7

- SC 7

T05A TAXIWAY BRAVO 39,075 GOOD

13.50 1.50

PCC

AC

6.00 PCC 700 - -

10.00 SM 7

- SC 7

T06A TAXIWAY BRAVO 74,675 GOOD

12.50 1.75

PCC

AC

6.00 PCC 700 - -

10.00 SM 7

- SC 7

T07A TAXIWAY BRAVO 51,100 GOOD - - - 14.50 PCC 790 6.00

WELL

GRADED

SAND

W/GRAVEL

11.00

POORLY

GRADED

SAND

W/GRAVEL

CLAYEY

SAND

PAVEMENT BASE SUBBASE SUBGRADE

PHYSICAL PROPERTY DATA

SECT IDENT

AREA

(SF FT)

SIMPLIFIED

PCI

OVERLAY PAVEMENT

NORTH FIELD, SC

C-1

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THICK

(in)

DESCRP

FLEX

(psi)

THICK

(in)

DESCRP

FLEX

(psi)

THICK

(in)

DESCRP K/CBR

THICK

(in)

DESCRP K/CBR DESCRP K/CBR

PAVEMENT BASE SUBBASE SUBGRADE

PHYSICAL PROPERTY DATA

SECT IDENT

AREA

(SF FT)

SIMPLIFIED

PCI

OVERLAY PAVEMENT

NORTH FIELD, SC

T08A TAXIWAY BRAVO 98,650 GOOD - - - 5.25 AC - 22.00

CRUSHED

STONE

CLAYEY

SAND

T09A TAXIWAY CHARLIE 118,925 GOOD - - - 14.75 PCC 755 10.00

WELL

GRADED

SAND

W/GRAVEL

CLAYEY

SAND

T10C TAXIWAY 2 - NE - - - - - - - -

T11C TAXIWAY 5 - NE - - - - - - - -

T12C TAXIWAY 4 - NE - - - - - - - -

T13A TAXIWAY ECHO 53,900 GOOD - - - 14.75 PCC 695 8.00

CRUSHED

STONE

10.00 SM 7

- SC 7

T14C TAXIWAY ALPHA 36,400 GOOD - - - 6.00 AC - 6.50

WELL

GRADED

SAND

W/GRAVEL

CLAYEY

SAND

T15C TAXIWAY ECHO 267,450 GOOD - - - 14.25 PCC 585 10.50 STAB

16.00

CLAYEY

SAND

CLAY

T16C TAXIWAY DELTA 278,800 GOOD - - - 14.25 PCC 665 11.00 STAB

20.00

CLAYEY

SAND

- SP-SM 8

175 8

T17C TAXIWAY FOXTROT - NE - - - - - - - -

T18C TAXIWAY ECHO 45,900 GOOD - - - 14.25 PCC 690 12.00 STAB

22.00

CLAYEY

SAND

- SM 8

125 8

T19C TAXIWAY ECHO - NE - - - - - - - -

NOTES:

1. Condition codes were determined using modified the Simplified PCI methods described in the narrative.

2. Flexural strengths for PCC pavements determined using split tensile method on samples taken from in-situ concrete from current and previous evaluations, capped at 800 psi.

3. PCC - Portland Cement Concrete.

RPCC - Reinforced Portland Cement Concrete AC - Asphaltic Concrete.

HQ STAB - High Quality Stabilized Base STAB - Stabilized Base CTB - Cement Treated Base CSB - Cement Stabilized Base RAP - Reclaimed Asphalt Pavement NT - Not Testable BB - Bond Breaker

4. A soil classification with no notation indicates laboratory USCS soil classification in 2013. All laboratory soil classifications conform to ASTM standards.

