SW8050427_HISTORICAL FILE_20050523

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8 U5 oak 27
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
20 a 5 OS 2 3
YYYYMMDD

of \NArF9
Michael F. Easley, Governor
CO
William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
N,
Alan W. Klimek, P.E. Director
Division of Water Quality
May 23, 2005
Mr. Sterling B. Cheatham
City Manager
City of Wilmington
P.O. Box 1810
Wilmington, NC 28402
Subject: Stormwater Permit No. SW8 050427
North Riverfront Parking Garage
High Density Project
New Hanover County
Dear Mr. Cheatham:
The Wilmington Regional Office received a complete Stormwater Management Permit
Application for North Riverfront Parking Garage on May 18, 2005. 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 050427 dated May 23, 2005, for the construction of the subject project.
This permit shall be effective from the date of issuance until May 23, 2015, 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 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 Paul Bartlett, or me at [phone].
Sincerev,!
Ed Beck'2"�
Regional Supervisor
Surface Water Protection Section
ENB/ptb: S:\WQS\STORMWATER\PERMIT\050427
cc: Criser Troutman Tanner Consulting Engineers
Tony Roberts, New Hanover County Building Inspections
City of Wilmington Stormwater Services
Beth Ec Wetherill, New Hanover County Engineering
Division of Coastal Management
Paul T:;Bartlett, P.E.
lWilmin`gton_Regional Office
Central Files
North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone [phone] Customer Servicel-877-623-6748
Wilmington Regional Office Wilmington, NC 28405-3845 FAX [phone] Internet h2o encstate.nc us One
N0CCh{al[ j/CaCO/1/1R3
An Equal Opportunity/Affirmative Action Employer— 50% Recycled/l0% Post Consumer Paper Naturally

State Stormwater Management Systems
Permit No. SW8 050427
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
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
Mr. Sterling B. Cheatham and the City of Wilmington
North Riverfront Parking Garage
New Hanover County
FOR THE
construction, operation and maintenance of an underground infiltration trench 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 May 23, 2015, 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.
This stormwater system has been approved for the management of stormwater
runoff as described in Section 1.6 on page 3 of this permit. The stormwater
control has been designed to handle the runoff from 67,340 square feet of
impervious area. This trench is designed for a 2-inch storm event and
stormwater in excess of the 2-inch event bypasses the trench and discharges to
the City stormwater system.
3. The tract will be limited to the amount of built -upon area indicated on page 3 of
this permit., and per approved plans. The built -upon area for the future
development is limited to 67,340 square feet.
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.
5. The runoff.'from all built -upon area within the permitted drainage area of this
project must be directed into the permitted stormwater control system.
Page 2 of 7

State Stormwater Management Systems
Permit No. SW8 050427
6. The following design criteria have been provided in the infiltration trench and
must be maintained at design condition:
a. Drainage Area, acres: 1.55
On'site, ft2: 67,340
Offsite, ft2: none
b. Total Impervious Surfaces, ft2: 67,340
C. Design Storm, inches: 2.0
d. Trench Dimensions, L x W x H, ft: 125 x 31 x 4.8
e.
Perforated Pipe Diameter/Length: 3.5'0/125'
(80 StormChamber units at 115 ft3 storage capacity each, or equivalent)
Bottom Elevation. FMSL:
Bypass Weir Elevation, FMSL:
Permitted Storage Volume, ft3:
Type of Soil:
Expected Infiltration Rate, in/hr:
Seasonal High Water Table, FMSL:
Time to Draw Down, hours:
Receiving Stream/River Basin:
Stream Index Number:
Classification of Water Body:
II. SCHEDULE OF COMPLIANCE
23.92
28.75
10,662
Sand
9.1
21
3.6
Cape Fear River / Cape Fear
18-74-(61)
"SC; Sw"
1. 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. Immediate repair of eroded areas.
d. Maintenance of all slopes in accordance with approved plans and
specifications.
e. Debris removal and unclogging of bypass structure, filter media, flow
spreader, catch basins, and piping.
f. A clear access path to the bypass structure must be available at all times.
g. No chemicals added to the solution for pressure -washing surfaces.
} Page 3 of 7

State Stormwater Management Systems
Permit No. SW8 050427
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. 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.
6. 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.
7. 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 occupancy of the facility.
8. Access to the stormwater facilities shall be maintained via appropriate
easements at all times.
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.
e. Further subdivision, acquisition, lease 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.
10. The permittee shall submit final site layout and grading plans for any permitted
future areas shown on the approved plans, 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. The Director may notify the permittee when the permitted site does not meet one
or more of1he minimum requirements of the permit. Within the time frame
specified ih 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.
Page 4 of 7

State Stormwater Management Systems
Permit No. SW8 050427
III. GENERAL CONDITIONS
This permit is not transferable except after notice to and approval by the Director.
In the event of a change of ownership, or a name change, the permittee 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.
3. 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) having 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.
7. Unless specified elsewhere, permanent seeding requirements for the stormwater
control must follow the guidelines established in the North Carolina Erosion and
Sedimenf'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 23rd day of May 2005.
NORTHtAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
,44 Alan imek, P.E., Director
Division of,. Water Quality
By Authority of the Environmental Management Commission
i
1
Page 5 of 7

State Stormwater Management Systems
Permit No. SW8 050427
North Riverfront Parking Garage
Stormwater Permit No. SW8 050427
New Hanover County
Designer's Certification
I, , as a duly registered
in the State of North Carolina, having been authorized to observe
full time) the construction of the project,
(Project)
(periodically/ weekly/
for I (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.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specification:
Signature
Registration Number
Date
SEAL
Page 6 of 7

State Stormwater Management Systems
Permit No. SW8 050427
Certification Requirements:
1. The drainage area to the system contains approximately the permitted
acreage.
2. The drainage area to the system contains no more than the permitted
amount of built -upon area.
3. All the built -upon area associated with the project is graded such that the
runoff drains to the system.
4. All roof drains are located such that the runoff is directed into the system.
5. The bypass structure elevations are per the approved plan.
6. The bypass structure is located per the approved plans.
7. A Trash Rack is provided on the outlet/bypass structure.
8. All slopes are grassed with permanent vegetation.
9. Vegetated slopes are no steeper than 3:1.
10. The inlets are located per the approved plans and do not cause short-
circuiting of the system.
11. The permitted amounts of surface area and/or volume have been
provided.
12. All required design depths are provided.
13. All required parts of the system are provided.
14. The required system dimensions are provided per the approved plans.
cc: NCDENR-DWQ Regional Office
Tony Roberts, New Hanover County Building Inspections
Page 7 of 7

"Y
OFFICE USE ONLY
Date Received
Fee Paid
Permit Number
2"l D'�D
4b1)b 0
2
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project):
G1Tf o'F Wit_M/NGTOAL
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
S1'E2Llt4Cr 5. CM64r"M ., GIT%( MAQ.MAGF-9
3. Mailing Address for person listed in item 2 above:
'P. o . P-nt�- 191 a
City: VtjILMJrj6--rOIJ State: /SIG Zip: Z8402-
Telephone Number: ( mil O )
4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
A1ccrm 21vEZtgz-*lT 'PARK►& G-,RA,GF_
5. Location of Project (street address):
. ` "rJpVffjZ
6. Directions to project (from nearest major intersection):
P2cP�2T`C AT In1'r stil of Z9-L&Oz 110G, Ar1D ScCt� lD
5T2=�S
Q 1
7. Latitude:_ f�_ 4 14 44 Longitude: W V S& 55 of project
8. Contact person who can
}answer questions about the project:
Name: /)AA o V l • �t�C�t�fc.! t ' Telephone Number.
II. PERMIT INFORMATION:
1. Specify whether project is (check one):
FormSWU-101 Version3.99
_New
Page I of 4
Renewal Modification

2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the
existing permit number and Its issue date (if known)
3. Specify the type of project (check one):
Low Density High Density _Redevelop _General Permit _Other
4. Additional Project Requirements (check applicable blanks):
_CAMA Major X Sedimentation/Erosion Control _404/401 Permit _NPDES Stormwater
Information on required state permits can be obtained by contacting the Customer Service Center at
1-877-623-6748.
in. PROJECT INFORMATION
1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative
(one to two pages) describing stormwater management for the project.
�So2M�w1 kTdL i5 CAEM . Vri 2ST rwo. t mcAeS W i tL 1 t'J'Fl �'_T9&TLw
C CA91h N/IJILle WPA46 'T'O GtTY STo2MWAIT-r. ' 10 S-MC- T.
2. Stormwater runoff from this project drains to the <:AP% FE d2 River basin.
3. Total Project Area: -7 acres 4. Project Built Upon Area: g'?• 1n.%
5. How many drainage areas does the project have? 1
6. Complete the following information for each drainage area. If there are more than two drainage areas in the
project, attach an additional sheet with the information for each area provided in the same format as below.
Basin Information
Drainage Area 1
Drainage Area 2
Receiving Stream Name
GAa QJVr;AQ1
Receiving Stream Class
St=l
Drainage Area
(0'7 2>40 SF
Existing Impervious' Area
G -rO M Ao
Proposed Impervious*Area
"J 40
% Impervious' Area (total)
1 CO
Impervious` Surface Area
Drainage Area 1
Drainage Area 2
On -site Buildings
'734.p 61-
On -site Streets
On -site Parking
On -site Sidewalks
Other on -site
Q
Off -site
Total: &7 1.0 5.1P
Total:
Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
Form SWU-101 Version 3.99
Page 2 of 4

