SW8961209_HISTORICAL FILE_20030731

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO. i SW
� DOC TYPE ❑ CURRENT PERMIT
❑ APPROVED PLANS
�iHISTORICAL FILE
El COMPLIANCE EVALUATION INSPECTION
DOC SATE I '73 f
YYYYMMDD

State Stormwater Management Systems
Permit No. SW8 961209 Modification
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
a
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North
Carolina as amended, and other applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
Primary Care Associates
New Hanover Medical Group Satellite Office #2
New Hanover County
FOR THE
construction, operation and maintenance of a wet detention pond in compliance with the
provisions of 15A NCAC 2H .1000 (hereafter referred to as the "stormwater rules') and the
approved stormwater management plans and specifications and other supporting data as attached
and on file with and approved by the Division of Water Quality and considered a part of this
permit.
This permit shall be effective from the date of issuance until July 31, 2013, and shall be subject
to the following specified conditions and limitations:
L •DESIGN STANDARDS
1. This permit is effective only with respect to the nature and volume of stormwater
described in the application and other supporting data.
2.,. This stormwater system has been approved for the management of stormwater runoff as
described on page 3 of this permit, the Project Data Sheet. The stormwater control has
been designed to handle the runoff from 86,909 square feet of impervious area.
The tract will be limited to the amount of built -upon area indicated on page 3 of this
permit, and per approved plans.
4. All stormwater collection and treatment systems must be located in either dedicated
common areas or recorded easements. The final plats for the project will be recorded
showing all such required easements, in accordance with the approved plans.
The runoff from all built -upon area within the permitted drainage area of this project must
be directed into the permitted stormwater control system. A permit modification must be
submitted and approved prior to the construction of additional built -upon area from
outside of the approved drainage area.
2

rz
State Stormwater Management Systems
Permit No. SW8 961209 Modification
DIVISION OF WATER QUALITY
PROJECT DESIGN DATA SHEET
Project Name: New Hanover Medical Group Satellite Office #2
Permit Number: SW8 961209 Modification
Location: New Hanover County
Applicant: Dr. J William Eakins
Mailing Address: Primary Care Associates
1960 South 16`h Street
Wilmington, NC 28401
Application Date: July 21, 2003
Receiving Stream/River Basin: Mott Creek / Cape Fear
Stream Index Number: CPF17 18-82
Classification of Water Body: "C SW"
Drainage Area, acres:
3.69
Onsite, sq. ft.:
160,612
Offsite, sq. ft.:
none, per engineer
Total Impervious Surfaces, sq. ft.:
86,909
Pond Depth, feet:
4.0
TSS removal efficiency:
90% (no filter is required)
Permanent Pool Elevation, FMSL:
22.5
Permitted Surface Area, sq. ft.:
8,388 @ Permanent Pool
Permitted Storage Volume, cubic ft.:
7,889
Temporary Storage Elevation, FMSL:
23.5,
Controlling Orifice:
1.625" � (drawdown in 2-5 days)
Permitted Forebay Volume, cubic ft.:
7,472
K

State Stormwater Management Systems
Permit No. SW8 961209 Modification
IL SCHEDULE OF COMPLIANCE
l . The stormwater management system shall be constructed in its entirety, vegetated and
operational for its intended use prior to the construction of any built -upon surface.
2. During construction, erosion shall be kept to a minimum and any eroded areas of the
system will be repaired immediately.
3. The permittee shall at all times provide the operation and maintenance necessary to assure
the permitted stormwater system functions at optimum efficiency. The approved
Operation and Maintenance Plan must be followed in its entirety and maintenance must
occur at the scheduled intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
C. Mowing and revegetation of slopes and the vegetated filter.
d. Immediate repair of eroded areas.
e. Maintenance of all slopes in accordance with approved plans and specifications.
f. Debris removal and unclogging of outlet structure, orifice device, flow spreader,
catch basins and piping.
g. Access to the outlet structure must be available at all times.
4. Records of maintenance activities must be kept and made available upon request to
authorized personnel of DWQ. The records will indicate the date, activity, name of
person performing the work and what actions were taken.
5'. Decorative spray fountains will not be allowed in the stormwater treatment system.
6' The facilities shall be constructed as shown on the approved plans. This permit shall
become voidable unless the facilities are constructed in accordance with the conditions of
this permit, the approved plans and specifications, and other supporting data.
7' Upon completion of construction, prior to issuance of a Certificate of Occupancy, and
prior to operation of this permitted facility, a certification must be received from an
appropriate designer for the system installed certifying that the permitted facility has been
installed in accordance with this permit, the approved plans and specifications, and other
supporting documentation. Any deviations from the approved plans and specifications
must be noted on the Certification. A modification may be required for those deviations.
8. If the stormwater system was used as an Erosion Control device, it must be restored to
design condition prior to operation as a stormwater treatment device, and prior to
E occupancy of the facility.
9. The permittee shall submit to the Director and shall have received approval for revised
plans, specifications, and calculations prior to construction, for any modification to the
approved plans, including, but not limited to, those listed below:
a. Any revision to any item shown on the approved plans, including the stormwater
management measures, built -upon area, details, etc.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area or to the drainage
area.
C. Further subdivision, acquisition, or sale of all or part of the project area. The
project area is defined as all property owned by the permittee, for which
Sedimentation and Erosion Control Plan approval or a CAMA Major permit was
sought.
f Filling in, altering, or piping of any vegetative conveyance shown on the approved
plan.
4

State Stonrnwater Management Systems
Permit No. SW8 961209 Modification
10. The permittee shall submit final site layout and grading plans for any permitted future
areas shown on the approved plans, prior to construction. If the proposed BUA exceeds
the amount permitted under this permit, a modification to the permit must be submitted
and approved prior to construction.
11. A copy of the approved plans and specifications shall be maintained on file by the
Permittee for a minimum of ten years from the date of the completion of construction.
12. At least 30 days prior to the sale or lease of any portion of the property, the permittee
shall notify DWQ and provide the name, mailing address and phone number of the
' purchaser or leasee. An access/maintenance easement to the stormwater facilities shall be
granted in favor of the permittee if access to the stormwater facilities will be restricted by
the sale or lease of any portion of the property.
0. The permittee must maintain compliance with the proposed built -upon area and ensure
that the runoff from all the built -upon is directed into the permitted system.
14. The Director may notify the permittee when the permitted site does not meet one or more
of the minimum requirements of the permit. Within the time frame specified in the notice,
the permittee shall submit a written time schedule to the Director for modifying the site to
meet minimum requirements. The permittee shall provide copies of revised plans and
certification in writing to the Director that the changes have been made.
15. The permittee must maintain the current permitted drainage area. No additional runoff
from outside of the permitted drainage area boundary may enter the permitted stormwater
facilities without first applying for and receiving a permit modification.
III. GENERAL CONDITIONS
s
1.; This permit is not transferable except after notice to and approval by the Director. In the
event of a change of owership, or a name change, the pennittee must submit a formal
permit transfer request to the Division of Water Quality, accompanied by a completed
name/ownership change form, documentation from the parties involved, and other
supporting materials as may be appropriate. The approval of this request will be
considered on its merits and may or may not be approved. The permittee is responsible
for compliance with all permit conditions until such time as the Division approves the
transfer request.
2.. Failure to abide by the conditions and limitations contained in this permit may subject the
Permittee to enforcement action by the Division of Water Quality, in accordance with
North Carolina General Statute 143-215.6A to 143-215.6C.
The issuance of this permit does not preclude the Permittee from complying with any and
all statutes, rules, regulations, or ordinances which may be imposed by other government
agencies (local,'state, and federal) which have jurisdiction.
4. In the event that the facilities fail to perform satisfactorily, including the creation of
nuisance conditions, the Permittee shall take immediate corrective action, including those
as may be required by this Division, such as the construction of additional or replacement
stormwater management systems.
5. The permittee grants DENR Staff permission to enter the property during normal business
hours for the purpose of inspecting all components of the permitted stormwater
management facility.
6. The permit may be modified, revoked and reissued or terminated for cause. The filing of
a request for a permit modification, revocation and reissuance or termination does not
stay any permit condition.
5

0
State Stormwater Management Systems
Permit No. SW8 961209 Modification
7. Unless specified elsewhere, permanent seeding requirements for the stormwater control
must follow the guidelines established in the North Carolina Erosion and Sediment
Control Planning and Design Manual.
8. Approved plans and specifications for this project are incorporated by reference and are
enforceable parts of the permit.
9. The permittee shall notify the Division any name, ownership or mailing address changes
within 30 days.
Permit issued this the 31st day of July, 2003,
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
Alan W. Klimek, RE', Director
Division of Water Quality
By Authority of the Environmental Management Commission
Al

Wrightsville Engineering Services
July 18, 2003
Ms. Laurie Munn
NCDENR, Division of Water Quality
127 Cardinal Drive Extension
Wilmington, NC 28405-3845
Re: New Hanover Medical Group -- Addition and Remodel
South College Road, New Hanover County
Modification to Permit: SW8 961209
Dear Ms. Munn:
File No.: 23007
As requested, please find enclosed revised data for the Addition and Remodel
project.
1. Revised original and (1) copy of page 2 Stormwater Application Form
showing the corrected total square footage of impervious.
2. Revised original copy of page 1 of the Wet Detention Basin Supplement Form
showing 90% TSS removal design criteria (conforms to talcs and charts used).
3. Two (2) copies of revised Sheet SD1 showing dimensions for buildings,
sidewalks and parking areas.
Should there be any question or additional copies desired, please feel free to
contact our office.
Sincerely,
WRIGHT ILLS ENGINEERING SERVICES, P.L.L.C.
J N K. KLEI N, PE
Enclosures
Cc: Mr. Michael R. McLeod, AIA
Ms. Jo Wilkins, Primary Care Associates
3410 Wrightsville Avenue Wilmington, North Carolina 28403 910.799.7967 Fax [phone]

W A rFRp
Michael F. Easley, Governor
�OF
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E.,Director
Division of Water Quality
Coleen H. Sullins, Deputy Director
Division of Water Quality
July 9, 2003
Dr. J. William Eakins
Phinary Care Associates
1960 South l6`'' Street
Wilmington, NC 28401
Subject: REQUEST FOR ADDITIONAL, INFORMATION
Stormwater Project No. SW8 961209 Modification
New Hanover Medical Group Satellite Office #2
New Hanover County
Dear Dr. Eakins:
The Wilmington Regional Office received a Stormwater Management Permit Application for
New Hanover Medical Group Satellite Office #2 on June 4, 2003, A preliminary review of that
information has determined that the application is not complete. The following information is needed to
continue the stormwater review:
Please provide dimensions for all buildings, parking, sidewalks, and driveways.
2. The i mpervious surface area on the application and in the calculations sum to 86,909
square feet. Please explain how you calculated 91,073 square feet.
3. For 85% TSS removal, you must provide a vegetated filter at the outlet. I have enclosed
a detail of the vegetative filter. If you do not wish to provide a vegetative filter, please
design the pond for 90% TSS removal.
Please note that this request for additional information is in response to a preliminary
review. The requested information should be received by this Office prior to August 9, 2003, or the
application will be returned as incomplete. The return of a project will necessitate resubmittal of all
required items, including the application fee.
If you need additional time to submit the information, please mail or fax your request for a time
extension to the Division 'at the address and fax number at the bottom of this letter. The request must
indicate the date by which you expect to submit the required information. The Division is allowed 90
days from the receipt of a completed application to issue the permit.
The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject to
enforcement action pursuant to NCGS 143-215.6A.
N. C. Division of Water Quality 127 Cardinal Drive Extension [phone] Customer Service AS -A
Wilmington Regional Office Wilmington, NC 28405 [phone] Fax [phone] �'VBONTRE

Dr. J. William Eakins
July 9, 2003
Stormwater Project No. SW8 961209 Modification
Please reference the State assigned project number on all correspondence. Any original
documents that need to be revised have been sent to the engineer or agent. All original documents must be
returned or new originals must be provided. Copies are not acceptable. If you have any questions
concerning this matter please feel free to call me at [phone].
Sincerely,
Laurie Munn
Environmental Engineer
RSS/:lsm S:1WQSlSTORMWATIADDINFO120031961209MOD.ju]y03.doc
cc: Laurie Munn
John Klein, P.E.

