HomeMy WebLinkAboutSW8030508_APPROVED PLANS_20060308STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
DOC TYPE El CURRENT PERMIT
c�APPROVED PLANS
� ❑ HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
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Construction Road Stabilization
Specification / 6.80 - Construction Specifications
1. Clear roadbed and parking arena of all vegetation, roots and other
objectionable material.
2. Ensure that rood construction follows the natural contours of the terrain If
It Is possible.
3. Locate parking areas on naturally flat woos If they are available. Keep
grades Sufficient for drainage but generally not moue than 2 to 3R
4. Provide Surface drainage, and divert excess runoff to stable areas by using
water bore or turnouts (References: Runoff Control Measures).
5. Keep cuts and fills at 2:1 or flatter for safety and stability and to
facilitate establishment of vegetation and maintenance.
6. Spread a 6-Inch course of "ABC" crushed stone evenly over the full width of
the road and smooth to avoid depressions,
7. Where seepage woos " seosmally wet woos must be crossed. Install
Subsurface drains or geotextile fabric cloth before placing the crushed state
(Practice 6.81, Subsurface Drain).
8. Vegetate all roadside ditches, cuts, file and other disturbed woos or
otherwise appropriately stabilize as soon as grading is complete (References:
Surface Stabilization).
9. Provide appropriate sediment control measures to prevent off -site
sedimentation.
Maintenance
Inspect construction roads and parking areas periodically for condition of
surface. Topless with new gravel as needed. Check road ditches and other
seeded woos for erosion and sedimentation after runoff -producing rain&
Maintain all vegetation In a healthy, vigorous condition. Sediment -producing
areas should be treated immediately.
Temporary Gravel ('construction Entrance/Ea
Specification / 8.% - construction Specifications
1. Clear the entrance and exit ores of all vegetation, roots and other
objectionable material and properly grade It.
2. Place the gravel to the specific grade and dimensions shown on the plans and
smooth it.
3. Provide drainage to carry water to a sediment trp or other Suitable outlet.
4. Use geotextile fabrics because they improve stability of the foundation in
locations Subject to sapage or high water table.
Maintenance
Maintain the grovel pad in o condition to prevent mud or sediment from leaving
the construction site. This may require periodic topdressing with 2-inch stone.
After each rainfall. Inspect any structure used to trap Sediment and clean it
Out as necessary, immediately remove ON objectionable materials spilled,
washed. or tracked onto public roadways.
Temporary Seeding
Specification / 6.10 - Specifications
Complete grading before preparing seedbeds and Install all necessary erosion
control practices, Such as dikes, waterways and basins. Minimize step sped
bscouse they make Seedbed preparotim difficult and Increase the woson hazard.
If Sao become compacted during grading, loosen them to a depth of 6-8 Inches
using a ripper, harrow, or chi" Wow.
Seedbed Prparatim
Good seedbed preparation Is essential to Successful plant establishment. A good
seedbed is well -pulverized, loose and uniform. Where hydroseading methods are
used, the wrfoce may be left with o more irregular surface of large clods and
Stan".
Liming - Apply line according to sad test recommendations, If the pH (acidity)
of the soil is not know, an application of ground agricultural limestone of the
rate of 1 to 1 1/2 tms/acre an coarse -textured soils and 2-3 toms/ones on
fine -textured Rode is usually Sufficient. Apply limestone uniformly and
Incorporate into the top 4-6 Inches of soil. Sails with a PH of 6 or higher
need not be limed.
Fertilizer- Bass application rates an soil tests. When these are not possible,
apply a 10-10-10 grade fertilizer of 700-1,000 lb./acre. Both fertilizer and
lime should be incorporated into the top 4-6 inches of SON. If o hydraulic
seeder Is used, do not mix and and fertilizer more than 30 minutes before
application.
Surface roughening- If recent tillage operations have resulted In a loom
wrfoce, additional roughening may not be required except to break up large
clod& It rainfall causes the Surface to became Reeled or crusted, loosen it
just prior to ending by disking, raking, harrowing, " other Suitable methods,
Groove w furrow slopes steeper than 3:1 an the contour before seeding (Practice
6:03. Surface Roughening).
Plant Selection
Select an appropriate species or species mixture from Table 6.100, for seeding
In late winter and cony spring, Table 6.10b for Summer, and Table 6.100 1"
foil.