7. How was the off -site impervious area listed above
L►rI��1�L�1 Ali �71i•7 (� Ii [�PiyJ►il7 •i:Liy � �illi►l �K�Pi �I� I:�►Y i.9
The following italicized deed restrictions and protective covenants are required to be recorded for all
subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table
listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment.
1. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number
as Issued by the Division of Water Quality. These covenants may not be
changed or deleted without the consent of the State.
2. No more than square feet of any lot shall be covered by structures or impervious materials.
Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood
decking or the water surface of swimming pools.
3. Swales shall not be filled in, piped, or altered except as necessary to provide driveway crossings.
4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to
construction.
5. All permitted runoff from outparcels or future development shall be directed into the permitted stormwater control
system. These connections to the stormwater control system shall be performed in a manner that maintains the integrity
and performance of the system as permitted.
By your signature below, you certify that the recorded deed restrictions and protective covenants for this project
shall include all the applicable items required above, that the covenants will be binding on all parties and persons
claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted
without concurrence from the State, and that they will be recorded prior to the sale of any lot.
V. SUPPLEMENT FORMS
The applicable state stormwater management permit supplement form(s) listed below must be submitted for each
BMP specified for this project. Contact the Stormwater and General Permits Unit at [phone] for the status
and availability of these forms.
Form SWU-102
Wet Detention Basin Supplement
Form SWU-103
Infiltration Basin Supplement
Form SWU-104
Low Density Supplement
Form SWU-105
Curb Outlet System Supplement
Form SWU-106
Off -Site System Supplement
Form SWU-107
Underground Infiltration Trench Supplement
Form SWU-108
Neuse River Basin Supplement
Form SWU-109
Innovative Best Management Practice Supplement
Form SWU-I01 Version 3.99
Page 3 of 4

A
VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ).
A complete package includes all of the items listed below. The complete application package should be
submitted to the appropriate DWQ Regional Office.
1. Please indicate that you have provided the following required information by initialing in the space provided
next to each item.
Initials
• Original and one copy of the Stormwater Management Permit Application Form —AATA
• One copy of the applicable Supplement Form(s) for each BMP WnT t
• Permit application processing fee ofA4W(payable to NCDENR) � 4'000 A T&
• Detailed narrative description of stormwater treatment/management AMA.
• Two copies of plans and specifications, including: AATA•
- Development/Project name
- Engineer and firm
-Legend
- North arrow
- Scale
- Revision number & date
- Mean high water line
- Dimensioned property/project boundary
- Location map with named streets or NCSR numbers
- Original contours, proposed contours, spot elevations, finished floor elevations
- Details of roads, drainage features, collection systems, and stormwater control measures
- Wetlands delineated, or a note on plans that none exist
- Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations
- Drainage areas delineated
- Vegetated buffers (where required)
VIL AGENT AUTHORIZATION
If you wish to designate authority to another individual or firm so that they may provide information on your
behalf, please complete this section.
Mw2y, T RRc�l21 Qlp�
Designated agent (individual or firm): GQ Yt;F,9 7lZWVMAO TANNE< Ccros . F-i.IG
Mailing Address: .+�1 FEA0+ —ZeE L1,LE. St11TE_ (OZ
City: W ILM f/J`oTp^( State: NG Zip: Z84'O3
Phone: ( 910 ) 39 7 — 2 9 Z9 Fax:( ar 10 ) S97 - 29 7
VIII. APPLICANT'S CERTIFICATION
I, (print or type name of person listed in General Information, item 2) S-r,-V_L, n) C.'9 _ GWATHA^9
certify that the information included on this permit application form is, to the best of my knowledge, correct and
that the project will be constructed in conformance with the approved plans, that the required deed restrictions
and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A
NCAC 2H .1000. n
Form SWU-101 Version 3.99 Page 4 of
.N.

.,
i.
�,

Permit No. SW � C)6 C)4,ZI-
(to be provided by DWQ)
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
UNDERGROUND INFILTRATION TRENCH SUPPLEMENT
This form may be photocopied for use as an original
DWO Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a stormwater management permit application, an
underground infiltration trench supplement for each system, design calculations, and plans and specifications
showing all stormwater conveyances and system details.
I. PROJECT INFORMATION
Project Name : NftrL'r1.4 TIL�i-A f4a G;h-T-? v
Contact Person: NAA Qlr, T. A.i2c.-t l Rlo PE Phone Number: (q1D ) 39 %- Z9 Z9
For projects with multiple infiltration systems, a supplement form must be completed for each system. This
worksheet applies to: Trench
(from plam)
in Drainage Area WA-5W ecs..E
(from Form SWU-101) sYSfE M
H. DESIGN INFORMATION (attach supporting calculations/documentation):
Soils Report Summary (based upon an actual field investigation and soil borings)
Soil Type 5ANr->
Infiltration Rate 9. t ri779*1ir cf/hr/sf (circle appropriate units)
SH WT Elevation 444F- S 1S.0- Z-1. o W (Seasonal High Water Table elevation)
i\I.vt> a5?
Trench Design Parameters
Design Volume ► 0' 44 aL- c.f.
Design Storm inch event (1.5 inch event for SA waters, 1 inch event for others)
Drawdown Time days H-bUJZS
Perforated Pipe Size AQLI+ inch diafa@w- 60 'BASF- - 34p 1- e C-++T
Perforated Pipe Length 1 Z5 ft. X 5 R#.'W:j = GZ5;1=-r 'rcq-^J-
No. Observation Wells (may be required on a case -by -case basis)
Stone Type (if used)
Stone Void Ratio 4-CP110
Trench Elevations (in feet mean sea level)
Bottom Elevation
Storage/Overflow Elevation
Z-SR7, fmsl
Z4•75 frisl
Fam SWU-107 Rev 3.99 Page 1 of 4

• � .,•` � �. _ . �... �. ,. .,. •. r
.4 �
..

Trench Dimensions }Q
Height � ft. Length l ZS ft.
Width _'31 ft. Volume Provided V0166 + cu.ft.
III. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual (N.C.
Department of Environment, Health and Natural Resources, November 1995) and Administrative Code Section: 15
A NCAC 2H .1008.
Initial in the space provided to indicate that the following design requirements have been met and supporting
documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit
Application Form, the agent may initial below. Attach justification if a requirement has not been met.
Applicants Initials
MTA a. System is located 50 feet from class SA waters and 30 feet from other surface waters.
f CU r� _ b. System is located at least 100 feet from water supply wells.
FiXt A c. Bottom of system is at least 2 feet above the seasonal high water table.
d. Bottom of the system is 3 feet above any bedrock or impervious soil horizon.
Al' h e. Off-line system, runoff in excess of the design volume bypasses the system (bypass detail
provided).
Afcl—:- f. System is designed to draw down the design storage volume to the proposed bottom
elevation under seasonal high water conditions within five days based upon infiltration
through the bottom only (a hydrogeologic evaluation may be required).
WA g. Soils have a minimum hydraulic conductivity of 0.52 inches per hour.
AWA h. System is not sited on or in fill material or DWQ approval has been obtained.
/M _ i. Plans ensure that the installed system will meet design specifications (constructed or
restored) upon initial operation once the project is complete and the entire drainage area is
stabilized.
!Z�L— j. System is sized to take into account the runoff at the ultimate built -out potential from all
surfaces draining to the system, including any off -site drainage.
iJA k. System is located in a recorded drainage easement for the purposes of operation and
maintenance and has recorded access easements to the nearest public right-of-way.
1. System captures and infiltrates the runoff from the first inch of rainfall (1.5 inch event
for areas draining to SA waters ). 0.0
WA in. Drainage area for the device is less than 5 acres.
AA n. A pretreatment device ( filter strip, grassed swale, sediment trap, etc.) is provided.
AkrA o. Trench bottom is covered with a layer of clean sand to an average depth of 4 inches.
AM p. Sides of the infiltration trench are lined with geotextile fabric.
AMR q. Rock used is free of fines (washed stone) and has a large void ratio.
&& r. Side to bottom area ratio is less than 4:1.
Fom SWU-107 Rev 3.99 Page 2 of 4

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s. Observation well(s) are provided (case -by -case basis).
WA t. Vegetated filter is provided for overflow (50 feet for SA waters, 30 feet for other waters)
and detail is shown on plans.
MIA u. A benchmark for checking sediment accumulation is provided.
IV. UNDERGROUND INFILTRATION TRENCH OPERATION AND MAINTENANCE AGREEMENT
1. After every runoff producing rainfall event and at least monthly inspect the bypass/overflow structure for
blockage and deterioration and the infiltration system for erosion, trash accumulation, grass cover, and general
condition.
2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetative
cover to maintain a maximum height of six inches, and remove trash and blockages as needed to maintain
system performance.
3. Remove accumulated sediment annually or when depth is reduced to 75% of the original design depth. Restore
depth to original design depth without over -excavating. Over -excavating may cause the required water table
separation to be reduced and may compromise the ability of the system to perform as designed.
4. The water level in any monitoring wells will be recorded after a 1 inch rainfall event and at least once a month.
Chronic high water table elevations (within 1 foot of the bottom of the system for a period of three months)
shall be reported to DWQ immediately.
5. If DWQ determines that the system is failing, the system will immediately be repaired or replaced to original
design specifications. If the system cannot be repaired to perform its design function, other stormwater control
devices as allowed by NCAC 2H .1000 must be designed, approved and constructed.
6. Remove accumulated sediment from the infiltration system annually or when depth in the unit is reduced to
75% of the original design depth. The system shall be restored to the original design depth without over -
excavating. Over -excavating may cause the required water table separation to be reduced and may
compromise the ability of the system to perform as designed. Removed sediment shall be disposed of in an
appropriate manner and shall not be handled in a manner that will adversely impact water quality (i.e.
stockpiling near a stormwater treatment device or stream, etc.).
A benchmark shall be established in the infiltration system. The benchmark will document the original
design depth so that accurate sediment accumulation readings can be taken. The measuring device used to
determine the depth at the benchmark shall be such that it will give an accurate depth reading and not
readily penetrate into accumulated sediments.
When the depth at the benchmark reads 2lr3 the accumulated sediment shall be removed
from the system.
I%1 T a"M6�IT AtI-r To 'ems 12 SUMP I►J Dom- sPAAJ1 TtW
Si2u�tU2E . lF:Neod To BE. emfakre -rw.
Fom SWU-107 Rev 3.99 Page 3 of 4