Wrightsville Engineering Services
June 3, 2003
Ms. Linda Lewis
NCDENR, Division of Water Quality
127 Cardinal Drive Extension
i Wilmington, NC 28405-3845
Re: New Hanover Medical Group — Addition and Remodel
South College Road, New Hanover County
Modification to Permit: SW8 961209
Dear Ms. Lewis:
File No.: 23007
'�OA
I'Da V cy,
On behalf of the Primary Care Associates, please find enclosed submittal for
modification to the above DWQ stormwater permit. Although the original pond
had been constructed to permit future expansion, the level of expansion has
exceeded that allowed; hence, the need to bring the pond into compliance with
current requirements. Enclosed for your review are:
Original and one (1) copy of the Stormwater Application Form
Original copy of the Wet Detention Basin Supplement Form
Permit application fee in the amount of $420
Two (2) copies of the Narrative which includes Calculations
Two (2) copies of Drawings
Should there be any question or additional copies desired, please feel free to
contact our office.
, Sincerely,
WRIGHTSVILLE ENGINEERING SERVICES, P.L.L.C.
RECEIVED
JOHN K. KLEIN, PE
Enclosures 1UN 0 4 2003
Cc: Mr. Michael R. McLeod, AIA DWQ
Ms. Jo Wilkins, Primary Care Associates PROJ #
I
3410 Wrightsville Avenue Wilmington, North Carolina 28403 910, 799. 7967 Fax [phone]

PRIMARY CARE ASSOCIATES 1479 '
1960 S. 16TH ST. -)63
WILMiNGTON, N.C. 28401 66 30l531
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Wilrirgton, N C. 2Ba01
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QCWIIV Arericwn GVARGIAM1p WETY BLUE VERt

STORM DRAINAGE DESIGN
for
NEW HANOVER MEDICAL GROUP - ADDITION AND REMODEL
5145 SOUTH COLLEGE ROAD
Wilmington
New Hanover County, North Carolina
PREPARED FOR
Primary Care Associates
1960 South 16th Street
WELMINGTON, NC 28401.
[phone]
File Number: 23007
Date: June 2003
�•' Q� k CRR0?7�'
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14109 '
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Prepared by
Wrightsville Engineering Services, PLLC
3410 Wrightsville Avenue
Wilmington, North Carolina 28403
[phone]

;1%
DESIGN NARRATIVE
1. GENERAL:
The project site is located near the Monkey Junction area of New Hanover County, north along
South College Road. Toward the south is a tributary ofMotts Creek which discharges into the Cape
Fear River. The project involves expansion of an existing DWQ permitted site with the construction
of additional building area as well as expansion to the parking facility. Located on a site
approximately 3.69 acres, the new ultimate development will require approximately 2.1 acres of
built -upon area. Prior submittal authorized expansion to 1.7 acres; hence the need to modify the
existing pond.
The purpose of this submittal is to redesign the detention facility for the proposed new expansion
of the site, Included within this submittal are the Drawings and Storm Drainage Calculations. All
items are part of the overall plan and included by reference.
2. PROPOSED IMPROVEMENTS:
Grading and drainage improvements include expansion of the building as well as pavement areas.
To accommodate this additional area, the stormwaterpond will need upgradingto meet current state
DWQ as well as New Hanover County (NEC) siormwater requirements. Indicated on the Drawings
are the proposed expansion areas which have also been incorporated into the design Calculations.
Grades have been constructed to discourage overland flow of runoff into the parking areas from
non -built upon areas.
3. STORM DRAINAGE CALCULATIONS:
Storm drainage calculations were aimed at satisfying NC DWQ requirements as well as
considerations for NHC pre and post design. Predevelopment rates are those occurring prior
utilizing the existing permitted pond and drainage areas; while, post development is the expanded
pond and impervious
Design considerations included, but not limited to, the following items:
a. Storage of the first one (1) inch of runoff
b. Release of the stored volume between two (2) and five (5) days
c. Use of forebay to promote solid deposition within the pond inlet area.
d. Limiting the rate of runoff to current development rates for the 2-year, 10-year and 25-year storm
events.

;.
r
STORM DRAINAGE CALCULATIONS
DWQ Runoff Calculations
NHC Pre and Post Development Calculations: 2-year Storm Event
NHC Pre and Post Development Calculations: 1 0-year Storm Event
NHC Pre and Post Development Calculations: 25-year Storm Event
Original DWQ Submittal Calculations

' Wriglftsville Engineering Services, PLLC
PROJECT: New Hanover Medical Group Addition and Remodel
CLIENT: Michael R. McLeod AIA PROJECT NO.: 23007
LOCATION: New Hanover County, NC DATE: June 2003
PREPARED BY: JKK
SUBJECT: Stormwater Calculations
GIVEN: Modify existing pond to accommodate new expansion plans.
Runoff Coefficients used for Design:
Postconstruction =
Turf (developed) _
TOTAL PROJECT AREA =
Area draining to pond =
Areas not draining to pond =
Design Storm Event = 10-year,
Rainfall Intensity =
SOLUTION:
1. Summary of Drainage Areas
0.80
0.20
160612 SF =
109053 SF =
51559 SF =
5 minute duration
7.23 inches/hour
AREAS DRAINING
TO POND
---------------------------
AREA AREA
TYPE
(SF) (AC)
BLDG
22874 0.525
SIDEW
3706 0.085
PVMNT
60329 1.385
TOTAL IMPERV.
93-073 2.091
? 0 9 09
TURF
17980 0.413
TOTALS 109053 2.50
Pond Design Criteria:
Percent Built -Upon: = 2.091 Ac 1
83.5 %
2. DELETED
2.504 Ac =
use: 85 %
3.69 Ac
2.50 Ac
1.18 Ac .
3. DETENTION POND DESIGN:
Design to store the first 1-inch of runoff from project area
Imperv. 1.00 x 91073 SF x V/12" = 7589
Turf 0.20 x 17980 SF x T/12" = 300
7889 C F
Based on state requirements for ponds without vegetative filter
and using the design impervious percent o 85 with a depth of 4.0
feet, the ratio of surface area (SF) to drainage area to drainage area (DA) = 7.45
23007 - NH Medical: Addition and Remodel

' Wrightsville Engineering Services, PLLC
Therefore, required pond surface area (SA) is:
7.45 x 2.50
/ 100 =
Pond Width at Design Surface:
see plan
Pond Length at Design Surface:
see plan
AVE.
CUMUL.
AREA AREA VOLUME
VOLUME
ELEV. (SF) (SF) (CF)
(CF)
18.5
22.5 8388
23.5 9652
24.5 10972
25.5 12349
0
0.19 Acres
8124 SF Use: 8388 SF
(Pond Design Bottom)
0 (Design Area)
9020 9020
9020
10312 10312
19332
11661 11661
30993
13066 13066
26.5 13783
44059
Depth where storage requirement met:
23.37
Depth of Required Storage.
0.87 VF or
Elevation of Top of Riser:
23.50
Depth of Storage Provided:
1.00 VF or
Volume of Storage Provided:
9020 CF
4. Restrictive Orifice Design:
Design orifice for discharge allowed using
the following equation
Q= C x A x (2gh)^0.5 where:
Q= CFS
C = orifice coefficient
A = orifice diameter (SF)
g = 32.2 ft/sec2
h = pressure head (ft)
Rearranging the above equation to solve for hole diameter
A=Q/Cx(2gh)^0.5
For our type of discharge, C =
0.60
Pond Outlet Invert =
22.50
Design Storage Level =
23.50
Ave Reqd Storage Level =
23.00
Trial Orifice Diameter =
1.63 " (1-5/8")
Trial Orifice Area =
0.0144 SF
Orifice centerline =
22.57
Ave. Pressure Head (h) =
0.43
10.5 Inches
12.0 Inches
Allowable discharge rate:
Design discharge so that ponds drain between two (2) day and five (5) days.
Pond Volume: 7889 CF Pond Volume: 7889 CF
23007 - NH Medical: Addition and Remodel

Wrigtftsville Engineering Services, PLLC
Time to drain: 2 days
or 172800 sec
Therefore, release rate =
7889 CFS / 172800 sec
or 0.046 CFS
A = 0.0144 SF
1.63 inches
Actual Time to drain pond:
Q = 0.046 CFS
Time = 7889 CF !
Time to drain: 5 days
or 432000 sec
Therefore, release rate =
7889 CFS 1 432000 sec
or 0.018 CFS
A = 0.0058 SF
1.03 inches
Else: 1.63 " (1-518")
0.046 CFS = 173025 Sec
= 48 Hrs.
5. Forebay Design Requirements:
Design forebay for 20 % of the total volume below the pool.
FOREBAY VOLUME
MAIN POND VOLUME
AVE.
CUMUL.
AVE.
CUMUL.
AREA AREA VOLUME
VOLUME
AREA
AREA
VOLUME
VOLUME
ELEV. (SF) (SF) (CF)
(CF)
(SF)
(SF)
(CF)
(CF)
18.5 222
0
1698
0
335 335
1985
1985
19.5 448
335
2271
1985
598 598
2590
2590
20.5 747
933
2908
4574
928 928
3338
3338
21.5 1109
1861
3768
7912
1556 2484
4581
7919
22.5 2002
4344
5393
15831
7472
30301
Total Volume Below Normal Pool Elevatior
37773
Percent Forebay vs Total Volume =
20%
6. Pond Outlet Design
Existing Outlet to be retained with modifications to orifice size. Refer to routing
analysis for detailed flow rates.
7. Overflow Weir Design for Forebay and Pond Emergency Spillway
Design Overflow Weir based on 25-year, 10-minutes storm which produce a volume
in excess of one (1) inch.
Q=CxixA C= 0.80
i = 7.13 inlhr
A = 2.50 Ac
Q = 14.3 CFS
Design weir to convey entire flow. Set weir invert above storage level.
weir equation: Q = C x H1312 x (L - 0.2H) where:
23007 - NH Medical: Addition and Remodel

Wrightsville Engineering Services, PLLC
Q = CFS
C = weir coefficient = 3.33
L = weir lenfth (FT) = 2 x H (min)
H = head (FT)
rearranging and solving for weir length yields the following:
L=(QICXH^312)f0.2H
Design weir capacity = 14.28 CFS
Design weir depth = 6.0
Therefore, required weir length =
12.11 FT
B. Summary:
Required Pond Surface Area = 8124 SF
Design Pond Surface Area =
Required Storage Volume = 7889 CF
Design Storage Volume =
Pond Outlet Invert = 22.50
Required Storage Elev. = 23.37
Design Storage Elevation =
use:
8388 SF
9020 CF
0.50 FT
12 FT
Depth = 0.87 VF
23.50 Depth = 1.00 VF
Pond Invert =
18.50
Outlet Orifice Diameter =
1.63 "
Ave Discharge Rate =
0.046 CFS
Anticipated drawdown time =
48 Hours =
2.0 Days
23007 - NH Medical: Addition and Remodel

N":
as au OVA.
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3.3
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4.5'
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5.5'
6.0'
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.3'
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1.7
1.3
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,i
.7 .6
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24
2.2
1.9
1.3
1.3
1.2 1.0
.0
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3,4
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1
1.9
1.6
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.2
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MS T83 OVAL
NO VMMATICD FILTER
DEM
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4.0'
4.5'
1.6
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5.5'
6.0'
6.5'
7.0'
7.5'
to%
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.8
.7
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.2
.1
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2.4
2.0
1.8
1.7
1.3
1.1
1.2
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.9
.(►
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3.5
3.0
2.7
2.5
2.2
1.9
1.6
1.3
1.1
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40%
4.5
4.0
3.5
3.1
2.8
2.5
2.1
I.8
1.4
1.1
30'8
5.6
5.0
4.3
3.9
3.5
3.1
2.7
2.3
1.9
1.5
60%
7.0
6.0
5 3
4.8
4.3
S_4
3.4
2.9
2.4
1.9
70%
8.1
7.0
6.0
5.5
5.0
4.5
3.9
3.4
2.9
2.3
80�
9.4
3.0
7.0
6.4
5.7
5.2
4.6
4.0
3.4
2.9
90 %
10.7
9.0
7.9
17.2
6.5
3.9
5.2
4.6
3.9
3.3
1.410'16
tZ.V
110.0
8.8
8.1
7.3
6.6
5.13
5.1
4.3
3.6
Uft
tt1
i4 to pnvbm
at bepenwommd
Dmk

(�, p,Ev15En
Cote CTE� U I z coy
- En tSrN� -_
=-
___
N w
cov��1►vLU
Ni, <fA L.c.vt_AT1OQS,
j v. Ilt�d:.
5ubcat/ Reach �,on _ , Lihk

PondCalcs2 Type Il 24-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 1
HydroCADO 6.00 sln 001707 ©1986-2001 Applied Microcomputer Systems 6/2/2003
Time span=0.10-20.00 hrs, dt=0.01 hrs, 1991 points
Runoff by SCS TR-20 method, UH=SCS, Type 11 24-hr Rainfall=4.50"
Reach routing by Stor-1nd+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Original Site Design
Subcatchment 2S: New Development
Subcatchment 3S: Uncollected Yard Areas
Tc=5.0 min CN=89 Area=2.200 ac Runoff-- 12.70 cfs 0.566 of
Tc=5.0 min CN=89 Area=2.500 ac Runoff= 14.43 cfs 0.643 of
Tc=5.0 min CN=61 Area=1.490 ac Runoff-- 2.87 cfs 0.119 of
Subcatchment 4S: Proposed Uncollected Flows
Tc=5.0 min CN=61 Area=1.180 ac Runoff-- 2.27 cfs 0.094 of
Pond 1 P: Stormwater Pond Peak Storage= 11,283 cf Inflow-- 12.70 cfs 0.566 of
Primary= 6.68 cfs 0.392 of Outflow-- 6.68 cfs 0.392 of
Pond 2P: Revised Pond Peak Storage= 13,530 cf Inflow-- 14.43 cfs 0.643 of
Prmary= 6.55 cfs 0.433 of Outflow-- 6.55 cfs 0.433 of
Link 1L: Existing Total Flow Inflow-- 9.02 cfs 0.511 of
Primary= 9.02 cfs 0.511 of
Link 2L: Proposed Combined Flow Inflow-- 8.24 cfs 0.527 of
Primary= 8.24 cfs 0.527 of
Runoff Area = 7.370 ac Volume =1.422 of Average Depth = 2.32"

