SW3220301_Plansheet 5 - SCM Detail_20220519

i i� III, i a- ii, In.,
a q.A .1 i ro, gi m, "ev x m now mimm
Entire BMP
Adjacent pavement (if
applicable)
Perimeter of sand filter
The perimeter of the dry pond
The inlet swale
The embankment
Forebay or pretreatment area
Filter be and underdraln
collection system
Outlet device
Receiving water
Trash1debris Is present.
Sediment is present on the
pavement surface.
Areas of bare soil and/or
erosive gullies have formed.
Vegetation is too short or too
long,
Areas of bare soil and/or
erosive gullies have formed.
Erosion is occurring in the
svmle.
Shrubs have started to grow on
the embankment.
Evidence of muskrat or beaver
activity is present.
A tree has started to grow on
the embankment.
An annual inspection by an
appropriate professional shows
that the embankment needs
repair.
Sediment has accumulated to a
depth of greater than six
inches.
Erosion has occurred.
Weeds are present.
Water is ponding on the surface
for more than 24 hours after a
storrn.
Clogging has occurred.
The outlet device is damaged
Erosion or other signs of
damage have occurred at the
outlet.
Remove the trash/debris.
as soon as possible.
Regrade soil if necessary to
remove the gully, and then
#tai*s wMar
until it is established. Provide
lime and a one-time fertilizer
application.
Maintain vegetation at an
appropriate height.
remove the gully, and then
until it is established. Provide
lime and a one-time fertilizer
2pplication,
NOON, 4111AWININANININI
to avoid future problems with
erosion.
Remove shrubs immediately.
and=IDA
lf a professional to
remove beavers.
to remove the tree.
Make all needed repairs.
Search for the source of the
sediment and remedy the
problem if possible� Remove
the sediment and stabilize or
it will not cause impacts to
streams or the BMP.
Provide additional erosion
protection such as reinforced
to prevent future erosion
problems.
log "-,Niro"roiwlgim
spraying.
Check to see if the collector
,lira
a '#W#_krJ'VVAW"
an expert.
Clean out the outlet device.
Repair or replace the outlet
device.
Contact the NC Division of
Water Resources,
SAND FILTER MAINTENANCE SCHEDULE
1 1. During the first 3 months after construction inspections should be made after every storm event.
Thereafter, the sand filter should be inspected at least once a quarter (every 3 months) and within 24
hours after every storm greater than 1.0 inch.
2. The sand chamber should be raked periodically to remove surface sediment, trash, and debris.
Frequency not to exceed one year.
3. First 2 or 3 Inches of sand should be removed and replaced with new sand when water Is ponding on the
surface for more than 24 hours after a storm.
4. Clean out sediment chamber whenever sediment has accumulated to a depth greater than 6 inches.
Remove sediment and stablIze, Remedy source of sediment if possible.
5. Replace the sand filter media whenever it falls to function property after maintenance.
6. All contaminated sand, and sediment removed is to be disposed of in accordance with local, state, and
federal regulations,
7. Maintain operation and maintenance records in a known set location. Operation and maintenance records
shall be made available upon request,
SANu FILTER SCM
20'x26(520sf) SAND CHAMBER 20'-6" PERF SCH-40 PVC
TOP OF WASHED STONE = 557.80---� SLOPED @ 0.5%
TOP OF SAND EL = 557.63
SLOPED @ 0.5%
PVC CLEANOUT
- - - - - - - - - - - - - - - - - - - - - - -- I
PVC CLEANOUT
INVERT = 555,60
10'-6" PERF SCH-40 PVC
SLOPED @ 0.5%
PVC CLEANOUT
INVERT = 555.54
7!-6" SOLID SCH-40 PVC
0 0 SLOPED @ 0.5%
0 OUTLET STRUCTURE
INVERT = 555.5
SEE OUTLET STRUCTURE
DETAIL THIS SHEET
40'- 15" HDPE
LOPED @ 0.75%
WITH FES
INVERT = 555.64 5b'i 1-11 /
A.
TOP OF DAM I'
MINIMUM WIDTH
SAND FILTER UNDERDRAIN LAYOUT (SCALE
0.17'(2"+/-) THICK LAYER
FILTER FABRIC 3'°457 WASHED STONE
(Bottom Layer) \_ SCARIFIED SUBGRADE
6" SCHEDULE 40 PERFORATED PVC (NOT COMPACTED)
3�457 WASHED STONE 4-HOLE, 3/8" PERFORATIONS, 6' ON CENTER
ALONG TOP & SIDES HOLE ROTATION AT SHOWN
1. Reference SKIMMER BASIN CONVERSION & SCM CONSTRUCTION SEQUENCE (Sheet 4). Notes 1-4 to be
completed prior to underdrain and sand filter construction
2. Temporary silt fence to be installed around perimeter of proposed sand chamber.
3. Subgrade of sand filter to be scarified (not compacted).
4Bottom of proposed filter to be lined with Mirafi 140n, or equal, filter fabric.
4. 6" Sch-40 perforated PVC pipes t o, be placed on top of filter fabric.
6. Perforations shall be 3/8" and spaced 6" on center along four longitudinal rows spaced 900 apart.
7. Perforated PVC pipe to be placed at a minimum slope of 0.5% and rotated such that holes are not placed on
bottom. Spacing of parallel PVC underdrain lines to not exceed 10'.