.. ., . -,-
I acknowledge and agree by my signature below that I am responsible for maintaining the stormwater
collection system in accordance with the six maintenance procedures listed above. I agree to notify DWQ
of any problems with the system or prior to any changes to the system or responsible party.
Print Name and Title: $TEfZUM r B. G44eAM4,&A t C-IT`f MANAAZX
Address: ?O. FiOi( 1191 O kl 1LMr1JCe�Dp� i ►., 2$4D2
Date: 1/ - 2 ° - 05,
Note.' The legally responsible parry should not be a homeowners association unless more than 50% of the lots have been sold and a
resident of the subdivision has been named the president.
I� a Notary Public for the State of 1 D1 +1' \ County of my,
IVY t 1 do hereby certify that (if' 1 _personally appeared before me this�V
day of and acknowledge t4c due execution of the forgoing infiltration basin maintenance
requirements. Witness my hand and official seal, 60&Av'�
SEAL My commission expires -7
40ig
- REBECCA BLUE'
p ° NOTARY ?UBLIC
r 4EW HANO'lER QU C .
�M�mmission Expires �`
Form SWU-107 Rev 3.99 Page 4 of 4

TRANSMITTAL LETTER
C R I S E R
TROUTMAN
TANNER
TO.
FROM:
T. Arcuri,
A
Paul Bartlett, PE
Mark PE
-
COMPANY.
DATE:
NCDENR - SW
May 18, 2005
ADDRESS:
CRISER & TROUTMAN'S PROJECT NUMBER:
Cardinal Drive
5446
Wilmington, NC
PHONE NUMBER:
CLIENT'S REI'ERENCE NUMBER:
395-3900
AE:
North Riverfront Parking Garage
MAy���
Stormwater Application Revisions
S W
WE TRANSMIT: ❑ ATTACHED ❑ UNDER SEPARATE COVER ❑ HAND CARRIED BY ❑ UPS/FEDEX
THE. FOLLOWING: ❑ TRACINGS ❑ PRINTS ❑ INSPECTIONREPORT ❑ SHOP DRAWINGS ❑ SPECIFICATIONS ❑ OTHER
COPIES
DATE
SHEET
DESCRIPI'ION
REMARKS
I COPY
NARRATIVE — NO CALCS
2 COPIES
C1.2
SITE LAYOUT AND UTILITY PLAN
GRADING, EROSION CONTROL &
2 COPIES
C1.3
STORMWATER PLAN
2 COPIES
C2.1
SITE AND PAVEMENT DETAILS
EROSION CONTROL & STORMWATER
2 COPIES
C2.3
DETAILS
In response to your comment letter, we have the following responses, numbered respectfully with your
comments,
1. Sheet C1.2 —Scale added, lane width corrected, parking space is dimensioned, and the boundary information is now
shown either on the property lines or in the curve data table.
2. Sheet C1.3 —The twin pipes are labeled and DI10 is corrected.
3. Sheet C2.3
a. Invert El added for bypass pipe
b. Invert Els added for inflow pipes and trench bottom
c. H-20 note added
d. Length and width of the system has been corrected. The single unit dimension was correct —see the product
literature submitted initially concerning difference in single unit length and laying length.
Also, see narrative with updated information concerning landscaping, hardscape, and sidewalks outside the building.
cc: John Farabow (2 copies of all)
CRISER TROUTMAN TANNER CONSULTING ENGINEERS
Post Office Box 3727 Wilmington, NC 28406 13809 Peachtree Ave. Suite 102 Wilmington, NC 28403 p 910.397.2929 f 910.397.2971
Email: unircun na cttengineering.com

STORMWATER NARRATIVE
AND DRAINAGE CALCULATIONS
Project:
NORTH RIVERFRONT PARKING GARAGE
Location:
Bounded by:
Front, Second, and Brunswick Streets
Wilmington, North Carolina
New Hanover County
Prepared for:
City of Wilmington
PO Box 1810
Wilmington, NC 28402
Prepared by:
Mark T. Arcuri, PE
Criser Troutman Tanner Consulting Engineers
3809 Peachtree Avenue
Suite 102
Wilmington, NC 28403
April 27, 2005
Revised: May 18, 2005 NCDENR Stormwater
CTT Project 5446.00
CEIV
D
Y 1 57c�o
BYE
0f

TABLE OF CONTENTS
Narrative.........................................................................................................1
Drainage Hydrograph Summary Reports ................................................ 2-3
StormDrain Layout........................................................................................4
Wier HGL Calculations.................................................................................4A
10 Year Storm Drain Tabulation...................................................................5
10 Year Storm Drain HGL Profiles........................................................6 -16
50 Year Storm Drain Tabulation................................................................ 17
50 Year Storm Drain HGL Profiles......................................................18 - 28
15" Bypass Pipe Sizing............................................................................... 29
Infiltration System Sizing and Drawdown...........................................30 - 31
Stormchamber Product Literature......................................................32 - 35
Pre and Post Development Runoff Comparison ....................................... 36

STORMWATER NARRATIVE
Revised information is bold and italicized
GENERAL
The City of Wilmington wishes to construct a parking garage as part of the Northern
Downtown Revitalization Effort. The existing property is 1.579 acres. Also, The City will be
realigning the intersection of Second and Front Streets to be a "Tee" configuration to
provide for safer traffic flow in the area. With this realignment, there will be additional
property converted from City of Wilmington Road Right of Way to be appended to the subject
property area (also owned by The City). The additional acreage will be approximately 0.141
acres and will result in a new project property area of 1.720 acres (74907 square feet).
EXISTING SITE FEATURES
The site is currently a parking lot all paved, and currently used by Cape Fear Commui
College. torm ramage in the Public Road Rights of Way exists at the intersection of
Br snu wick and Front Streets. This storm drainage is directed to The Cape Fear River.
Topography across the site is down from east to west.
A March 15, 2005 report by S&ME revealed an infiltration rate of 9.1 inches per hour.
PROPOSEDIMPROVEMENTS
The parking garage will be six stories. It will result in 67,340 SF of impervious surface on
the property, resulting in a built upon area of 90%. Remaining areas between the garage
building and the property line will be landscaped contain a combination of landscaping,
hardscape, and sidewalks. Roof drains from the top deck will be routed down along
columns and sheer walls to below the bottom floor elevation. From there, they will be
collected in a storm drain system under the first floor pavement and routed to a flow
separation structure, below ground. This structure will direct the first flush (2") to an
underground infiltration system. The separation structure will cause the runoff in excess of
the first two inches to bypass the infiltration system and flow to the aforementioned storm
drains in the City Road Right of Way. The infiltration system will be at least 2 feet above the
seasonal high water table. The system will utilize plastic arched domes for the core of the
infiltration system. The arches will be encased in #4 stone (1" grain size). The entire
system will then be wrapped in filter fabric.
As required by The City of Wilmington, storm drains will be sized to convey the 10-year storm
flow and prevent flooding during the 50-year storm flow.

Mar 17 05 02:38p Criser Troutman Tanner
[phone] p.2
INFILTRATION SITE VISIT REQUEST
Name of the Project :_No
Location (attach a clear vicinity map):
i LAA u.IG'rCWA —
address, SA number, community, etc.
Directions from the nearest major intersection: -'-Zowt US 76P (W eoSte-tL�
�4,v� US d-ZI QfZoG�� f�ozTti- 's'o ,Zu►�15uilGr'� sT
fiti l LiEFST . e t TF is c po j t_ 13 rx K 04 -t-N-r 2tc ItT.
Owner/Applicant Name: G tT`f Or W t LM 104*Zt tJ
Consultant Name:--,--j'LlS�t'L Ti2orlTNt�J Td,. Mcir, MArzIL AfZetCf2
Consultant Contact Information: Vk . 9I~7
Phorie,
Existing ground elev. @basin/trench=
Bottom Elev. of infiltration basin/trench=
Existing ground minus bottom elev.=
Add 2' (max. bottom elevation)=
Z47-
etc.
#1 #2 #3 #4 #5 #6 #7 #8
Date/Time of Soils Investigation : TkA o MARC f 2¢ 9 c')M .
Summarize results of Investigation:
Please have all basins and existing, active utility lines located within the proposed
basin/trench areas marked. If these areas are not marked, the Soils Scientist reserves the
right to decline to do the investigation. The soils investigation does not take the place of a
soils report prepared by an appropriate professional. The Soils Scientist will only verify the
soil conditions that are reported in the required Soils Report, and assumes no liability should
the system fail.

