20210125 - Modification Maps

. 0
intermittent Stream
S8 ° 07'-68 38756
am
73.56 Total ECM -ECM �s><te /
- - -- - - 390 - -
C'
ECM CP ,
-- - ECM
Mine Permit S82° 05' 59"E 86 0'
35.0o Limps and Pr -
��- -
25sturbed g s81 ° 40' 03 °pe�y Line
-- - -- r Uffer "E410.75, 42 31 E3419
400 S80°
II ERB Plant Approx. 650 Lineal Feet of Shrubs, Trees, or Bambo%,*ong East Permit Limits
-41
I -- --- ---ECM-
-i/
q00
-4Stone to Remain nplace
- - --
i
- - -- - - - -- - �1a� mp ��� ,!
- - -- - �- _ ago
�ePdlmentuO 6
�f/- _ �� Trap, i r ROC i'
Legend
External Mine Limits/ Property Lines
Internal Mine Property Line & Easements
Adjacent Property Lines
25' Buffer (Undisturbed and Unexcavated)
Basin/ Pond
Drainage Feature
Dirt Haul Road/ Driveways
Structures
Existing Topography (10' intervals)
U) I� -- 4oa370
ine SI , , r,
° Protection"'
-0,. Prote rl >> � ,, Proposed Topography (10' Intervals)
390
; Rock Outlet/ Discharge Loaction for Pump ��� �\ �
� � -0! Dewatering Pump Location
Beneficial Fill � �, �s��, 0(DC
/ ' Cov
�`� 9SQ♦N11Q o .5 High Temporary Soil Berm
i�N\
o Sa
O�
Add Beneficial Fill in Buffer. Slope Ground Downward at 1 % �S,u°.O V
Toward Mine Excavation. Once Past 25' Buffer, Slope Ground\ �I/> Lr \ A� Immediately Install Temproary Silt Fence and Soil Berm and revegetate /
,
at 2:1 (H:V) or Flatter. Revegetate Ground Immediately. �s ♦�� Ground Between Berra and 25' Buffer.
f r'
/7` I �
N
LOCATION MAP
_HWY 15-501
1IWY 54
Not -to -Scale
Chapel Hill
Greensboro
St- - - -
BY PASS
Smith Level Rd..
SITE
SR-1994
Damascus Ch. Rd.
�0
HWY 15-501_
Limits of Disturbance
(Outside of Permit Limits)
Limits of Disturbance (life Of Mine)
Existing limits of Beneficial Fill
0.035 itlft -
Proposed Ditch
Ditcfi Trivert Slope and Flow Direction
Proposed Stone Lined Ditch
Proposed Proposed Sediment Basin
Proposed Silt Fence
Stone Fitter Outlet
Proposed Soil Berm
- - -- Deeded Access Right -of -Way
@ ,l .Remove Existing PVC Pipe and Grade
- - - - - - - - - Present Mine Area
R w a Ground to Slope o Active Mine
rNote: Install Silt Fence before Soil Berms.
f Internal Parcel LineC14 �.
� . / Internal Parcel Lin_ e -
��,
Plant Approx. ine Feet ofShrub s, Trees or Bamboo along East Permit Limits t
PROJECT Dewatering Pump Inlet Location i� �' OJ CT DISCUSSION
' � N \ NRBw/Cap
�\ Wet Pond - / e subject mine contains 26.12 acres of IandModifications are proposed and include:
�A ''Nft 1. Relocation of the pump discharge basin.
11l2. Placement of fill in the northeast comer of the mine to develop the 25 ft. undisturbed buffer
♦ / "�I (about 12,400 cubic yards of fill soil required) .
450 -- 3. Plant shrubs, trees, orbamboo along portions of the east undisturbed buffer (about 650
l r - - - - ',; \sti`et� lineal feet of buffer area requires the vegetation for screening the mine).
• NRBw/Cap 1 4. Slope ground along the eastside of the mine excavation toward the mine and a 1% slope
r s P
or steeper.
/ 5. Install Culvert N o. 1 down slope of the access/haul road to divert water into the mine.
the slo Revegetate
6. / j I Basin A (Pump Discharge Basin) - --- - s�6',. ���� g ped, undisturbed blfiler along the west side of the mine limits.
