SW5120101_Stormwater Report_20130410

GINEERING
CUE
4-3-2013
Robert Patterson, PE
Stormwater Permitting Unit
NCDENR-DWQ
1617 Mail Service Center
Raleigh, NC 27699-1617
RE: SW5120101 Cantonment Trailer Relocations
Proposed Revisions- Bioretention Basin 41
Dear Robert,
Construction on this project was substantially completed last fall with the exception of
getting a stand of grass to take hold. Therefore we have left the sediment basins in place
over the winter and will convert them to bioretention basins once the newest effort of
seeding grass is established.
During construction we encountered some rock while digging out the sediment basin at
Bioretention Cell #1 and anticipate additional rock as we convert the basins to
bioretention cells. To minimize the amount of rock effort and the associated costs, I am
proposing to reduce the footprint of bioretention media and under -drains to an amount
that approximates the media area that would be required if we were using 12" of storage.
All parameters proposed for change are in the permissible range. The infiltration rate for
the media remains 2"/hr and storage drawdown time will be 7.5 hours. The required
storage is 5548 cubic feet and the provided volume remains 6413 cubic feet. The square
footage of a basin with 12" of storage would require approximately 5548 SF of media. I
am proposing approximately 5100 SF of media based on encountered and anticipated
rock at the basin.
Basin 92 will remain the same as previously approved.
Please see the enclosed plans to evaluate these revisions.
Sincerely,
Eric Tweed. PE
CH Engineering, PLI,C
APR
;J lfJl3
tTllvrV., _
0 3220 Glen Royal Road, Raleigh, NC 27617 • TEL 919.788,0224 • FAx 919,788.0232

5;W5-1 Zo 1 of
December 29, 2011
Stormwater Narrative Update
Camp Butner Cantonment Trailer Relocations _
Owner: North Carolina National Guard i It, �� _I r_ 1_� _- • i,'�
Engineer: CH Engineering, PLLC APR 2 2032 l
This project involves the relocation of trailers from their current location.on-Reedy-Creek-
Road in Raleigh, NC to the Camp Butner Training Facility in Butner, NC. Parking
facilities will be provided for the trailer units as well as ADA accessible walkways into
the building. Additional parking will be constructed south of the trailers in order to
provide overflow parking since the facility experiences parking shortages.
The project is in the Neuse River basin and drains to an unnamed tributary to Knapp of
the Reeds Creek. This project occurs well uphill from the tributary and at its closest is
approximately 650 feet from the drainage way.
Basin 1:
At the southern overflow parking lot, a large parking lot already exists in the area and
will be regraded such that the stor nwater will flow towards proposed additional parking.
The existing landscape is a mix of underbrush dominated woods and some lawn. A
proposed basin will treat the new parking as well as the existing parking lot which is
stoned and has no stormwater treatment. The basin will start as skimmer basin #1 and
will be converted to a grass -lined bioretention basin with internal water storage once the
area is stabilized. The discharge for the bioretention basin will be piped to a nearby pipe
crossing Roberts Chapel Road. This existing pipe already drains this area, but will be
fitted with a new grated inlet. An overflow area on the dam will allow larger storms to
escape to a grass -lined ditch that runs to the grated inlet. Maintenance access will be from
the parking lot that is immediately adjacent to both the forebay and the basin.
The bioretention basin will be fed by effluent from flow from a portion of the parking lot
and a proposed gravel road. The grading will require two forebays at the bioretention
basin since the low spots are separate. The outlet device is located distant from both
forebays to prevent short circuiting and the basin is slightly triangular to help with this
distance.
A portion of the parking lot will drain to another swale that is too low to feed into
Bioretention Basin 41 and will be ditched to the new grated inlet.
Basin 2:

The existing landscape where the trailers and parking will go consists of a mostly pine
wooded area that is well maintained and mowed by facility personnel. This area slopes
mostly northward with gentle slopes increasing to 8%. The site will only require minor
grading for the parking lot and trailers and a protective berm is to be constructed per
owners request. A grass lined swale will direct stormwater flow from the area to a basin.
The swale will also catch waters from existing buildings that were previously not treated.
The basin will start out as a skimmer basin until the site is established, after which it will
be converted into a bioretention basin. The basin will be grassed and will have an access
drive from Roberts Chapel Road for maintenance and mowing. Effluent will go to a
splitter box which will feed a level spreader and will have a bypass pipe for flows over 2
cis. The level spreader will be 40' long and will see 2 efs which it will deposit into a 30'
wide grass tiller strip. Between the filter strip and the stream down hill is over 600' of
woods and underbrush. Overflow from larger storms will outlet over a grassed spillway.
The NC National Guard has existing personnel in place capable of keeping the
stormwater facilities mowed and otherwise maintained.