Mar 17 05 02:38p Criser Troutman Tanner
[phone] p.3
1
1
f
,
l
1
A

Mar 17 05 02:38p Criser Troutman Tanner
[phone] p.4
PROPOSED PROPERTY /+DJJ5TME4T
J
/ I
EXISTING PROPERTY LME
I ,\
1
I
1
/ 1
I
1
1 `
I
I
I
1
I
t
0RUA6MCh S EET/
LEGEND
• Approximate Location
of Infiltrometer Testing
SCALE: NOT TO SCALE
CHECKED BY: MWBS =1
DRAWN BY: JNS
ENGINEERING • TESTING
DATE: 3-1405 ENVIRONMENTAL SERVICES
I—
W
y
WW
Note: Site plan drawing provided to SBME
by H.R. Associates personnel.
INFILTROMETER TESTING Figure
NORTH RIVERFRONT PARKING GARAGE Number
BRUNSWICK STREET
WILMINGTON, NORTH CAROLINA 1
JOB NUMBER: 106"5-085

P. 01
TRANSACTION REPORT
APR-28-2005 THU 04:10 PM
FOR:
DATE START RECEIVER
APR-28 04:09 PM 93972971
TX TIME PAGES TYPE NOTE
58" 3 SEND OK
TOTAL : 58S PAGES: 3
State of North Carolina
Department of Environment and Natural Resources
Wilmington Regional Office
Michael F. Easley, Governor
FAX COVER SHEET
Date:
4/28/05
To:
Mark Arcuri
Company:
Criser Troutman Tanner
FAX #:
910-397-2971
M# DP
222
William G. Ross, Jr., Secretary
No. of Pages: 3 (Incl. Cover)
From: Paul Bartlett
Water Quality Section -
Stormwater
FAX #: [phone]
Phone #: [phone]
DWQ Stormwater Project Number: SW8 050427
Project Name: North Riverfront, Parking Garage
MESSAGE:
Mark,
A Request for Additional Information is attached for the referenced project. The original
will be mailed to Mr. Cheatham, and a copy will be mailed to you.

A
State of North Carolina
Department of Environment and Natural Resources
Wilmington Regional Office
Michael F. Easley, Governor
FAX COVER SHEET
Date: 4/28/05
To: Mark Arcuri
Company: Criser Troutman Tanner
FAX #: [phone]
William G. Ross, Jr., Secretary
No. of Pages: 3 (Incl. Cover)
From: Paul Bartlett
Water Quality Section -
Stormwater
FAX #: [phone]
Phone #: [phone]
DWQ Stormwater Project Number: SW8 050427
Project Name: North Riverfront Parking Garage
MESSAGE:
Mark,
A Request for Additional Information is attached for the referenced project. The original
will be mailed to Mr. Cheatham, and a copy will be mailed to you.
/�X2-r/9
ENB\ptb: S:\WQS\STORMWATER\ADDINFO\2005\050427
127 Cardinal Drive Extension, Wilmington, NC 29405-3845 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer

o�QF W ATF9oG
r
1 y
Michael F. Easley, Governor
William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
April 28, 2005
Mr. Sterling B. Cheatham,
City of Wilmington
P.O. Box 1810
Wilmington, NC 28402
City Manager
Subject: Request for Additional Information
Stormwater Project No. SW8 050427
North Riverfront Parking Garage
New Hanover County
Dear Mr. Cheatham:
The Wilmington Regional Office received a Stormwater Management Permit Application for
North Riverfront Parking Garage on April 27, 2005. 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 label the scale on Drawl/g Cl.2, correct the dimension for lane width
between parking spaces (24' vs. 30' if 1" 3,"30' scale), dimension a typical parking
space,,width, and confirm the eastern property line dimension of 250.3'.
Please label on Drawing C1 either "(2) 15" RCP" for the pip n between D11
and the Infiltration Syste or show 2 pipes. Please corr DIO" to read "D110"
on Drawing C1.3.
Please make the following modifications to Drawing C2.3:
✓(a) Label the invert elevation for the 15" RCP Bypass Out on the DI1 Drop Inlet
detail,
fib) Label the invert elevations for the Inflow PiDes and the trench bottom
elevation on�ie Infi ra Ion System trench cross section,
✓ Icl Provide a note for the Infiltration System details stating that the design has an
H-20 load capacity for vehicular traffic,
V(d) Correct the overall width and length for the 5 unit by 16 unit Infiltration system
detail and correct the length for the single unit Infiltration System detail.
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 May 5, 2005, or the
application will be returned as incomplete. The return of a project will necessitate resubmittal of
all required items, including the application fee.
North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone [phone] Customer Services-877-623-6748
Wilmington Regional Office Wilmington, NC 28405-3845 FAX [phone] Internet: h2oenrstatencus One
NprthCarolina
An Equal QpportunitylAffirmatve Action Employer— 50 % Recycled110% Post Consumer Paper aturallU

Mr. Sterling B. Cheatham
April 28, 2005
Stormwater Application No. SW8 050427
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 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.
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].
Since,fely,
J
Paul T. Bartlett, P.E.
Environmental Engineer
ENB/ptb
cc:
S:\WQS\STORMWATER\ADDINFO\2005\050427
J
Criser Troutman Tanner Consulting Engineers
Paul Bartlett
Page 2 of 2

Apr 28 05 07:55a Criser Troutman Tanner
[phone]
p.1
FAX MEMORANDUM
M
C R I S E R
TROUTMAN
TANNER
TO+
PAUL BARTLET
rROM:
Mark T. Arcoai, PE 44
COMPANY:
DATE:
NCDENR - SW
April 28, 2005
FAX NUMBER:
TOTAL NO. OF PAGES INCLUDING COVER
350-2004
5
PHONE NUMBER:
CRISER h TROUTMAN'S PROJECT NUMBER:
395-39W
54"
RE:
CLIENTS REIFF.RENCE NUMBER:
NoNh Riverfront Paticing Garage
InSlnation Teat Resuhs
❑ URGENT ❑ FORRL•'VIEW ❑ PLEASE COMMENT ❑ PLEASE REPLY ❑ FOR YOUR INFORMATION
NOTES/COMMENTS:
Here are the test results - forgot to include them in the application package. Look forward to healing from you.
Thanks.
pP �ac��o
S n >�
CRISER TROUTMAN TANNER CONSULTING ENGINEERS
Post Office Box 3727 Wilmington, NC 28406 1 3809 Peachtree Ave. Suite 102 Wilmington, NC 28403 p 910.397.2929 /910.397.2971
r.....u.

TopoZone - The Web's Topographic Map ��/� C,«%(r� .�em,�s Page I of 1
SW� rrw�aw d� NQsSc.k. IbcRaic°'ier:
•u
�
-
�"
MEM
�.—
rr
M*
0 0.3 0.6 0.9 1.2 1.5 km
0 0.1 0.2 0.3 0.4 0.5 mi
Map center is 340 14' 42"N, 770 56' 55"W (WGS84/NAD83)
Wilmington quadrangle M--8.964
Projection is UTM Zone 18 NAD83 Datum G--1.661
http://www. topozone. com/print. asp?z=18&n=379325 5.85245018&e=228442.100082917&... 4/28/2005

TRANSMITTAL LETTER I � � TROUTMAN
TANNER
to
Linda Lewis
FROM.
Mark T. Arcud, PE
COMPANY.
DATE:
NCDENR - SW
April 27, 2W5
ADDRFSS:
CRISER&TROUTMAN'S PROJECT'
NUMBER:
Cardinal Drive
5446
Wilmington, NC
PHONE NUMBER:
CLIENT'S REFERENCE NUMBER:
vj�
+ ji
395-39W
RE:
North Riverfront Parking Garage
Stormwater Application
)i
WE'IRANSMCf: ❑ ATTACHED ❑ UNDER SEPARATE COVER ❑ HAND CARRIED BY ❑ UPS/ILEX
THE FOLLOWING ❑ TRACINGS ❑ PRINTS ❑ INSPECTION REPORT ❑ SI40P DRAWINGS ❑ SPECIFICATIONS ❑ OTHER
COPIES
DATE
SI IEET
DESCRIPTION
REMARKS
1 ORIG & 1
COPY
STORMWATER MANAGEMENT PERMIT APP
1 ORIG
INFILTRATION TRENCH SUPPLEMENT
PERMIT APP FEE - CK#186906 - $4,000
1 COPY
NARRATIVE AND CALCS
2 COPIES
CL2
SITE LAYOUT AND UTILITY PLAN
2 COPIES
C1.3
GRADING, EROSION CONTROL &
STORMWATER PLAN
2 COPIES
C2.1
SITE AND PAVEMENT DETAILS
2 COPIES
C2.3
EROSION CONTROL & STORMWATER
DETAILS
2
ASS
NOTES/COMMENTS:
CC: JOHN FARABOW (2 COPIES OF ALL)
'
by:—
CRISER TROUTMAN TANNER CONSULTING ENGINEERS
4
Post Office Box 3727 Wilmington, NC 28406 1 3809 Peachtree Ave. Suite 102 Wilmington, NC 28403 p 910.397.2929 f 910.397.2971
Email: marcuri(aictteneineerine.com

STORMWATER NARRATIVE
Project:
NORTH RIVERFRONT PARKING GARAGE
Location:
Bounded by:
Front, Second, and Brunswick Streets
Wilmington, North Carolina
New Hanover County
Prepared for:
City of Wilmington
PO Box 1810
Wilmington, NC 28402
Prepared by:
Mark T. Arcuri, PE
Criser Troutman Tanner Consulting Engineers
3809 Peachtree Avenue
Suite 102
Wilmington, NC 28403
April 27, 2005
CTT Project 5446.00
Apr-,( 2V&Z ;

TABLE OF CONTENTS
Narrative.........................................................................................................1
Drainage Hydrograph Summary Reports ................................................ 2-3
StormDrain Layout........................................................................................4
WierHGL Calculations.................................................................................4A
10 Year Storm Drain Tabulation...................................................................5
10 Year Storm Drain HGL Profiles........................................................6 -16
50 Year Storm Drain Tabulation................................................................ 17
50 Year Storm Drain HGL Profiles......................................................18 - 28
15" Bypass Pipe Sizing............................................................................... 29
Infiltration System Sizing and Drawdown...........................................30 - 31
Stormchamber Product Literature......................................................32 -35
Pre and Post Development Runoff Comparison ....................................... 36

