HomeMy WebLinkAboutWPO201800027 Approval - County 2020-10-30DRY DETENTION CELL DETAIL: SCALE J "=30'
PR8P65EB FLAT (0%) 18' LONG, 1.5' DEEP
VDOT STD. CL. AI RIPRAP LINED OUTLET --
/
PROTECTION. WIDTH AT FLOODPLAIN=14', \
C.?
WIDTH AT PIPE OUTFACE-10' SEE THIS
7 / / / ____- __ _ - __ ___ SHEET FOR ADDITIONAL NOTES &
INSTALLATI'N REQUIREMENTS. \ \ \O \ \ \■I I I I / /
/ /
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/ THEORY DETENTION CELL IS LOPL
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MINIMUM 9VAC25-870-66 REGULATIONS.,SYNNEL � I
/ / / / / PROTECTION IS MET VIA SUBSECTION B.3 ( NERGY-
/ / / \BALANCE C�ULATIONS). FLOOD PROTECTIO IS MET VIA \
/ / i SUBSECTION C.2.a (CONFINES THE POST-W,10-yr FLOW \ �7 3+07 J
/ / // / / WJI'THIN THE DETENTION CELL & RIPRAP VIA _SC�,tH-,_ANNELOWITH-Ar 3+00\ \ �\
/ / / / LIMITS
DISCHARGES ES TO A AP MAPPED FLOODPLAINION ) 3.c .. ; �`.` \ \\ I \
/� � 0 YEA
- FLO6DPLAIf�7
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/
/
(RELOCATED STR. 502; THE STR 5 1 TED STR 502
RIM -TO -INVERT MEASUREMENTS WERE RELO �A ) \
MAINTAINED, BUT THE ANGLE BETWEEN
THE PIPE IN & PIPE OUT WAS MODIFIED.)
i
PROPOSED OUTFACE SYSTEM, SEE q \ \
/ PROFILE ON THIS SHEET FOR DETAILS. 4�
NOTE: THIS REDLINED EET ROTATES
CONTRACTOR SHALL INSTALL A VDOT MH-1 WITH A RIM
--- R
_- o
/ --STR. 503 &STR. 50 BY 14 . T�
� \ELEVATION OF 357.33' 357.50'. A TRASHRACK SHALL BE
RISER's LOCATION WAS NOT MODIFIED. / sr INSTALLED OVER THE MH-1's UPPER 024" OPENING
INSTEAD OF A MH-1 FRAME & COVER. RISER TO
/ -----� /
A CLUDE 03� 2 ib "LOW FLOW ORIFICE WITH AN
i
/ O
TO REDUCE THE RISK OF FLOATP?'ION, / � � IN EFT-352.00'. RISER BASE & BARREL ONNECTION SHALL
/ BE FIRMLY EMBEDDED 6" INT AN IS- O \ \ \
yy- - IS -
IC K REINFORCED ED CONCRETE F NDATI N \ / / C 0 C CO E OU 0 50' WIDE VDOT CL. Al, EC-1 RIPRAP
// THAT IS 8'x8' &BURIED 0 SIDE THE / `' LINED EMERGENCY SPILLWAY CREST
/ A-IMITS TSF THE EXCA ATIOM1T.- STR 504 \�\
/ / \ \ ELEVATION= 358.66'. SPILLWAY TO
VAR.IpTH % k`' _-, \ HAVE 4:1 SIDE SLOPES
/ DRAINAGE & SWM %i - '� APPROVED 10' WIDE TOP OF
/ \ ESMT COINCIDES 9f - ����� \ DAM ELEV.=360'. LEVEL TOP
WITH ROPERTY LINE , 1/' OF DAM TO SERVE AS ACCESS
\
C"Ll FOR SWM MAINTENANCE.