5. Full depth of base course could not be penetrated by the DCP rod in some areas due to refusal.

6. Data taken from neighboring feature.

7. Information taken from the 1983 USAF Engineering & Servies Center report.

8. Information taken for the 1993 AFCESA report.

9. Information taken from 2003 AFCESA report.

10. Information taken from construction drawings.

C-2

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SECTION

LAYER 1

THICKNESS

(in)

TYPE

E

MODULUS

FLEXURAL

STRENGTH

(psi)

LAYER 2

THICKNESS

(in)

TYPE

E

MODULU

S

FLEXURAL

STRENGT

H (psi)

LAYER 3

THICKNES

S (in)

TYPE

E

MODULUS

O01C 15.00 PCC 5,000,000 555 - - - - 225.00 SG 31,046

O02C 5.25 AC 411,433 - 21.00 UN 42,304 - 213.75 SG 37,003

R01A 15.75 AC 391,825 - 6.50 PCC 5,000,000 755 217.75 SG 50,784

R02A 5.00 AC 239,967 - 13.50 * ST 124,289 - 221.50 SG 38,578

R03A 14.75 AC 290,378 - 6.25 PCC 5,000,000 800 219.00 SG 53,206

R04A 4.75 AC 337,300 - 15.25 * ST 99,325 - 218.75 SG 40,937

R05A 15.75 AC 415,944 - 6.25 PCC 5,000,000 705 218.00 SG 70,716

R06A 4.50 AC 341,387 - 15.00 * ST 96,369 - 219.25 SG 40,220

R07A 5.00 AC 493,076 - 21.00 UN 61,000 - 214.00 SG 15,000

T01A 15.75 PCC 6,626,803 760 7.50 * HQ 1,000,000 - 216.75 SG 36,217

T02A 15.00 PCC 4,337,142 710 6.50 * HQ 1,000,000 - 218.50 SG 35,906

T03A 13.75 PCC 4,256,431 765 6.50 * HQ 1,000,000 - 219.75 SG 33,563

T04A 15.00 PCC 4,108,308 800 6.50 * HQ 1,000,000 - 218.50 SG 27,077

T05A 14.25 * PCC 3,483,077 770 6.50 * HQ 1,000,000 - 219.25 SG 23,518

T06A 12.50 PCC 4,798,344 730 6.50 * HQ 703,011 - 221.00 SG 19,294

T07A 14.50 PCC 4,690,800 790 17.00 UN 61,000 - 208.50 SG 18,200

T08A 5.25 AC 350,000 - 22.00 UN 61,000 - 212.75 SG 19,207

T09A 14.75 PCC 5,000,000 755 - - - - 225.25 SG 47,241

T13A 14.75 PCC 5,000,000 695 - - - - 225.25 SG 30,434

T14C 6.00 AC 627,381 - 6.50 UN 25,555 - 227.50 SG 67,995

T15C 14.25 PCC 4,761,362 585 10.50 ST 650,000 - 215.25 SG 34,907

T16C 14.25 PCC 5,000,000 665 - - - - 225.50 SG 46,017

T18C 14.25 PCC 4,866,275 690 12.00 ST 650,000 - 213.75 SG 44,376

Layer Type: PCC - Portland Cement Concrete UN - Unstabilized Base/Subbase ST - Stabilized Base/Subbase AC - Asphat Concrete HQ - High Quality Stabilized Base SG - Subgrade

Notes:

2. An asterisk (*) denotes equivalent thicknesses for pavement layers used.

LAYERED ELASTIC MODEL DATA

1. This table contains the WESDEF layered system models which were used, along with flexural strengths for PCC layers, to compute the AGL's and PCN's using WESPAVE. These models do not necessarily coincide with the actual pavement layer structure as presented in the Physical Property Data Summary, but are those where the computed deflections most closely approximated those measured in the field.

NORTH FIELD, SC

C-3

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NEW

SECTION

OLD

SECTION

DESIGNATION

APPROXIMATE

CONSTRUCTION

PERIOD

THICKNESS

(IN)