STORMWATER NARRATIVE
GENERAL
The City of Wilmington wishes to construct a parking garage as part of the Northern
Downtown Revitalization Effort. The existing property is 1.579 acres. Also, The City will be
realigning the intersection of Second and Front Streets to be a "Tee" configuration to
provide for safer traffic flow in the area. With this realignment, there will be additional
property converted from City of Wilmington Road Right of Way to be appended to the subject
property area (also owned by The City). The additional acreage will be approximately 0.141
acres and will result in a new project property area of 1.720 acres (74907 square feet).
EXISTING SITE FEATURES
The site is currently a parking lot, all paved, and currently used by Cape Fear Community
College. Storm drainage in the Public Road Rights of Way exists at the intersection of
Brunswick and Front Streets. This storm drainage is directed to The Cape Fear River.
Topography across the site is down from east to west.
A March 15, 2005 report by S&ME revealed an infiltration rate of 9.1 inches per hour.
PROPOSEDIMPROVEMENTS
The parking garage will be six stories. It will result in 67,340 SF of impervious surface on
the property, resulting in a built upon area of 90%. Remaining areas between the garage
building and the property line will be landscaped. Roof drains from the top deck will be
routed down along columns and sheer walls to below the bottom floor elevation. From
there, they will be collected in a storm drain system under the first floor pavement and
routed to a flow separation structure, below ground. This structure will direct the first flush
(2") to an underground infiltration system. The separation structure will cause the runoff in
excess of the first two inches to bypass the infiltration system and flow to the
aforementioned storm drains in the City Road Right of Way. The infiltration system will be at
least 2 feet above the seasonal high water table. The system will utilize plastic arched
domes for the core of the infiltration system. The arches will be encased in #4 stone (1"
grain size). The entire system will then be wrapped in filter fabric.
As required by The City of Wilmington, storm drains will be sized to convey the 10-year storm
flow and prevent flooding during the 50-year storm flow.

Hydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
Rational
0.25
1
5
75
—
Post Development Landscaping
garage hydrographs rev.gpw
Return Per d: 2 Year
Wednesday, Apr 27 2005, 2:54 PM
Hydraflow Hydrographs by Intelisolve

Hydrograph Summary Report
3
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
Rational
0.31
1
5
92
—
Post Development Landscaping
garage hydrographs rev.gpw
Return Period: 10 Year
Wednesday, Apr 27 2005, 2:54 PM
Hydraflow Hydrographs by Intelisolve

Hydraflow Plan View
r�uc► NG— C—�s.-f�G� � STi
OCiEfa � 6 P�
Outfall1I ps�O
F41 1L pS2
17
� to
SflN�2 Z Qy L3 �tl
N
'ts� a' i3 TJl3 t 8
L �
f i
to q 8 4 9
UM sT 3
PO
Project file: 5446 rev with pipe els.stm No. Lines: 23 04-26-2005
Hydratlow Storm Sewers 2003
G7

DATE DESIGN CRISER & TROUTMAN sH EET
4-27--c5 lks R Wilmington, Consulting Engineers Norn Carolina �>4
OF
CHECK JOB M "121- - elf/ EL'5:'204T FOR . 1 JOE. N0.
PA-r2..1L WIS Cw C1 i � C� �A-i1 -11,�i 11JG70N 044,(p
✓1G(LM1 �E }}CL C5/15Z. WIr--2 1�j
FT
t 0-(P— . Z 3,'] 5 + =>,-7 8 = z�7. S 3 f=7
a `re.. z 8 .-1 S 4 a, 9 4 = v9 . G9 T--T

To Line In
Total Runoff Inlet Time Rnfal Total Adnl Total Capac Pipe Pipe Inv Elev In Elev HGL HGL iGrnd/Rim Grnd/Rim
Liner Veloc
Line Length Area ! Area Coeff. Time Conc Int Runoff Flow Flow Full Size Slope Up Dn Up I Dn .Up Dn
-- �-- -- -- ----- --- -- f - -- ---- --- im ------ - - el ) - -- --
(ft) (ac) l (ac) (C) (min) (mm) (in/hr) (cfs) (cfs) (cfs) (cfs) (ft/s (in) (%) (It) (ft) (ft) (ft) (ft) (ft)
-- - --- - ---------- -- -- -n) mi -- - - - ---- ?)- - - ----� - ---- '-- )
1 Outfall 59.00 0.00 0.64 0.00 0.0 21.2 4.9 3.01 0.00 3.0 366 2.45 15 0.32 27.69 27.50 29.66 29.53 31.00 31 00
2 1 89.00 0.00 0.57 0.00 0.0 20.7 5.0 2.71 0.00 2.71 3.69 2.20 15 0.33 27.98 27.69 29.95 29.80 31.00 31.00
3 2 60.00 0.00 0.40 0.00 0.0 20.1 5.0 1.92 0.00 1.92 4.25 156 15 0.43 28.24 27.98 30.12 30.07 31.20 31.00
4 3 14.00 0.00 033 0.00 0.0 20.0 5.1 1.59 0.00 1.59 4.23 1.29 15 0.43 28.30 28.24 30.17 30.16 31.00 31.20
5 4 61.00 0.00 0.33 0.00 0.0 19.3 51 1.61 0.00 1.61 4.30 1.31 15 0.44 28.57 28.30 3024 30.21 31.00 31.00
6 5 17.00 0.00 027 0.00 0.0 10.1 6.3 1.61 0.00 1.61 2.44 2.05 12 0.47 28.90 28.82 30.31 30.27 31.25 31.00
7 6 18.00 0.27 0.27 0.95 10.0 10.0 6.3 1.62 000 1.62 2.22 2.06 12 0.39 28.97 28.90 30.39 30.36 31.92 31.25
8 5 50.00 0.00 0.06 0.00 0.0 16.5 6.4 0.31 0.00 0.31 4.28 0.25 15 0.44 28.79 28.57 30.27 30.27 31.00 3100
9 8 31.00 0.00 0.03 0.00 0.0 12.9 5.9 0.17 - 0.00 0.17 4.34 0.14 15 0.45 28.93 28.79 3028 30.28 31.00 31.00
10 9 40.00 0.03 0.03 0.95 10.0 10.0 6.3 0.18 0.00 0.18 2.32 0.23 12 0.43 2935 29.18 30.28 30.28 32.50 31.00
11 8 20.00 0.03 0.03 095 10.0 10.0 6.3 0.18 0.00 0.18 4.33 0.15 15 045 28.88 28.79 3028 30.28 31.00 31.00
12 1 32.00 0.07' 0.07 0.95 10.0 10.0 6.3 0.42 0.00 0.42 2.36 0.53 12 0.44 28.08 27.94 29.80 29.80 32.05 31.00
13 2 29.00 0.17 0.17 0.95 10.0 10.0 6.3 1.02 0.00 1.02 2.38 1.30 12 045 '28.36 28.23 30.09 30.07 32.40 31.00
14 3 29.00 0.07 0.07 0.95 10.0 10.0 6.3 0.42 0.00 0.42 2.38 0.53 12 0.45 2862 28.49 30.16 30.15 31.80 31.20
15 Outfall 4400 0.00 0.92 0.00 0.0 27.9 4.4 3.84 0.00 S4 5.25 2.18 18 0.25 27.61 27.50 29.59 29 53 31.00 31.00
16 15 37.00 0.00 0.89 0.00 0.0 27.7 4.4 3.73 0.00 3.73 546 2.11 18 0.27 27.71 27.61 29.75 2970 31.00 31.00
17 16 9900 0.00 0.52 0.00 0.0 270 4.5 220 0.00 2.20 3.67 1.80 15 0.32 28.28 27.96 2997 29.85 31.00 31.00
18 17 67.00 0.00 0.18 0.00 0.0 26.2 4.5 0.77 0.00 0.77 2.34 0.99 12 0.43 28.82 28.53 30.07 3004 31.00 31.00
19 18 7400 0.01 0.01 0.95 10.0 100 6.3 006 0.00 0.06 234 0.08 12 0.43 29.14 28.82 3008 30.08 32.30 31 00
20 18 41 00 0.17 0.17 0.95 10.0 10.0 6.3 1.02 0.00 1.02 2.36 1 30 12 0.44 2900 28.82 30.12 30.08 32.03 31.00
21 15 69.00 0.03 0.03 0.95 100 100 63 0.18 0.00 0.18 2.35 0.23 12 0.43 2841 28.11 29.70 29.70 32.34 31 00
22 16 28.00 0.37 0.37 0.95 10.0 10.0 6.3 2.22 0.00 2.22 2.33 2.82 12 0.43 28.33 28.21 29.96 29.85 32.05 31.00
23 17 28.00 0.34 0.34 0.95 100 100 6.3 2.04 0.00 2.04 2.33 259 12 0.43 28.65 28.53 30.13 30.04 32.07 31.00
24 Outfall 0 00 0.00 0.00 0.00 0.0 0.0 8.5 0.00 0.00 0.00 2.38 0.72 0 0.00 0.00 000 0.00 0.00 0.00 0.00
Hydraflow DOT Report
S\