REC@F,tDEb,PU BL%
I / APPROVED RIPRAP �� \\�, \ F ILITII & A CES
ENERGY \�4 0� \ \\ � \ D(3 52EASEMENT\FOR SWM
$,�PG 40 09)
DISSIPATER. /` \
\ N
\ / \ -CONTRACTOR SHALL EMOVE N \ ROPOSED EXPANSION
SEDIME�T LADEN MAT IAL FRONL-- \
\ TO THE PUBLIC
\ \ \ THE SEDIMENT�B"ASI SHALL \ \ FACILITIES &ACCESS
\ / / /IiEGRADEE THE BASIN TO THE \ \ �f\\ \ EASEMENT FOR SWM
PROPOSED CONTOURS SHOWN -ON'- \
\ \ / THI,"LAN A's )COENV�IONOF THE
'FACILI sff!L` I
/
\ V
IS
wi
\36 \ \
\ AT THE TIME OF TEMPORARY SEDIMENT BASIN �\ -
\ #2's CONVERSION TO A PERMANENT SWM\�:--
\ FACILITY, THE CONTRACTOR SHALL UNPLUG \1cp�,
THE LOW -FLOW ORIFICE, INSTALL THE
LOW -FLOW ORIFICE's TRASHRACK, REMOVE
THE TEMP. 048" ESC TRASHRACK, INSTALL THE
UPPER SECTION OF THE MH-1 (FINAL RISER
/ / ,,`'' 41 RIM ELEV.=357.50), INSTALL THE. \ 4.
024" RISER TRASHRACK &PERMANENTLY PLUG \
WATERTIGHT THE ESC DEWATERING ORIFICE
/ �9o-- W
StormRaXT11
ROUND SERIES TRASH RACK (OR EQUIVALENT)
CONCRETE MANHOLE
STANDARD 60 INCH RACK SHOWN
DIMENSIONS IN INCHES
PLAN
I
P.
* CONTRACTOR SHALL INSTALL THE STORMRAX ROUND SERIES
TRASHRACK WITH AN ANTI -VORTEX DEVICE, OR EQUIVALENT, TO
ON THE RISERS FOR THE WET POND &THE DRY DETENTION CELL.
** CONTRACTOR SHALL INSTALL THE STORMRAX ROUND SERIES
TRASHRACK WITH AN ANTI -VORTEX DEVICE, OR EQUIVALENT, ON
THE TEMPORARY SEDIMENT BASIN's RISER
HWESMVCT RqI PVl4ncS
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28.
24
30
W316
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14
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36
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18YA
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60
70
Plastic Solutions, Inc. CUSTOhER
PO Bon 43%, Winchester, VA Z2604
Z39 McGhee Rd. Winche , VA 7.2603
07) 877-5727 phone PR0IEC.T-
(540) 722-2219 fax
htip: //vNrva.plastic-sal utial.cam
awwrLRSEcnoH
REMOVABLE FOR MC. ESS
ISOMETRIC
CONCRETE STRUCTURE DIMENSIONS
INSIDE STRUCTURE DIMENSION
OUTSIDE STRUCTURE DIMENSION
AVAILABLE OPTIONS
CROSS BRACING FOR OVERHANG
HOPE ANTI -VORTEX PLATE (REQ'D)
DATE --
DRAWN BY:
APP➢BY:
DETAL
APPROVED DRY DETENTION CELL CONSTRUCTION NOTES:
FACILITY PLANTING SPECIFICATIONS:
1. THE DETENTION BASIN SHALL HAVE TURF GROUND COVER, SUCH AS GRASS, MULCH OR SOME OTHER FORM OF A VEGETATIVE GROUNDCOVER. LANDSCAPING BEYOND
THIS IS OPTIONAL AND IS NOT REQUIRED.
2. THE PROPOSED SIDE SLOPES OF THE BASIN SHALL BE A MAXIMUM OF 4:1 TO REDUCE THE RISK OF EROSION. THE PROPOSED FLOOR SLOPES SHALL BE GRADED TO
PROVIDE POSITIVE DRAINAGE AT ALL TIMES TO THE RISER STRUCTURE.
3. WOODY VEGETATION SHALL NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEET OF THE TOE OF THE EMBANKMENT NOR WITHIN 25 FEET OF THE PRINCIPAL
SPILLWAY STRUCTURE.
4. A VEGETATED BUFFER SHALL BE PROVIDED THAT EXTENDS AT LEAST 20 FEET OUTWARD FROM THE BASIN TOP OF DAM ELEVATION. PERMANENT STRUCTURES E.G.
BUILDINGS, SHEDS, etc.) SHOULD NOT BE CONSTRUCTED WITHIN THE BUFFER AREA. EXISTING TREES SHALL BE PRESERVED IN THE BUFFER AREA DURING CONSTRUCTION
IF AT ALL POSSIBLE.