r�
Ecosystem
,linaRiue nem
PROGRAM
RECEIPT
NUTRIENT OFFSET PAYMENT
February 28, 2012
NC National Guard
c/o Eric Tweed
CH Engineering
3220 Glen Royal Road
Raleigh, NC 27617
12@20 V
D
FEB 292012
WE AfVDS AND STORMWATER BRANCH
7
I
APR 2 2Q12
Ra+n... 'V9, F
Project Name:
Camp Butner Cantonment Trailer Relocation
Local Government:
NCDENR-DWQ
Local Government Transaction Number:
None given
Basin:
Neuse/ Falls Lake
8-digit Catalo Unit:
03020201
10-digit Catalog Unit:
0302020104
Nitrogen
151.1 pounds x $21.64 = $3,269.81
Phosphorous
67.8 pounds x $134.23 = $9,100.80
Check Number:
10718
Amount Paid:
$12,370.61
The North Carolina Ecosystem Enhancement Program has received payment for nutrient offset for the above referenced
project. Nutrient offset payments made to EEP as part of fulfilling the requirements of the Falls Lake Nutrient Sensitive
Waters Management Strategy shall be at a rate specified in 15A NCAC 02B.0274.
You must also comply with any other state, federal or local government permits or authorization associated with this
activity including Session Law 2009-337, An Act to Promote Compensatory Mitigation Banks, as amended by
S.L. 201 1-343, Payments into the Nutrient Offset Program are not transferable. Refunds of payments made to NCEEP
are only approved under certain conditions. All refund requests must be submitted in accordance with ESP's refund
policy at www.nceep.net,
If you have any questions or need additional information, please contact Kelly Williams at [phone] or
[e-mail].
Sincerely,
;'
�i, I IIison Q
Deputy Director
cc: Robert Patterson, PE
File
Jzut ru' i9... E ... PIrDtEGtf.Gt� 0" State
l*�
NCDENR
North Carolina Ecosystem Enhancement Program, 1652 Mail Service Center, Raleigh, NC 27699-1652 / 919-715-0476 / www.nceep.net

VEcosystem
PROGRAM
NUTRIENT OFFSET PAYMENT
Fcbruary 28, 2012
NC National Guard
c/o Eric ']'weed
CH Engincering
3220 Glen Royal Road
Raleigh, NC 27617
ER&MIKEN
FEB 2 3 2012
DENR - WATER QUALITY
WETLANDS AND STORMWATER BRANCH
VM P-M 4-IL - R-�>r'
You have requested to fulfill nutrient offset requirements by paying into the North Carolina Ecosystem Enhancement
Program (NCEEP) Nutrient Offset In-I,lell Fee Mitigation Program. 'file purpose ofthis letter is to notify you that the
NCE 1711 is willing to accept payment for impacts as specified in the following table. The named Local Government
specified and verified the total pounds of offset necessary for permit approval.
Project Name:
Canip Butner Cantonment ']'railer Relocation
Local Government:
NCDENR-DW
Local Government'1'ransaction Number:
None jgiven
Basin:
NCIISe/ Falls Lake
8-digit Catalog Unit:
03020201
10-di it Catalog Unit:
0302020104
Nitrogen
151.1 pounds x $21.64 = $3.269.81
Phosphorous
67.8 pounds x $134.23 = K 100,80
Nutrient Offset Mitigation Payment Due:
$12,370.61
APR - 2 2012
WC I),-\R
Rill-h 4n.,i—,, Office
Nutrient offset payments made to EEf as part of fulfilling the requirements of the Falls I..ake Nutrient Sensitive Waters
Management Strategy shall be at a rate specified by 15A NCAC 0213.0274. Upon receipt of payment, f?I-P will take
responsibility for providing the compensatory mitigation. 'I'he amount due indicated above is based on the current
nutrient offset rates. 15A NCAC 0213.0274 (f) specifies that NCFEP will adjust nutrient offset rates in Ju1y of each year
or quarterly if certain criteria are met. 'E'his invoice expires in 30 (thirty) days or when the rates are adjusted, whichever
is sooner. If payment is not received prior to that time, you must request an updated invoice from NCII;P,
You must also comply with any other state, federal or local government permits or autharizalion associated with this
activity including Session Law 2009-337, An Act to Promote Compensatory Mitigation Banks. as amended by
S.L. 201 1-343, Payments into the Nutrient Offset Program are not transferable. Please send a check payable to NCEI P
for the 'Total Amount Due to the address below and enclose a copy of this invoice.
US Mail:
NCDENR Ecosystem Enhancement Program
1652 Mail Service Center
Raleigh, NC 27699-1652
ke,s-toriptg— .. Not-"' Oar r Sta g
NCDENR
North Carolina Ecosystem Enhancement Program, 1652 Mail Service Center, Raleigh, NC 27699-1652 / 919-715-0476) www.nceep.net

Page 2
Refunds of payments made to NCEEP are only approved under certain conditions. All refund requests must be subi-nitted
in accordance with NCEF.,P's refund policy at www.nccep.net, If you have any questions or need additional information,
please contact Kelly Williams at [phone] or [e-mail].
ncdenr.gov.
Sincerely,
rrC,,coLe'; (4A- 1,1
Michael Ellison
Deputy Director
cc: Robert Patterson, PE- NCDWQ Stormwater Permitting;
File
kutoYiptj... F ... nrotectr' o" stag
e��
NCDIENR
North Carolina Ecosystem Enhancement Program, 1652 Mail Service Center, Raleigh, NC 27699-1652 1 919-715-0476 1 www.nceep.net