1. #57 washed stone to be placed along bottom of filter chamber and sides and top of PVC to a thickness of 3".
9. #57 stone to be covered with 2" of #89 washed stone.
10. An 18" thick layer of clean, washed, course masonry sand (ASTM C33 or equal) with particles less than 2mm
average diameter is to be placed in the sand chamber.
11. Refer to note # 6 of SKIMMER BASIN CONVERSION & SCM CONSTRUCTION SEQUENCE (Sheet 4).
01,919 1111111111:1 IkIN-11010111111:4 *V'1111114LA.11 ILI 'jp Ip(0
21 hTl I IT, 2
M
Class B
RIPRAF
■ I A
Em
0
GENERAL NOTES:
1. CLASS "B" CONCRETE TO BE USED THROUGHOUT.
PIPE IN OUTLET STRUCTURE TO BE STRUCK EVEN WITH THE
INSIDE WALL, GROUTED AND BRUSHED SMOOTH,
3, FORMS TO BE USED FOR CONSTRUCTION OF BOTTOM SLAB,
4, CONCRETE COVER TO BE 4" THICK MIN.
0
1. AREA UNDER EMBANKMENT SHALL BE CLEARED, GRUBBED, AND STRIPPED OF
ANY VEGETATION AND ROOT MAT. THE POOL AREA SHALL BE CLEARED.
2_ SUBGRADE FOR DAM TO BE PROOFROLLED PRIOR TO EARTH FILL PLACEMENT.
ANY SOFT OR PUMPING AREAS ARE TO BE UNDERCUT AND REPLACED WITH
COMPACTED EARTH FILL.
3. CORE TRENCH TO BE EXCAVATED TO GOOD CLAY SOIL MATERIAL. TRENCH
EARTH FILL TO BE COMPACTED TO MINIMUM OF 95% OF STD. PROCTOR
MAXIMUM DRY DENSITY.
4. THE FILL MATERIAL FOR THE EMBANKMENT SHALL BE FREE OF ROOTS OR
OTHER WOODY VEGETATION AS WELL AS OVERSIZED STONES, ROCKS, ORGANIC
MATERIAL OR OTHER OBJECTIONABLE MATERIAL. THE EMBANKMENT SHALL
BE COMPACTED 13Y TRAVERSING WITH EQUIPMENT WHILE BEING CONSTRUCTED.
15. COMPACTED EARTH FILL TO HAVE DRY UNIT WEIGHT OF AT LEAST 90 PCF.
ALL EARTH FILL TO BE COMPACTED TO MINIMUM OF 95% OF STD. PROCTOR
MAXIMUM DRY DENSITY.
6. EXCAVATED SIDE SLOPES TO BE STABILIZED WITH SOD IN ACCORDANCE WITH
SPECIFICATIONS.
47. FINAL DAM INTERNAL EMBANKMENT SLOPES TO BE TRACKED AND STABILIZED
WITH SOD IN ACCORDANCE WITH SPECIFICATIONS.
-*- 10'
RIP RAP
SPILLWAY EL. 560.3
CR05S SECTION
4"CONCRETE 4'-U - ------- 4'CONCRETE EMERGENCY SPILLWAY NTS
CoVER 560.3 560.3 COVER 18'w x ff'h
I 8'w x 8"h
PENING (38idos) PENING (3 Sides)
559.30
259 _3
a.
IMCH NUM
3" Threaded Capped PVC r Threaded Capped PVC
,�-(For Emergency Dran) TRENCH
mol"
--(For Emergency Drain)
557.60 To of Sand =ITT 7
G�RADE
IT
=M
- 5
b. M-
15"HDPE
PIPE erdrain A
6" PVC =U.dIQ
III li�l
555,5 h,
ZD
44
SECTION X-X
SECTION Y-Y MITI -SUP COUAR
u
I I -A
"4
CONCRETE OUTLET STRUCTURE DETAIL (NTS)
W, _IE�41
BE REMOVED CONCRETE OUTLET STRUCTURE
(SEE DETAIL THIS SHEET)
PVC CLEANOUT
11111101 Al 11111101
AT ENDS
Q100 EI:560.45
Q50 El 560.33
---------------------------
Q10 EI=560.05
"T -----------
Q2 E655916 - - -
SAND CHAMBER t44Q1
EI=559.58
WQV(Adi)=559.09
MIN. 520 SF SURFACE AREA
TOP OF WASHED STONE = 557.80
1" Storm EI=558.26 - - - - - -
- - --- -
TOP OF SAND = 557,63
.7
layer #89,".
12" MIN COVER
Natural Ground
18"2" of
SAND , washed stone
557±
0 0 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0
_________
77
(ASTM 033 or equal) with particl
less than 2mm average diamet
2 Runs-6" Sch-40 Perforated PVC
3-Hole, 5/8" Perforations, 5" on center
55.5 Bottom
IN -SITU SOIL of Sand Filter
rap Lined Emer. pillway
A
PLANVIEW
ANTI-SEEP COLLAR NTS
POND DAM
(i
�/ o PIrH
MIN.
R E T R E INIC H
DETAIL N TS