Storm Sewer Profile Proj. file: 5446 rev with pipe els.stm
4o YtiD�-
Elev. (ft) t�l
36.00
34.00
it
32.00
30.00
28.00
LL
26.00
0 25 50
75 100 125 150
175
200 225 250 275 300 325
350 375
Reach (ft)
Ln: 1
15 (in)
-
Ln: 2
15 (in)
15 (in)
� Ln:
� 15 (i)
Ln: 5
15 (in)
``^n
Ln: 8
--15"(in)
� Ln:
-'15
11r�
in)V4/
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
36.00
l 0 �CAct�
34.00
Ln:
12 (n)
12
32.00
30.00
28.00
26.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
36.00
34.00
32.00
30.00
28.00
26.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
Hydraflow, Storm Sewers 2003
Al

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
Ln:1
33.00
�l
31.00
29.00
27.00
0
10 20 30 40 50 60 70 80 90 100
Reach (ft)
t
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
10
Elev. (ft)
37.00
35.00
I
--
33.00
Ln:
nH
1
(in)
—
-
31.00
29.00
27.00
0
10 20
30 40 50 60 70 80 90 100
Reach (ft)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
Ln:10
12 (in)
V
33.00
n: 9
- 15 (i)
r
Ir�\Ii
-
-
31.00
29.00
27.00
0 10 20 30 40 50 60 70 80 90 100
Reach(ft)
HydraFlow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (fit)
40.00
37.00
34.00
31.00
28.00
10
)/EA-V--
25 50 75 100 125 150 175 200 225 250 275 300 325
Reach (ft)

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
I C)
36.00
-
34.00
32.00
Cj—
12 (in)N
I
—
30.00
28.00
26.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
1 O
Elev. (ft)
36.00
34.00
Ln: 2
12 (in)
32.00
30.00
28.00 MM
26.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
HydraFlow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
33.00
Ln:2
12 (in)
—1
31.00
29.00
27.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
HydraFlow Storm Sewers 2003
lT"

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
Ln:20
12 (in)
33.00
31.00
29.00
27.00
0 10 20 30 40
50 60 70 80 90 100
Reach (ft)
Hydraflow Storm Sewers 2003

5o -f4fz-
To Line Incr. Total Runoff Inlet I Time Rnfal I,To'al Adnl Total Capac I Pipei Pipe Inv Elev Inv Elev HGL HGL I Grnd/Rim d/Rim
Line Line Length Area Area Coeff. Time Conc Int Runoff Flow Flow Full Velo Sizel Slope Up Dn Up Dn Up Dn
--f------ - 0 -- -- --
(fp (ac) ((ac) -(C) (min), (min) (in/hr) (CIS) (CIS) _ (CIS) (CIS) (ftls)j-(in)(/o) )--(k) (k) _ (k) (k) (k) I(ft)
1 Ouffall 59.00 0.00 0.64 0.00 0.0 19.0 6.5 3.97 0.0 3.9 3.66 3.23 15 0.32 27.69 27.50 29.91 29.69 3100 31.00
2 1 89.00 0.00 0.57 0.00 0.0 18.6 6.6 3.56 0.00 3.56 3.69 2.90 15 0.33 27.98 27.69 30.43 30.16 31.00 31.00
3 2 6000 0.00 0.40 0.00 0.0 18.1 6.6 2.52 0.00 2.52 4.25 2.05 15 0.43 28.24 2798 30.72 3063 31.20 31.00
4 3 14.00 0.00 0.33 0.00 0.0 18.0 6.6 2.08 0.00 2.08 4.23 1.70 15 0.43 28.30 28.24 30.80 30.78 31.00 31.20
5 4 61.00 0.00 0.33 0.00 0.0 17.5 6.7 210 0.00 2.10 4.30 1.72 15 0.44 28.57 28.30 30.93 30.86 3100 31.00
6 5 17.00 0.00 0.27 0.00 0.0 10.1 7.8 2.01 0.00 2.01 2.44 256 12 0.47 28.90 28.82 31 03 30.98 31.25 31.00
7 6 18.00 0.27 0.27 0.95 10.0 10.0 78 2.01 0.00 2.01 2.22 2.56 12 0.39 28.97 28.90 31.17 31.11 31.92 31.25
8 5 50.00 0.00 0.06 0.00 0.0 15.2 7.0 0.40 0.00 0.40 4.28 0.33 15 0.44 28.79 28.57 30.98 30.98 31.00 31.00
9 8 31.00 0.00 0.03 0.00 0.0 12.3 7.5 0.21 0.00 0.21 4.34 0.17 15 0.45 2893 28.79 30.98 30.98 31.00 31.00
10 9 40.00 0.03 0.03 095 10.0 10.0 7.8 0.22 0.00 0.22 2.32 0.28 12 0.43 29.35 29.18 30.99 30.98 32.50 31.00
11 8 20.00 0.03 0.03 0.95 10.0 10.0 7.8 0.22 0.00 0.22 4.33 0.18 15 0.45 28.88 28.79 30.98 30.98 31.00 3100
12 1 32.00 0.07 0.07 095 10.0 10.0 7.8 0.52 0.00 0.52 2.36 0.66 12 0.44 28.08 27.94 30.16 30.16 32.05 31.00
13 2 29.00 0.17 0.17 0.95 10.0 10.0 7.8 1.27 0.00 1.27 2.38 1.61 12 0.45 28.36 28.23 30.66 30.63 32.40 31.00
14 3 29.00 0.07 0.07 095 10.0 10.0 7.8 0.52 0.00 052 2.38 0.66 12 0.45 28.62 28.49 30.79 30.78 31.80 31.20
15 Outfall 44.00 0.00 0.92 0.00 0.0 24.4 5.9 5.20 0.0 5.20 5.25 2.94 18 0.25 27.61 27.50 29.80 29.69 31.00 31.00
16 15 37.00 0.00 0.89 0.00 0.0 24.2 6.0 5.04 0.00 5"04 5.46 2.85 18 027 27.71 27.61 30.08 30.00 31.00 31.00
17 16 99.00 0.00 0.52 0.00 0.0 23.7 60 2.97 0.00 2.97 3.67 2.42 15 0.32 28.28 27.96 30.48 30.27 31.00 31.00
18 17 6700 0.00 0.18 0.00 00 23.0 6.1 1.04 000 1.04 2.34 1.32 12 0.43 28.82 28.53 30.68 30.62 31.00 31.00
19 18 74.00 0.01 0.01 0.95 10.0 10.0 7.8 0.07 0.00 0.07 2.34 0.09 12 0.43 29.14 28.82 30.70 30.70 32.30 31.00
20 18 41.00 0.17 0.17 0.95 10.0 10.0 7.8 1.27 0.00 1.27 2.36 1.61 12 0.44 29.00 28.82 30.75 30.70 32.03 31.00
21 15 69.00 0.03 0.03 0.95 10.0 10.0 7.8 0.22 0.00 0.22 2.35 0.28 12 0.43 2841 28.11 30.00 30.00 32.34 31.00
22 16 28.00 0.37 0.37 0.95 10.0 10.0 7.8 2.76 0.00 2.76 2.33 3.51 12 0.43 28.33 28.21 30.44 30.27 32.05 31.00
23 17 28.00 0.34 0.34 0.95 10.0 10.0 7.8 2.54 0.00 2.54 2.33 323 12 0.43 28.65 28.53 30.76 30.62 32.07 31.00
24 Ouffall 0.00 0.00 0.00 0.00 0.0 0.0 8.5 0.00 0.00 0.00 2.38 0.72 0 0.00 0.00 000 0.00 0.00 0.00 0.00
Hydraflow DOT Report

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
N
Elev. (ft)
36.00
34.00
32.00
30.00
28.00
26.00
0
Ln:1
15 (in)
-
- " — "
- D
Ln:2
-15"(in)- "---
-- --
-- M
-- -- -
-- ---
Ln: 3
15 (in) _
Ln:
--15"(i)
Ln:5
15(in)_
.
.
Ln:8
"- 15 (in)
v Ln:
15
11
�
in)
- -
- - --
-
- -
1-'� -
-
-
25 50 75 100 125 150 175 200 225 250 275 300 325 350 375
Reach (ft)

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
36.00
34.00
32.00
Ln:
12(n)
12
J
30.00
28.00
26.00
0 10 20 30
40 50 60 70 80 90 100
Reach (ft)
HydraFlow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
�U -(�1fL-
Elev. (ft)
36.00
34.00
12 (in)
-
K1 - LV
32.00
30.00
28.00
26.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
33.00
Ln: 1
- -
31.00
29.00
27.00 .
0
10 20 30 40 50 60 70 80 90 100
Reach (ft)
N
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
Ind- -
Ln: 7- - -
33.00 LI V fa
Y -
31.00
29.00
27.00
0 10 20 30 40 50 60 70 80 90 100
Reach(fit)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
35.00
Ln:_10.
�f
12_ (in)
33.00
n:
15 (in)
- -
31.00
29.00
27.00
0 10 20 30 40 50 60 70 60 90 100
Reach(fit)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
40.00
37.00
O'KIN
31.00
O ye;16"-g,
25 50 75 100 125 150 175 200 225 250 275 300 325
Reach(ft)
N
4-
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
36.00
34.00
12.'in
32.00
30.00
28.00
26.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
36.00
34.00
Ln: 2
12 (in)-
32.00
TIE-
30.00
28.00
26.00
0
10 20 30 40 50 60 70 80 90 100
Reach(ft)
Hydraflow Storm Sewers 2003

Storm Sewer Profile
Prof file: 5446 rev with pipe els.stm
Elev. (ft)
37.00
15D
35.00
33.00
Ln: 2
12 (in
-
-
31.00
29.00
27.00
0 10 20 30 40
50 60 70 80 90 100
Reach (ft)
N
HydraFlow, Storm Sewers 2003