PAVEMENT

TYPE

REMARKS

- A01B1 PARKING APRON A 1943 7.25 PCC ORIGINAL CONSTRUCTION

- A01B2 PARKING APRON A 1943 7.25 PCC ORIGINAL CONSTRUCTION

O01C O01C SAF RUNWAY OVERRUN

9.50 14.00

PCC

PCC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

O02C O02C SAF RUNWAY OVERRUN 2003 2.50 AC ORIGINAL CONSTRUCTION

R01A R01A RUNWAY 06/24

7.00 16.25

PCC

AC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

R02A R02A RUNWAY 06/24

6.00 2.00 6.75 5.00

PCC

AC

BC-A

AC

ORIGINAL CONSTRUCTION

OVERLAY

BASE COURE AGGREGATE

OVERLAY

R03A R03C RUNWAY 06/24

6.50 14.75

PCC

AC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

R04A R04C RUNWAY 06/24

6.00 2.00 8.00 4.50

PCC

AC

BC-A

AC

ORIGINAL CONSTRUCTION

OVERLAY

BASE COURE AGGREGATE

OVERLAY

R05A R05A RUNWAY 06/24

5.75 16.25

PCC

AC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

R06A R06A RUNWAY 06/24

5.50 1.75 7.50 4.00

PCC

AC

BC-A

AC

ORIGINAL CONSTRUCTION

OVERLAY

BASE COURE AGGREGATE

OVERLAY

R07A R07A RUNWAY 05/23

6.00 5.50 2.50 3.00

PCC

AC

AC

AC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

OVERLAY

AC PATCHING AT TAXIWAY CHARLIE INTERSECTION

T01A T01A TAXIWAY ECHO

7.00 1.75

16.00

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T02A T02A TAXIWAY ECHO

6.00 1.50

15.00

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T03A T03A TAXIWAY ECHO

6.00 1.00

14.50

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T04A T04A TAXIWAY BRAVO

6.75 2.00

15.00

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T05A T05A TAXIWAY BRAVO

6.00 1.75

12.50

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T06A T06A TAXIWAY BRAVO

5.50 1.75

12.25

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T07A T07A TAXIWAY BRAVO

5.75 14.00

PCC

PCC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

T08A T08A TAXIWAY BRAVO

5.00 2.00 5.00

PCC

AC

AC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T09A T09A TAXIWAY CHARLIE

5.75 5.50

14.00

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

- T10C TAXIWAY 2 1943 7.25 PCC ORIGINAL CONSTRUCTION

- T11C TAXIWAY 5 1943 6.00 PCC ORIGINAL CONSTRUCTION

- T12C TAXIWAY 4 1943 6.25 PCC ORIGINAL CONSTRUCTION

T13A T13A TAXIWAY ECHO

7.50 14.00

PCC

PCC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

T14C T14C TAXIWAY ALPHA

5.00 3.00

AC

AC

ORIGINAL CONSTRUCTION

MILL & OVERLAY

T15C T15A TAXIWAY ECHO

6.25 2.25

14.00

PCC

AC

PCC

ORIGINAL CONSTRUCTION

OVERLAY

COMPLETE RECONSTRUCTION

T16C T16C TAXIWAY DELTA

7.50 14.00

PCC

PCC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

T17C T17C TAXIWAY FOXTROT 1943 5.50 PCC ORIGINAL CONSTRUCTION

T18C T18A TAXIWAY ECHO

6.25 14.00

PCC

PCC

ORIGINAL CONSTRUCTION

COMPLETE RECONSTRUCTION

- T19C TAXIWAY ECHO

6.25 14.00

PCC

AC

ORIGINAL CONSTRUCTION

OVERLAY

CONSTRUCTION HISTORY

NORTH FIELD, SC

C-4

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ADC Project No. 14178 Page 33 May 8, 2015

APPENDIX C – STORM DRAINAGE CALCULATIONS

Drainage Areas / Curve Numbers / Times of Concentration

DATE: LOCATION North Auxiliary Airfield DESIGNED BY: CDG PROJECT Repair C17 Landing Zone - NAAF COUNTY Orangeburg CHECKED BY: CDG

PROJECT NO.: 14178

Hydraulic SCDOT

Existing Soil Type Soil Group Storm Event 2 Intensity Constants B County: Orangeburg a 257.70309 B b 32.87932 B c 1.01850

AREAS OVERLAND FLOW TC SHALLOW CONCENTRATED FLOW TC CHANNELIZED FLOW TC TOTAL TC Intensity Paved Grassed Total Composite Composite Overland Vertical Mannings 2yr 24hr Overland Horizontal Vertical Slope Velocity Shallow Cross Wetted Hyrdraulic Travel Vertical Channel Velocity Channel Total Total Runoff c 0.95 0.17 Area C CN Travel Fall N Rainfall TC Travel Fall TC Section Perimeter Radius Length Fall Mannings TC TC TC TC Intensity Q CN 98 61 Depth Area N calculated (used) a I =CIA