Seeding
Evenly apply seed using a cyclone seeder (broadcast), drill, cultipoeker seeder,
or hydro seder. Use seeding rates given in Table 6.10o-6,10c. Broadcast ending
and hyroseedng are appropriate for steep slop" where equipment cannot be
driven. Hand broadcasting is not recommended because of the difficulty In
achieving o uniform distribution. Small grains should be planted no more than 1
Inch deep, and grasses and legumes no more than 1/2 Inch. Broadcast seed must
be cowered by raking or chain dragging, and then lightly firmed with a roller or
cultipacker. Hydros"ded mixtures should include a wood flow (cellulose) mulch.
Th� of appropriate mulch will help ensure establishment under normal
conditions and is essential to Seeding wconse under harsh site conditim
(Practice 6.14, Mulching). Harsh site conditions include:
-seeding In fall for winter cover (wood fiber mulch" are not considered
adequate for this use),
-alp" steeper thin 3:1.
-excessively hot or dry weather,
-adverse wds(shallow, rocky, " high in day or sand), and
-woos receiving concentroted flow.
If the area to be mulched is Subject to concentrated walerflow, as in channels,
anchor mulch with netting (Practice 6.14, Mulching).
Table 6.10o - Temporary Seeding Recommendation for Late Winter and Early Spring
Seeding mixture
Species- Rye(groin), Annual lespedeza (Kobe in Piedmont and Coastal Plain
Rate (lb/ocre)- 120
Omit annual lespedozo when duration of temporary cover is not to extend beyond
June
Seeding dates -Coastal Plain - Dec. 1 - Apr. 15.
Sod amendments- Follow recommendations of Ball torts or apply 2,000 Ib/ocre
ground agricultural limestone and 750 lb/ache 10-10-10 fertilizer.
Mulch -Apply 4,000Ib/owe straw. Anchor straw by tacking with asphalt, netting
or a mulch anchoring tool. A disk with blades set nearly straight can be used
as a mulch anchoring tool.
Maintenance - Refertipin It growth Is not fully adequate. Reseed, mfertilize
and mulch immediately following wosim or other damage.
Table 6.10b - Temporary Seeding Recommendotione for Summw
Seeding mixture
Speclea-Germm millet
Rote(Ib/ocre)- 40
Seeding dates -Coastal Plain- Apr, 15-Aug. 15
SON omandments-Fallow recommendations of sail into or apply 2.000 Ib/ocre
ground agricultural limestone and 750 Ib/ocre 10-10-10 fertilizer.
Mulch -Apply 4,000 lb/acre straw. Anchor straw by tacking with asphalt, netting
" a mulch anchoring tool. A disk with blades set nearly straight con be used
as a mulch anchoring tool.
Maintenance-Refertilize if growth is not fully adequate. Reseed, refertilize
and mulch immediately following erasion or other damage.
Table 6.10c - Temporary Seeding Recommendation for Fall
Seeding mixture
Species-Rye(grain)
Rate(lb/ocre) - 120
Seeding date - Coastal Plain and Piedmont -Aug 15 - Dec. 30
Soil amendments - Follow soil tests or apply 2,000 lb./acre ground agriculture,
limestane and 1,000 ID/acre 10-10-10 fertilizer,
Mulch- Apply 4,000 b/ocre straw. Anchor straw by tacking with asphalt.
netting, or a mulch anchoring tool. A disk with blades set nearly straight con
be used 09 a mulch anchoring tool.
Maintenance- Repair and ref"tilize damaged areas immediately. Topdress with 50
b/ocre of nitrogen in March, if It is necessary to extend temporary cow
beyond June 15, overseed with 50 Ib/ocre Kobe (Piedmanl and Coastal Plain)
Permanent Seeding
Specifications Y 6.11 - Specifications
Seedbed Requirements
Establishment of vegetation should not be attempted on sites that we unsuitable
due to inappropriate soil texture (Table 6.110), pact drainage, concentrated -
overland flow, or steepness of slope until measures have been token to correct
these problems.
To maintain a good stand of vegetation, the soil must meet contain minimum
requirements as a growth medium. The existing SON should haw these criteria:
- Enough fine-grained (silt and day) material to maintain adequate
moisture and nutrient Supply (available water capacity of at least .05
Inches water to I inch of soil).
- Sufficient pare pace to permit root penetration.