Storm Sewer Profile
Proj. file: 5446 rev with pipe els.stm
Elev. (ft)
5o Y�
37.00
35.00
�.
t "
Ln_20--
12 (in)
33.00
31.00
29.00
27.00
0 10 20 30 40 50 60 70 80 90 100
Reach (ft)
N
Cfi
Hydraflow, Storm Sewers 2003

I Hduutad Methods FlowMaster
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DATE DESIGN SHEET
CRISER Sc TROUT�IAN
4-Z7-05 M ( Wilmington, COnSlliling Engineers North Carolina : OF
CHEC< JOB 007,Gr4 laVew--m-cf-R FOR JOB. NO.
Ga -%T-r ci: v�l►�.u�1G'1'at l S;146
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StormChamber Design Calculator
Cubic Feet of Storage Required: 10,662 < Start Here
Modify Storage With
Number of Number Number Trench
Min. Trench Min. Trench
Square Ft.
CY of
CY of
Sq. Yards
Additional Stone'
Chambers Wide
Long Depth (Ft)
Width in Ft. Length In Ft.
of System
Excavation
Stone
Filter Fabric
Storage Just In
StormChamber 75CF
142
#DIV/O!
2
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/01
With Stone Up To Top Of
StormChamber 110CF
97
#DIV/O!
2
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/01
Standard With 6" Stone
Above & Below 115CF
93
#DIV101
2
#DIV/01
#DIV/Ol
#DIV101
#DIV101
#DIV/01
With Additional 6"
Stone 124CF
86
80 ( 5J
�/
#DIV/O!
16 5.8333
2
31
#DIV/O! #DIV/01
125 3,839
#DIV/O!
829
#DIV/O!
687
#DIV/0!
628
With Additions 2"
Stone 133CF
With Additional 18"
Stone 142CF
75
#DIV/O!
2
#DIV/O!
#DIVIO!
#DIV/01
#DIV/0!
#DIV/01.
With Additional 24"
Stone 151CF
71
#DIV/O!
2
#DIV/01
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/O!
With Additional 30"
Stone 160CF
67
#DIV/O!
2
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/O!
#DIV/01
With Additional 36"
Stone 169CF
63
#DIV/O! 2 #DIV/O!
IGNORE ERROR MESSAGES
#DIV/O!
#DIV/O!
#DIV/01
#DIV/O!
Storage capacity of stone
based on 40% void.
dint. F2\11 2;0 (I I S Zor} (,S �nl� At��o�!'- 4- R —ICLU

w
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1*22 _�
BENEFITS OVER OTHER TYPES OF BMPS
>> Helps counter drought conditions by maintaining groundwater base flow to streams.
>> Replicates pre -development hydrology.
» Eliminates thermal discharge loadings.
Replenishes groundwater supplies.„-
>> Achieves higher pollutant removal rates through soil filtration and accelerated
microbial actions (bio-remediation).
Achieves Low Impact Development and Zero Discharge goals..'%%r�.;'�-;i
>> Reduces dependence on stormwater ponds and associated maintenance costs, /t,If'
liability and mosquito problems and allows for use of higher value real estate.
>> Provides a lower cost and longer effective life alternative to perforated pipe, it .I; r
>> Provides a lower cost alternative to pipe drainage i e for conveyance, with added
Y
. benefits of groundwater recharge and water quality enhancement.
* In soils that do not perk well, the benefits of microbial actions still occur.
AVERAGE % REMOVAL RATES
POLLUTANT
Water ':
riltering
Water
PARAMETER
INFILTRATION i
Wetland
i QualityPond i
system
QualitySwale
Total Phosphorus
...........................................a...................................................................................................
65
51
45.5
45
14.5
Total Nitrogen
..............................................................................................................'
8z.5
zo.9
30
......................................................1...................................
32
10.5
Lead
.............................................................................................................................................
98
63
66.5
i....................................................................
71
50
Zinc
.........................................._.................................:.................................................._
99
53.5
50.5
69
49
............................ ...
Suspended Solids':
................;.................................
88.5
_........................
78 4........
70
. .................................
81
..........................
66
............................
Organic Carbon
82
28
35
57
23
Source: Brown, Whitney, Schueler, Thomas. National Pollutant Removal Performance Database for
Stormwater BMPs, August 1997, Center for Watershed Protection, Ellicott City, Maryland.
BENEFITS OVER SIMILAR TECHNOLOGIES
>> Direct connect side openings eliminate expensive header pipe
manifold feed and discharge pipe systems and related extra
excavation and stone.
Over 6o% more storage capacity, with a design storage capacity
Of 115 cubic feet per StormChamber.
Less time and labor cost for installation.
/> Tested to exceed AASHTO H-20 wheel load rating by 3 times by
Rensselare Polytechnic Institute.
>> Integrated end walls; no extra cost for end plates.
Smaller system foot print and less stone and filter fabric required.
» io" inspection/clean out risers for quick and easy sediment
removal.
8.5'
77
jg
,''h
••• www hydrolocgicsolutions.com

StormChamber storage= 75CF
Design storage capacity= i
RECOMMENDED INSTALLATION OFSTORMCHAMBER
FOR STORM WATER MANAGEMENT UNDER PAVEMENT
ASPHALT SURFACE —
PAVEMENTBi
90 o COMPACTED CL
HILL OR 1'.2'
CRUSHED WASHED
STONE
31C AT
. INTERFP
RUSHED
)STONE
FABRIC
T
i WALL
(SUPPLIED)
CLEAN OUT AND/OR INSPECTION WELL
COMPACTED CLEAN
CAST IRON FRAME WITH COVER FILL OR 1 -2"
INSPECTION COVER CRUSHED. WASHED,
V X T REINFORCED STONE
CONCRETE PAD \ANGLE IRONS TO/ \PAVEMENT
8' SUPPORT INSE.4i ED
PIPE
I[. 6"MIN
B"Ofl 10'PVC -----'*_.�.::.:>�F_:.`.;i:"•:i.��'�''.:.�.'1 �D;�'��:
PIPE PISER
SCH40 OR OL35
I -2' CRUSHED, �'\� FILTER FABRIC
WASHED, STONE
4X� I
HEAVYWEIGHT o'MW
STABILIZATION
NETTING
(SUPPLIED)
EXAMPLE CONFIGURATION CATCH BASIN
�,�OPTIONAL OUT -FALL
TX
HEAVYWEIGHT 14' X T
STABILIZATION
NETTING / / HEAVYWEIGHT
(SUPPLIED) O O ' O O STABILIZATION
NETTING
(SUPPLIED)
)1
,F1
11,1
1m
HEAVYWEIGHT
z SL1BrILIZAT ION
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Re: North Ri rfont Parking Garage
Subject: Re: North Riverfont Parking Garage
From: Linda Lewis <[e-mail]>
Date: Tue, 12 Apr 2005 12:49:49 -0400
To: Mark Arcuri <[e-mail]>
CC: Cameron Weaver <[e-mail]>, Paul Bartlett <[e-mail]>
Mark:
Thank you for clarifying the location of this site. I found Vincent's report of the 8
foot water table. He noted however, that the site had 12-15 feet of fill material
which will need to be removed and backfilled with clean sand.
Based on the deep water table, and the clean sand backfill material, I can revise my
initial requirement for a 2.5" storm down to the minimum 2" storm you initially
requested, in lieu of a vegetated filter.
Paul and Cameron will get together to schedule the pre -application meeting. Cameron
should get back in touch with you regarding the date and time.
Linda
Mark Arcuri wrote:.
Linda,
I talked with the Architect and The City of Wilmington. We have the
following thoughts.
1. City asked to confirm we're all talking about the same project site
because they are doing a number of downtown projects now. This project is
the proposed "North Riverfront Parking Garage." It will be built at the
triangular shaped property currently in use as a parking lot for CFCC. The
property is bounded by Second, Front, and Brunswick Streets.
2. The water table was observed by Vincent to be 8 feet deep. Groundwater
across the complete area of the infiltration system ranges from 6 to 12 feet
below grade, according to S&ME. In my experience, that's pretty deep for
the Wilmington area. In comparison, the water table was estimated at 3 feet
below grade at Almont Marina.
3. Because the groundwater slopes across the site, the SHWT separation will
vary between 2.5 and 7.0 across the infiltration system, much more than
required. We only provided an even 2 feet separation at the Almont project.
4. The infiltration rate by S&ME is 9.1 inches per hour, a decent rate.
S. Soils are sand.
6. The site is farther away from the receiving water than Almont Marina.
I understand you did not have some of these details when I initially asked
about the additional storage option. Now that you have this information, I
ask you to provide a revised storage requirement, if appropriate.
7. Also, need to have our initial meeting with you. We are ready. Should
I call Cameron to set a time? I am available any time this week.
Thanks for your continued help with this project. Look forward to hearing
back from you.
Mark T. Arcuri, PE
-----Original Message -----
From: Mark Arcuri[mailto:[e-mail]] Sent: Monday, April 11, 2005
4:01 PM
To: Linda Lewis
1 of 2 4/14/2005 8:45 AM