PondCalcs2 Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 2
H droCAM 6.00 sln 001707 © 1986-2001 Applied Microcom uter Systems 6/2/2003
Subcatchment 1S: Original Site Design
Runoff = 12.70 cfs @ 11.96 hrs, Volume= 0.566 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=4.50"
Area (ac) CN Description
2.200 - 89 Urban commercial, 85% imp, HSG A
Tc Length Slope Velocity Capacity Description
(min) (feet) (fVft) (ft/sec) (cfs)
5.0 Direct Entry, Direct Enry
O
IL
Subcatchment 1S: Original Site Design
Hydrograph Plot
4 - - _ - - ' - ---- -- - -
! I 12`70-cfs E..
,
3 . --' - '
i e i
i
i
I
I
7 ....... .._.............. ,._. _ ----- i- --- - ---- ---
: i
i
r
i
,.—_._._._ _ r I ! i
�� i
r
I I
4 - _ -------- -_-- -- -
I
,
e i i i i i j , 1 i ,
3
' - - - - Time (hours)--
- Runo#f

PondCalcs2 Type 11 24-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page
HydroCA_D® 6.00 s/n D01707 01 , pMicrocomputer c 1988-2001 Applied Systems 6/2/2003T
Subcatchment 3S: Uncollected Yard Areas
Runoff = 2.87 cfs @ 11.97 hrs, Volume= 0.119 of
Runoff by SCS TR-20 method, UH-SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=4.50"
Area (ac) CN Description
1.490 61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (M) (ft sec) (cfs) _
5.0 Direct Entry, yard sheet flow
Subcatchment 3S: Uncollected Yard Areas
Hydrograph Plot
3
7
w
y
0
U.
2 8Z<cis.' --- - - -
3 i I I 4 I
I I
I I I 1 I j I 1 i I
E ' i E
i i f
" .. .. Time (hours) ,� .,. .. ... ... ,. ,., ... �.,
— RunoH

PondCalcs2
Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 6
HydroCAD® 6.00 sln 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Pond 1 P. Stormwater Pond
Inflow - 12.70 cfs @ 11.96 hrs, Volume= 0.566 of
Outflow = 6.68 cfs @ 12.04 hrs, Volume= 0,392 af, Atten= 47%, Lag= 4.8 min
Primary = 6.68 cfs @ 12.04 hrs, Volume= 0.392 of
Routing by Stor-Ind method, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Peak Elev= 23.95' Storage= 11,283 cf
Plug -Flow detention time= 119.9 min calculated for 0.392 of (69% of inflow)
Storage and wetted areas determined by Prismatic sections
Elevation
Surf.Area
lnc.Store
Cum.Store
(feet)
(sq-ft)
(cubic -feet)
(cubic -feet)
22.50
6,890
0
0
23.50
8,060
7,475
7,475
24.50
8,700
8,380
15,855
25.50
9,980
9,340
25,195
26.50
10,650
10,315
35,510
Primary OutFlow (Free Discharge)
L1=Culvert
t
2=Orifice/Grate
3=Orifice/Grate
#
Routing
Invert
Outlet Devices
1
Primary
22.50'
24.0" x 40.0' long Culvert Ke= 0.500
Outlet Invert-- 22.42' S= 0.0020 T n= 0.013 Cc= 0.900
2
Device 1
23.50'
2.00' x 3.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600
3
Device 1
22.50'
1.5" Vert. Orifice/Grate C= 0.600

PondCalcs2 Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 7
HydroCAD® 6.00 sin 001707 © 1986-2001 Applied Microcomputer Systems 612I2003
Pond 1 P: Stormwater Pond
Hydrograph Plot
12.70 Cf5
r
E_
I '
r
i
'i i
!
....I
i..-.-._.__.._._----- _. i
1 i :
! I ... ` i ! j
i j ! 1 '.6'.68.`ct'S i .._.L, i i
7 _._.-. .--- ----- -------- -._...--- ---- --_--- ---'- —'-'-- -'--
E
i it i i
, r
' I j I
i
i ! ;
_ _.--
j
j I -------- ------------------- -
2- i t.'''';'''' i
I ; i
a-.- i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time jhoumj
— Inflow
— Primary

PondCalcs2 Type Il 24-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 10
HydroCAD® 6.00 sln 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Link IL: Existing Total Flow
Inflow - 9.02 cfs @ 12.00 hrs, Volume= 0.511 of
Primary = 9.02 cfs @ 12.00 hrs, Volume= 0.511 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
1
Link 1L: Existing Total Flow
Hydrograph Plot
0
-�i --- I --- -- �I - -
— -- "'i=---- - ----�E ---
- ----
•
j
W-0--2
Gfs
i
s
, --
..---- ---
---------
-
;
•
i i
�I :'
j
i
I
7.
�
I
E I
I
•
I y i
I
i I
i
j '
i i
I I
I
I E
I I
..i
I I
i
E
'
�
3-
2 -
-
I-._..._._.
E _
aE
I
I
!
[
I
- - - - - � Time (hours) -- .- - '- -- -- �- --
— infiow
— Primary

PondCalcs2 Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 3
HydroCAD® 6,00 sln 001707 O 1986-2001 Applied Microcomputer Systems _ _ 6/2/2003
Subcatchment 2S: New Development
Runoff = 14.43 cfs @ 11.96 hrs, Volume= 0.643 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type 1124-hr Rainfall=4.50"
Area (ac) CN Description
2.500 89 Urban commercial, 85% imp, HSG A
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Sheet and Pipe travel time
III
Subcatchment 2S: New Development
Hydrograph Plot
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
_ Runoff

PondCalcs2 Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C, Page 5
HydroCAD® 6.00 sln 001707 ® 1986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 4S: Proposed Uncollected Flows
Runoff = 2.27 cfs @ 11.97 hrs, Volume= 0.094 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=4.50"
Area (ac) CN Description
1.180 61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftfft) (ftlsec) (cfs) _
5.0 Direct Entry, Sheet Flow Runoff
Subcatchment 4S: Proposed Uncollected Flows
Hydrograph Plot
— Runaff
1 L J Y J O ! V A IV 11 lL IJ IY IJ IV I IV lM LV
Time (hours)

PondCalcs2 Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 8
HydroCADO6.00 s/n 001707 © 1986-2001 ARplied Microcomputer_ Systems 6/2/2003
Pond 2P: Revised Pond
Inflow - 14.43 cfs @ 11.96 hrs, Volume= 0.643 of
Outflow = 6.55 cfs @ 12.05 hrs, Volume= 0.433 af, Men= 55%, Lag= 5.4 min
Primary = 6.55 cfs @ 12.05 hrs, Volume= 0.433 of
Routing by Stor-Ind method, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Peak Elev= 23.94' Storage= 13,530 cf
Plug -Flow detention time= 125.8 min calculated for 0.433 of (67% of inflow)
Storage and wetted areas determined by Prismatic sections
Elevation
Surf.Area
Inc.Store
Cum.Store
(feet)
(sq-ft)
(cubic -feet)
(cubic -feet)
22.50
8,388
0
0
23.50
9,652
9,020
9,020
24.50
10,972
10,312
19,332
25.50
12,349
11,661
30,993
26.50
13,783
13,066
44,059
Primary Outflow (Free Discharge)
t1=Culvert
I
2=Orifice/Grate
3=Orifice/Grate
#
Routing
invert
Outlet Devices
1
Primary
22.59
24.T x 40.0' long Culvert Ke= 0.500
Outlet Invert= 22.42' S= 0.0020 7 n= 0.013 Cc= 0.900
2
Device 1
23.50'
3.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600
3
Device 1
22.50'
1.6" Vert. Orifice/Grate C= 0.600

PondCalcs2 Type It 24-hrRainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 9
hlydroCAD® 6.00-sin 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
1
1
1
i
1
1
3
0
Pond 2P: Revised Pond
Hydrograph Plot
B-
--- - _ E- - - -- -- ---- -
-------- -i- -- - -- - ;
4-
— —1... -- _-- --- - --
:
-- -- - - - - - - -- - - - -;— —
j
...........
.
i
1:
........................_..._...,._...._._... ,.._-._._._:... -_......._:_._._._...;......._....,._._._....... -
.._._._._._........ '.._:_._._._;_...._._._._!.............. ...._._.
..
------------------ -- - - —
9-
---'- - - -- ' -- — - ---- - - -- - - -- ----
-- - - -- — _
i
I
' <.6`.55`cis"
7:
— - -- - - --- ---- ---- --'--- ---
-- - - -- =----- --- ---' -
i i j
: 1
i
i
5 :
-
_ ....... ---- - ---------- ... ..............
' ...
_ ._ _I ........... ..... ...'....-._._._
i i
E:
j
2-
-- --- -- '
j i i- �
— - - -
�
0=._
..
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
-- Infiow
- Primary

PondCa11cs2 Type 1124-hr Rainfall=4.50"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 11
HydroCAD® 6.00 s/n 001707 © 1986-2001 Applied Microcomputer Systems 612l2003
Link 2L: Proposed Combined Flow
Inflow — 8.24 cfs @ 12.00 hrs, Volume= 0.527 of
Primary = 8.24 cfs @ 12.00 hrs, Volume= 0.527 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
7-
6-
5-
FL
4-
1-I
Link 2L: Proposed Combined Flow
Hydrograph Plot
Time (hours)
—L Inflow
—� Primary

F- C, -AL ED
� S Cot P,) e- o L �F-CTFA
'cc
3 I S rt
NCR�P-0i"As
1JEW POST

PondCaicO Type li 24-hr Rainfall= 7. 00"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 1
HydroCADO) 6.00 sin 001707 01986-2001 Applied Microcomputer Systems 6IM003
Time span=0.10-20.00 hrs, dt=0.01 hrs, 1991 points
Runoff by SCS TR-20 method, UH=SCS, Type II 24-hr Rainfall=7.00"
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-ind method
Subcatchment 1S: Original Site Design
Subcatchment 2S: New Deveidpm6ni
Subcatchment 3S: Uncollected Yard Areas
Tc=5.0 min CN=89 Area=2.200 ac Runoff-- 21.20 cfs 0.935 of
Tc=5.0 min CN=89 Area=2.500 ac Runoff-- 24.09 cfs 1.120 of
Tc=5.0 min CN=61 Area=1.490 ac Runoff- 7.50 cfs 0.305 of
Subcatchment 4S: Proposed Uncollected Flows
Tc=5.0 min CN=61 Area=1.160 ac Runoff-- 5.94 cfs 0.242 of
Pond 1 P: Stormwater Pond Peak Storage= 16,325 rf Inflow-- 21.20 efs 0.985 of
Primary= 11.66 cfs 0.809 of Outflow-- 11.66 cfs 0.809 of
Pond 2P: Revised Pond Peak Storage= 20,181 cf Inflow-- 24.09 efs 1.120 of
Primary= 11.84 cfs 0.906 of Outflow-- 11.84 cfs 0.906 of
Link 1L: Existing Total Flow Inflow-- 18.09 cfs 1.114 of
Primary= 18.09 cfs 1.114 of
Link 2L: Proposed Combined Flow Inflow= 16.68 cfs 1.148 of
Primary= 16.68 cfs 1.148 of
Runoff Area = 7.370 ac Volume = 2.652 of Average Depth = 4.32"

PondCalcs2 Type 1124-hr Rainfall=7.00"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 2
HydroCADO 6.00 sln 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003.
Subcatchment 1S: Original Site Design
Runoff = 21.20 cfs @ 11.96 hrs, Volume= 0.985 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, tit= 0.01 hrs
Type 1124hr Rainfall=7.00"
Area ac CN Description
2.200 89 Urban commercial, 85% imp, HSG A
Tc Length Slope Velocity Capacity Description
(min) -(feet) (ftfft) ^ (ftlsec) (cfs) _
5.0 Direct Entry, Direct Enry
Subcatchment 1S: Original Site Design
Hydrograph Plot
22, ;-_-----_._._._._.!.___...._. __._._................ _ ---- ...._'-----.- -._._ ._.__...__._..._......_._.__l.._._._._...;............. .............
i
'i':24 c'f
,
f i
16- --- - ! -- - - -I— -- -- ---' -- — -- —'— -- -- —
i _
L_...._._._.
E
:
i
I c I j i _. ._.l... y r
i ! :
6 - -- -- --
i f 't '. i I i I '
,
1 2 3 4 5 6 7 8 9 14 11 12 13 14 15 16 17 18 19 20
Time (hours)
— Runoff
mom

PondCalcs2 Type 1124-hr Rainfall= 7. 00 "
Prepared by Wrightsville Engineering Services, P.L.L.C. Page
HydroCAD® 6.00 sln 001707 OO 1986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 3S: Uncollected Yard Areas
Runoff = 7.50 cfs @ 11.97 hrs, Volume= 0.305 of
Runoff by SCS TR-20 method, UH =SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=7.00"
Area (ac) C_N Description
1.490 61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, yard sheet flow
w
U
O
LL
M
O
Subcatchment 3S: Uncollected Yard Areas
Hydrograph Plot
I L J Y J V ! V 3 IV i I I L 10 1 1 I J IV 1/ 1 V 19 L V
Time (hours)
— Runoff