'0
S�. �� The proposed mine modification also includes the addition of 0.71 acres of land where the
access/haul oad is located. The permit limit is proposed at the west side of the 60 ft. easement to
' 1( I --- _ . � --- � `\ • `_-, / i � � cs? �� � 9 � House forma 55 ft. wide unexcavated buffer. With the added land, the total permitted land will be 26.
83
P P p
l 1 _ 1 // ♦ �p acres. Total disturbed land will be 23.73 acres for the life of the m ine (about 20 years).
Revegetate Ground / % / �� CIC The mine is an excavation below the surrounding ground levels. No stormwater gravity flow is
allowed. Stormwater accumulates in the excavation and the water level generally reflects the
l , 1 Shallow groundwater table. During heavy rains, and typically between late fall and early spring,
pumping
is required. Pumping will be at a maximum rate of 1000 gpm. The pump discharge is through a
Excavation
1 Area e a lea a -micro ice size. w p
the 40 particle Total ate
1 - daily ill not exceed 1gallons.P
cavatio sediment basin that is sized to remove n a r pumped
�� ail w O,000
l' 1 "� ♦ Qi�. Concurrently with mining , beneficial fill will be used to fill the excavation and reclaim the mine
area As the mine excavation is filled and before stormwater can no longer be contained in the
'1 isturbanc
mine excavation two sediment basins are required to accommodategravity stormwater runoff.
Limit
l % ��I'� �% ;/ - ..♦5 ,���0 ��• Upon completion of mining, beneficial fill placement, and ground stabilization, the pump basin
and sediment basins will be removed and vegetated. However, the berm and outlet structure for
,1
Z - to the adjacent pond. The haul road
located in a easement an e office building I remain in -place.
_ � � � •�' <<' Basin No 2 will remain in place to convey the stormwater to the adja t o
♦ � �� d dth ff b Id ng will place
" \
-- YProposed 24" Dia HDPE Pipe
— — (Culvert No. 1) /
/ e /Zoj
----- '\
�v
w/Shelters EIP IVEr
N -- -- - -- — — — _ _ _ _ _ 8 __ `_ " Old
SEC
�o���
Or ' NRB /Ca o JIIL 1Q8Z£g-Dl Axle- Ip r Foundation B / Jr�N 251021
0000 ��.00� ,
- _
- - - - - -
`— -L —' OGLand Disturbance(Life of Mine) LAND PRP�i"T;
3' Deep Excavation 1'062.68' =_ _ - Office ;� / Itemized Distrubance Area Acres
mis __ _
Beneficial Fill ENGINEERING &ENVIRONMENTAL DATE'
tmi_ 4'5 2C SCIENCE COMPANY 01/25/2021
3008 Anderson Drive Suite 102
Gray@ham-��E - Raleigh, NC 27609 DRAWN:
— — —` Existing Mine Excavation [phone] TIPS
Excavate 3' Deep Excavation at Culvert Outlet. Install 2' Dia. Pipe
Inlet and Outlet. Processing Area/ Haul Roads EXISTING CONDITIONS REVISED
and Install Class B Erosion Control Stone at Culvert :
1 /25/21
Tony Merritt s Gravel Pit
\ sign
Perm �o �yit No. 68-04 SCALE:
Tailiings/Seiment Ponds 1.8 _ Orange County NC 1"=60'
Q
480 = [ SEAL
Total = t 15472 / / i� Sheet No.
,;; Tony Merritts Gravel Pit
23.73 = O-E'rcr>� 3200 Damascus Chruch Road _
"' Chapel Hill, NC 27516

A
.
wE� E
�73.5eTotal ECM -ECM inn
S���i
j 2
ECM CP-
- - - EGM-' _
i
Note. Slope Ground Away
From Exterior Slope
`NTVross—Section A -A'
�I/11ne permit LI , A _ Benifical Fill
35.00' mits end P S82° 05' 59"E 8:00' -��/ " "
2. Undisturbed s81 °40,031,-
- - - -- -- -- - -- - -- Buffer 410.75' roperty Line /-
400 S800 42' 31 "E 34,19' %
-- ---
---._ ERB Undisturbed ,.,_------
_ _ -- - ----- _---•�-,_ - -- -4 ___ _ EE{N-- i Buffer Mine Excavation Floor
I' 400 ------
--_ _ i Maintenance Plan
-- - - 430 - -- _ l --e = -SIP -- � ---
----- 1. All erosion and sediment control practices shall be checked for stability
� �- \\
----___ --------. - -- and operation following every runoff -producing rainfall but in no case less
t} b
', , � � , ; �„s s ___ ',�� ,' thanonce weekly. Any needed repairs will be made immediately to maintain
tap r__i"J J.., l C o 0 t 0 o O l o o O o ` i,
II C c k Ll o 0 o all practices as designed. e
re a
�a° " ,�-�'' e e 0 � t> o-�e���� 0 2. Sediment will be removed from the basins when accumulation is 2 ft.