Basin (acres) (acres) (acres) (acres) (acres) (acres) (ft) (ft) (in) (hrs) (ft) (ft) (ft/ft) (ft/sec) (hrs) (sf) (ft) (ft) (ft) (ft) (ft/sec) (hrs) (hrs) (min) (min) a b c b+TC (b+TC)c (b+TC)c (in/hr) (cfs)

NW-3 21 64 85 0.36 70 100 2 0.15 3.6 0.15 2200 15 0.007 1 0.61 0.77 46 46 257.7031 32.87932 1.0185 78.78358 85.41218 3.02 3.02 93.02

NW-2 21.30 0.70 22 0.93 97 100 1 0.011 3.6 0.03 200 1 0.005 1 0.06 0.08 5 6 257.7031 32.87932 1.0185 38.87932 41.60336 6.19 6.19 126.08

NW-1B 1.05 33.20 34.25 0.19 62 100 1 0.2 3.6 0.26 1850 9 0.005 1 0.51 0.77 46 46 257.7031 32.87932 1.0185 79.05607 85.71306 3.01 3.01 19.97 NW-1A 1.10 3.65 4.75 0.35 70 100 3 0.15 3.6 0.13 200 7 0.035 1 0.06 0.19 11 11 257.7031 32.87932 1.0185 44.06723 47.26415 5.45 5.45 9.08

NW Total 44.45 101.55 146.00 0.41 72 0 0 NW Boundary Q 57 257.7031 32.87932 1.0185 89.87932 97.67929 2.64 2.64 156.95

E-1 3.1 17 20.1 0.29 67 100 2 0.15 3.6 0.15 1200 8 0.007 1 0.33 0.49 29 29 257.7031 32.87932 1.0185 62.11692 67.04776 3.84 3.84 22.43

E Total 3.1 17 20.10 0.29 67 East Boundary Q 29 257.7031 32.87932 1.0185 61.87932 66.78657 3.86 3.84 22.43

S-1B 3.8 44.2 48 0.23 64 100 2 0.2 3.6 0.19 2800 25.5 0.009 1.25 0.62 0.82 49 49 257.7031 32.87932 1.0185 81.84079 88.78912 2.90 2.90 32.29 S-1A 7 163 170 0.20 63 100 2 0.2 3.6 0.19 3000 8 0.003 1.00 0.83 1.03 62 62 257.7031 32.87932 1.0185 94.50745 102.8045 2.51 2.51 86.13 SE-1B 13.4 51.6 65 0.33 69 100 1 0.2 3.6 0.26 3600 30 0.008 1.00 1.00 1.26 75 75 257.7031 32.87932 1.0185 108.2227 118.0194 2.18 2.18 46.95 SE-1A 10 67 77 0.27 66 100 2 0.2 3.6 0.19 2900 28 0.010 1.00 0.81 1.00 60 60 257.7031 32.87932 1.0185 92.84079 100.9583 2.55 2.55 53.32

0 0 S Total 34.2 325.8 360.00 0.24 65 0 0 South Boundary Q 135 257.7031 32.87932 1.0185 167.8793 184.5694 1.40 1.40 122.70

Total Site 81.75 444.35 526.10 0.29 67

FLOW

April 24, 2015

SC

SP

Design Soil

Pre Development Conditions PRE-DEVELOPMENT

14178_TC_RAT2.xls 4/23/2015 1

DATE: LOCATION North Auxiliary Airfield DESIGNED BY: CDG PROJECT Repair C17 Landing Zone - NAAF COUNTY Orangeburg CHECKED BY: CDG

PROJECT NO.: 14178

Hydraulic SCDOT

Existing Soil Type Soil Group Storm Event 10 Intensity Constants B County: Orangeburg a 279.22150 B b 29.67198 B c 0.99788

AREAS OVERLAND FLOW TC SHALLOW CONCENTRATED FLOW TC CHANNELIZED FLOW TC TOTAL TC Intensity Paved Grassed Total Composite Composite Overland Vertical Mannings 2yr 24hr Overland Horizontal Vertical Slope Velocity Shallow Cross Wetted Hyrdraulic Travel Vertical Channel Velocity Channel Total Total Runoff c 0.95 0.17 Area C CN Travel Fall N Rainfall TC Travel Fall TC Section Perimeter Radius Length Fall Mannings TC TC TC TC Intensity Q CN 98 61 Depth Area N calculated (used) a I =CIA