- Sufficient depth of soil to provide an adequate root zone. The depth to rock
or impermeable layers Such as hardpans should be 12 incheu or more, except on
slopes sleeper than 2:1 where the additive of soil is not tensible.
- A favorable pH range for plant growth, usually 6.0-6.5,
- Freedom from large roots, branches, stones, large clods of Korth, or trash of
any kind. Gods and stones may be left an slopes steeper than 3:1 if they are
to be hydroseeded.
If any of the above criteria are not mat -Le., if the existing soil is too
coarse, dense, shallow or acidic to foster vegetation -special amendments ore
required. The sod conditioners described below may be beneficial or,
preferably, topsoil may be applied in accordance with Practice 5.04. Topsoding.
Soil Conditioners
In Order to improve the structure or drainage characteristics o' a soil, the
following material may be added. These amendments should only be necessary
where Soils how limitations that make them poor for plant growth or for tine
turf estobllshment (see Chapter 3, Vegetative Considerations).
Peat -Appropriate types ore phognum moss pool, hypnum moss peal, reedsedge peal,
or pact humus, all from fresh -water Sources. Petit Should be shredded and
conditioned in storage piles for of least 6 months after excovation.
Sand -clean and free of toxic materials
Vermiculite -horticultural grade and free of toxic substances.
Rotted manure -stable or cattle manure not containing undue amounts of straw or
other bedding materials.
Thoroughly rotted Sawdust- free of stones and debris. Add 6 lb. Of nitrogen to
each cubic yard.
Sludge -Treated sewage and Industrial Sludges we available in varlous forms:
these should be used only in accordance with local, State and Federal
regulations.
Species Selection
Use the key to Permanent Seeding Mixtures (Table 6.1 its) to select the most
appropriate seeding mixture boded on the general site and maintenance factors.
A listing of species, including scientific names and charoctwist cs, is given
in Appendix 8.02.
Seedbed Preparation
Install necessary mechanical erosion and sedimentation control practices before
seeding, and complete grading according to the approved plan
Lime and fertilizer needs should be determined by soil tests. Soil testing is
performed free of charge by the North Carolina Deportment of Agriculture soil
testing laboratory. Directions, sample cartons, and Informatior, sheets are
available through county agricultural extension offices or from NCDA. Because
the NCDA soil testing lob requires 1-6 weeks for Sample turn -around, sampling
must be planned well In advance of final grading. Testing is aw done by
commercial laboratories.
When soil test ore not available, follow roles suggested m the Individual
Specification sheet for the Beetling mix chosen (Tables 6,11c through 6.11v).
Applcalims rates usually foil Into the following ranges:
- Ground agricultural limestone
Light -textured, sandy sails; 1-1 1/2 tons/ocre
Heavy textured, clayey sods 2-3 tone/ocre
- Fertilizer:
Grasses 800-1200 lb/ocre of 10-10-10 (or the equivalent;
Gross -legume mixtures: 800-1200 Ib/ocre of 5-10-10 (or the equivalent)
Apply lime and fertilizer evenly and incorporate into the top 46 inches of BON
by disking or other Suitable means. Operate machinery an the contour. When
using a hydroseeder, apply lime and fertilizer to a rough, loom: Surface.
Roughen surfaces according to Practice 6,03, Surface Roughening.
Complete seedbed preparation by breaking up large clods and raking Into a
smooth, uniform surface (slope less than 3:1) FNI in or level depressions than
can collect water. Broadcast seed into a freshly loosened Seedbed that has not
been sealed by rainfall.
Table 6.11s - Seeding No. 4CP for
Well -Drained Sandy looms to Dry Sands, Coastal Plain; Low to Medium -Core Lowns
Seeding mixture
Species - Centipedegross - Rote - 10-20 Ib/ocre (seed) or .10 bu/ocre (sprigs)
Seeding dal" - Mw. - June, (Sprigging con be done through July where water is
available far Irrigation.)
Soil amendments - Apply line and fertilizer according to SON best, or apply 300
lb/acre 10-10-10.
Sprigging - Plant prigs in furrows with a tractor -drown transplanter. or
broadcast by hand.
Furrows should be 4-6 inches deep and 2ft apart. Place prigs about 2 ft. aport
In the raw with we end at or above ground level (Figure 6.114).