390 - - - 0 0 0 0 3. Check Faircloth Skimmer for any defects and repair as needed. If skimmer
fi
Roo outleU oiscnarge Loactlon for Pump S - -- ° ° °o ° is imbedded in the sediment, pull skimmer from the sediment and allow
Beneficial Fill °°
C ,� � the skimmer to rest on to of the sediment surface.
�i i �' 440 �Ssue♦ °o°o 0 4. Check silt fence for any failure and repair as needed.
/�� ♦ 000
a o�.� ° Reclamation Considerations
,
/ 7 1. Revegetate all areas exposed.
,
2. Remove errosion control structures except
�^ for Basin No. 2. For this basin leave downstream berm
and outlet structure in-place-
o i
' / \ 70„ 3. Leave access drive in -place.
cIr
co
NRBw/Cap
Internal Parcel Line --------
Intern 1 Parcel Line _ _ _ - - — Scale: 1 "=60'
NF \ NRBw/Cap
\" rk�°
,j
i
'fn
�e
01
/ Bw/Cap ,N�
Wet Pam! 1100r-
S
T
f 0
3asin No.2 ✓ i s 7�House
CP
40,
<r ,
i
i
f
- - Excavation /
NF
ArearJ�
-
-
L_ - -- -- --✓- a -
Isturbanc©0
,ram
\'
\r /
' 1n V� `• Ground tr t vstdun
Proposed 2' Dia. HDPE Pipe j % i / ' / /
(Culvert No. 1) / ,/,w/Shelters / h�
---
i
_ �
o r / Old 5
NRBw/Ca
y--_ rT Foundation B ,
Axle=EIP /
I /
=— - 1'062.68' d Buffer Office
_ _
rI _ -ermi Imt s 1SFD
rave/_ /
Gravel _ � - _ ---_. —� JKLE
P
A'
lit . rt Sign480
/\
Site Area
Stabilization
Stabilization '['line
Description
Time Frame
Frame Exceptions
• Ki litter dikcs,
sw des ditches
7 days
None
and alu -s
• I ltbh Quality
Water(HQW)
7days
None
Zones
Ifslopes are 10' or
• Slopes steeper
7 days
less in length and are
than 3:1
not steeper than 2:1,
14 days are allowed.
• Slopes 3:1 or
7-days for slopes
natter
14 dais
greater than 50 feel
in length
• All other nrr;ts
None
Willi Slopes Ilauer
14 days
(except lbr
(hut 4:1
perimeters and
llW Zones)
- "Lxleasions of time may be approved by the permitting authority
basal on weather or other •.ire speeilic Comlgtions that make compliance
impracticable!' (Section ll B(2)lb)) --
Note: Slope Ground Away
From Exterior Slope
25' IUnexcavated.
Buffer - —
A'
n�
I a`a
Road
60' Easement
Erosion Control Sequence and Reclamation Considerations
1. Relocate Pump Basin.
2. Continue mining to the east and north with beneficial fill
placed for reclamation of the mine. Final beneficial fill
slopes shall be 2:1 (H:V) or flatter.
3. Place benficial fill so all runoff drains into the mine and not
onto the perimeter 2:1 (H:V) slopes.
4. Construct Basins 1 and 2 when runoff from the.beneificial
areas can not direct stormwater runoff to the mine.
5. Install silt fence and stone outlets to aid runoff collection.
6. Construct Ditches 1 and 2 as needed to divert stormwater to basins.
7. Re -vegetate the ground per the existing mine permit
requirements.
8. Once ground cover is established, remove basins and extend
diversion ditches through the basins.
