SW8060407_COMPLIANCE_20060511

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW�(/(IlD��I
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO,
SW
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
DOC DATE
YYYYMMDD

DETENTION POND ANALYSIS FILE NAME: G:\DATA\WPDATA\WQS\POND1060407.WK1
I
PROJECT#: SW8 060407 REVIEWER: P.Bartlett
PROJECT NAME: Coastal Mini -Storage
DATE: 11 -May-06
Receiving Stream: Little Cawcaw Swamp Class: C; SW
Drainage Basin: Lumber Index No. 15-23-1
Site Area 12.00 acres
Drainage Area jii�!�406'4 square feet Area = 9.33 acres
IMPERVIOUS AREAS
Rational C
OS BIdgs
142145.00
square feet
0.95
OS Sts/Prkg
128615.00
square feet
0.95
OS Sidewalks
OS Future
145.00
27460.00
square feet
square feet
0.95
0.95
1)
square feet
square feet
TOTAL
k .98365:
square feet
Rational Cc= 0.75
SURFACE AREA CALCULATION
% IMPERVIOUS
73.41%
SA/DA Ratio
2.47%
Des. Depth
7.5
Req. SA
10041 sf
TSS:
90
Prov. SA [7111171:10347
sf
VOLUME CALCULATION place a " 1 " in the box if Rational is used
Rational ?*
Des. Storm
inches
Rv= .
0.71
Bottom
36.25 msl
Perm. Pool
43 7 msl
Design Pool
44.85 msl
Design SA
26000 sf
Req. Volume
cf
Prov. Volume
cf
ORIFICE CALCULATION
Avg. Head =
Flow Q2, cfs
Flow Q5, cfs
No. of Orifices
Diameter, inches
Drawdown =
FOREBAY
Perm. Pool Volurne=
Req. Forebay Volume=
Provided Volume=
Percent=
SA @
Elevation=
Q2 Area =
Q5 Area =
Orifice Area
Q=
COMMENTS
Surface Area , Volume and Orifice are within Design GuidelineE
in
92394
18478.8
18990.00
5.84
sq. in.
2.34
sq. in.
3.14
sq. in.
0.075
cfs
x
in ..... .....

STORMWATER SYSTEM & EROSION CONTROL NARRATIVE
COASTAL MINI STORAGE OF SOUTH BRUNSWICK
BRUNSWICK COUNTY, NORTH CAROLINA
For
Robert High Properties, LLC
5725 Oleander Drive, #E-7
Wilmington, NC 28403
[phone] p
[phone] f
CAR—
:� SS/
• 'Q � j
e
19851
! 1,1 Gay .
t�rre�i�Ne APR
March 2, 2006
Prepared by:
NORRIS, KUSKE & TUNSTALL
CONSULTING ENGINEERS, INC.
902 Market Street
Wilmington, North Carolina 28401
[phone] p
[phone] f
E-mail: [e-mail]
NKT Project No. 05080

i
STORMWATER SYSTEM & EROSION CONTROL NARRATIVE
COASTAL MINI STORAGE of SOUTH BRUNSWICK
BRUNSWICK COUNTY, NORTH CAROLINA
DESCRIPTION:
The site is located approximately 2 miles west from the intersection of US Hwy 97
from intersection and Hwy 904 in Brunswick County. The site is lightly vegetated and the
wetlands have been delineated as shown on plan.
The new development will consist of construction of new Mini Storage Facility.
Approximately 8.5 acres will be disturbed by the construction work.
STORMWATER MANAGEMENT MEASURES:
The project site is located in Brunswick County. Land disturbing on the site will exceed
one acre, which requires the site to comply with the State and Brunswick County
--Std-r-rffw—aite� Regulations. The stormwater runoff from the development will be directed
to the stormwater detention pond. The stormwater detention pond was designed to
accommodate this site and the future developable lot at 75% impervious area lot
coverage.
EROSION CONTROL MEASURES:
The attached plans and specrFications outline the requirements for erosion
control measures. Silt fencing will be provided along each side of the entrance drive
where stormwater would be expected to sheet flow from disturbed areas directly to
adjacent property. Gravel check dams will not be provided unless the Contractor has to
temporarily discharge into an open ditch instead of the proposed storm drain outfall.
The detention pond will be used as a silt basin during construction and restored to its
design contours prior to completion. A gravel construction entrance will be constructed
at the new entrance. Maintenance will be provided by the grading contractor and
developer.
CONSTRUCTION SEQUENCE:
The Contractor will install the gravel construction entrance and silt fence prior to
beginning any clearing and grading operations. Additional silt fence will be installed
when and if conditions warrant during construction. The detention pond/silt basin will be
constructed immediately after that portion of the site is cleared, and outlet structure with
protection will be installed. Disturbed areas will be landscaped or seeded upon
completion.