PondCa1cs2 Type 11 24-hr Rainfaii=7.00"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 6
H droCADO 6.00 s/n 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Pond 1 P: Stormwater Pond
Inflow - 21.20 cfs @ 11.96 hrs, Volume= 0.985 of
Outflow = 11.66 cfs @ 12.03 hrs, Volume= 0.809 af, Atten= 45%, Lag= 4.7 min
Primary = 11.66 cfs @ 12.03 hrs, Volume= 0.809 of
Routing by Stor-Ind method, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Peak Elev= 24.55' Storage= 16,325 cf
Plug -Plow detention time= 96.0 min calculated for 0.809 of (82% of inflow)
Storage and wetted areas determined by Prismatic sections
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic -feet) (cubic -feet)
22.50 6,890 0 0
23.50 8,060 7,475 7,475
24.50 8,700 8,380 15,855
25.50 9,980 9,340 25,195
26.50 10,650 10,315 35,510
Primary OutFlow (Free Discharge)
t1=Culvert
I2=0rifice/Grate
3=Orifice/Grate
_ # Routing _ Invert Outlet Devices
1 Primary 22.50' 24.0" x 40.0' long Culvert Ke= 0.500 T^�
Outlet Invert-- 22.42' S= 0.0020 7 n= 0.013 Cc= 0.900
2 Device 1 23.50' 2.00' x 3.00' Horiz. Orif ce/Grate Limited to weir flow C= 0.600
3 Device 1 22.50' 1.5" Vert. Orifice/Grate C= 0.600

PondCafcs2 Type 1124-hr Rainfall= 7. 00"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 7
H droCAD® 6.00 sln 001707 01986-2001 A2plied Microcom uter Systems 6/2/2003
22
Pond 1P: Stormwater Pond
Hydrograph Plot
Time (hours)
— knflow
— Primary

PondCalcs2 Type I! 24-hr Rainfall= 7. 00 "
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 10
HydroCAD® 6.00 sln 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Link 1L: Existing Total Flow
Inflow = 18.09 ds @ 11.99 hrs, Volume= 1.114 of
Primary = 18.09 ds @ 11.99 hrs, Volume= 1.114 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
3
kL
Link 1L: Existing Total Flow
Hydrograph Plot
�-------------
i
i
!
16 ...... . ...... ' —
i
15" --- ----- --
14 -._._. .......... .t _. ........ I_.__._._._i- ,_._.�._._._._ i.._._._._._r_ -. .._._._-_._ _._.,�.__._._- ------._.�._.-----
13-
I f i I i i t i
—.—
i ,
i
i
2 -'— - -- -I ._._._._._l . ----- --
E I I
Time (hours)
L.—Inflow
Primary

PondlCalcs2 Type It 24-hr Rainfall=7.00"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 3
HydroCAM 6.00 s/n 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 2S: New Development
Runoff = 24.09 cfs @ 11.96 hrs, Volume= 1.120 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=7.00"
Area (ac)_CN Description
2.500 89 Urban commercial, 85°% imp, HSG A
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftfft) (ft/sec) (cfs)
5.0 Direct Entry, Sheet and Pipe travel time
Subcatchment 2S: New Development
Hydrograph Plot
26 _._._. _._._._._._._._._.._._._...._'._.-........_._.-......_._.__..._..._ -.-.- !__--._
• � i � E i i i I i
I , I I
24' D9`ivfs ;
j
i
18-
I i i 1 I I
---- ------ --- -----
a.- ----- ._l.
i i i j f I 31 E
i
i
i j
n _. 1__._.___.__._—_— i i i� 'i
-------------
I j e
i
4.
i
2---1------- ---- - ._. ..
- --- - - - -' -- -' = -
0 �'
1 2 3 4 5 5 7 S 9 10 11 12 13 14 15 16 17 18 -19 20
Time (hours).
- Runoff

PondCalcs2 Type lI 24-hr Rainfall= 7. 00 "
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 5
HydroCADO 6.00 sin 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 4S: Proposed Uncollected Flows
Runoff = 5.94 cfs @ 11.97 hrs, Volume= 0.242 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=7.00"
Area (acl CN Description
1.180 61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feed___ (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, Sheet Flow Runoff
Subcatchment 4S: Proposed Uncollected Flows
Hydrograph Plot
— RunoSf
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

PondCalcs2
Type 1124-hr Rainfall= 7. 00 "
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 8
HydroCADO 6.00 s/n 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Pond 2P: Revised Pond
Inflow = 24.09 cfs @ 11.96 hrs, Volume= 1.120 of
Outflow = 11.84 cfs @ 12.04 hrs, Volume= 0.906 af, Atten= 51 %, Lag= 5.1 min
Primary = 11.84 cfs @ 12.04 hrs, Volume= 0.906 of
Routing by Stor-Ind method, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Peak Elev= 24.57' Storage= 20,181 cf
Plug -Flow detention time= 101.0 min calculated for 0.906 of (81 % of inflow)
Storage and wetted areas determined by Prismatic sections
Elevation
Surf.Area
Inc.Store
Cum.Store
feet
s -ft
cubic-feet
cubic -feet
22.50
8,388
0
0
23.50
9,652
9,020
9,020
24.50
10,972
10,312
19,332
25.50
12,349
11,661
30,993
26.50
13,783
13,066
44,059
Primary OutFlow (Free Discharge)
L1=Culvert
L
2=Orifice/Grate
3=Orifice/Grate
#
Routing
Invert
Outlet Devices _
1
Primary
22,50'
24.0" x 40.0' long Culvert Ke= 0.500
Outlet Invert-- 22.42' S= 0.0020 7 n= 0.013 Cc= 0.900
2
Device 1
23,50'
3.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600
3
Device 1
22,50'
1.6" Vert. Orifice/Grate C= 0.600

PondCalcs2 Type Il 24-hr Rainfall= 7. 00"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 9
HydroCAD® 6.00 s1r1001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Pond 2P: Revised Pond
Hydrograph Plot
26- - - -
24- --- - --- — - -- - --- ; -- -- - - - - - - - — - --- - -- --- ---------- -- -- -- ---
, r
22 -- !.._._._._._'
r
i I
,
i i i
_... .
r
I I I
I
--- - - - _ - -
.'.
i
_! _ i I i
14- ---- ----- ---- -... - - .. - - - - - - -
1 li84cfs 1
!
10
r ._.------- ------- --- ' r r
!
r e -
__._..._... 1.....__.._.I—.-----._._:._.__._._i i i. I i i i I 1
i I 1
;............ .__--------- ------- __._r._._._.__,.._._._ i f r
f
a
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
- Inflow
- Primary

PondCalcs2 Type 11 24-hr Rainfall=7.00`'
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 11
Hy_droCAD® 6.00 sh 001707 01986-2001 Applied Microcomputer Systems _ 6I212003
Link 2L: Proposed Combined Flow
Inflow = 16.68 cfs @ 11.99 hrs, Volume= 1.148 of
Primary = 16.68 cfs @ 11.99 hrs, Volume= 1.148 af, Men= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Link 2L: Proposed Combined Flow
Hydrograph Plot
— inflow
— Primary
w
10:
l� --'
g_
___---
8:
- —
7--
—
I
5-
... -'
4-._._._..T-
i
3.---
--- --
i
2=
i
0"
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

a 4S
- 2S
�1S ti.4Ka
�cSr
, � nE�Ew�ENr
'Pl2�d�VELol��N7-
�
�5—�EAP2 Ct�t-Cvu4Tioi.J�S
Drainage Diagram for PondCalcs2
5� .-ubcat) Reach on` ink Prepared by Wrightsville Engineering Services, P.L.L.C. 6/2/2003
.� 2 HydroCAD9) 6.00 sln 001707 0 1986-2001 Applied Microcomputer Systems

PondCalcs2 Type 1124-hr Rainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 1
HydroCADO 6.00 s/n 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Time span=0.10-20.00 hrs, dt=0.01 hrs, 1991 points
Runoff by SCS TR-20 method, UH=SCS, Type II 24-hr Rainfall=8.05"
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Original Site Design
Subcatchment 2S: New Development
Subcatchment 3S: Uncollected Yard Areas
Tc=5.0 min CN=89 Area=2.200 ac Runoff-- 24.73 cfs 1.164 of
Tc=5.0 min CN=89 Area=2.500 ac Runoff-- 28.11 cfs 1.323 of
Tc=5.0 rein CN=61 Area=1.490 ac Runoff= 9.67 cfs 0.395 of
Subcatchment 4S: Proposed Uncollected Flows
Tc=5.0 min CN=61 Area=1.180 ac Runoff` 7.65 cfs 0.313 of
Pond 1 P: Stormwater Pond Peak Storage= 18,211 of Inflow-- 24.73 cfs 1.164 of
Primary= 13.27 cfs 0.987 of Outflow-- 13.27 cfs 0.987 of
Pond 2P: Revised Pond Peak Storage= 22,654 cf Inflow-- 28.11 cfs 1.323 of
Primary-- 13.51 cfs 1,108 of Outflow= 13.51 Us 1.108 of
Link 1 L: Existing Total Flow Inflow-- 21.68 cfs 1.382 of
Primary= 21.68 cfs 1,382 of
Link 2L: Proposed Combined Flow Inflow-- 19.86 cfs 1.421 of
Primary= 19.86 cfs 1.421 of
Runoff Area = 7.370 ac Volume = 3.195 of Average Depth = 5.20"

PondCalcs2 Type Il 24-hr Rainfall=8. 05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 2
HydroCADO 6.00 s!n 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment IS: Original Site Design
Runoff = 24.73 cfs @ 11.96 hrs, Volume= 1.164 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0,10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=8.05"
Area ac CN Description
2.200 89 Urban commercial, 85% imp, HSG A
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (fUsec) (cfs)
5.0 Direct Entry, Direct Enry
?6'
?4=
16
14
Subcatchment 1S: Original Site Design
Hydrograph Plot
1 L J Y J V ! Q 0 14 I 16 IJ Ins IJ IV I! 10 10 LV
Time (hours)
Runoff

PondCalcs2 Type 1l 24-hr Rainfall=8.05"
Prepares! by Wrightsville Engineering Services, P.L.L.C. Page 3
HydroCAD® 6.00 s/n 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 2S: New Development
Runoff = 28.11 cfs @ 11.96 hrs, Volume= 1.323 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=8.05"
Area ac CN Description
2.500 89 Urban commercial, 85% imp, MSG A
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ft/sec) (cfs)
5.0 Direct Entry, Sheet and Pipe travel time
Subcatchment 2S: New Development
Hydrograph Plot
I i
I i 28.11:;cfs !
I i I I I I i
ii �, I I E E
24^ I i -- - -- - - -- - - -'------
-.--- '-
_ - - -
22: _--
i
18= ._....- ----- ? - - r -- -`
! ;
I------- -'
I 10
8 i i � ! i
I I
! ! I ;
:
i i I
2- ; ............................
I
4
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

PondCalcs2 Type I/ 24-hr Rainfa11=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 4
HydroCAD® 6.00 sln 001707 O 1986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 3S: Uncollected Yard Areas
Runoff = 9.67 cfs @ 11.96 hrs, Volume= 0.395 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type 1124-hr Rainfall=8.05"
Area (ac) CN Description
1.490 61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftfft) Sft/sec) (cfs)
5.0 Direct Entry, yard sheet flow
Subcatchment 3S: Uncollected Yard Areas
Hydrograph Plot
-- Runoif
i i
i
3 i i
r
r I!i it
7 _ _ _ -._ _ _ _._._._.t__._.—.._ __ _E_ _-_ _..__.___ _._-__ _ -_ _w _ - _ _-__3 _ __.-._..._._._
I �
j. i..
I I I I
i f 1
o- .. ,
., � ., .. .. Time {hours} .� :., :. ... ... .: .., ._ ....