10. Remove silt fence once Basin areas are stabilized.
Vegetation Plan
1 Spread topsoil over disturbed areas and leave surface reasonably smooth and uniform
2 Scarify surface in prepare a seedbed four to six inches deep. Use such equipment as
idling, discing, tracing, or the teeth on a front end loader.
3.Mix lime and fertilizer with the soil during seedbed preparation.
4.Seed on freshly prepared seedbed following the application rates for the appropriate season.
3 Mulch all seeded areas immediately.
5 Tack mulch on slopes 3:1 (Horizontal : Vertical) or steeper by spraying with emulsified asphalt.
Use an anchoring tool such as a fanning disc set in a vertical position on slopes less than 3:1.
Mulch netting may also be used on slopes.
4.Inspect seeded areas and make repairs within the planting season. If vegetation is over 60%
damaged, repeat steps 2 through 5.
gPermanent revegetation shall be accomplished at the specified times of the year. Temporary
vegetation shall be applied outside of the optimal times for establishment of permanent vegetation
9.Seeding Schedule.
TEMPORARY SEEDING SCHEDULE
Seeding Date: August 15 to December 15
Seed Type Rate
Rye (grain) 120lbs /acre
10-10-10 Fertilizer 1,000 lbs /acre
Lime 2,0001bs./acre
Mulch 4,000lbs /acre
Seeding Date: January 1 to May 1
Seed Type Rate
Rye (grain) 120 lbs./acre
Lime 2,000 lbs /acre
10-10-10Fertihzer 750 lbs./acre
Mulch 4,000 lbs./acre
Seeding Date: May I to August 15
I
Seed Type Rate
German Millet 40 lbs./acre
10-10-10 Fertilizer 7501bs./acre
Lime 2,0001bs./acre
Mulch 4,000 lbs1acre
PERMANENT SEEDING SCHEDULE
Seeding Date: Best Possible
Fall. August 25- September 15 August 20- October 25
Late Winter: February 15- March 21 February 1- April 15
Seed Type Rate
Tall Fescue 100 lbs1acre
Sericea Lespedeza 30 Ibs./acre
Kobe Lespedeza 10 lbs./acre
10-1040 Fertilizer I,0001bs./acre
Lime 3,0001bs./acre
Mulch 4,000 Itax/acre
Note 1 Fertilizer and lime application rates may deviate from above if soils are analyzed
for optimum rates.
Nate 2 Mulch shall be tacked with emulsified asphalt at rate of 14 to 28 gallons/1,000 sq. ft.
on slopes of 3:1 HI N) or steeper. ,
Note 3: After August 15, use Unscathed Settles seed for permanent seeding period.
3Na 2 5 1611
i_AND QR®_liV ,
IlNIND
ENGINEERING & ENVIRONMENTAL
DATE:
2 C SCIENCE COMPANY
01/25/2021
J 3008 Anderson Drive Suite 102
DRAWN:
Raleigh, NC 27609
TPS
[phone]
RECLAMATION PLAN
REVISED:
1 /25/21
„onIIIllttrttrrr r
Tony Merritt's Gravel Pit
SCALE:
"=60'
��.��p,�,(HaZir'''%
Permit No. 68-04
Grange County, NC
1
.SEAL.
Sheet No.
z. 15472 �!r
Tony Merritt's Gravel Pit
•.
s` F1'°�
"''4,47�K
3200 Damascus Chruch Road
C 21
sN���`r °'
r'vpttn1110 "`
Chapel Hill, NC 27516

SEDIMENT BASIN W/ SKIMMER DETAIL,
TOP OF EMBANKMENT
RISER STRUCTURE
IF MIN
vu,totv.pmml.,i.y
\ TRASHRAC �� m""ry i•�'L ' �_
fRerlwaao- A1�-Ti'NH��Nk EMERGENCY SPILLWAY
i/i 1'MIN �.IWU^MY�IsYU..-.u{'�_.
SKIMMER -►
4
t'Z
CLASS B STONE PAD
(4' X 4' X 1' MIN.)