Patterson, Robert
From: Patterson, Robert
Sent: Tuesday, February 07, 2012 T31 AM
To: 'Eric Tweed'
Cc: [e-mail]; 'Johnson, Jack T CTR NG NCARNG'; Smith, Danny
Subject: RE: SW5120101 - Cantonment Trailer Relocations, Butner
Eric,
Looks great) Please take this email as the preliminary approval of the subiect project. Once the offset payment has
been made to EEP, please send me a copy of the receipt and I will issue the permit. Let me know if you have any
questions.
Thanks
Robert D. Patterson, PE
Environmental Engineer
NCDENR I DWQ I Stormwater Permitting
1617 Mail Service Center, Raleigh, NC 27699-1617 Mriil 1 512 N. Snlisbury St, Raleigh, NC 27604 1 9u, floor Loc+ lioii & I' iwccls
[phone] Phone [phone] Fix I Robert. Pattersonanedenr.gov Eltn>3il I http://portal.nedenr.org/web/w4/ws/su ti. o siio
.A Buforc printing this email, please consider your budget and the environntcnt.
E-mail correspondence to and from this address may be subject to the North Carolina Pubfic Records taw and may be disclosed to third parties unless the content is
exempt by statute or other regulation.
From: Eric Tweed [maiIto: [e-mail]�
Sent: Monday, February 06, 2012 4:06 PM
To: Patterson, Robert
Cc: toni.cgats(a)us.army.mil; 'Johnson, Jack T CTR NG NCARNG'; Smith, Danny
Subject: RE: SW5120101 - Cantonment Trailer Relocations, Butner - Additional Information Request
I see it. The two numbers are from only drainage basin #2, and then drainage basin #2 with the J4 Annex square footage
added. I ran the sizing calculations with the J4 Annex added to it.
I have corrected the numbers to match. These numbers include the J4 Annex. I have attached the supplement and the
chart from SWU101 along with the Accounting tool spreadsheet.
Eric
From: Patterson, Robert [maiIto:robert,[e-mail]
Sent: Monday, February 06, 2012 2:11 PM
To: Eric Tweed
Cc: toni.coats(a)us.army.mil; 'Johnson, Jack T CTR NG NCARNG; Smith, Danny
Subject: RE: SW5120101 - Cantonment Trailer Relocations, Butner - Additional Information Request
Eric,
received the hardcopies today. It looks good. All but a pair of the items was taken care of.
1. The DA and impervious area for bioretention cell #2 are still not consistently shown on SWU-101, supplement,
and calculations.
2. Also, please email me the revised nutrient accounting tool xls file.

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ENGINEERING
CUI
February 3, 2012
Robert Patterson, PE
Stormwater Permitting Unit
NCDENR-DWQ
1617 Mail Service Center,
Raleigh, North Carolina 27699-1617
kFM@F=OWMP
FEB - 0 201z
DI NR-WATER QUALITY
WEZ OS AND STORMWATER BRANCH
RE Comment Reply to Feb. 1 comments
SW5120101 Cantonment Trailer Relocations
Dear Robert, -9
1 have received your comments from February I" and have adjusted calculations ands°��
plans to address them. Corrections are reflected throughout the calculations and also
O
impacted three of the plan sheets C5, C6 and DWQ 1. These are included with this Reply\;
package. See reply comments in bold below: �P
1. Please provide the revised calculations for the offset payments through EEP
that reflect the lower amounts discussed today on the phone. These are
included in the package.
✓ 2. The J4 Annex site and grading plans were not submitted. Please submit 2
copies. Two copies are provided in the Plans.
,o 0The impervious area and % BUA shown on the supplement form for bioretention
cell (BR) #2 is not consistent with that shown in the calculations and the upper
portion of the table on SWU-101, IV.10. Based on this inconsistency, it appears
the volume provided in BR#2 is not large enough for the 50.2% BUA (90,281 sf).
The areas have been re-evaluated and updated throughout the calculations
and the SWU101 application.
,/4. A soils report must be provided that specifically states what the SHWT
elevation is based on boring(s) within each of the bioretention cell footprints.
The determination is done based on visual observations of mottling of the soil.
The soils information submitted only states that no groundwater was
encountered during the time of the borings. Also, the borings need to be
shown on a map with respect to the proposed cells. A letter has been included
stating no mottled soil was found within the boring which was greater than
2' beneath the proposed basins. A color map is included marking these
locations and showing locations of future development.
✓5. For BR#2, the temporary pool elevation shown on the supplement is 477.75',
but it is shown lower on the cross-section and calculations at 477.60'. Please
revise. This is now corrected.
0 3220 Glen Royal Road, Raleigh, NC 27617 - TEL 919,788,0224 0 FAX 919,788.0232

6. For both BR#1 and BR#2:
,.a. On the supplements, the separation of IWS Ft surface should be a depth
in feet, not an elevation. This is now corrected.
'b. The supplements state no IWS is used, but an IWS is shown on the cross-
section and nutrient tool. This is now corrected.
C. The supplements and cross -sections need to state the elevation of the
IWS. This is now corrected.
'�. The supplements show incorrect VFS lengths. There is no VFS proposed
for BR#1, and the VFS for BR#2 is 40', not 504'. This is now corrected.
✓e. The supplements show incorrect planting media depths of 2.5. Only
2.0' is shown on the cross -sections. This is now corrected.
�. The supplements show 0.5' of washed sand, but none is shown in the
cross -sections. The sand was taken down to 0" since we are going to
install these bioretention basins with a filter fabric overtop of gravel.
g. The bottom of the planting media elevation is not shown consistently
between the supplements and cross -sections. This is now corrected.
7. The bioretention cross -sections need the following information shown/detailed.
✓a. When proposing grass cells, sod must be specified along with grass
species of the sod. The plan sheet has now added Fescue as the
species.
b. The media mix specification needs to be shown. The mix specification
is shown on the detail on Sheet C6.
The updated SWU101 chart is included along with the soil report and map. Included
calculations are a complete set of calculations for the stormwater meant to entirely
replace previous version.
Sincerely,
Lric Tweed, E
CH Engineering