rA
EROSION CONTROL NOTES AND MAINTENANCE PLAN
1. Install erosion control measures before beginning construction or as soon
thereafter as possible. All erosion and sediment control practices will be checked
for stability and operation following every runoff -producing rainfall but in no case
less than once every week. Any needed repairs will be made immediately to
maintain all practices as designed.
2. Maintain the gravel construction entrances in a condition to prevent mud or
sediment from leaving ' the construction site. The contractor shall inspect the
construction entrances on a daily basis. This will require periodic top dressing
with additional No. 4 stone. Any objectionable materials spilled, washed, or
tracked onto public roadways shall be removed immediately.
3. Install erosion control measures around the drop inlets as shown on the plans to
trap silt during construction. Inspect the erosion control around the inlets after
each rain and make repairs immediately. Remove sediment when it -becomes
0.50 deep to provide adequate storage volume for subsequent rains. When the
contributing drainage area has been adequately stabilized, remove all materials
and any unstable soil and either salvage or dispose of it properly. Bring the
disturbed area to proper grade and appropriately stabilize all bare areas around
the drop inlets.
4. Sediment will be removed from behind the silt fence when it becomes 0.5 feet
deep at the fence. The sediment fence will be repaired as necessary to maintain
a barrier. Silt fence stakes shall be spaced 6 feet apart unless a wire backing is
used with 8 foot stake spacing.
5. Inspect temporary sediment traps 1 check dams after each period of significant
rainfall. Remove sediment and restore the trap to its original dimensions when
the sediment has accumulated to one-half the design depth of the trap. Place
the sediment that is removed in the designated disposal area and replace the
contaminated part of the gravel facing. Check the structure for damage from
erosion or piping. Periodically check the depth of the spillway to ensure it is a
minimum of 1.5 ft below the low point of the embankment. Immediately fill any
settlement of the embankment to slightly above design grade. Any riprap
displaced from the spillway must be replaced immediately. After all sediment -
producing areas have been permanently stabilized, remove the structure and all
unstable sediment. Smooth the area to blend with the adjoining areas and
stabilize properly.
6. The stormwater ponds will act as sediment basins and will be cleaned out when
the level of sediment reaches 2.0 ft below the top of the riser. Gravel will be
cleaned or replaced when the sediment pool no longer drains properly.

J
7. The angle for graded slopes and fills shall be no greater than the angle that can
be retained by vegetative cover or other adequate erosion -control devices or
structures. In any event, slopes left exposed will, within 21 calendar days of
completion of any phase of grading, be planted or otherwise provided with
temporary or permanent ground cover, devices, or structures sufficient to restrain
erosion.
8. All disturbed areas shall be seeded within 15 days of disturbance. All seeded
areas will be fertilized, reseeded as necessary and mulched according to
specifications in the vegetative plan to maintain a vigorous, dense vegetative
cover.
9. More stringent measures shall be used to halt erosion if those shown on this plan
are not effective.
10. All erosion shall be controlled including side slopes before the project is
completed.
11. RemQve temporary measures upon completion of project. All permanent
measures will be well established before project closeout.

SECTION 02920
SOIL EROSION AND SEDIMENTATION CONTROL
1. GENERAL
1.1 Contractor shall take every reasonable precaution throughout construction to
prevent the erosion of soil and the sedimentation of streams, lakes, reservoirs, other water
impoundments, ground surfaces, or other property as required by State and Local
regulations.
1.2 The Contractor shall install all required silt fences, and construction entrances at
the initiation of work, and have these measures reviewed and approved by the local permit
authority prior to clearing and grading operations.
1.3- The Contractor shall, within 15 days of suspension or completion of land
disturbing activities, provide permanent protective covering for disturbed areas.
Temporary and permanent erosion control measures shall be coordinated to _ assure _
economical,' effective, and continuous erosion and siltation control throughout the
construction and post -construction period. Use the specified seed for both temporary and
permanent seeding.
2. PRODUCTS
2.1 Asphalt for anchoring mulch shall be Type SS-1 Emulsion.
2.2 Fertilizer shall be 10-10-10 grade or equivalent.
2.3 Lime shall be dolomitic agricultural ground limestone containing not less than 10
percent magnesium oxide.
2.4 Mulch shall be small grain straw, hay, wood chips, asphalt emulsion, jute or other
suitable material free of undesirable weed seed.
2.5 Phosphate shall be 20 percent superphosphate or equivalent.
2.6 Seed shall be 20% carpet grass, 24% Bermuda, 20% turf Fescue, 10% Creeping
Red Fescue, and 24% Annual Rye grain. Bermuda seed shall be hulled for warm weather
planting and unhulled for cool weather planting. Purity of seed shall be a minimum of 98
percent and germination shall be a minimum of 85 percent.
2.7 Silt fence shall consist of NCDOT Class A fabric supported by wood or metal
posts spaced not more than 6 feet on center. The bottom of the fabric shall be buried a
minimum of 6 inches.
2.8 Gravel for check dams shall be #57 washed stone.