ANTIFL TO A ION BLOCK
SECTIONAL VIEW t
CUT-0FF
ANTI_SEE
TRENCH
EOLLAft
2' DEEP
1.1
NOTES
1. SEED AND PLACE MATTING FOR EROSION CONTROL ON INTERIOR AND EXTERIOR SIDESLOPES.
2. INSTALL A MINIMUM OF 3 COIR FIBER BAFFLES IN ACCORDANCE WITH PRACTICE STANDARD 6.65.
3. INSTALL SKIMMER AND COUPLING TO RISER STRUCTURE OR DIRECTLY INTO EMBANKMENT 1 FT. FROM BOTTOM OF
4. THE ARM PIPE SHALL HAVE A MINIMUM LENGTH OF 6 FT. BETWEEN THE SKIMMER AND COUPLING.
BARREL
PIPE
STABILIZED
OUTLET
NOT TO SCALE
Pipe Connections
- Ensure that all conduit connections are watertight. Rod and
lug type connector bands with gaskets are preferred for corrugated
metal pipe to assure watertightness under maximum loading and internal
pressure. Do not use dimple (universal) connectors under any
circumstances.
Trash guard
-It is important that a suitable trash guard be installed to prevent the riser
and barrel pipes from becoming clogged. Install a trash guard on the
top of the riser to prevent trash and other debris from clogging the conduit.
A combination anti -vortex device and trash guard improves the efficiency
of the principal spillway and protects against trash intake.
Protection against piping
- Install at least one watertight antiseep collar with a minimum projection
of 1.5 feet around the barrel of principal spillway conduits, 8 inches or
larger in diameter. Locate the anti -seep collar slightly downstream from
the dam center line. A properly designed drainage diaphragm installed
around the barrel may be used instead of an anti -seep collar when it is
appropriate.
Proposed Sediment Basin Calculations
- -_ Design Elevations ft. EL
Surface Area at normal pout, Horizontal brief IIOIz� Crest Of
Watershed Weighted Inflow 3 Hare h._ Storage Volume, Cubic Ft. Skimmer Draw Down (3) Invert of To of To of
Area Average To, (t) 4 - 2 Area q 'set Did.,' Barrel Dia., Height of i Invert of P P 10 yr 24-hr 25-yr 24-hr
Basin Q cfs - O (2) Orifice, Time, hours Riser Secondary Berm Storm Elev. Storm Elev.
(acres) CN minutes 10, Required Provided Dist., acre Re cored Provided ches inches Berm, ft. I
-. _ inches _ Pie Pipe Spillway
A 3.91 74 - - 6,800 - - -
Rnm 13asR) 8.8 15.54 6,760 3.60 6,480 7,376 -2 -- - --- -- --
1 12" 102.75
p_ .... tnaxszs'>_ 53.9 5 5.5' 100.00 99.00 ]02.00 103.00 104.50 103.20
1 4.10 75 9.2 16.59 7,216 7,400 12" 5.5' 102.00 103.00 104.50 102.85 103.26
T24xss])t 3.80 6,840 I 7,990 2 58.4 15" 100.00 99.00
9.8 88.88 38,663 38,700 18.82 33,876 4Q 158 3 - 12" 5.5' -
2 19.83 79 g80'x,362') 101.4 181, 100.00 1 99.00 102.00 103.00 104.50 103.43 103.83
(1) Required Surface Area is based on 435 sf per cfs of Q10 peak inflow NOTE: ONCRETE ANTI -FLOTATION BLOCKS FOR RISERS SHALL BE 24" X 24" X 15" HIGH.
(2) Required Volume is based on 1800 cf/ac. of disturbed area CAST -IN -PLACE CONCRETE SHALL HAVE A MINIMUM 28-DAY COMPRESSIVE
(3) From invert of horizontal pipe to top of berm STRENGTH OF 3,000 PSI.
A I -FLOTATION CALCULATIONS
Basin Maintenance TiII RISER AREA= 3.14*9..75AT= 1'.77 Sir
Inspect skimmer sediment basins least weekly and after each significant (one half inch HIGHT OF RISER= 2 FT
VOLUME DISPLACED BY RISER= 1.77 FT' 2 FT = 3.54 FT
or greater) rainfall event and repairit immediately. Remove sediment and restore the basin BOUYANT FORCE= 3.54 CF' 62.4 LB/CF = 221 LB
to its original dimensions when sediment accumulates to one-half the height of the first
baffle. Pull the skimmer to one side so that the sediment underneath it can be excavated. FACTOR OF SAFETY= 1.5
Excavate the sediment from the entire basin, not just around the skimmer or the first cell. 221 LB * 1.5 (FS) = Vconc (145-62.4)
Make sure vegetation growing in the bottom of the basin does not hold down the VOLUME OF CONCRETE NEEDED = 4.01 CF
skimmer. USE 2' X 2' X 1.25' CONCRETE ANTI -FLOTATION BLOCK
Repair the baffles if they are damaged. Re -anchor the baffles if water is flowing
underneath or around them.