Broadcast at rates shown above, and press sprigs into the top 1 1/2 inches of
SON with a disk set straight So that sprigs me not brought bo(k toward the
Surface.
Mulch - Do not mulch
Maintenance - Fertilize very Sparingly- 20 Ib/ocre nitrogen in spring with no
phosphorus. Centipedegross cannot tolerate high pH or excess fertilizer.
Table 6.11 t - Seeding No. 5CP for: Well -Drained Sandy Looms to Dry Sands; Low
Maintenance
Seeding mixture
Species Rota (lb/acre)
Pensacola Bohiogross 50
Sericeo lespedezo 30
Commm Bermudograss 10
German millet 10
Seeding not"
1. Where a neat appearance is desired, omit sericeo
2. Use common Bermudograss only m isolated sit" where it cannot become a pest.
Bermudogross may be replaced with 5 lb/acre centipedgrost.
Seeding dot" - Apr. 1 - July 15
Soil amendments - Apply lime and fertilizer according to soil lusts, or apply
3,000 lb/acre ground agricultural limestone and 500 lb/acre 10-10-10 fertilizer.
Mulch
Apply 4,000 Ib/ocre grain straw or equivalent cover of onother Suitable mulch.
Anchor by tacking with asphalt, roving and netting or by crimping with a mulch
anchoring tool. A disk with blades set newly straight can be used as o mulch
mchoring tool.
Maintenance - Refertilize the following Apr. with 50 lb/acre nitrogen. Repeat
as growth requires. May be moved Only Once a year. Where .) neat appearance is
desired, arnit sericao and now as often as needed.
Table 6.11v - Seeding No. 7CP for: Gross -lineal Channels; Coastal Plain
Seeding Mixture
Species - Common Bermudogross - Rate - 40-80 (1/2 Ib A,300 ft )
Seeding dotes - Coastal Plain; Apr - July
SON amendments - Apply lime and fertilizer according to veil :asts, or apply
3,000 lb/acre ground agricultural limestone and 500 Ib/ocre 13-10-10 fertilizer.
Mulch - Use lute, excels!" matting, or other effective channel lining material
to cover the bottom of channels and ditches. The lining should extend above the
highest calculated depth of flow. On channel side slopes above this height, and
in drainages not requiring temporary linings, apply 4,000 Ib/ose grain straw
and anchor straw by stapling netting over the top.
Mulch and anchoring materials must be allowed to wash down dopes where they cm
clog drainage devices.
Maintenance -A minimum of 3 weeks is required for establishr•hent. Inspect and
repair mulch frequently. Refertilize the following Apr. with 50 b/ocre
nitrogen.
Rater to Appendix 8.02 far botanical names
Outlet Stabilization Structure
Specification i 6.41 - Construction Specifications
1. Ensure that the wbgrode for the filter and riprop follows the required lines
and grades shown in the plan. Compact any fill required In the wbgrode to
the density of the surrounding undisturbed material. Low areas In the
subgrade con undisturbed SON may also be filled by Increasing the riprop
thickness.
2. The riprop and gravel filter must conform to the specified grading limits
shown on the plans.
3. Filter cloth, when used, must meet design requirements and be property
protected Mom punching or leasing oaring Installation. Repair any damage by
removing the riprop and placing nnother piece of filter cloth over the
damaged greet• All connecting joints should overlap a minimum of I ft. If
the damage is extensive, replace the entire filter cloth.
4. Riprp may be placed by equipment, but take care to avoid damaging the
filter.
5. The minimum thickness of the riprop should be 1.5 times the maximum stone
diameter.
6. Riprop may be field Stan* or rough quarry stone. It should be hard, angular,
highly weather-resistont and well graded.
6. Construct the apron on zero gross, with no overfoll at the end. Make the top
of the riprop at the downstream and level with the receiving area or slightly
below it.
8. Ensure that the apron is properl; aligned with the receiving stream and
preferably straight throughout its length. If a curve is needed to fit site
conditions, place it in the uppersection of the apron.
9. Immediately ofler construction, stobilize all disturbed areas with vegetation
(Practice 6.10, Temporary Seeding, and 6.11, Permanent Seeding).
Maintenance
Inspect riprop Outlet structures after heavy rains to see if any erosion around
or below the riprop has taken place a If stones have been dislodged.
Immediately make all needed repairs to prevent further demoge.