2.9 Aggregate for construction entrance shall be #4 washed stone.
2.10 Stone rip rap for check dams and erosion control shall be NCDCT Class A or B
as shown.
3. EXECUTION
3.1 General: Take every practicable measure during construction or suspension to
work to minimize erosion and siltation. Measures should include good construction
practices, temporary physical barriers to sediment travel, settling basins for new ditches, .
and establishment of vegetative cover.
3.2 Construction Practices
3.2.1 Avoid dumping soil or sediment into any wetland or watercourse.
3.2.2 Maintain an undisturbed vegetative buffer where possible between a natural
watercourse and trenching and ! jading operations.
3.2.3 Avoid equipment crossings of streams, creeks, and ditches where practicable.
3.2.4 Grade all cut, fill and ditch slopes to minimum slope of 3:1, unless otherwise
shown or directed.
3.3 Temporary Physical Barriers are required where sedimentation on off site
property or excessive erosion is a problem.
3.3.1 Mulch shall be used for temporary stabilization of areas subject to excessive
erosion and for protection of seedbeds after planting where required.
1. Apply grain straw and hay at a rate of 75 to 100 pounds per 1000 square feet
and wood chips at a rate of 500 pounds per 1000 square feet. Jute and mesh
should be installed as per manufacturer's instructions.
2. Asphalt emulsion for slope stabilization should be applied at a rate of 1,000
gallons per acre. Asphalt emulsion used for anchoring straw should be applied at a
rate of 150 gallons per ton of straw.
3.3.2 Silt Fences shall be used at the base of slopes to restrict movement of sediment
from the site. Clean silt fence of accumulated sediment after each rainfall event or
when it exceeds a depth of 0.5 feet above natural grade.

r
3.3.3 Stone Check Dams, placed at the discharges of creeks, ditches, and swales, shall
consist of Class A or Class B erosion control stone at minimum two feet high and three
feet thick across the watercourse, with a one foot thick layer of gravel on upstream side.
Remove sediment if accumulated to'a depth of 1.0 feet at upstream face.
3.4 Vegetative Cover: Establish and maintain permanent vegetative cover on all
unpaved areas disturbed by the work.
3.4.1 Preparation of Seedbed: Areas to be seeded shall be scarified to a depth of 4
inches and until a firm, well pulverized, uniform seedbed is prepared. Lime, phosphorous
and fertilizer shall be applied during the scarification process in accordance with the
following rates:
Lime: 45 pounds per 1000 square feet
Phosphorous: 20 pounds per 1000 square feet
Fertilizer: 17 pounds per 1000 square feet
_3.4.2 Seeding: Disturbed areas -shall -be -seeded with 2 to 3 pounds per 1000 square ---
feet of the.specified seed mixture. Seed shall be worked into the bed to a depth of 1/4
inch. Regrade and seed eroded areas immediately
3.4.3 Mulch all areas immediately after seeding. Mulch shall be applied and anchored
as specified hereinbefore. Reapply as necessary to retain cover until grass is established.
3.5 Construction Entrance: Provide an aggregate drive, 20 feet wide by 50 feet long
by 6 inches thick at each entrance to the site used by construction vehicles, until such time
as the permanent roadway is constructed. Remove soil if accumulated to a depth greater
than 0.5 inches.
3.6 Maintenance: The Owner and Contractor shall be responsible for maintaining all
temporary and permanent erosion control measures. Temporary structures shall be
maintained until such time as vegetation is firmly established in the area protected by
the structure. Permanent streambank protection and grassed areas shall be maintained
until completion of the project. Areas that fail to show a suitable stand of grass or which
are damaged by erosion shall be immediately repaired.
End of Section