Minimum 10 Gauge Line Wires
SILT FENCE DETAILS
Minimum 12-1/2 Gauge Intermediate Wires
8'MAXIM1JM -_
(venebk as Jvs lbY Nernginm) ..._-� I
� II
-- --------
Will
TOP OF SILT FENCE
MUST BE AT LEAST Y
ABOVE THE TOP OF
THE wASHED STONE
If the skimmer is clogged with trash and there is water in the basin, usually jerking on the CROSS-SECTION BAFFLE (NTS )
rope will make the skimmer bob up and down and dislodge the debris and restore flow. If
this does not work, pull the skimmer over to the side oft he basin and remove the debris.
Also check the orifice inside the skimmer to see if it is clogged; if so remove the debris. Support Post, 24' into Stake to support wire
OUTLET PROTECTION DETAILS bottom or side
If the skimmer arm or barrel pipe is clogged, the orifice can be removed and the
obstruction cleared with a plumber's snake or by flushing with water. Be sure and replace FOR BASINS
the orifice before repositioning the skimmer. - - - -
1 Support rope to wire
Check the fabric lined spillway for damage and make any re quired repairs with fabric that to prevent sagging - - -
spans the full width of the spillway. Check the embank menr, spillways, and outlet for
erosion damage, and inspect the embankment for piping and settlement. Make all �}
necessary repairs immediately. Remove all trash and other debris from the slimmer and -C% (� (�c �' Coir mesh or similar, stapled or
pool areas. .� o �Ci �/��_�,
\J trenched Into bottom or side
3 ft.
2" FAIRCLOTH SKIMMER
Skimmer shown in - --
floating position
1" Vent Aluminum straps
4" Sch 40 with Yellow tip suspending
coupling horizontal intake
connection t
o /
a c float
r r-
_� zr
1 ' z" Seh 40 sotto ppo <. --„�
barrel a "arm" ,
SUPPLIED BY USER
%r
- /
' 2' OAfice]
1, •. . ^>- inlet
1 I/F hose, as clamps 2" inlet 2" HEAD disfance
2' threaded male fitting 1
on outlet end extension from center or
ornlef to water
surface]
3" FAIRCLOTH SKIMMER
Skimmer shown in 2" vent Aluminum straps
floating position with Blue lip suspending
4' Sch 40 3" pvc float horizontal intake
coupling /
connection tr --
29"
2' Sch 40 SOLID pvc barrel �, 4 yl� �►
or "arm"
SUPPLIED BY USER c ;,
\ /
\\\,
3" Orifice/
Inlet
- ��r.: saza.r6,
2" hose, ss clamps 3" inlet 3" HEAD [distance,
2" threaded male nipple extension rrom center of
on outlet end o�ce/]n/et to water
surface]
Coupling can be removed and hose attached to outlet using the threaded nipple.
Attach directly to metal riser ensuring a water tight connection.
Note: SCH 40 solid PVC barrel/arm should be between 6' and 10' in length.
Design Flow Rates For Skimmers
2" Skimmer: 0.038 cfs
3" Skimmer: 0.11 cfs
Note: Flow rates are from Faircloth product cut sheets.
12" CMP
8 ft
L'lll'1i
Note:
Inspect outlet protection structures weekly and after significant (1/2" or greater)
rainfall events to see if any erosion around or below the riprap has taken place,
or if stones have been dislodged. Immediately make all needed repairs to
prevent further damage.
SECONDARY SPILLWAY
Basin A 10'
Basin 1: 1 Or
1 Basin 2: 12'
Laminated Pl.stic Lining or
Impermeable eotextile Fabric
SOIL BERM CROSS-SECTION
z z
3.
Collection Berm Specifications
1. Construct berm by placement of overburden.
2. Prior to placement of materials for berm formation, cut vegetation
nearly flush with ground (if applicable).