Basin 1
South
2/2/2012
Post Construction Subbasin To Treatment
C
Total Area
2.94 Ac
0.60 Composit
Impervious
1.53 Ac
0.95 Assume lot gets paved in future
Woods
0.299 Ac
0.2
Grass
1.109 Ac
0.22 Soil is well drained
Intensity 010
inlhr CFS
2-yr
5.76 10.15
Not adjusted for Tc
10-yr
7.08 12.47
Not adjusted for Tc
1yr-24hr
4.46 7.86
REQUIRED VOLUME
Simple Method
Rv= 0.519
Storm Size (in)
1 5548 CuFt
PROVIDED VOLUME
Elev
Area
Depth
F—Vol—u—m—e-1
Ratio
487
7817
0.75
6413
1.16
487.75
9283
feet
CUFt
116%

Camp Butner Trailer Relocations 2/312012
Drainage Basin 1 Pre -Post
Calculations do include full future development including projects not included in the trailer relocation project.
PRE DEVELOPMENT
All development =
5.39 Acres
Area
C
SF
Impervious
0.95
50,073
Woods
0.2
115.722
Grass Areas
0.25
69,201
Composit
0.37
234,996 Total
Q10 Using Worksheet 3, ToC= 11 min and
5.6 "Ihr is the intensity
11.31 CFS
POST DEVELOPMENT
Basin #1 has 3 sub -basins
A Flows to Basin 1
B Flows to Swale #2
C Untreated area below basin
Q1 yr-24hr
3.53 'Yhr is intensity
7.13 CFS
SF TYPE C
Sub -basin A. 66,856 Impervious 0.95
35,698 Grass wi Trees 0.22 (flat area)
13,028 Woods 0.2
115,582 Total 0.64 Comp C
Using Worksheet 3, Time of Concentration is 12 minutes and 1yr-24hr storm
Q10 ="/hr is the intensity 3.52 inlhrCFS = for sub -basin A (Flow to Bioret Basin #1) 5.98 CFS
SF
TYPE
C
Sub -basin C: 17,759
Woods
0.2
18,794
Impervious
0.95
39,005
Grass
0.22
75,558
Total
0.40 Comp, C
Using Worksheet 3, Time of Concentration is 15 minutes and 1yr-24hr storm
Q10 4.78 "Ihr is the intensity 3.01 "Ihr
3.29 CFS for untreated sub -basin C 2.07 CFS
Sub -basin Q10 1Tr-24hr_storm
A 9.51 CFS 5.98 CFS
B 2.35 CFS 1.48 CFS
C 3.29 CFS 2.07 CFS
Total 15.16 CFS Before Bioretention Basin #1
9.53 CFS
3.06 Flow OUT of Bioretention Basin #1 0.00
TOTAL 010 including Bioretention Basin #1 Total 1yr-24hr storm
POST = 8.70 CFS Entire Basin #1 1post = 3.56 CFS

NCNG
Vegetated Swale #2
Sub -basin of Basin #1
Subdrainage Basin acres C-value
Impervious 10667 0.95
Grass 14512 0.3
Total area 25179 0.58 0.58
Using Worksheet 3 the Time of Concentration
Tc = 5 Min
Intensity = 7.08 inlhr
Q10 = 2.35 CFS
1vr-24hr= 1.48 CFS at 4
In order to verify velocity in swale is less than 1 ftls at Q10
At Depth of 0.82'
Flow is 2.27 cfs
Velocity is 0.34 ft/s
Surface Breakdown
Grave! 11331 sf
Grass 12051 sf
Swale 2461 sf
n

Basin 2 North
Post Construction Subbasin To Treatment
C
Total Area
4.047 Ac
Impervious
1.746 Ac
Woods
0.242 Ac
Grass & basin
2.059 Ac
2l212012
0.53 Composit
0.95 Assume lot gets paved in future
0.2
0,22 Soil is well drained
Intensity
Q10
inlhr
CFS
2-yr
5.76
12,44 Not adjusted for Tc
10-yr
7.08
15.29 Not adjusted for Tc
1yr-24hr
0.12
0.26
REQUIRED VOLUME
Simple Method
Rv=
0.438
Storm Size (in) 1 F 6439 CuFt
PROVIDED VOLUME
Elev Area
Depth Volume Ratio
476.8 8082
0.80 7042 1.09
477.6 9523
feet CuFt 109%