PondICalcs2 Type 1124-hr Rainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 5
HydroCAD® 6.00 s!n 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Subcatchment 4S: Proposed Uncollected Flows
Runoff = 7.65 cfs @ 11.96 hrs, Volume= 0.313 of
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Type II 24-hr Rainfall=8.05"
Area ac CN Description
1.180 61 >75% Grass cover, Good, HSG B
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftt t) (ft/sec) (cfs) _
5.0 Direct Entry, Sheet Flow Runoff
w
O
LL
Subcatchment 4S: Proposed Uncollected Flows
Hydrograph Plot
!
1 ! I
--- i ------ ::7.65. Cf5
-...-.... ..... ._
r: —T -' ' '-_ ' ' ' -'I'....... .....
i
7-
--_._.
- ---'
- - -'a-'- - ------ -'-
�.4.
--'-'- - - - -' ' --
}
i. ;
E
i. ,.
:
i 11 i
i i
i it
:
: E
; !
i
� ._...�. ..._._.__i..
I 1
i
k i
: i
i
j i
I j li i
i I I i
j
: !
i
:
I
i i
1
-------- II
i I
._._._._...;._.... 'I' -._._._
i
..--'-' .........._._ 1._._._._._.._._._..- --
---- 1 -.i
0-,.
1
i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
— Runoff

PondCallcs2 Type 1124-hr Rainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 6
HydroCAD® 6.00 s/n 001707 © 1986-2001 Applied Microcomputer Systems 6/2/2003
Pond 1P: Stormwater Pond
Inflow = 24.73 cfs @ 11.96 hrs, Volume= 1.164 of
Outflow - 13.27 cfs @ 12.04 hrs, Volume= 0.987 af, Aften= 46%, Lag= 4.8 min
Primary = 13.27 cfs @ 12.04 hrs, Volume= 0.987 of
Routing by Stor-Ind method, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Peak Elev= 24.75' Storage= 18,211 cf
Plug -Flow detention time= 90.5 min calculated for 0.987 of (85% of inflow)
Storage and wetted areas determined by Prismatic sections
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) cubic -feet) (cubic -feet)
22.50 6,890 0 0
23.50 8,060 7,475 7,475
24.50 8,700 8,380 15,855
25.50 9,980 9,340 25,195
26.50 10,650 10,315 35,510
Primary OutFlow (Free Discharge)
L1=Culvert
I2=Orifice/Grate
3=Orifice/Grate
# Routing Invert Outlet Devices
1 Primary 22.50' 24.0" x 40.0' long Culvert Ke= 0.500
Outlet Invert= 22.42' S= 0.0020 T n= 0.013 Cc= 0.900
2 Device 1 23.50' 2.00' x 3.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600
3 Device 1 22.50' 1.5" Vert Orifice/Grate C= 0.600

PondCalcs2 Type it 24-hr Rainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 7
H droCAD® 6.00 s/n 001707 O 1986-2001 Applied Microcomputer Systems 6/2/2003
w
3
0
U.
Pond 1 P: Stormwater Pond
Hydrograph Plot
,
t
---...._....
i
3
2473� .._ ; _._._. I26-
24 '
... ............
_...
............. -
I I
j }
I f 1
; r
----- . ._._.
r ,._. .
20,:i
i
I
i
,
, ;
13'.2Tcfs`
- _
-- - -- - --- ----
- - ---- — ----
12-
i
i
;
10
i
1
r Y
r '
i,
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
lRfi0N1
Pnmary

PondCa1cs2 Type 1! 24-hr Rainfaii=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 8
HydroCADO6.00 _sln 001707 © 1.986-2001 Applied Microcomputer Systems 6/2/2003
Pond 2P: Revised Pond
Inflow - 28.11 cfs @ 11.96 hrs, Volume= 1.323 of
Outflow = 13.51 cfs @ 12.04 hrs, Volume= 1.108 af, Atten= 52%, Lag= 5.2 min
Primary = 13.51 cfs @ 12.04 hrs, Volume= 1.108 of
Routing by Stor-Ind method, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Peak Elev= 24.78' Storage= 22,654 cf
Plug -Flow detention time= 95.7 min calculated for 1,108 of (84% of inflow)
Storage and wetted areas determined by Prismatic sections
Elevation
Surf.Area
Inc.Store
Cum.Store
(feet)
(sq-ft)
(cubic -feet)
(cubic -feet)
22.50
8,388
0
0
23.50
9,652
9,020
9,020
24.50
10,972
10,312
19,332
25.50
12,349
11,661
30,993
26.50
13,783
13,066
44,059
Primary OutFlow (Free Discharge)
t1=Culvert
t
2=Orifice/Grate
3=OrificelGrate
# Routing
Invert
Outlet Devices
1 Primary
22.50'
24.0" x 40.0' long Culvert Ke= 0.500
Outlet Invert-- 22.42' S= 0.0020 7 n= 0.013 Cc= 0.900
2 Device 1
23.50'
3.00' x 2.00' Horiz. OrificelGrate Limited to weir flow C= 0.600
3 Device 1
22.50'
1.6" Vert. Orifice/Grate C= 0.600

PondCalcs2 Type 1124-hr Rainfail=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 9
HydroCAD® 6.00 sin 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
7
0
LL
Pond 2P: Revised Pond
Hydrograph Plot
y , ;
i
i
i
26= - --- - -- - -- -- -f - ---
!
f !
i f
22 - - - ---- - - --- --- _ -
--
20�^-
!_....__....; r f.......... I! '...,....._....._--- ------ ... _......
16 _ - - - - k -------- - - --- - - - - -- -- - -----
14 ------ 13 5licfs: ! - -- ------- --- - -k ------ ---
I
10
r
4... .....
- -- -' - -- L- - --- - - -- -- - - ! - - - - ----i - - ' -- - -- -- ----
e �
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
-- lnfiow
- Primary

PondCalcs2 Type 1124-hr Rainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 10
HydroCAD® 6.00 sin 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Link 1L: Existing Total Flow
Inflow = 21.68 cfs @ 11.98 hrs, Volume= 1.382 of
Primary = 21.68 cfs @ 11.98 hrs, Volume= 1.382 af, Atien= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Z4-
Z2
18=1.
Link 1L: Existing Total Flow
Hydrograph Plot
Time (hours)
F1 n ow
— Primary

PondCalcs2 Type 1124-hr Rainfall=&05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 11
HydroCAD® 6.00 sln 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Link 2L: Proposed Combined Flow
Inflow = 19.86 cfs @ 11.99 hrs, Volume= 1.421 of
Primary = 19.86 cfs @ 11.99 hrs, Volume= 1.421 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Link 2L: Proposed Combined Flow
Hydrograph Plot
Inflow 11
Primary
Time (hours}

PondCalcs2 Type II 24-hrRainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 1
HydroCAD® 6.00 sin 001707 01986-2001 Applied Microcomputer Systems 6/2/2003
Time span=0.10-20.00 hrs, dt=0.01 hrs, 1991 points
Runoff by SCS TR-20 method, UH=SCS, Type II 24-hr Rainfall=8.05"
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Intl method
Link 1 L: Existing Total Flow Inflow= 21.68 cfs 1.382 of
Primary= 21.68 cfs 1.382 of

r
PondCa1cs2 Type I! 24-hr Rainfall=8.05"
Prepared by Wrightsville Engineering Services, P.L.L.C. Page 2
H droCAD® 6.00 sin 001707 O 1986-2001 Applied Microcomputer Systems 6i212003
Link 1 L: Existing Total Flow
Inflow = 21.68 cfs @ 11.98 hrs, Volume= 1.382 of
Primary - 21.68 cfs @ 11.98 hrs, Volume= 1.382 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.10-20.00 hrs, dt= 0.01 hrs
Link 1 L: Existing Total Flow
Hydrograph Plot
Time (hours)
0
w- Inflow
— Primary

DESIGN NARRATIVE,
STORM. DRAINAGE CALCULATIONS,
EROSION CONTROL TECHNICAL SPECIFICATION
AND
STORMWATER MANAGEMENT OPERATION & MAINTENANCE PLAN
SATELLITE OFFICE, NEW HANOVER MEDICAL GROUP
SOUTH COLLEGE ROAD
Monkey Junction.
New Hanover County, North Carolina
PREPARED FOR
Primary Care Associates
1960 South l 6th Street
WILM]NGTON, NC 28401
[phone]
File Number: 97019
Date: January 1998
���,as�ce�aaao�oe ..
�`te C,AP A aye
e
i
mF
• 14109 `
ire,
r
k�
Prepared by
Klein Engineering and Associates
322 South 4th Street
Wilmington, North Carolina 28401
[phone]

`KLEIN*EIJGINEERING AND ASSOCIATES
PROJECT: New Hanover Medical, Monkey Jct. PROJECT NO.: 97019
CLIENT: NH Medical Group DATE: November 1997
LOCATION: New Hanover County, NC PREPARED BY: JKK
SUBJECT: Stormwater Calculations
GIVEN: Design for single collection pond.
Runoff Coefficients used for Design:
Postconstruction = 0.80
Turf (developed) = 0.20
TOTAL PROJECT AREA = 160612 SF = 3.69 Ac
Area draining to pond = 95925 SF = 2.20 Ac
Areas not draining to pond = 64687 SF = 1.49 Ac
Design Storm Event = 10-year, 5 minute duration
Rainfall Intensity = 7.23 inches/hour
SOLUTION:
1. Summary of Drainage Areas
AREAS DRAINING
TO POND
AREA AREA
TYPE
(SF) (AC)
BLDG
19170 0.440
SIDEW
3180 0.073
PVMNT
52320 1.201
TOTAL 1MPERV.
74670
1.714
TURF
21255
0,488
TOTALS
95925
2.20
Pond Design Criteria:
Percent Built -Upon: =
1.714 Ac 1
2.202 Ac
=
77.8 %
use:
80 %
2. STORM DRAINAGE
DESIGN:
10-Year, 5-Minute Storm, i =
723
In/hr
DRAIN
CUMUL
REQ'D
DESIGN
PIPE
AREA RUNOFF
RUNOFF
DIA SLOPE
SLOPE
LENGTH
UPPER
LOWER
NO. C
(ac) (CFS)
(CFS)
(IN) (%)
(%}
(LF)
INVERT
INVERT
5 0.80
0.44 2.5
2.5
15 0,15
0.20
64
23.03
22.90
4 0.80
0.50 2.9
5A
18 0.27
0,30
132
22.90
22.51
3 0.80
0.27 1.6
7.0
18 0.44
0.45
124
22.51
21.95
2 0.80
0.22 1.3
8.3
18 0.62
0.65
144
21,95
21.01
NH Medical DEM Stormwaler Calculations

-KLEINO'EIJGINEERING AND ASSOCIATES
1 0.80 0.46 2.7 10.9 24
Note: Pipes based on RCP with n = 0.013.
3. DETENTION POND DESIGN:
Design to store the first 1-inch of runoff from project area
Imperv. 1.00 x 74670 SF x 1'I12" =
Turf 0.20 x 21255 SF x V/12" =
0.23 0.25
6223
354
6577 CF
Based on state requirements for ponds without vegetative filter
and using the design impervious percent o'; 80 with a depth of
feet, the ratio of surface area (SF) to drainage area to drainage area (DA) _
Therefore, required pond surface area (SA) is:
5.86 x 2.20 / 100 = 0.13 Acres
5621 SF Use:
Pond Width at Design Surface: see plan
Pond Length at Design Surface: see plan
AVE. CUMUL.
AREA AREA VOLUME VOLUME
ELEV. (SF) (SF) (CF) (CF)
17.5 (Pond Design Bottom)
0
22.5 57-tV 0 (Design Area)
6885 6885
23.5 8060 6885
8380 838.0
24.5 8700 15265
9340 9340
25.5 9980 24605
10315 10315
26.5 10650 34920
Depth where storage requirement met: 23.46
Depth of Required Storage: 0.96 VF or
Elevation of Top of Riser: 23.50
Depth of Storage Provided: 1.00 VF or
4. Restrictive Orifice Design:
Design orifice for discharge allowed using the following equation
Q= C x A x (2gh)"0.5 where: Q= CFS
C = orifice coefficient
A = orifice diameter (SF)
g = 32.2 ft/sec2
h = pressure head (ft)
Rearranging the above equation to solve for hole diameter
A = Q / C x (2gh)^0.5
5.86
5710 SF
64 21.01 20.85
Lt',
11.5 Inches
12.0 Inches
NH Medical DEM Stormwater Calculations

=KLEIN ENGINEERING AND ASSOCIATES
For our type of discharge, C =
0.60
Pond Outlet Invert =
99.50
Max. Reqd Storage Level =
23.46
Ave Reqd Storage Level =
22.98
Trial Orifice Diameter =
1.50 inches
Orifice centerline =
22.56
Ave. Pressure Head (h) =
0.42
Allowable discharge rate:
Design discharge so that ponds drain between two (2) day
and five (5) days.
Pond Volume: 6577 CF
Pond Volume:
6577 CF
Time to drain: 2 days
Time to drain:
5 days
or 172800 sec
or
432000 sec
Therefore, release rate =
Therefore, release rate =
6577 CFS 1 172800 sec
6577 CFS 1
432000 sec
or 0.038 CFS
or
0.015 CFS
A = 0.0123 SF
A =
0.0049 SF
1.5 inches
0.9 inches
Use: 1.50 "
5. Forebay Design Requirements:
Design forebay for 20 % of the required storage volume.
Required Storage Volume = 6577 CF (see above)
Required Forebay volume = 1315 CF
Refer to Drawings for Cross-section of forebay for volume estimates.
Forebay Cross-section = 60.6 CF/Ft Length
Required Length of Forebay = 21.7 LF
Design Length of Forebay = 35 LF
Therefore, design forebay volume = 2121 CF
which is greater than required volume.
6. Pond Outlet Design
Design pond outlet pipe to convey runoff in excess of 1-inch generated from a 10-year storm event.
Tc Rate
Depth
(min) (inlhr)
(in)
Comments
5 7.23
0.6
less than pond storage
10 6.3
1.1
approx. pond storage
15 5.45
1.4
exceeds storage use
Q = C x i x A
C=
0.80
i =
5.45 inlhr
A =
2.20 Ac
Q = 9.6
CFS
REQ'D DESIGN
RUNOFF DIA SLOPE SLOPE
(CFS) (IN) (%) (%)
LENGTH UPPER LOWER
(LF) INVERT INVERT Comments
NH Medical DEM Stormwater Calculations