3. Compact materials in lft. lifts by construction traffic.
Maintenance
Inspect temporary diversions once a week and after every rainfall. Immediately
remove sediment from the flow area and repair the diversion ridge. Carefully
check outlets and make timely repairs as needed. When the area protected is
permanently stabilized, remove the ridge and the channel to blend with the
natural ground level and appropriately stabilize it.
Note:
Remove vegetation and topsoil from sTrEL FENCE POET
stone filter section. set miss it APART if
MIN.,W INTO SOLID
GROUND
Grade
T-0"
26"
T-0"
Silt Fence Geotextile Fabric
4"Mn.
1� .Grade
8" Minimum
4" Minimum
I
SILT FENCE STONE OUTLET
WIRE FENCE
-- 4'MIN_ -- - StTFFNOE
HARDWARE CLOTri
- - - I FILTER OF ryS]
ti--F�----��1 WASHED STONE
i� I I I I I I
WASHED STONE
FRONT VIEW
Porous Baffle Specifications
Coir Fiber Mat Specifications
1. Grade the basin so that the bottom is at equal elevation.
Thickness.
Tensile Str
'10 in. minimum
the 1348x 626 If/ft minimum
Z. Stec] posts shall be driven to at leas[ 24 inches below ground surface and spaced at 4 fr. centers.
Elongation
Flexibility.
% x 38% maximum
cm): 65030 x 29590
3. Top of fabric shall be at least 6 inches above stone spillway elevation and 2 inches lower than
Flow veto `
; Observed I 1 Trans;
berm elevation.
Weight: 2 '
SY
Size: 6.6 x°
R (120 SY)
4. Bottom and sides of fabric shall be anchored in a 6 inch tench of pinned with 8 inch long erosion "C" Fact
2
control matting staples.
Open A
assured): 50%
5. The baffles shall be composed of coin fiber matting with the following specifications.
100% co
fiber (coir) twine woven into high strength matrix
Note: Porous
s are to be tied back into basin embankments
at bottom and
of the weir.
NOTE: 3 BAFFLES ARE REQUIRED FOR
EACH S
IMENT BASIN.
BASIN N AFFLE SPACIN
A
29.5 FT.
(PUMP BASIN)
1
31 FT.
2
-70 FT.
TRASH RACK DETAILS
Perspective View
Top Grate Consists of 1 /T' Metal Bars
On 6" centers each way
Note: Angle iron welded to vortex pia _ Support Bar
with metal bolt conected to riser _
Side View
DI
D2
Riser
12„
12"
Support Bar
(#6 Rebar minimum)
Basin DI
D2
A15tt
21 if
1 15"
21"
2 18"
24"
ONOROUND
C-IN TRENCH
Silt Fence Specifications
I. Steel posts shall be a minimum of 5 fir long weigh a minimum of 1.3 lb/ft, and
have protections to aid in fastening the wire or fabric. Steel posts shall also
have a metal plate welded near the bottom such that when the post is driven
to the proper depth, the plate will be below the ground level for added stability.
2. Woven Wire Fence shall conform to the requirements of ASTM A 116,
Class I tins, (Name for wire The fence shall he at least 32 Jr. high and shall
have a Iazst 6law (horzoman wives. Stay (vertical) wires shall be spared
12 in. apart. The top and bottom wires shell be 10 gage. All other wires shall
be 12 X gage.
n*
-
3. Filter Fabric Shan be composed of fibers consisting of long chain synthetic
1 mers composed of at least 85% b weight of 1 olefins 1 esters or
PnY top Y !;b WY .PoY
P 1 OY amides. The fibers shall be formed into a network such that the filaments
or yams retain dimensional stability relative to each other. The filter fabric shall
be free of Bay treatment or coating which might adversely alter its physical
properties after installation. The fabric shall be free of defects or Flaws which
significantly affect its physical and/or filtering properties. The fabric shall have
a minimum width of 36 inches.
The filter fabric shall he furnished with suitable wrapping for protection against
moisture and extended ultraviolet prior to placement.