Fabric Oroo Inlet Protection (Temporary)
Specification / 6.51 - Construction: Specifications
1. As synthetic fabric, use o pervious sheet of nylon, polyester, or ethylene
yam -extra strength (50 Ib/I inch minimum) -that contains ultraviolet ray
Inhibitors and stabilizers. Fabric should be sufficiently porous to provide
adequate drainage of the lemporory sediment pool. Burlap may be used for
short-term applications. It mus: be replaced every 60 days.
2. Cut fabric ham a continuous roll to eliminate joints.
3. For stakes, use 2 x 4 Inch wood (preferred) or equivalent metal with a
minimum length of 3 ft.
4. Space stakes evenly around the perimeter of the Inlet a maximum of 311.
oporl, and securely drive them Into the ground, approximately 18 inches deep.
5. To provide needed stability to the Installation, frame with 2 x 4-Inch wood
strips around the crest of the overflow ores at a maximum of 1.5 ft above the
drop Inlet crest.
6. Place the bottom 12 Inches of he fabric In a trench and backfll the trench
with at least 4 inches of crushes stone or 12 inches of compacted Soil.
7. Fosten fabric securely to the stars and frame. Joints must be overtopped to
the next stake.
S. The top of the from@ and fobelc must be well below the ground elevation down
dope from the drop inlet to keep runoff ft= bypassing the Inlet. It may be
necessary to build a temporary dike on the down slope side of the structure
to prevent bypass flow. Material from within the sediment pod may be used
far diking.
Mointwonce
Inspect the fabric borrier after each rain and make repairs at needed.
Remove sediment from the pod arm as necessary to provide adequate storage
volume for the next rain. Take care not to damage or undercut the fabric during
sediment removal.
When the contributing drainage or" has been adequately stabilized, remove all
materials and my unstable sedimeni and dispose of them property. Bring the
disturbed area to the grade of tha drop Inlet and smooth and compact it.
Appropriately stabilize all bare arechound the Inlet.
Land Grading
Specifications / 6.02 - Construction Specifications
1.Cmstruct and maintain all erosion sad sectimentalim control practices and
measures in accordance with the approved sedimentalim control plan and
construction schedule.
2.Remove good topsail from woos to be graded and filled, and preserve it for
use in finishing the grading of all critical areas.
3.Scorify areas to be tpsoiled to a minimum depth of 2 inches before placing
topsoil (Practice 6.04, Topsoding).
4.Clear and grub areas to be flied to remove trees, vegetation, roots, or other
objectionable material that would affect the planned stability of the fill.
5.Ensure that fill material Is free of brush, rubbish, rocks, logs, stumps,
budding debris, and other molartds Inappropriate for constructing stable
fills,
6.Pface all fill in layers not to excess 9 Inches In thickness, and compact the
layers as required to reduce eroslae, slippage, settlement, or other related
problems.
7.Do not incorporate frozen material or soft, mucky, or highly compressible
materials into fill dopes.
8.Do not place fill an a frozen foundstiOn, due to possible Subsidence and
slippage.
9.Keep diversions and other water conveyance meosures free of sediment during
all phases of development.
10.Hondle seeps or springs encountered during construction in accordance with
approved methods (Practice 6.81, Subsurface Drain),
I I.Permanently stabilize all graded areas Immediately after find grading Is
completed an each area In the grading plan. Apply temporary stabilization
measures an all graded areas when work is to be interrupted or delayed for 30
working days or longer.
12.Ensure that topsoil stockpiles, bmow areas, and spar woos ore adequately
protected from erosion with lemparory and find stabdizotim measures, including
sediment fencing and temporary seedhig as necessary.
Maintenance
Periodically check all graded areas and the supporting w"im and sedknentolion
control practices, especially after heavy roinfolls. Promptly remove all
sediment from diversions and other water -disposal practices. If washouts or
breaks occur, repair them Immediately. Prompt maintenance of small eroded areas
before they become significant gullies is an essential port of an effective
erosion and sedimentation control pin.
EROSION CONTROL DETAILS AND SPECIFICATIONS ARE AS PER THE "EROSION
AND SEDIMENT CONTROL PLANNING AND DESIGN MANUAL" OF THE STATE OF
NORTH CAROLINA, DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES,
LATEST EDITION. PRACTICE NUMBERS REFER TO THIS MANUAL.