°'KL.EIN'ENGINEERING AND ASSOCIATES
9.6 18 0.84 1.00
24 0.18 0.20
40 22.50 22.10
40 22.50 22.42
Use
7. Overflow Weir Design for Forebay and Pond Emergency Spillway
Design Overflow Weir based on 25-year, 10-minutes storm which produce a volume
in excess of one (1) inch.
Q = C x i x A C= 0.80
i = 7.13 in/hr
A = 2.20 Ac
Q = 12.6 CFS
Design weir to convey entire flow. Set weir invert above storage level.
weir equation: Q = C x H13/2 x (L - 0.2H) where:
Q=CFS
C = weir coefficient = 3.33
L = weir lenfth (FT) = 2 x H (min)
H = head (FT)
rearranging and solving for weir length yields the following:
L=(Q/CXH"3/2)+0.2H
Design weir capacity = 12.56 CFS
Design weir depth = 6
Therefore, required weir length =
8. Summary:
Required Volume =
Pond Volume Provided =
Pond Outlet Invert =
Required Storage Elev. _
Design Storage Elevation =
Pond Invert
Outlet Orifice Diameter =
Ave Discharge Rate =
Anticipated drawdown time =
10.77 FT USE
6577 CF
6885
22.50
23.46 Depth =
23.50 Depth =
17.50
1.50 "
0.038 CFS
48.0 Hours
0.5 FT
12 FT
0.96 VF
1.00 VF
2.0 Days
NH Medical DEM Stormwater Calculations

State of North Carolina
Department of Environment
and Natural Resources
Wilmington Regional Office
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
Division of Water Quality
April 17, 1998
Dr. J. William Eakins, President
Primary Care Associates
1960 South 16th Street
Wilmington, NC 28401
Subject: Permit No. SW8 961209 Modification
New Hanover Medical Group Satellite Office #2
High Density Commercial Stormwater Project
New Hanover County
Dear Dr. Eakins:
The Wilmington Regional Office received the Stormwater Management Permit Application for New Hanover Medical
Group Satellite Office #2 on December 2, 1997, with final information on March 4, 1998. Staff review of the plans and
specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth in Title
15A NCAC 2H.1000. We are forwarding Permit No. SW8 961209 Modification dated April 17, 1998, for the construction
of New Hanover Medical Group Satellite Office #2.
This permit shall be effective from the date of issuance until April 17, 2008, and shall be subject to the conditions -and
limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit.
Failure to establish an adequate system for operation and maintenance of the stormwater management system will result
in future compliance problems.
If any parts, requirements, or Iimitations contained in this permit are unacceptable, you have the right to request an
adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be
in the form of a written. petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the
M
Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this
permit shall be final and binding.
If you have any questions, or need additional information concerning this matter, please contact Linda Lewis, or me at
[phone].
Sincerely,
(26 �' Y�' �,
Rick Shiver, P.G.
Acting Regional Water Quality Supervisor
RSS/arl: S:IWQSISTORMWATIPERMIT1961209.APR
;cc: John Klein, P.E.
Tony Roberts, New Hanover County Inspections
Beth Easley, New Hanover County Engineering
Linda Lewis
Wilmington Regional Office
Central Files
127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled11011/o post -consumer paper

State Stormwater Management Systems
Permit No. W
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
�,I I i .L�J1* K Id ru `J5[" ua�' 7l� M_�l
HIGH DENSITY DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other
applicable Laws, Rules; and Regulations
PERMISSION IS HEREBY GRANTED TO
Primary Care Associates
New Hanover Medical Group Satellite Office #2
New Hanover County
FOR THE
construction, operation and maintenance of a detention pond in compliance with the provisions of 15A NCAC 2H .1000
(hereafter referred to as the "stormwater rules") and the approved stormwater management plans and specifications and
other supporting data as attached and on fife with and approved by the Division of Water Quality and considered a part of
this permit.
This permit shall be effective from the date of issuance until April 17, 2008 and shall be subject to the following specified
conditions and limitations:
I. DESIGN STANDARDS
This permit is effective only with respect to the nature and volume of stormwater described in the application and
other supporting data.
2. This stormwater system has been approved for the management of stormwater runoff as described on page 3 of this
permit, the Project Data Sheet. The stormwater control has been designed to handle the runoff from 74,670 square
feet of impervious area.
3. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the
permit.
4. The tract will be Iimited to the amount of built -upon area indicated on page 3 of this permit, and per approved
plans.
2

State Stormwater Management Systems
Permit No. SW8 961209i
DIVISION OF WATER QUALITY
PROJECT DATA SHEET
Project Name: New Hanover Medical Group Satellite Office #2
Permit Number: SW8 961209 Modification
Location: New Hanover County
Applicant: Dr. J. William Eakins, President
Mailing Address: Primary Care Associates
1960 South 16th Street
Wilmington, NC 28401
Application Date: December 2, 1997
Water Body Receiving Stormwater Runoff:
Classification of Water Body:
If Class SA, chloride sampling results:
Pond Depth, feet:
Permanent Pool Elevation, FMSL:
Total Impervious Surfaces, ftz:
Future, ftz
Offsite Area entering Pond, ftz:
Required Surface Area, ftz:
Provided Surface Area, ftz:
Required Storage Volume, ft3:
Provided Storage Volume, ft3:
Temporary Storage Elevation, FMSL:
Controlling Orifice:
Mott Creek
"C Sw"
n/a
5
22.5
74,670
19,359 (Future building and parking)
None, per Engineer
5,323
6,890
6,000
7,475
23.5
1.5"4 pipe
C

State Stormwater Management Systems
Permit No. 3W8 961204 Mod'ficatio
S. The permittee is responsible for verifying that the proposed built -upon area does not exceed the allowable built -
upon area.
6. The following items will require a modification to the permit:
a. Any revision to the approved plans, regardless of size.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area.
e. Further subdivision of the project area.
f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan.
In addition, the Director may determine that other revisions to the project should require a modification to the
permit.
7. The Director may notify the permittee when the permitted site does not meet one or more of the minimum
requirements of the permit. Within the time frame specified in the notice, the permittee shall submit a written time
schedule to the Director for modifying the site to meet minimum requirements. The permittee shall provide copies
of revised plans and certification in writing to the Director that the changes have been made.
H. SCHEDULE OF COMPLIANCE
The permittee will comply with the following schedule for construction and maintenance of the stormwater
management system:
a. The stormwater management system shall be constructed in it's entirety, vegetated and operational for it's
interided use prior to the construction of any built -upon surface except roads.
b. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be
repaired immediately.
2. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater
system functions at optimum efficiency. The approved Operation and Maintenance Plan must be followed in its
entirety and maintenance must occur at the scheduled intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
c. Mowing and revegetation of side slopes.
d. Immediate repair of eroded areas.
e. Maintenance of side slopes in accordance with approved plans and specifications.
f. Debris removal and unclogging of outlet structure, orifice device and catch basins and piping.
g. Access to the outlet structure must be available at all times.
Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ.
The records will indicate the date, activity, name of person performing the work and what actions were taken.
4. Decorative spray fountains will not be allowed in the ponds.
This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this
permit, the approved plans and specifications, and other supporting data.
A copy of the approved plans and specifications shaII be maintained on file by the Permittee for a minimum of ten
years from the date of the completion of construction.
id

State Stormwater Management Systems
Permit No. SW$ 261209 Modificatignn
7. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this
permitted facility, a certification must be received from an appropriate designer for the system installed certifying
that the permitted facility has been installed in accordance with this permit, the approved plans and specifications,
and other supporting documentation. Any deviations from the approved plans and specifications must be noted on
the Certification.
8. Prior to the sale of any portion of the property, an access/maintenance easement to the stormwater facilities shall
be granted in favor of the permittee if access to the stormwater facilities will be restricted by the sale of any portion
of the property.
9. The connection into the stormwater control system from all future impervious areas shall be made such that short-
circuiting of the system does not occur.
10. All built -upon area on the site must be directed into the permitted stormwater control system.
III. GENERAL CONDITIONS
This permit is not transferable. In the event there is a desire for the facilities to change ownership, or there is a
name change of the Permittee, a formal permit request must be submitted to the Division of Water Quality
accompanied by an application fee, documentation from the parties involved, and other supporting materials as may
be appropriate. The approval of this request will be considered on its merits and may or may not be approved.
2. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to enforcement
action by the Division of Water Quality, in accordance with North Carolina General Statute 143-215.6A to 143-
215.6C.
The issuance of this permit does not preclude the Permittee from complying with any and all statutes, rules,
regulations, or ordinances which may be imposed by other government agencies (local, state, and federal) which
have jurisdiction.
4. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the
Permittee shall take immediate corrective action, including those as may be required by this Division, such as the
construction of additional or replacement stormwater management systems. .
The permittee grants DENR Staff permission to enter the property for the purpose of inspecting all components
of the permitted stormwater management facility.
6. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit
modification, revocation and reissuance or termination does not stay any permit condition.
Permit issued this the 17th day of April, 1998.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
(2b 4VI
A. Preston Howard, 7r., .E., Director
Division of Water Quality
By Authority of the Environmental Management Commission
Permit Number SW8 961209 Modification
5

State Stormwater Management Systems
Permit No. SW8 961209 Modification
New Hanover Medical Group Satellite Office #2
Stormwater Permit No. SW8 961209 Modification
New Hanover County
Engineer's Certification
1, , as a duly registered Professional Engineer in the State of North
Carolina, having been authorized to observe (periodically/weekly/full time) the construction of the project,
(Project)
for (Project Owner) hereby state that, to the best of my abilities, due care and
diligence was used in the observation,of the project construction such that the construction was observed to be built within
substantial compliance and intent of the approved plans and specifications.
Noted deviations from approved plans and specification:
Signature
Registration Number
Date
SEAL
no

DIVISION OF ENVIRONMENTAL MANAGEMENT
NORTH CAROLINA STORM WATER MANAGEMENT PERMIT APPLICATION
1. GENERAL INFORMATION
1. Project Name Satellite Office - New Hanover Medical Group
2. Location, directions to project (include County, Address, State Road) Attach map New Hanover Coun__ty_
_ South College Road (NC Highway 132). apprx. 500' south of intersection of NC 132 and SR 1698 (Greenbriar Rd)
3. Owner's Name Primary Care Associates Phone [phone]
4. Owner's Mailing Address 1960 South 16th Street
City Wilmington State NC Zip 28401
5. Nearest Receiving Stream Tributa to Mott Creek Class C-Sw
6. Project description Construction of medical facility and parking lot to service the facility
II. PERMIT INFORMATION
1. Permit No. (To be Gllcd in by DWQ) 15w 3 q & 1 Z09
2. Application Date November 26, 1997 Fee enclosed $385
3. Permit Type X New — Renewal _X_ Modification (excluding; Permit No.) SWO Q Col ZOO(
4. Project Type:_ Low Density X Detention _ Infiltration _ Redevelop_ General _ Alter Offsite
5. Other State/Federal Permits/Approvals Required (Check appropriate blanks)
CAMA Major Sedimentation/Erosion Control X 404 Permit
III. BUILT UPON AREA (please see NCAC 2H 1005 thru 1007 for applicable density limits)
Classification
Existing; Built -upon Area
Proposed Built -upon Area
Total Project Area
% Built -upon Area
Drainage Drainaae
Basin Basin
C-Sw
0
1.71 Ac
3.69 Ac
46.3 %
Breakdown of Impervious Area
(Please: indicate below the drainage inipenlous am)
Buildings 0.44 Ac
Streets
Parking/SW 1.27 Ac
Other
Totals 1.71 Ac
IV. STORMWATER TREATMENT (Describe how the runoff will be treated)
Collection into DEM stormwater_pond

V. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
Deed restrictions and protective covenants are required to be recorded for all low density projects and all
subdivisions prior to the sale of any lot. Please see Attachment A for the specific items that must be recorded for
the type of project applied for.
By your signature below, you certify that the recorded deed restrictions and protective covenants for this project
shall include all the items required by the permit, that the covenants will be binding on all parties and persons
claiming under them, that they will run with the land, that the covenant cannot be changed or deleted without
concurrence from the State, and that they will be recorded prior to the sale of any lot.
VI. OWNER'S CERTIFICATION
1, J. William Eakins , certify that the information included on this permit
(Please print or type name clearly)
application form is correct, that the project will be constructed in conformance with the approved plans, that
the deed restrictions will be recorded with all required permit conditions, and that to the best of my knowledge,
the proposed project complies with the requirements of 15A NCAC 214.1000.
I authorize the =s:=mit stormwater plans on my behalf.
s Jent
O er/Authorized Agent Signature and Title Date
VI1. AGE THORIZATION ((Please fti3 in the name of the enginecrlsurveyor authorized to submit plans on the owncrs hehalt)
Person or firm name Klein_ Engineering and Associates
Mailing Address 322 South 4th Street
City Wilmington „ _ _ State NC Zip 28401 Phone [phone]
Please submit application, fee, plans and calculations to the appropriate Regional Office.
CC'. Applicant/WiRO//Central Files
Office use only
iORMWATE
E C E I V E
DEC 0 21997
a >E M
PROJ #5W-5q 1'-09

i

STORMWATER NE OE�Ea z,997 r'
SATELLITE OFFICE -NEW HANOVER MEDICAL GRd" # P f oIZbQ M 0 0
South College Road (N.C. Highway 132)
STORM WATER MANAGEMENT OPERATION AND MAINTENANCE PLAN
L GENERAL
The project area will contain improvements which will require perpetual maintenance and include
a storm water management system which relies on the treatment of surface runoff through the use
of a detention pond facility.
2. OPERATION OF DETENTION POND SYSTEM
The detention pond is intended to provide some measure of sediment and nutrient filtration within
the vegetation along the pond perimeter as well as promoting infiltration of runoff into the
subsurface groundwater,
The use of a ponds allows a more intensive built -upon area to be developed and is a permitted
method for stormwater treatment in compliance with the State of North Carolina Administrative
code Section 15 NCAC 2H.1000, Stormwater Runoff Disposal.
3. MAINTENANCE RESPONSIBILITIES
Routine maintenance as detailed below is required for the detention pond. To provide for this, the
OWNER shall be responsible for all required maintenance. In lieu of performing the direct
maintenance, the OWNER may contract this service to an independent maintenance entity;
however, all responsibilities for enforcing these restrictive covenants shall reside with the actual
owner.
4. DETENTION POND SYSTEM MAINTENANCE
As a minimum, the following maintenance procedures shall be followed for the pond:
(1) General: Side slopes shall be kept mowed and clear of debris. Vegetation shall be kept to a
maximum height of eight (8) inches and mowing shall be scheduled accordingly.
(2) Upon Completion of Construction:
(a) Any sediment deposited in detention pond shall be removed to obtain design depth, slopes and
specifications.