Camp Butner Trailer Relocations 2/3/2012
Drainage Basin 2 Pre -Post
Calculations do include full future development including projects not included in the trailer relocation project.
PRE DEVELOPMENT
All development =
5.76 Acres
Area
C
SF
Impervious
0.95
25,863
Woods
0.2
174,204
Grass Areas
0.25
50,757
Composit
0.29
250,824 Total
Q10 Using Worksheet 3, ToC is 23 min and
4.12 "Ihr is the intensity
6.82 CFS
POST DEVELOPMENT
Basin #2 has 4 sub -basins
A Flows to Swale #3
B Flows to Swale #4
C Untreated area of Roberts Chapel Road to Berm
D Untreated area below basin
0-111111 111LelISLly Ill 1111
Q10 7.08
01yr-24hr 4.46
Q1 yr-24Hr
2.60 "Ihr intensity
4.30 CFS
SF TYPE C
Sub -basin C: 6,601 Impervious rd 0.95
46,243 Grass wl Trees 0.3 (steep area)
52,844 Total 0.38 Comp C
Using Worksheet 3, Time of Conc. is 19 min.
Q10 Q1yr-24hr
4.34 "Ihr is the intensity 2.73
2.01 1 CFS is the Q for untreated sub -basin C 1.26
SF TYPE C
Sub -Basin D: 19504 grass 0.3 Steep area
No Time of Concentration adjustment
Q10 Q1yr-24hr
7.08 "Ihr is the intensity 4.46
0.95 CFS is the Q for untreated sub -basin D 0.60
Sub -basin
010
1yr-24hr
A
4.31
CFS
2.71
B
4.50
CFS
2.83
C
2.01
CFS
1.26
D
0.95
CFS
0.60
Total
11.76
CFS Before Bioretention Basin #2
7.41
8.80 Flow into Bioret. Basin #2 from Sub -basins A & B
2.76 Flow Out of Bioretention Basin #2
TOTAL Q10 1
5.54
0.47

NCNG
Vegetated Swale #3
Sub -basin of Basin #2
Drains to Bioretention Basin #2
Subdraina a Basin acres C-value
Impervious 31,428 0.95
Grass 32,654 0.22
Woods 6,165 0.2
Total area 70,247 1.61 0.54
Using Worksheet 3 the Time of Concentration
Q10
1yr-24hr =
Tc =
15
Min
15
Adjusted Intensity =
4.90
inlhr
3.09
5Min Intensity=
7.08
inlhr
4.46
FLOW
4.31
CFS
2.71
In order to verify velocity in swale is less than 1 ftls
At Depth of 10.12"
Flow is 4.18 cfs
Velocity is 0.55 ftls
Surface Breakdown
Parking Lot
29,403
sf
Sidewalk
2,025
sf
Grass
27,609
sf
Swale
5,045
sf
Woods
6,165
sf

NCNG
Vegetated Swale #4
Sub -basin of Basin #2
Drains to Bioretention Basin #2
Subdrainage Basin acres C-value
Impervious 43,425
0.95
Grass 42,218
0.22
Woods 4,359
0.2
Total area 90,002
2.07 0.57
Using Worksheet 3 the Time of Concentration
_ Q10
1yr-24Hr
Tc =
26
Min
Adjust. Intensity =
3.81
inlhr
2.40
5 Min. Intensity=
7.08
inlhr
4.46
Q =
4.50
CFS
2.83
In order to verify velocity in swale is less than 1 ftls
At Depth of 12.55"
Flow is 4.50 cfs
Velocity is 0.42 ftIs
Surface Breakdown
Parking Lot 18,268 sf
Road
4,871
sf
Grass
39,984
sf
Sidewalk
7,219
sf
Swale
2,234
sf
Roof
13,047
sf
Woods
4,359
sf

Camp Butner Trailer Relocations
PRE/POST
The J4-Annex Trailer will be placed in another basin without treatment.
This will be offset by storage in other basins.
inlhr
J4- Annex 7.08
Type SF AC C
POST [Grass
mpervious 2625 0.06 0.95
PRE 2625 0.06 0.22
Post -Pre
Required Storage (Simple Method)
Rv = 0.95
Storm (") 1
Volume 208 CuFt
PROJECT Pre Dev. Post Dev.
TOTAL
Q10 Q10
BASIN 1
11.31 8.70
BASIN 2
6.82 5.72
J4-Annex
0.09 0.41
213I2012
inlhr
4.46
Q10 (CFS)
Q1yr-24hr
0.405
0.255
0.094
0.059
0.31
0.196
GFs GF5
Req'd Provided
Pre Dev, Post Dev.
'torage
Storage
Q1yr-24hr
Q1yr-24hr
5548
6413
7.13
3.56
6439
7042
4.30
2.33
208
0
0.059
0.255
12.195
13.455 1
11.49
6.14

C TD E F G
Physiographic/Geologic Region:
Piedmont
Soil Hydrologic Group
C
Precipitation location:
Butner
COLUMN t -- NON-RESIDENTIAL LAND USE
N EMC
TT�mg/L)
TP EMC
(mg/L)
Pre-
Development
(kr)
Post-
Development
(h=)
COMMERCIAL
Parking lot 1.44 0.16 31,543 111,238
Roof 1,09 1 0.15 5,604 12,819
Open/Landscaped 2.2A I 0.44 112,084 I 242,949
INDUSTRIAL
Parking lot 1 1,44 I 0.39
Roof 1 1.08 I 0.15
Open/Landscaped I 2.24 0.44
TRANSPORTATION
High Density (interstate, main)_ I 3.67 I 0.43 i
1
Low Density (secondary, feeder) 1 1.4 I _0.52
Rural 0.47 33,902
38,506
Sidewalk I 1.4 1 1.16 5,187
10,973
PERVIOUS
Managed pervious 3.06 1 0.59
Jk
Unmanaged jpasture)- 3.61
1.56
Forest 1.47 i
0.25 } 296,800
44,490
JURISDICTIONAL LANDS'
Natural wetland I -
Riparian buffer ( -
Open water
LANDTAKEN UP 3Y BMPs 1 1.08 I 0.15
24,145
rlsdlttfonal land uses are not inctuded in nutrient/flow calculations.
L I M F N 1 0 I P ) Q V R
Total Development Area (ft):
485,020
Development Name:
Camp Butner Cantonment
I
Model Prepared By:
EMT
It COLUMN 2 -- RESIDENTIAL LAND USES I
Custom Lot
Size (ac)
Age
TN EMC
TP EMC
Pre-
Development
Post -
Development
PART A
Y.-ac lots
-
-
Y.-ac lots-
! Y-ac lots
1-aclots
-
-
2-ac iots
Multi-farnily
Townhomes �
- I
-
Custom Lot Size
-
PART B
Roadway -
1.4
0.52
}
Driveway I 1.0
1.44
0.39
Parkingiot 1
1.44
0.39
Roof I -
1.09
0.15 !
Sidewalk/Patio } -
1.4
1.16
Lawn _ _
2.24
0.44
I
_
rmanaged pervious ��- -
106
0-59
Forest I
1.47
0.25 1
I
Natural wetland' 1 -
Riparian buffer' -
-
-
Open water'
-
LAND TAKEN UP BY BMPs -
LOS
0-15
I
.y .._ :--'G_: -�-.. �1- :- -.LAND-USE'AREACHECK%: c- •. }..• :°_
�• �r` otal Develop men[AreaEntered {ft) i � Fh �.,� �� +
"R!' r �.� r s - 5�� �'-^*i, i ' o, #••= ,, fir ''b.
'"- •�,Tota! Pre -Development Calculated'Area (ft