CONTRACTOR IS RESPONSIBLE FOR MAINTAINING A COPY OF THIS MANUAL
ON -SITE AND ENSURING THAT ALL SUPERVISORS ARE FAMILIAR WITH THE
STANDARDS AND SPECIFICATIONS SHOWN IN THE MANUAL AND ON THE PLAN.
Sediment Fence (Silt Fence)
Specification 6.62 - Construction Specifications
MATERIALS
1.Use a synthetic filter fabric or o pervious sheet of polypropylene, nylon,
polyester, or polyethylene yarn, which is certified by the manufacturer or
suppliw as conforming to the requirements shown in Table 6.62b. Synthetic
filter fabric should contain ultraviolet toy inhibitors and stabilizers to
provide a minimum of 6 months of expected usable construction life at a
temperature range of 0 to 120 F.
2.Ensure that posts for sediment fences are either 4-inch diameter pine, 2-Inch
diameter oak, or 1.33 lb/linear ft steel with o minimum length of 4 ft. Make
Sure that at" posts how projections to facilitate foslening the fabric.
3.F" reinforcement of standard strength fllter fabric, use wire fence with o
minimum 14 gouge and a maximum mash pacing of 6 Inches.
Table 6.62b
Specifications For Sedknent Fence Fabric
Physical Property Requirements
Filtering Efficiency - 85R (mm)
Tensile Strength at Standard Strength- 30 lbAin in (min)
Extra Strength- 50 Ib/IIn in (men)
Slurry now Rate - 0.3 got/sq It/min (min)
CONSTRUCTION
1.Constmet the sediment barrier of standard strength or extra strength
synthetic filter fabrics.
2.Ensure that the height of the sediment fence does not exceed 18 inches above
the ground Surface. (Higher fences may impound volumes of water Sufficient to
cause failure of the structure.)
3.Construct the filter fabric from a continuous roil cut to the length of the
barrier to avoid Joints. Man joints are necessary, securely foslen the fill"
cloth only at a Support post with overlap to the next post.
4.Suport standard strength filter fabric by wire mesh fostered securely to the
up dope side of the posts using heavy duty wire staples at least 1 inch long,
or tie wires. Extend the wire mesh Support to the bolt= of the trench.
5.1Man a wire mesh Support fence Is used, pace posts a maximum of 8 ft opor:.
Support poets should be liven securely Into the ground to 0 minimum of 18
inches.
S.Extro Strength filter fabric with Bit post pacing does not require wire mash
Support fence. Staple or wire the flit" fabric directly to posts.
7.Excavate a trench approximately 4 Inches wide and 8 inches deep along the
proposed line of posts and upsiope from the barrier (figure 6.62a).
S.Backfill the trench with compacted sod or gravel placed over the filler
fabric.
9.Do not attach filter fabric to existing trees.
Maintenance
Inspect sediment fences of least once a week and after each rainfall. Make any
required repairs immediately.
Should the fabric of a sediment fence collapse, tow, decompose or became
Ineffective, replace it promptly. Replace burlap every 60 days.
Remove sediment deposits as necessary to provide adequate storage volume for tie
next rain and to reduce pressure on the fence. Take care to avoid undermining
the fence during clewout.
Remove all fencing materials and unstable sediment deposits and bring the area
to grade and stabilize it after the contributing drainage area has been property
stabilized.
Sediment Basin
Specifications /1 6.61 - Construction Specifications
i.Site preparations -Clear, grub and strip topsoil from areas under the
embankment to remove trees, vegetation, roots and other objectionable material,
Delay clearing the pod wadi until the dam is complete and than rernove brush,
trees and other objectionable materials to facilitate sediment clemout.
Stockpile ail topsoil or soil cmtoining organic matter for use on the outer
shell of the embankment to facilitate vegetative establishment. Place temporary
sediment control measures below the basin as needed.
2.Cut-off trench -Excavate a cut-off trench olwg the centerline of the earth
fill embankment. Cut the trench to stable soil material, but in no coact make it
less than 2 ft, deep. The cut-off trench must extend into both abutments to a
least the slewtim of the riser crest. Make the minimum boll= width wide
enough to permit operation of excavation and compaction equipment but in no tase
Ion than 2 ft. Make side dopes of the trench no steeper than 1: 1, Compaction
requirements are the Same as those for the embankment. Keep the trench dry
during backfilling and compaction operatims.