Page Two
Operation and Maintenance Plan
Satellite Office -New Hanover Medical Group
South College Road
(b) The wetted perimeter shall be planted with water resilient vegetation appropriate to soil and site
characteristics; the remaining pond slopes shall also be vegetated and planted with vegetation
appropriate to soil and site characteristics. All slopes shall be maintained to ensure growth of such
vegetations.
C All drainage features shall be inspected and cleaned of sand, silt or foreign materials. These
features include, but not limited to, the pond outlet structure trash screen, outlet orifice and site
drop inlet and catch basin grates.
(d) Any component which is determined to be not performing satisfactory in its intended usage shall
be repaired or replaced to original design specifications.
(3) After Each Runoff Producing Rain:
(a) Any sloughing, erosion or vegetative wash -out of the pond slopes shall be repaired immediately.
(b) All drainage features shall be inspected and cleaned of trash or foreign materials. These
features include the pond side slopes, pond outlet structure trash screen, outlet orifice and site drop
inlet and catch basin grates.
C Any component which is determined to be not performing satisfactory in its intended usage shall
be repaired or replaced to original design specifications.
(4) Semi -Annually:
(a) The detention pond shall be checked for siltation and filling. Should the bottom elevation
exceed the design bottom elevation, the pond shall be excavated six (b) inches below the design
elevation to allow solids accumulation due to siltation and filling.

Page Three
Operation and Maintenance Plan
Satellite Office -New Hanover Medical Group
South College Road
OWNER:
Primary Care Associates
4960 South 16th Street
Wilmington, NC 28401
Phone: [phone]
STATE OF NORTH CAROLINA
COUNTY OF NEW HANOVER
C
/ (Signature)
(Title)
(Date)
I, . +Lr V, A A L. , a Notary Public of the State of North Carolina,
County of M4, Hanover, Hereby certify that J. William Eakins personally appeared before me this
day and executed the above certification.
Witness my hand and notarial seal, this ( day of OCAE be r , 1997.
(j tary Public)
My Commission expires') - 14 - Z -- 62 o 1 -

n 4 1 .
KLEIN ENGINEERING
AND ASSOCIATES
February 27, 1998
Ms. Linda Lewis
NC DEHNR, DWQ
127 Cardinal Drive Extension
Wilmington, NC 28405-3845
Re: Satellite Office for New Hanover Medical Group
Monkey Junction, New Hanover County
Stormwater Project No.: SW8 961209 Modification
Additional Information
Dear Ms. Lewis:
322 South 4th Street
Wilmington, NC 28401
[phone]
File No.: 97019
STORMWATER
D E C E i E
MAR 04p U
598
PRpJ
E M
# _
As requested in letter dated February 4, 1998, please find enclosed revised submittal items for the
above referenced project. Enclosed are the following:
three (3) copies of the revised Drawing
three (3) copies of the revised Calculations
Regarding the request for additional information, the following is provided:
1. J.W. Eakins signed as the President of the Associates. This is shown on the signed O&M
Agreement.
2. The future building area is accounted for in the Calculations. This has been clarified on the new
Layout Plan provided.
3. An entire Layout Plan designated SD2A has been provided for your use. Within the General
Notes you will find that all dimensions are to the face of curb or face of building unless otherwise
noted.
4. No wetlands are currently on the project site. A note has been added to Sheet SD2.
5. No offsite drainage is planned. Current finished grades on the Drawings are to elevate the
building and parking areas. With existing drainage ditches to the north, east and west, the majority
of the grassed areas will be drained to these features.
6. The forebay has been reduced to 20 percent of the total storage volume.
7. The orifice calculations have changed since the original submittal due to the reconfiguring of the
vegetative shelf. Although the orifice size has not changed, the pond volume has increased which
brings the diameter within the desired range for drawdown.
8. The vegetative shelf has been relocated as requested.

Page Two
Ms. Linda Lewis
February 27, 1998
We hope'the enclosed information is found satisfactory. As the applicant is anxious to get
underway with the project, should there be any questions concerning the enclosed items or
additional copies desired, please contact our office by phone to expedite the process.
Sincerely,
KLEIN ENGINEERING AND ASSOCIATES
r
3HN K. KLEIN, PE
enclosures
cc: Mr. Michael R. McLeod, AlA
Neill H. Musselwhite, MD

•; 1
STORM DRAINAGE CALCULATIONS (REVISED)
SATELLITE OFFICE, NEW HANOVER MEDICAL GROUP
SOUTH COLLEGE ROAD
Monkey !unction
New Hanover County, North Carolina
PREPARED FOR
Primary Care Associates
1960 South 16th Street
WILMINGTON, NC 28401
[phone]
File Number: 97019
Date: February 1998
FS�'3'1"Ref. a
ZEAL
141Q�
Prepared by
Klein Engineering and Associates
322 South 4th Street
Wilmington, North Carolina 28401
[phone]
�"ORMWATER
E C E I V E
MAR
0 4 1998
PRQ,1 # `�Cv 209

KLEIN ENGINEERING AND ASSOCIATES
PROJECT: New Hanover Medical, Monkey Jct. PROJECT NO.: 97019
CLIENT: NH Medical Group DATE: November 1997
LOCATION: 'New Hanover County, NC PREPARED BY: JKK
SUBJECT: Stormwater Calculations
GIVEN: Design for single collection pond
Runoff Coefficients used for Design:
Postconstruction =
0.80
Turf (developed) =
0.20
TOTAL PROJECT AREA =
160612 SF = 3.69 Ac
Area draining to pond =
95925 SF = 2.20 Ac
Areas not draining to pond =
64687 SF = 1.49 Ac
Design Storm Event = 10-year,
Rainfall Intensity =
SOLUTION:
5 minute duration
7.23 inches/hour
1. Summary of Drainage Areas
AREAS DRAINING
TO POND
AREA
AREA
TYPE
(SF)
(AC)
BLDG
19170
0.440
SIDEW
3180
0.073
PVMNT
52320
1.201
TOTAL IMPERV.
74670
1.714
TURF
21255
0.488
TOTALS
95925
2.20
Pond Design Criteria:
Percent Built -Upon: =
1.714
Ac 1
2.202 Ac
77.8
%
use:
80
%
2. STORM DRAINAGE DESIGN:
10-Year, 5-Minute
Storm, i =
7.23
Inlhr
DRAIN
CUMUL
REQ'D
DESIGN
PIPE
AREA
RUNOFF
RUNOFF
DIA
SLOPE
SLOPE
LENGTH
UPPER
LOWER
NO. C
(ac)
(CFS)
(CFS)
(IN)
(%)
(%)
(LF)
INVERT
INVERT
5 0.80
0.44
2.5
2.5
15
0.15
0.20
64
23.03
22.90
4 0.80
0.50
2.9
5.4
18
0.27
0.30
132
22.90
22.51
3 0.80
0.27
1.6
7.0
18
0.44
0.45
124
22.51
21.95
2 0.80
0.22
1.3
8.3
18
0.62
0.65
144
21.95
21.01
1 0.80
0.46
2.7
10.9
24
0.23
0.25
64
21.01
20.85
NH Medical DWQ Stormwater Calculations (Rev 2-23-98)

1
KLEIN ENGINEERING AND ASSOCIATES
Note: Pipes based on RCP with n = 0.013.
3. DETENTION POND DESIGN:
Design to store the first 1-inch of runoff from project area
Imperv. 1.00 x 74670 SF x 1712" = 6223
Turf 0.20 x 21255 SF x V/12" = 354
6577 CF
Based on state requirements for ponds without vegetative filter
and using the design impervious percent o 80 with a depth of
feet, the ratio of surface area (SF) to drainage area to drainage area (DA) =
Therefore, required pond surface area (SA) is:
7.00 x 2.20 / 100 = 0.15 Acres
6715 SF Use.
Pond Width at Design Surface: see plan
Pond Length at Design Surface: see plan
AVE. CUMUL.
AREA AREA VOLUME VOLUME
ELEV. (SF) (SF) (CF) (CF)
18.5 (Pond Design Bottom)
0
22.5 6890 0 (Design Area)
7475 7475
23.5 8060 7475
8380 8380
24.5 8700 15855
9340 9340
25.5 9980 25195
10315 10315
26.5 10650
35510
Depth where storage requirement met:
23.38
Depth of Required Storage:
0.88 VF or
Elevation of Top of Riser:
23.50
Depth of Storage Provided:
1.00 VF or
Volume of Storage Provided:
7475 CF
4. Restrictive Orifice Design:
Design orifice for discharge allowed using the following equation
Q= C x A x (2gh)^0.5 where:
Q= CFS
C = orifice coefficient
A = orifice diameter (SF)
g = 32.2 ft/sec2
h = pressure head (ft)
Rearranging the above equation to solve
for hole diameter
A= Q I C x (2gh)10.5
4.0
7.00
10.6 Inches
12.0 Inches
• 1)b99
NH Medical DWQ Stormwater Calculations (Rev 2-23-98)

. KLEIN ENGINEERING AND ASSOCIATES
For our type of discharge, C =
0.60
Pond Outlet Invert =
22.50
Design Storage Level =
23.50
Ave Reqd Storage Level =
23.00
Trial Orifice Diameter =
1.50 inches
Orifice centerline =
22.56
Ave. Pressure Head (h) =
0.44
Allowable discharge rate:
Design discharge so that ponds drain between two (2) day
and five (5) days,
Pond Volume: 7475 CF
Pond Volume:
7475 CF
Time to drain: 2 days
Time to drain:
5 days
or 172800 sec
or
432000 sec
Therefore, release rate =
Therefore, release rate =
7475 CFS / 172800 sec
7475 CFS 1
432000 sec
or 0.043 CFS
or
0.017 CFS
A = 0.0136 SF
A =
0.0054 SF
1.6 inches
1.0 inches
Use: 1.50 "
5. Forebay Design Requirements:
Design forebay for 20 % of the storage volume.
Design Storage Volume = 7475 CF (see above)
Required Forebay volume = 1495 CF
AVE. CUMUL.
AREA AREA VOLUME VOLUME
ELEV. (SF) (SF) (CF) (CF)
19.5 50 0
113 113
20.5 175 113
268 380
21.5 360 493
0
630 1010
22.5 900 1503
Therefore, design forebay volume = 1503 CF or 20 % or Storage Volume
6. Pond Outlet Design
Design pond outlet pipe to convey runoff in excess of 1-inch generated from a 10-year storm event.
Tc Rate Depth
(min) (inlhr) (in) Comments
5 7.23 0.6 less than pond storage
10 6.3 1.1 approx, pond storage
15 5.45 1.4 exceeds storage use
NH Medical DWQ Stormwater Calculations (Rev 2-23-98)

KLEIN ENGINEERING AND ASSOCIATES
Q=CXiXA C=
i=
A=
Q = 9.6 CFS
REQ'D DESIGN
RUNOFF DIA SLOPE SLOPE
(CFS) (IN) N M
9.6 18 0.84 1.00
24 0.18 0.20
0.80
5.45 in/hr
2.20 Ac
LENGTH UPPER LOWER
(LF) INVERT INVERT Comments
40 22.50 22.10
40 22.50 22.42 use
7. Overflow Weir Design for Forebay and Pond Emergency Spillway
Design Overflow Weir based on 25-year, 10-minutes storm which produce a volume
in excess of one (1) inch.
Q = C x i x A C= 0.80
i = 7.13 in/hr
A = 2.20 Ac
Q = 12.6 CFS
Design weir to convey entire flow. Set weir invert above storage level.
weir equation: Q = C x HA3/2 x (L - 0.2H) where:
Q=CFS
C = weir coefficient = 3.33
L = weir lenfth (FT) = 2 x H (min)
H = head (FT)
rearranging and solving for weir length yields the following:
L=(Q/CxHA312)+0.2H
Design weir capacity = 12.56 CFS
Design weir depth = 6 " = 0.5 FT
Therefore, required weir length =
10.77 FT USE 12 FT
8. Summary:
Required Pond Surface Area =
6715 SF
Design Pond Surface Area =
6890 SF
Required Storage Volume =
6577 CF
Design Storage Volume =
7475 CF
Pond Outlet Invert =
22.50
Required Storage Elev. =
23.38 Depth = 0.88 VF
Design Storage Elevation =
23.50 Depth = 1.00 VF
Pond Invert =
18.50
Outlet Orifice Diameter =
1.50 "
Ave Discharge Rate =
0.039 CFS
Anticipated drawdown time =
46.7 Hours = 1.9 Days
NH Medical DWQ Stormwater Calculations (Rev 2-23-98)