Basin (acres) (acres) (acres) (acres) (acres) (acres) (ft) (ft) (in) (hrs) (ft) (ft) (ft/ft) (ft/sec) (hrs) (sf) (ft) (ft) (ft) (ft) (ft/sec) (hrs) (hrs) (min) (min) a b c b+TC (b+TC)c (b+TC)c (in/hr) (cfs)

NW-3 21 64 85 0.36 70 100 2 0.15 3.6 0.15 2200 15 0.007 1 0.61 0.77 46 46 279.2215 29.67198 0.99788 75.57624 74.88643 3.73 3.73 114.95

NW-2 21.30 0.70 22 0.93 97 100 1 0.011 3.6 0.03 200 1 0.005 1 0.06 0.08 5 6 279.2215 29.67198 0.99788 35.67198 35.40269 7.89 7.89 160.53

NW-1B 1.05 33.20 34.25 0.19 62 100 1 0.2 3.6 0.26 1850 9 0.005 1 0.51 0.77 46 46 279.2215 29.67198 0.99788 75.84873 75.15585 3.72 3.72 24.67 NW-1A 1.10 3.65 4.75 0.35 70 100 3 0.15 3.6 0.13 200 7 0.035 1 0.06 0.19 11 11 279.2215 29.67198 0.99788 40.85989 40.53976 6.89 6.89 11.47

NW Total 44.45 101.55 146.00 0.41 72 0 0 NW Boundary Q 57 279.2215 29.67198 0.99788 86.67198 85.85595 3.25 3.25 193.48

E-1 3.1 17 20.1 0.29 67 100 2 0.15 3.6 0.15 1200 8 0.007 1 0.33 0.49 29 29 279.2215 29.67198 0.99788 58.90958 58.40273 4.78 4.78 27.90

E Total 3.1 17 20.10 0.29 67 East Boundary Q 29 279.2215 29.67198 0.99788 58.67198 58.16767 4.80 4.78 27.90

S-1B 3.8 44.2 48 0.23 64 100 2 0.2 3.6 0.19 2800 25.5 0.009 1.25 0.62 0.82 49 49 279.2215 29.67198 0.99788 78.63345 77.90918 3.58 3.58 39.87 S-1A 7 163 170 0.20 63 100 2 0.2 3.6 0.19 3000 8 0.003 1.00 0.83 1.03 62 62 279.2215 29.67198 0.99788 91.30011 90.43054 3.09 3.09 106.09 SE-1B 13.4 51.6 65 0.33 69 100 1 0.2 3.6 0.26 3600 30 0.008 1.00 1.00 1.26 75 75 279.2215 29.67198 0.99788 105.0154 103.9843 2.69 2.69 57.74 SE-1A 10 67 77 0.27 66 100 2 0.2 3.6 0.19 2900 28 0.010 1.00 0.81 1.00 60 60 279.2215 29.67198 0.99788 89.63345 88.78321 3.14 3.14 65.70

0 0 S Total 34.2 325.8 360.00 0.24 65 0 0 South Boundary Q 135 279.2215 29.67198 0.99788 164.672 162.8998 1.71 1.71 150.63

Total Site 81.75 444.35 526.10 0.29 67

FLOW

April 24, 2015

SC

SP

Design Soil

Pre Development Conditions PRE-DEVELOPMENT

LOCATION North Auxiliary Airfield DESIGNED BY: CDG Repair C17 Landing Zone - NAAF COUNTY Orangeburg CHECKED BY: CDG

PROJECT NO. 14178

Hydraulic

Proposed Soil Type Soil Group

Post Development Conditions

AREAS OVERLAND FLOW TC SHALLOW CONCENTRATED FLOW TC CHANNELIZED FLOW TC 2 YEAR

Paved Grassed Total Composite Composite Overland Vertical Mannings 2yr 24hr Overland Horizontal Vertical Slope Velocity Shallow Cross Wetted Hyrdraulic Travel Vertical Channel Velocity Channel Total Total TC Inlet c 0.95 0.17 Area C CN Travel Fall N Rainfall TC Travel Fall TC Section Perimeter Radius Length Fall Mannings TC TC TC (used) Intensity Q