IL
a�;»�r�z.stvc-rss�wa�crdi+?cY��:."sty'ra:�.�ti�u.�el��A�:fro-.'rb'�c.}4�:.�'vF.11atFiw.iu�:�.A�6�Wn1K ui'�

WATrR54ED SUMMARY
prvdoom.nv _ [ampo"! GnLpn
P rePPred 9y: EMT
f1EGgx:
P�pPt
i mrµ DFYE14nME,FI Mi�lxlk
MSA10
Neps+lop,r„[Mtlixan
Pn,-0.rMtgmna CarEldorn
vtxtar..foM„mawl a MP,
Pertan] lmp.rvbu,
ss.Jx
� w.l%
ao.2%
I%1
amval PumffYW.r+
S61A99
19P ue
a00,aPs
Ii W4
Tmal N,rpam EMC
Ll]
{mEM
Toth Ntroam Loa q
1.]a
60T
2.W
ToW p P„ — EML
OSS
0.]!
t135
pnefLl
�
Taul PkmPMnn,o kg
o.J]
v,16
0.z
IWl�lrrl
Pnarn, ]uH.rrrxr ee-
Pu„-0.Mbvant ru
Pwm.Llnwa.na�s ixl
]sx
]sx
vx
�r xu,ax YaWnr Icl.1
11p%
10%
�9]L
Taal Wtro{m EmC I•rWLI
0%
-11%
-11%
Taal Mt— L,,dhm (W/arfrrj
Sia%
-3%
-SblL
TPW Priesp,rPnrs EMC 1-91L) W
-141L
-1lM
-Il%
JPW PFarpawur latllr�{iW/.tfyrl
1E% i—%
M
RMP VOLUME REOOCnONSIEFFLULK CONCENMAilONS
Vpurr aedu[uon
{%1
lx E,M1,en carrea�
Irn1L1
ry F1Py.ne l�M1
Ir,WLI
°1oi1n°0"""I'
lws
sox
o.9s
a.v
Bbnr.mlm rn,kcv,
lw5
35%
L00
0,1]
pry Ortmllon Pend
Of
1.10
0.N
Grwatl S�aW
OF
].11
0.n
Gnm P"m
501E
].m
t a.ss
I
,wY Syd,. FPMr
slap
adK
Ll0
0.15
nniiih1i
ox
l.m
on
- F..
S%
1,v2
a
w.Mrxwnuc
w.. a.r .a
]De
a.15
L4Yl O.raTtlpn Pud
]t1%
1.0]
G.Ir
•xer>a.r pr[ama,k.wxewM -'-.a> Gevx,.nrudf.tlwnr, ptlWu�rt oYamu>mn a poa+unt,u•6K Pu•G+..YN.Miramnn axrT>f.. 'R ur>tuL mmmardal parYyn6lu]. 1p rxlurnt mncrntrxion = 0.16 mE1L
l,.Wrn Nx.s,mnWa, .
A.,vrn t. W...k.d t�uaL1HLLLW
prrwa lP PAP[h> .kw
AktSumn•ul' _ _

3. t3erebpnen[ Summary
13eveIop-1; _ GMy Butner Gnton_ment
Prepared BY- EMT
BMP j MMA Y
6pr(a1MEITI
(SICHMEM] I wT—3
CE
f T(TIMFM¢
CATCBME-,
caTO�MEM6
BMP3
{ 8MP] I BMp3
BW
I amp BMP3
BMPl
BMP3 iBMP3
{ BMPL
BMP] BMP3
BMPI { Mp3 I BMP3
BMp] 1 BMP2 BMP3
Bbrttentbn wilh
BIPrtlantbn v.6lh
level 6Pnadn, ;..
�
1I
1
I _yT— 1 y_• 3
_
I-
I
_
EBter 6WP
-
- -
-
i
_
_
11
_ � _ _
TPW IBv TrenlW
K}
2.93
_ _
4A3
TOW Inibw tltlume
I
I�F.I _
3p]j61
- I -
331.333
I 1]a.6T3
I
} I
ii
T.talll
�xl,.vBe]t
InMw PhwPMruf 6MC-
SmJ4
Total lnn.nw3Plrnue
MtrPEen Uba1 W KI I
c�t�hmant Punlour NitrvBen EMc lmplLl 1.03
6lclmen[ONibw
i
� 3.36
Tnt.lrtinefen{Ib/e�/Y.I
t.B6 - - -
I -
Percmigedutlynln wiroten LPW{%1 ; 62%
99%
Catthn'enl Ou[nwe PhosPlwru:EMc 0.131
-53-
[ ImJU
I
CatcNnenl Outflow 0.445
O.240 -_ _
_
rotel PnmPlww3l�*leelY�l
4
Pemant Re -- in Phwphorun Land %} 6]%
]5%
-