5. THE SOILS IN THE STORMWATER BUFFER AREA ARE OFTEN SEVERELY COMPACTED DURING THE CONSTRUCTION PROCESS, TO ENSURE STABILITY THE DENSITY OF THESE
COMPACTED SOILS CAN BE SO GREAT THAT IT EFFECTIVELY PREVENTS ROOT PENETRATION AND THEREFORE MAY LEAD TO PREMATURE MORTALITY OR LOSS OF
VIGOR. AS A RULE OF THUMB, PLANTING HOLES SHOULD BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE FOOTBALL FOR BALL -AND -BURLAP STOCK,
AND FIVE TIMES DEEPER AND WIDER FOR CONTAINER -GROWN STOCK.
6. AVOID SPECIES THAT REQUIRE FULL SHADE, OR ARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASE OF TREES AND SHRUBS IS STRONGLY
RECOMMENDED AS A MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS.
CONTRACTOR REQUIREMENTS:
1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS.
2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FOR THE STATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE
CONTRACTOR SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS
MANUAL (COPIES ARE AVAILABLE FOR A FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS, VIRGINIA NURSERYMEN'S
ASSOCIATION, INC. AND THE VIRGINIA SOCIETY OF LANDSCAPE DESIGNERS).
3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY
STOCK, PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250 STREET, NW, SUITE 500, WASHINGTON, DC 20005.
4. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN.
5. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES CALL MISS UTILITY 1-800-552-7001 BEFORE ANY EXCAVATION).
6. REFER TO THE APPROVED FINAL SITE PLANS FOR ANY DETAILED SITE INFORMATION.
7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES.
8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK BUDS BRANCHES STEMS OR OVERALL SHAPE OF THE STOCK.
CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE GROWN.
9. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY,
VIGOROUS AND FREE FROM DEFECTS DECAY DISEASES INSECT PEST EGGS AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH FREE FROM
TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED.
10. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL.
CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED.
11. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND
PROTECTED FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH
MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL.
12. THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE INSPECTOR
INITIALLY, AND THEN THE DESIGNER.
13. MINOR FIELD ADJUSTMENTS MAY BE NECESSARY DUE TO SITE CONDITIONS (EX: FOOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BY THE
DESIGNER.
14. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN.
15. PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENT TO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS,
WITHOUT CRAMPING ROOT STOCK.
16. THE CONTRACTOR SHALL MAINTAIN A ONE 1 CALENDAR YEAR 90%CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND
REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR.
17. THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS.
18. THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE
CONTRACTOR's CONTROL.
FACILITY CONSTRUCTION
1. THE DETENTION BASIN MAY SERVE AS A SEDIMENT BASIN AND/OR TRAP DURING PROJECT CONSTRUCTION. IF THIS IS DONE THE VOLUME SHALL BE BASED ON THE
MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMENTS VS. STORMWATER TREATMENT REQUIREMENTS). INSTALLATION OF THE
PERMANENT RISER SHALL BE INITIATED DURING THE CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHALL BE SET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN
AND CONVERSION TO THE POST -CONSTRUCTION POND IN MIND. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBULENT
WATERS WHEN THE BASIN IS BEING CONVERTED INTO AN DETENTION BASIN. FOR THIS DESIGN IN PARTICULAR THE RISER RISER FOUNDATION BARRELAND
LOW -FLOW ORIFICE SHALL BE INSTALLED AT THE TIME OF THE SEDIMENT TRAP's CONSTRUCTION AND SHALL REMAIN WATERTIGHT UNTIL THE TRAP IS CONVERTED TO A
PERMANENT FACILITY.
2. THE DETENTION BASIN SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETELY STABILIZED. IF THE PROPOSED POND
SITE WILL BE USED AS A SEDIMENT TRAP OR BASIN DURING THE CONSTRUCTION PHASE THEN THE FACILITY WILL BE DEWATERED DREDGED AND RE -GRADED TO
DESIGN DIMENSIONS AFTER THE ORIGINAL SITE CONSTRUCTION IS COMPLETE.
3. INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION OF THE BASIN, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION PRACTICES. ALL
AREAS SURROUNDING THE BASIN THAT ARE GRADED OR DENUDED DURING CONSTRUCTION SHALL BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER
APPROVED METHODS OF SOIL STABILIZATION.
4. CONTRACTOR SHALL EXCAVATE THE CORE TRENCH AND INSTALL THE SPILLWAY PIPE DURING THE ESC PHASE.
5. CONTRACTOR SHALL ALSO INSTALL THE RISER, OUTFLOW STRUCTURE AND/OR THE BARREL(s) DURING THE ESC PHASE TO ENSURE THE TOP INVERT OF THE OVERFLOW
WEIR IS CONSTRUCTED LEVEL AT THE DESIGN ELEVATION.