CN 98 61 Depth Area N I =CIA

(acres) (acres) (acres) (acres) (acres) (ft) (ft) (in) (hrs) (ft) (ft) (ft/ft) (ft/sec) (hrs) (sf) (ft) (ft) (ft) (ft) (ft/sec) (hrs) (hrs) (min) (min) a b c b+TC (b+TC)c a/(b+TC)c (in/hr) (cfs)

NW-3 21.00 64.00 85.00 0.36 70 100 2 0.15 3.6 0.15 2200 15 0.007 1.00 0.61 0.00 0.77 46 46 257.703 32.879 1.019 78.784 85.412 3.02 3.02 93.02 NW-3 Total 21.00 64.00 85.00 0.36 70

NW-2 21.30 0.70 22.00 0.93 97 100 1 0.011 3.6 0.03 200 1 0.01 1.00 0.06 0.00 0.08 5 6 257.703 32.879 1.019 38.879 41.603 6.19 6.19 126.08 NW-2 Total 21.30 0.70 22.00 0.93 97

NW-1B 1.05 33.20 34.25 0.19 62 100 1 0.2 3.6 0.26 1850 9 0.005 1.00 0.51 0.00 0.77 46 46 257.703 32.879 1.019 79.056 85.713 3.01 3.01 19.97 NW-1A 1.10 3.65 4.75 0.35 70 100 3 0.15 3.6 0.13 200 7 0.035 1.00 0.06 0.00 0.19 11 11 257.703 32.879 1.019 44.067 47.264 5.45 5.45 9.08 NW-1 Total 2.15 36.85 39.00 0.21 63

NW Total 44.45 101.55 146.00 0.41 72 NW Boundary Q 57 257.703 32.879 1.019 89.879 97.679 2.64 2.64 156.95

E-1 3.3 16.8 20.10 0.30 67 100 2 0.15 3.6 0.15 1200 8 0.007 1.00 0.33 0.00 0.49 29 29 257.703 32.879 1.019 62.117 67.048 3.84 3.84 23.03 E-1 Total 3.30 16.80 20.10 0.30 67

E Total 3.30 16.80 20.10 0.30 67 East Boundary Q 29 257.703 32.879 1.019 62.117 67.048 3.84 3.84 23.02

S-1B 5.8 42.2 48.00 0.26 65 100 2 0.2 3.6 0.19 2800 25.5 0.009 1.25 0.62 0.00 0.82 49 49 257.703 32.879 1.019 81.841 88.789 2.90 2.90 36.81 S-1A 7 163 170.00 0.20 63 100 2 0.2 3.6 0.19 3000 8 0.003 1.00 0.83 0.00 1.03 62 62 257.703 32.879 1.019 94.507 102.805 2.51 2.51 86.13 SE-1B 11 54 65.00 0.30 67 100 1 0.2 3.6 0.26 3600 30 0.008 1.00 1.00 0.00 1.26 75 75 257.703 32.879 1.019 108.223 118.019 2.18 2.18 42.86 SE-1A 10 67 77.00 0.27 66 100 2 0.2 3.6 0.19 2900 28 0.010 1.00 0.81 0.00 1.00 60 60 257.703 32.879 1.019 92.841 100.958 2.55 2.55 53.32 S-1 Total 33.80 326.20 360.00 0.24 64

S Total 33.80 326.20 360.00 0.24 64 South Boundary Q 135 257.703 32.879 1.019 167.879 184.569 1.40 1.40 122.26

TOTAL 81.55 444.55 526.10 0.29 67

DATE: April 24, 2015

B

PROJECT

SC B

BASIN

SP B

Design Soil

LOCATION North Auxiliary Airfield DESIGNED BY: CDG Repair C17 Landing Zone - NAAF COUNTY Orangeburg CHECKED BY: CDG

PROJECT NO. 14178

Hydraulic

Proposed Soil Type Soil Group

Post Development Conditions

AREAS OVERLAND FLOW TC SHALLOW CONCENTRATED FLOW TC CHANNELIZED FLOW TC 10 YEAR

Paved Grassed Total Composite Composite Overland Vertical Mannings 2yr 24hr Overland Horizontal Vertical Slope Velocity Shallow Cross Wetted Hyrdraulic Travel Vertical Channel Velocity Channel…