Re: N'-.tth i iverfont Parking Garage
Cc: John Farabow
Subject: FW: North Riverfont Parking Garage
Linda,
Thanks for the information. Look forward to a call so we can set up the
initial meeting. Thanks again.
Mark Arcuri
-----Original Message -----
From: Linda Lewis [mailto:[e-mail]] Sent: Monday, April 11, 2005
3:47 PM
To: Mark Arcuri
Subject: Re: North Riverfont Parking Garage
A'.1
Mark:
The ability to provide additional storage in lieu of a vegetated filter is done on
a case by case basis. The criteria include depth to the SHWT, expected
infiltration rate, and distance to the receiving stream. The deeper, faster and
farther away, the less design storm, the shallower, slower, and closer, the more
design storm is`hecessary. Based on this site's shallow water table, marginal
soils and close proximity to the receiving waters, I would feel comfortable with
storage for a 2.5" design storm. That's a pretty good volume for the summer
thunderstorm season around here.
Linda
Mark Arcuri wrote:
Linda,
We faxed the Express App to Cameron this morning. The City does not want to
provide a vegetative filter on the bypass of the infiltration system. Can we
provide 2" volume in lieu of the vegetative filter? This was talked about at
the Almont Marina project I worked on with Paul Bartlet recently, although we
did not take that route. I need to know if this 2 inch option is available for
this Garage site. Thanks.
Mark Arcuri
910-397-2929
2 of 2 4/14/2005 8:45 AM

Apr Ub Ub U/:30a Cnser Troutman Tanner p - p.2
(� ! NCDENR uu/T l
11 North Carolina Department 01 E 5
127 Cardnal Drive. Wilmington NC 28405 [phone] FAX [phone]
r2� Request for Express Permit Review
P /�,, 14CiJc� G�
FILL-IN all information below and CHECK /I s
required Permiks).
FAX or email to Cameron. Weaver@ncmailnet along with a narrative and vicinity may of the protect location.
Projects must be submitted by 9:00 A.M. of the review date, unless prior arrangements are made.
PROJECT Name 'E3iV�Klt\�G
PROJECT LOCATED IN c'�Pr- >rFa2 DR=DAe1W
WE
-10
❑ STREAM ORIGINATION CERTIFICATION; Stream Name
- -- - -- -- - - ------- —----------- ---------------------------•-•-------- .-.—----------- ------ —
WN STORMWATER [ILow Density ElHigh Density -Detention Pond ❑ High Density -Other
❑ Low Density -Curb & Gutter High Density -Infiltration ❑ Off Site
------- -- ...... -- -- - -- - — — - - - - - ------------ —-------------•----- -
❑ COASTAL ❑ Excavation & Fill ❑ Bridges & Culverts ❑ Structures Information
MANAGEMENT ❑ Upland Development ❑ Marina Development ❑ Urban Waterfront
❑ LAND QUALITY ❑ Erosion and Sedimentation Control Plan with acres to be disturbed.
❑ WETLANDS (401) ❑ No Wetlands on Site (letter from COE) ❑Wetlands Delineated/No JD
❑ Greater than 0.1 AC Wetlands Impacted ❑Jurisdictional Determination has been done
❑ Less than 0.1 AC Wetlands Impacted ❑Greater than 0.5 AC Wetlands Impacted
The legislation allows additional fees, not to exceed 50% of the original Express Review permit application
fee, to be charged for subsequent reviews due to the insufficiency of the permit applications.
For DENA use only
SUBMITTAL DATES: Fee Split for multiple permits:
SW $
CAMA $
LOS $
Total Fee Amount $

Apr 08 05 07:30a Criser Troutman Tanner [phone] - p.3 1,
STORMWATER NARRATIVE
Project:
NORTH RIVERFRONT PARKING GARAGE
Location:
Bounded by:
Front, Second, and Brunswick Streets
Wilmington, North Carolina
New Hanover County
Prepared for:
City of Wilmington
PO Box 1810
Wilmington, NC 28402
Prepared by:
Mark T. Arcuri, PE
Criser Troutman Tanner Consulting Engineers
3809 Peachtree Avenue
Suite 102
Wilmington, NC 28403
April 8, 2005
CTT Project 5446.00

Apr 08 05 07:30a Criser Troutman Tanner [phone] p.4
STORMWATER NARRATIVE
GENERAL
The City of Wilmington wishes to construct a parking garage as part of the Northern
Downtown Revitalization Effort. The existing property is 1.579 acres. Also, The City will
be realigning the intersection of Second and Front Streets to be a 'Tee" configuration to
provide for safer traffic flow in the area. With this realignment, there will be additional
property converted from City of Wilmington Road Right of Way to be appended to the
subject property area (also owned by The City). The additional acreage will be
approximately 0.141 acres and will result in a new project property area of 1.720 acres
(74907 square feet). ✓'
EXISTING SITE FEATURES
The site is currently a parking lot, all paved, and currently used by Cape Fear
Community College. Storm drainage in the Public Road Rights of Way exists at the
intersection of Brunswick and Front Streets. This storm drainage is directed to The
Cape Fear River. Topography across the site is down from east to west.
PROPOSEDIMPROVEMENTS j
The parking garage will be five stories. It will result in 67,340 SF oflmoervious surface
on the property, resulting in a built upon _area 9.Wo. Remaining areas between the
garage building and the property line
From there, they will be routel*be landscaped. Roof drains from the top deck
will be routed down along colum �andsFieer walls to below the bottom floor elevation.
4to lla flow separation structure, below ground This
structur recLth@ first fJ}+ an un ound infiltration SVWem. The
structure will
th
The infiltration system will be at least 2 feet above the seasonal high water table. It is
the intent to utilize plastic arched domes for the core of the infiltration system.. The
arches will be encased in #4 stone (1" grain size). The entire system will then be
wrapped in filter fabric.
As required by The City of Wilmington, storm drains will be sized to convey the 10-year
storm flow and prevent flooding during the 50-year storm flow.
A March 15, 2005 report by S&ME revealed an infiltration rate of 9.1 inches per hour.

Apr 08 05 07:31a Criser Troutman Tanner [phone] p.5
CHORD BEARING CHORD LENGTH
N 22.15.41" E 1 195.84-
S 7534'37- E 1 121.67'
LOCH TION MAP
NOT TO SCALE
HARNETT ST.
BLADEN ST
AS
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Apr 08 05 07:30a Criser Troutman Tanner [phone] p.1
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TROUTMAN
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FAX MEMORANDUM
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NOTES/COMMENTS:
i RECEIVED
APR 0 8 Z005
BY:
CRISER TROUTMAN TANNER CONSULTING ENGINEERS
Post Office Box 3727 Nhlnnngtan. NC 29406 1 3809 Peachtree A.e Swte 102 Wdm:ngton, NC 28403 p 910.397.2929 /910.397.2971

Apr 28 05 07:55a Criser Troutman Tanner [phone] p.2
*SM
March 15, 2005
City of Wilmington
Post OfficeBox 1810
Wilmington, North Carolina 29402
Attention: Mr. Jim Flechtner
Reference: Double Ring Infiltrometer Testing
North River&ont Parking Chwage
Brunswick Street
Wilmington, North Carolina
Job No.1061-05-085
Dear Mr. Flechtner:
In accordance with S&ME Proposal 594-05 dated February 2, 2005, S&NiE personnel have recently
conducted one double -ring infiltrometer test of the surfrcial soils at the subject site at the
approximate location shown in Figure 1. Specifically, our representatives visited the site on March
12, 2005, and conducted one double -ring infiltrometer test at a depth of 15 inches below the asphalt
surface. This testing was conducted in general accordance with American Society for Testing and
Materials (ASTM) procedure D-3385 entitled, "Infiltration Rate of Soils in Field Using Double -
Ring Infrltrometer".
'NUle on site, our representative attempted to advance hand-augered borings near the infiltrometer
test location. However, our personnel were not able to advance a boring beyond a maximum depth
of 18 inches at two locations due to the presence of rubble debris.
The average infiltration rate at the test location was approximately 9.1 inches per hour. A summary
of the field test results is presented in Table 1.
SWE, Inc. I (910( 799-99dS
6409 Amalerd= Woy, Building 83 (9101 799-9958 Fox
Wifmingb . North Cardin 28405 I w .smeinc.mm

Apr 28 05 07:56a
c
Criser Troutman Tanner
[phone]
p.3
City of Wilmington
S&ME Job Number 1063-05-085
March 15, 2005
Page Two
S&ME appreciates the opporttmity to provide our services during this phase of the project. Should
you have any questions after reviewing this letter, or if we can be of additional assistance, please do
not hesitate to contact us at your convenience.
Sincerely,
S&ME, INC.
I ^ d Ce ��✓(��ct ✓b
C. Richard Connell,11
Senior Engineering Technician
Michael W. Behen, P.E.
Senior Geotechnical Engineer
CRC:MWnlns
Atsachmmts
Copies: Criser & Troutman Consulting Engineers, Mr. David Criser (Fax)
HR Associates, Mr. John Farabow (E-Mail)

Apr 28 05 07:56a Criser Troutman Tanner [phone] p.4
P ,
TABLE 1
Double Ring infiltrometer Testing
North Riverliont Parking Garage
Brunswick Street
Wilrttington, North Carolina
Job No. 1061-05-085
Date of Test
Depth of Test Below Site Grade
Depth of Water in Rings
Inner Diameter of Inner Ring
Inner Diameter of Outer Ring
Average Infiltration Rate
March 12, 2005
15 inches below asphalt surface
3 inches
11'/ inches
22'Y2 inches
9.1 inches per hour

[phone] p.5
Apr 28 05 07:56a Criser Troutman Tanner
PROPOSED PROPERTY AD-MTMMWr
E>UST,NB PROP62TY LINE
LEGEND
• Approximate Location Note: Site plan drawing provided to SBME
of Inflltrorneter Testing by H.R. Associates personneL
SCALE: NOT TO SCALE INFILTROMETER TESTING FISU1e
NORTH RR/ERFROMT PARKING GARAGE mbw
CHECKED BY: MWB BRUNSWICKSTREET
_
DRAWN BY: JNS SM WILMINGTON, NORTH CAROLPW 1
ENCINErAWG . TESnI'IC
I DATE: 3.10-05
JOB NUMBER: 1061-05-095