3.Embonkment-Take fill material from the approved areas shown an the plans. II
should be dean mineral soil. Mee of roots, woody vegetation, rocks and other
objectimobie material. Scarify areas an which fill is be placed before placing
fill. The fill material must contain sufficient moisture So it cm be formed by
hand Into a ball without crumbling, if water can be squeezed out of the ball. It
Is too wet far proper compaction. Place fill material in 6 to 8-Inch
continuous layers over the entire length of the fill area and than compact It.
Compoclim may be obtained by routing the crostruotim hauling equipment over
the fill so that the entire Surface of each layer Is traversed by at least we
wheel w tread track of the heavy equipment, or a compactor may be used.
Cmetrucl the embankment to on elevation 10% higher than the design height to
allow for settling.
4.Cwduit spillways-Seeuraly attach the riser to the barrel or barrel stub to
make a watertight structural connection. Secure all connections between barrel
Sections by approved watertight assemblies. Place the barrel and riser on a
firm, smooth foundation of impervious soil. Do not use pervious material such
as sand, gravel, or crushed stone as bockfill oround the pipe or anti -seep
call"& Place the fill material wound the pipe spillway in 4-inch layers and
compocl it under and around the pipe to at least the same density n the
adjacent embankment. Core must be taken not to raise the pipe from firm contact
with its foundatm when compoctin under the pipe haunches.
Place a minimum depth of 2ft. of hand -compacted backflll over the pipe spillpy
before crossing it with construction equipment. Anchor the riser In place by
concrete or other satisfactory means to prevent flotation. In no case should the
pipe conduit be Installed by cutting a trench through the dam after the
embankment is complete.
5.Emergency spillway-Inaloll the emergency spillway in undisturbed Sod. The
achievement of planned elevations, grade, design width, and entrance and exit
channel slopes are critical to the successful operation of emergency pillway.
6.Inlets-Discharge water Into the basin in a manner to prevent orosim, Use
diversims with outlet protection to divert sediment-loden water to the upper
and of the pod wee to Improve basin trap efficiency (References: Runoff
Control Measures and Outlet Protection),
7.Er"ion control -Construct the structure so that the disturbed or" is
minimized. Divert surface water away from bare areas. Complete the embankment
before the areas is dewed. Stabilize the emergency spillway embankment and al
other disturbed areas above the crest of the principal spillway immediately
after construction (References: Surface Stabilization).
B.Sofety-Sediment basins may attract children and can be dongerous, Avoid stoap
aide slopes, and fence and mark basins with warning signs if trespassing is
likely. Follow all slate and local requirements.
Maintenance
Check sediment basins ofler periods of significant runoff. Remove sediment one.
restore the basin to its original dimensions when sediment accumulates to ors -
halt the design depth.
Check the embankment, spillways, and outlet for erosion damage, and inspect the
embankment far piping and settlement. Make all necessary repairs immediately
Remo" all trash and other debris from the riser and pod area
NOTE:
DETAILS SHOWN ARE TYPICAL OF INSTALLATIONS REQUIRED BY NEW HANOVER COUNTY.
THIS SHEET DOES NOT PURPORT TO SHOW ALL REQUIRED CONSTRUCTION DETAILS, BUT
RATHER SERVES AS A GUIDE. THE CONTRACTOR IS RESPONSIBLE FOR ADHERWG TO ALL
COUTY AND STATE CODES AND CONSTRUCTION STANDARDS.
REV, NO. REVISIONS DATE
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GENERAL EROSION CONTROL SPECIFICATIONS and ADDITIONAL DETAILS for
CAROMNA COAST HARLEY DAVIDSON
LOCATED IN JACKSONVILLE TOWNSHIP
ONSLOW COUNTY, NORTH CAROLINA
OWNER; NOYES HOLDINGS COMPANY, LLC
6620 MARKET STREET
WILMINGTON, NC 28405
(910) 791-9997
FiANOVER DESIGN SERVICES, P.A.
LAND SURVEYORS, ENGINEERS efr LAND PLANNERS S
319 WALNUT STREET
WLMINGTON. N.C. 28401
PHONE: (910) 343-8002
Dote:
5-5-0.3
Scale:
AS SHOWN
Drawn:
HSR
a
3HSR
Sheet No:
3
Of: ._
: 10:',4:22 05/05/2003
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