The filter fabric shall meet the following minimum physical requirements:
PROPERTP _ TEST hIETHOD i REQUIRED VALUE _
Tensile Strength ASTM D 4632 100 Newtons (901b)
_
Elongation IASTMD 4632 <50%- lebric self supporting
> 50%. fabric requires woven
wire backi�_ _
ApparentY P g ( )** meter N.S. Sieve #20)-
Perrautiv0(m Seo� ----
Ultravioh (retamed ASTMD55
strength after 500hrs of
ultraviolet exposure)
4 A 6 m x 6 in. trench shall be dug o r the upstream side of the silt fence.
The silt fence shall line the wench and extend up the posts for the remainder
of the fabric width The [reach shall then be backfrlled and tamped. Silt fence
a
fabrms shall cappliced together only at supporting posts with a mmmum of
fi in. a, a rlap and in such a mama to prevent silt from passing between
the two ends. At [he time of inatalia[iom the I'abnc will be rejected if it has any
defects, delcriomtioq or other, damage incurred during manufacture,
transportation. Or 6rnrdgF,.
Silt Fence Maintenance Considerations
1. Inspect sill fences at least once a week and after each rainfall. Make any required repairs immediately.
EDGE OF
PENCE
2. Should the fabric of a sediment fence collapse, tear, decompose or become ineffective, replace it promptly.
3. Remove the sediment deposits as necessary to provide adequate storage volume for the next rain and to
reduce pressure on the fence. Take cafe to avoid undermmrng the fence during cleanout.
VIEW
E. Rtmtuve alf tencrng marcends and'rmstable sediment deposits and bring the area to grade and stabinze a
after the wnrribuung drainage area has been properly stabilized.
DITCH NO. I DITCH NO. 2
_ _ _
1.0' FREEBOARD 1.0' FREEBOARD
3 3
1 i 0.9' 1� 1 2.5' 11-1
1
Filter Fabrics Class 2 Rip -Rap (D50=15")/ t
Thickness= 34" Filter Fabric " Class 1 Rip -Rap (d50=12")
3' 3' Thickness= 27"
k
No. Total H i
1 1.40 1.01
Flier Fabric
EL
Total Weighted tG (min Q w ROate, cfs Slope,Ditch IfUft V2 ft/sec Perpm. Stabilization Vto, fit/sec Depth25, ft
Ditch Watershed CN z m s Depth ft Ib/ft3
Area, ac.
1 4.10 75 - 9.2 8.58 16.59 21.57 0.103 8.67 0.90 5.01 3.99 0.89
2 -- 17.54 78 ---- - 9.8 41.45 76.29 97.fi2 0.026 BAD 1 2.50 -4.01 3.59 2.47
CULVERT NO. I DETAILS
Cross -Section (NTS)
=aLI--t
Slope= 0.2 ft/ft
L
i NOTE EXTEND FILTER FABRIC AND
---___- I RIPRAP TO TOP OF CULVERTS
PLass B Erosion Control Stone T
� Filter Fabric/
La
OUTLET PROTECTION DETAILS
FOR
CULVERT NO. 1
1
6, fl
Class B
14 ft
24°HOPE
Erosion Contiol Stone
Thickness= 18"
a
Culvert And Stone Outlet Schedule
- 9 � to(min --
pe CN ) Fiow R Q aches ft/sec in. Le, ft 'W, ft Stone Type T, in. Note:
Wei hted
Rat CIS
Ito ry Q10 25- H25 t/se Inspect outlet protection structures weekly and after significant (1/2" or greater)
, L, ft : So, ft/it
- - _ 24 18 11.2 Class B 18 rainfall events to see if any erosion around or below the tiptop has taken place,
0.39 58 8.8 2.62 3.93 11.52 2.33 50 0.2
- or if stones have been dislodged. Immediately make all needed repairs to
prevent further damage. * P
1t�k�l �"j'VF1D
2,5It"
1 RND 00n-l"Y
SLOPE STABILIZATION (WEST BUFFER)
Slope Cross -Section
Not to Scale
i�
2 \
Place 4" Topsoil on Slope
^ ENGINEERING & ENVIRONMENTAL
2
SCIEs NCE COMPANY
Anderson Drive e10
J
Raleigh, 27609
[phone]
DETAILS
/25/2,
rttttn,,.
so`��/�p��o��"'
Tony Merritt's Gravel Pit
Is ;SEAL
Permit No. 68-04
l
Orange County, NC
-
"Aycln��`>�t°=s
/N
1 15472 All
Tony Merritt's Gravel Pit
�;' °
3200 Damascus Chluch Road
"In
Chapel Hill, NC 27516
DATE:
01 /25/2021
DRAWN:
TPS
REVISED:
SCALE:
Sheet No.1
D F