J
Camp Butner Trailer Relocations
Map Basin 3020201 213/2012
Nutrient Offset Calculation Sheet
Nitrogen
Phosphorus
Pre -Development
2.78
0.71 Ibslacrelyr
Post -Development
6.07
1.25lbslacrelyr
Required 50% Treatment
4A3
0.98 Ibslacrelyr
Post -Development with BMP's
2.69
0.55 Ibslacrelyr
Regulated Amount (Falls)
2.2
0.33 Ibslacrelyr
Amount Over
0.49
0.22 Ibslacrelyr
Offset Fees (Falls)
$ 21.64
$
134.23 per pound
Calculated for
30
yrs
Buydown
$ 318.11
$
885.92 per acre
Total onsite area (non -DOT)
447,952
10.28 acres
Buydown Amount
$ 3,271.28
$
9,110.39
Total Buydown Amount
$12,381.68
WITH IWS
LBSIAcreNear was determined using Accounting tool Version 2.0 From NCDENR and
Utilizing Biorention Basins 1&2 at 100%

OSHER
ENGINEERING
February 2, 2012
CH Engineering
3220 Glen Royal Road
Raleigh, NC 27617
Attention: Mr. Eric Tweed
Reference: Seasonal High Ground Water Table at Proposed Bio-Retention Ponds
Camp Butner Training Center
Roberts Chapel Road
Butner, North Carolina
Mosher Proposal No. 12.001.GE
At your request, Mosher Engineering conducted a subsurface exploration at the above referenced
facility and installed temporary piezometers in order to help estimate the Seasonal High Ground
Water Table (SHGWT) for design of three (3) proposed bio-retention ponds for this project.
A single boring was drilled within each of the three (3) proposed bio-retention pond areas by an
ATV CME 550 mechanical drilling rig. Standard Penetration Tests were performed in the soil test
borings at designated intervals in general accordance with ASTM D 1586. The Standard
Penetration Test (SPT) is used to provide an index for estimating relative soil consistency. In
conjunction with the penetration testing, split -barrel soil samples were recovered for visual
classification by the project engineer. The results of the visual classifications along with SPT
values are presented on the attached "test Boring Records.
Upon completion of drilling borings B10-1 and BI0-2, a slotted 1-inch diameter PVC pipe was
placed to the bottom of each borehole to serve as a temporary piezometer. The annulus around
each pipe was baekfilled with coarse sand to within 2 feet of the ground surface and the upper 2
feet was baekfilled with tamped soil. Measurements obtained about 24 hours after installation
indicated no groundwater was present in either piezometer. Consequently, the current ground
water table appears to be below a depth of 10 feet at BIO-I and 8.5 feet at B10-2.
Besides field measurements of groundwater depths, we observed the color, texture and plasticity
characteristics of each soil sample in general accordance with the Unified Soil Classification
System (USCS). In particular we looked for mottled coloring that could be indicative of seasonal
soil saturation from high ground water.
Based upon the field ground water measurements and the soil samples we obtained from each
borehole, it is our opinion that the SHGWT is below the termination depths of the three borings.
Mosher Engineering, Inc. • 557-B Pylon Drive • Raleigh, NC 27606 (OFf ) 919.856-1550 - (Fax] 919-856.1555

Mr. Eric Tweed ®S H E R
Project No. 12.001.GE
ENGINEERING February 2, 2012
Page 2
Mosher Engineering appreciates this opportunity to be of service on this project. If you have any
questions or require additional inforniation, please contact us.
Respectfully,
MOSHER ENGINEERING, INC.
1`5l�irIirrrrr `
SEAL
William R. Mosher, P.E.
Principal Engineer
�f'--/y�� Z-: 1
NC License No. 17909
=;'t'IVc;f�j��`
frrrrrrrr��}`'
Attachments

DEPTH DESCRIPTION
(FT.)
0.0
0.3
3.0
10.0
ELEVATION 0 STANDARD PENETRATION TEST
(FT.) BLOWSIFT
100.0 0 10 20 30 40 60 so 100
Topsoil and roots
' " '
99.7
RESIDUUM: Stiff brown and gray fine
sandy CLAY
10
97.0
Hard brown clayey SILT with some fine
sand
41
-A
42
92.0
PARTIALLY WEATHERED ROCK: When
sampled becomes brown fine sandy SILT
5015
90.0
Boring terminated at 10 feet
Piezometer set: No groundwater
encountered
CONTRACTOR: Soil Drilling Services Inc.
DRILL RIG: ATV CME 550 cat head hammer
f TEST BORING RECORD
BORING NUMBER
BIO-1
DATE DRILLED
1 /612012
PROJECT NUMBER
12.001.GE
PROJECT
Camp Butner Training Center
PAGE 1 OF 1
MOSHER
ENGINEERING
Mosher Engineering, Inc.