State of North Carolina
Department of Environment
and Natural Resources
Wilmington Regional Office
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
Division of Water Quality
February 4, 1998
Mr. John Klein, P.E.
Klein Engineering and Associates
322 South Fourth Street
Wilmington, NC 28401
Subject: ACKNOWLEDGEMENT OF RECEIPT AND
REQUEST FOR ADDITIONAL INFORMATION
Stormwater Project No. SW8 961209 Modification
New Hanover Medical Group Satellite Office #2
New Hanover County
Dear Mr. Klein:
The Wilmington Regional Office received a Stormwater Management Permit Application for New
Hanover Medical Group Satellite Office #2 on December 2, 1997. A preliminary review of that information
has determined that the application is not complete. The following information is needed to continue the
stormwater review:
A. What is the title of J. W. Eakins? Please be sure to add the titles of the applicants on the
application form.
The future parking area is noted as accounted for in the talcs, but the future building
expansion is not noted as accounted for. Is it?
3. Please provide the dimensions of the building, parking and walks. Please note the dimensions
as FC-FC or BC -BC.
✓4. Delineate all wetlands on site, or note on the plans that none exist.
15. Is there any offsite drainage?.
✓6. Try not to oversize the forebay. Since the forebay counts as part of the required surface area,
unnecessarily large forebays cut down on the available surface area at the required design
depth, resulting in inadequate TSS removal.
✓7. The 1.5" orifice is barely on the edge of providing a 2 day drawdown. Will you consider
decreasing the size to ensure a 2 day minimum detention time?
127 Cardinal Dr. Ext-, Wilmington, North Carolina 28405 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/10% post -consumer paper

Mr. Klein
February 4, 1998
Stormwater Project No
SW8 961209 Modification
8. Please relocate the vegetated shelf below the permanent pool. I know in the past I have
requested it to be above the permanent pool, but the Central Office has provided new
information that it should be located below the permanent pool. The shelf should end at the
permanent pool elevation and extend below it at a 6:1 slope.
Please note that this request for additional information is in response to a preliminary review. The
requested information should be received by this Office prior to March 4, 1998, or the application will be
returned as incomplete. The return of a project will necessitate resubmittal of all required items, including
the application fee.
RSS/arl
cc
If you have any questions concerning this matter please feel free to call me at [phone].
Sincerely,
Ms. Linda Lewis
Environmental Engineer
S:1W QSISTORMWATIADDINF01961209.FEB
Linda Lewis
Central Files
127 Cardinal Dr. Ext.., Wilmington, North Carolina 28405 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/I0% post -consumer paper

KLEIN ENGINEERING 322 South 4th,Strcet.:.v:
AND ASSOCIATES w�� (910) 763 900401 w
November 26, 1997
File No.: 97019
Ms. Linda Lewis
NC DEHNR, DWQ
127 Cardinal Drive Extension 7DEC
��!EI
Wilmington, NC 28405-3845 0 2 97g7Re: Satellite Office for New Hanover Medical Group9ColZC
Monkey Junction, New Hanover County
Engineered Submittal jvv v
1�
Dear Ms. Lewis:
Please find enclosed submittal for the above referenced project. The project will involve the
construction of approximately 1.71 acres of built -upon area. Included for your review are the
following items:
completed application form
application fee in the amount of $385
three (3) copies of the Drawing
three (3) copies of the Narrative which includes Calculations and 0&M Agreement
Should there be any questions concerning the enclosed items or additional copies desired, please
feel free to contact our office.
Sincerely,
KLEIN ENGINEERING AND ASSOCIATES
eM ��KKLEIN, PE
enclosures
cc: Mr. Michael R. McLeod, AIA
Neill H. Musselwhite, MD

ti ,;
•tea.

State of North Carolina
Department of Environment,
Health and Natural Resources 7�
Division of Water Quality ±Aff
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
January 9, 1997
Dr. William J. Eakins
Primary Care Associates
1960 S. 16th Street
Wilmington, North Carolina 28401
Subject: Permit No. SW8 961209
New Hanover Medical Group - Satellite Office #2
General Permit Stormwater
New Hanover County
Dear Dr. Eakins:
The Wilmington Regional Office received the Stormwater Management Permit Application for New Hanover Medical
Group - Satellite Office #2 on December 9, 1996, with final information on January 9, 1997. Staff review of the plans
and specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth
in Title 15A NCAC 2H .1000. We are forwarding Permit No. SW8 961209 dated January 9, 1997 , for the construction
of New Hanover Medical Group - Satellite Office #2.
This permit shall be effective from the date of issuance until rescinded and shall be subject to the conditions and
limitations as specified therein.
If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an
adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be
in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the
Office_of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this
permit shall be final and binding.
If you have any questions, or need additional information concerning this matter, please contact either me or Greg Stutts
at [phone].
Si
lgl on
al Zater Quality Supervisor
KElges: S:IWQSISTORMWATIPERMIT1961209.JAN
cc: John K. Klein, P.E.. Klein Engineering & Associates
Tony Roberts, New Hanover County Inspections
Beth Easley, New Hanover County Engineering
Greg Stutts
Wilmington Regional Office
Central Files
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer

State Stormwater Management Systems
Permit No.SW8 961209
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT, HEALTH AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
["B1 1"61 O 081401�11
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended,
and other applicable Laws, Rules and Regulations
PERMISSION IS HEREBY GRANTED TO
Primary Care Associates
New Hanover Medical Group - Satellite Office #2
New Hanover County
FOR THE
construction of site clearing and grading in compliance with the provisions of 15A NCAC 2H .1000 (hereafter
referred to as the "stormwater rules °) and the approved stormwater management plans and specifications, and
other supporting data as attached and on file with and approved by the Division of Water Quality and
considered a part of this permit for New Hanover Medical Group - Satellite Office #2.
- The Permit shall be effective from the date of issuance until rescinded and shall be subject to the following
specific conditions and limitations:
I. DESIGN STANDARDS
1. This permit covers the construction of 0 square feet of built -upon area.
2. The approved Erosion Control plan will be followed.
3. Approved plans and specifications for projects covered by this permit are incorporated by reference and
are enforceable parts of the permit.
-2-

State Stormwater Management Systems
Permit No.5W8 961209
4. No stormwater piping in addition to the existing piping shall be allowed except:
a. That minimum amount necessary to direct runoff beneath an impervious surface such as a road.
b. That minimum amount needed under driveways to provide access to lots.
5. The permittee shall submit to the Director and shall have received approval for revised plans,
specifications, and calculations prior to construction for the following items:
a. Any revision to the approved plans, regardless of size.
b. Project name change.
C. Transfer of ownership.
d. Redesign of, addition to or deletion of the approved amount of built -upon area, regardless of
size.
e. Further subdivision of the project area.
f. Alteration of the proposed drainage.
In addition, the Director may determine that other revisions to the project should require a modification
to the permit.
6. The Director may notify the permittee when the permitted site does not meet one or more of the
minimum requirements of the permit. Within the time frame specified in the notice, the permittee shall
submit a written time schedule to the Director for modifying the site to meet minimum requirements.
The permittee shall provide copies of revised plans and certification in writing to the Director that the
changes have been made.
II. SCHEDULE OF COiMTLIANCE
1. The permittee shall at all times comply with the following schedule for construction and maintenance
of the project:
2. The permittee shall at all times provide adequate erosion control measures in conformance with the
approved Erosion Control Plan.
3. The permittee shall submit all information requested by the Director or his representative within the
time frame specified in the written information request.
III. GENERAL CONDITIONS
1. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to
an enforcement action by the Division of Water Quality, in accordance with North Carolina General
Statutes 143-215.6A to 143-215.6C.
2. The permit issued shall continue in force and effect until revoked or terminated.
3. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for
a permit modification, revocation and reissuance, or termination does not stay any permit condition.
-3-

State Stormwater Management Systems
Permit No.SW8 961209
4. The issuance of this permit does not prohibit the Director from reopening and modifying the permit,
revoking and reissuing the permit, or terminating the permit as allowed by the laws, rules, and
regulations contained in Title 15A of the North Carolina Administrative Code, Subchapter 2H.1000;
and North Carolina General Statute 143-215.1 et. at.
5. The permit is not transferable to any person except after notice to and approval by the Director. The
Director may require modification or revocation and reissuance of the permit to change the name and
incorporate such other requirements as may be necessary. A formal permit request must be submitted
to the Division of Water Quality accompanied by the appropriate fee, documentation from both parties
involved, and other supporting materials as may be appropriate. The approval of this request will be
considered on its merits, and may or may not be approved.
6. The issuance of this permit does not preclude the Permittee from complying with any and all statutes,
rules, regulations, or ordinances which may be imposed by other government agencies (local, state and
federal) which have jurisdiction.
7. The permittee grants permission to DEHNR Staff to enter the property for the purpose of inspecting
the project.
Permit issued this the 9th day of January, 1997
NORTH CAWUNA/ENVTRONMENTAL MANAGEMENT COMMISSION
1
rPresln
----�------------f
---------------------�-_---
ward, Jr., rector
Division of Water Quality
By Authority of the Environmental Management Commission
Permit Number SWS 961209
_Z

r
DIVISION OF ENVIRONMENTAL MANAGEMENT
NORTH CAROLINA STORM WATER MANAGEMENT PERMIT APPLICATION
1. GENERAL INFORMATION
1. Project Name
Satellite Office #2 for the New Hanover Medical Group on
South College Road.
2. Location, directions'to project (include County, Address, State Road) Attach map East side Qf SQuth
College Road, NC HWY 132, 200+ feet south of Greenbriar Road.
3, Owner's Name pri mFarru Cart- AGGnr.i atas Phone i 91 0 }.343-g991
4. Owner's Mailing Address 1960 S. 16th Street, Wilmington_, NC_ 28401
City Wilmington. State NC Zip 28401
5. Nearest Receiving Stream Motts Creek Class
6. Project description _ Grading of site and existing Swale. -No_proposed
built -upon..
H. PERMIT INFORMATION
1. Permit No. ('ro be filled in by pwQ)
2. Application Date 6 December 1 9 9 6 Fee enclosed $ 5 0. 0 0
3. Permit Type x New — Renewal Modification (excluding Permit No.)
4. Project Type:_ Low Density— Detention _ _ Infiltration .___ Redevelop--! General _ Alter— Offsite
5. Other State/Federal Permits/Approvals Required (cheek appropriate blanks)
CAMA Major Sedimentation/Erosion Control X 404 Permit
111. BUILT UPON AREA (please see NCAC 2H 1005 thru 1007 for applicable density limits)
Drainaae Drainage Bmakdom_-of .lwpervigus Area
Basin bm n (Pimse indicate below the drainage in�ous area)
Classification 3.69 ac Buildings
Existing Built -upon Area 0 Streets
Proposed Built -upon Area 0 Parkmg/SW
Total Project Area 3-69 ac Other
% Built -upon Area 0 % Totals
IV. STORMWATER TREATMENT (Describe how the runoff will be treated)
Draina e to existing swales

V. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
Deed restrictions and protective covenants are required to be recorded for all low density projects and all
subdivisions prior to the sale of any lot. Please see Attachment A for the specific items that must be recorded for
the type of project applied for.
By your signature below, you certify that the recorded deed restrictions and protective covenants for this project
.shall include all the items required by the permit, that the covenants will be binding on all parties and persons
claiming under them, that they will run with the land, that the covenant cannot be changed or deleted without
concurrence from the State, and that they will be recorded prior to the sale of any lot.
VI. OWNER'S CERTIFICATION
I, /V I / C. /I certify that the information included on this permit
(Please print cw'type name clearly)
a plication form is correct, that the project will be constructed in conformance with the approved plans, that
the deed restrictions will be recorded with all required permit conditions, and that to the best of my knowledge,
the proposed project complies with the requirements of 15A NCAC 2H.1000,
I authorize the below named person or firth to submit stormwater plans on my behalf.
Authorized Agent Signature and Title Date
V11. AGENT AUTHORIZATION ((Please rill in the name of the engineer/arwyor authorized to submit plans on the owners behalf)
Person or firm name -Klein Engv_ecring and Associates
Mailing Address 322 Soutb 41h Street
City —Wilmington on _ _ State " NC _ Zip 28401 Phone [phone]
Please submit application, fee, plans and calculations to the appropriate Regional Office.
cc: Applicant/WiRO//Central Files
Office use only
[1[ 0 9 1
��6

KLEIN ENGINEERING G 0 19961322 South 4th Street
AND ASSOCIATES S o5'�1Z ° "--`•- Wilmington, NC 28401
[phone]
December 6, 1996
Mr. Greg Stutts
NC DEHNR
Division of Water Quality
127 Cardinal Drive Extension
Wilmington, NC 28405-3845
Re: General Permit Application
Future Site of New Hanover Medical Group
South College Road (NC 132), New Hanover County
Dear Mr. Stutts:
File No.: 96025
Please find enclose application for General Water Quality Permit for the above project area. The
project involves site preparation only and no built -upon areas are proposed at this time. Included
are the following:
completed application and application fee of $50
two (2) copies of the Drawings which include both onsite work as well as the ditch modifications
Should there be any questions concerning the enclosed items or additional copies desired, please `
contact our office. Under separate cover, we are submitting information to Ms. Beth Easley for
Erosion and Sedimentation Control consideration. 1.
Sincerely,
KLEIN ENGINEERING AND ASSOCIATES
rHNKLEIN, PE
enclosures
cc: Mr. Michael R. McLeod