DEPTH
(FT.)
0.0
0.1
3.0
4.5
&5
DESCRIPTION ELEVATION 0 STANDARD PENETRATION TEST
(FT.) BLOWSIFT
ton n n In .)n 'In An an RA inn
Topsoil and roots
99.9
RESIDUUM: Stiff tan and gray silty CLAY
with some fine sand
9
97.0
Hard below 3 feet
95.5
921$
PARTIALLY WEATHERED ROCK: When
sampled becomes tan and gray fine sandy
SILT with PW R fragments
94.0
PARTIALLY WEATHERED ROCK: When
sampled becomes silty fine SAND with
PW R fragments
- 5014
91.5
'
5010
Auger refusal at 8.5 feet
Piezometer set: No groundwater
encountered
CONTRACTOR: Soil Drilling Services, Inc.
DRILL RIG: ATV CME 550 cat head hammer
11 TEST BORING RECORD II
BORING NUMBER B10-2
DATE DRILLED 1/10/2012
PROJECT NUMBER 12.001.GE
PROJECT Camp Butner Training Center
PAGE 1 OF 1
MOSHER,
ENGINEERING
j Mosher Engineering, Inc.

DEPTH DESCRIPTION
(FT.)
0.0
ELEVATION O STANDARD PENETRATION TEST
(FT.) BLOWSIFT
1000 n in 9n Mtn An Fn An ann
10
4.5
10.0
RESIDUUM: Firm tan silty CLAY with
some fine sand
Note: Top 1.5 feet of subgrade was
noticebly wet during drilling
0
6
97.0
Dense below 3 feet
95.5
7919
PARTIALLY WEATHERED ROCK: When
sampled becomes gray and brown silty
coarse to fine SAND
>f
5015
>
5016
90.0
Boring terminated at 10 feet
No groundwater encountered
CONTRACTOR: Soil Drilling Services, Inc.
DRILL RIG: ATV CME 550 cat head hammer
I TEST BORING RECORD
BORING NUMBER BIO-F
DATE DRILLED 1/10/2012
PROJECT NUMBER 12.001.GE
PROJECT Camp Butner Training Center
PAGE 1 OF 1
MOSHER
ENGINEERING
11 Mosher Engineering, Inc. I

5, /5-1107 0 Z
Lwalaa9[wN: Camp Grtmr Cantanmant
9nparad By: EMT
Cat,: (kfebr 5. Mi
WAT_7 SHED SUMMARY
BMP VOLUME REWCrIONSIEFFLUEN7 CONCENTRATIONS
Rrtlrmn[
YESOPa[ENl NNE�{tl 1:
d116]59
vrea.rebpr.M cumebm
Pmt09wIRRN%N[(NrdtlLxa
9N.iprtl9pment w(dMRa
Panen[IrnPwMan
16.9%
Sb.]%
Jb-Te
(1L}
Amwl Rwcft YalurM
390,960
IA1L61
196,Tl5
fal.I
TeW Mlvvpn EMC
1.31
1.lb
107
Imd/t}
Tmal nagen [ab�ry
x 93
5 50
9 98
IIef.J9•I
iMdl PfiaPlaw CW [
0.51
0 ]d
0.}4
INrAI
Tani PboLPrane twdH
0 69
1 13
0 b6
li�lul5rl
_
PrtDw�. l
[alOrv. wNlwatauR9
Pn-llewbpnrrt i
Pw[Av wl�Nw[ p[IH i
M 1— n 1%}
�N.m11
9pk
0%
vw„T I,.rJ
d9z
lax
-3.x
raw r.a[� Exlc t•./tl
Tz
>Ix
-31x
rew NI49w� LvaMrt PN�InI
xx
tex
ToW Pduporv. EMC 1�xlll
�19%
)1x
-Is%
laU� P[mdcrvl wmHlhJwl9r1
!%
J I%
>o93i
VOWmeNMuctlpn
Ix}
1N Eflluem CarcNn.
INxl11
10 FlfWM[arcen,
(.MAI
.1��[l�witit
5l1%
O95
0.1]
tlENRambn wiNeu[
��
3sx
I.w
a.lr
[NYlSahntlm Dab
Ox
IA
N.m
raudESWe
ox
t21
Noel
Sox
1 oe
U.15
Spd,,Fhn
d[A
SM
U.il
va,�em.m�
14,
59ntlfhn
5%
09]
O.34
Warr larvn[dy
uv�artnee
IrA
0.15
[Ya[ [manxlen pane
Io%
lei
0.11
N..e
3a
toe
ae
Fli?IW724> /%!/ I, !
(` Iw.arw.l.ar:+rs :sirLti
MtYA q �>tEN VarNaYrIRJp
^NIYEl� v
'Wys-ynuw bn...o.abw rYrwae.n..-n.r[oN.o✓R, POMNamrcNwaaonw pWLt'ant batµ •oidx.NrlaNcater�nv.Nc lire✓ FmobD,r-Y
I-TAS R.�C,? 'D -
rw- 3rS -2,rL
Ti - 11 3 - 01 33- = O f V
/ ad-f-
f 2Yg3-{z-9'�(0_4)� I,7S3f 2- z-�S0, 5 2rz pis-T4,e�p
qo-A -r J �21, o}' -T- p F'tyZ. = oLsq - (0,6R 09 33
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