6. THE CONTRACTOR SHALLTHEN CONSTRUCT THE EMBANKMENT, AND ANY INTERNAL BERMS IF APPLICABLE, IN 8 TO 12-INCH LIFTS AND COMPACT THE LIFTS WITH
APPROPRIATE EQUIPMENT.
7. UPON COMPLETION OF THE EMBANKMENT GRADING, THE CONTRACTOR SHALL EXCAVATE/GRADE UNTILTHE APPROPRIATE ELEVATION AND DESIRED CONTOURS ARE
ACHIEVED FOR THE BOTTOM AND SIDE SLOPES OF THE BASIN.
8. CONTRACTOR SHALLTHEN CONSTRUCT THE EMERGENCY SPILLWAY IN CUT OR STRUCTURALLY STABILIZED SOILS. 375
9. THE CONTRACTOR SHALL THEN FINISH CONSTRUCTION OF ALL OUTLET STRUCTURES, INCLUDING DOWNSTREAM RIP -RAP APRON PROTECTION.
10. THE CONTRACTOR SHALL NEXT STABILIZE EXPOSED SOILS BY HYDROSEEDING OR SEEDING OVER STRAW.
11. THE CONTRACTOR SHALL THEN INSTALL THE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS.
FACILITY MAINTENANCE:
MAINTENANCE OF THE DETENTION BASIN IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE FACILITIES. DURING THESE
INSPECTIONS THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION, AND THE OWNER THEREAFTER:
1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE BASIN.
2. MONITOR THE GROWTH OF THE GROUNDCOVER AND ANY TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE
AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES, AS APPLICABLE.
3. INSPECT THE CONDITION OF STORMWATER INLETS TO THE BASIN FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING.
4. INSPECT THE BANKS OF UPSTREAM AND DOWNSTREAM CHANNELS FOR EVIDENCE OF SLOUGHING, ANIMAL BURROWS, BOGGY AREAS, WOODY GROWTH, OR GULLY
EROSION THAT MAY UNDERMINE EMBANKMENT INTEGRITY.
5. INSPECT BASIN OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, etc.
6. INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING JOINT FAILURE LEAKAGE CORROSION OR OTHER FAILURES.
7. INSPECT CONDITION OF ALL TRASH RACKS, REVERSE SLOPED PIPES OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION OR OTH
FAILURES.
8. INSPECT MAINTENANCE ACCESS TO ENSURE IT IS FREE OF WOODY VEGETATION, AND CHECK TO SEE WHETHER VALVES, MANHOLES AND LOCKS CAN BE OPENED AN
OPERATED.
9. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE BASIN FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING.
10. OWNER OR CONTRACTOR SHALL MAKE NEEDED REPAIRS IMMEDIATELY.
FACILITY INSPECTION:
MULTIPLE INSPECTIONS ARE CRITICALTO ENSURE THE BASIN(s) ARE PROPERLY CONSTRUCTED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE
CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND
INSPECTIONS ARE REQUIRED TO BE SCHEDULED BY THE CONTRACTOR WITH THE ENGINEER AND INSPECTOR DURING THE FOLLOWING STAGES OF THE DETENTION BASIN'
Q
CONSTRUCTION PROCESS:
1. PRE -CONSTRUCTION MEETING
2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS)
3. EXCAVATION/GRADING (e.g., INTERIM/FINAL ELEVATIONS)
4. EXTENDED DETENTION BASIN INSTALLATION (e.g., INTERIM AND FINAL ELEVATIONS)
5. INSTALLATION OF THE EMBANKMENT, THE RISER/PRIMARY SPILLWAY, AND THE OUTLET STRUCTURE(s).
G. PLANTING PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT/DIRECTING)
7. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE)
DRY DETENTION CELL SPILLWAY
50' WIDE VDOT CL. A:
RIPRAP LINED EMER(
SPILLWAY CREST ELEV
358.66'. SPILLWAY TO F
SIDE SLOPES
APPROVED 10' WIDE TOP
365 OF DAM ELEV.=360'.
365
ROPOS
D
360
GRAD
360
n
a
so
EC-1
IENCY
NTION=
355
XISTIN
355
RA
IAVE 4:1
350
350
J J
N
0 N
W W
o
W lei
PROFILE SCALES:
1"=5' (V)
1"=5o' (H)
RIPRAP LINED OUTLET PROTECTION DESIGN REQUIREMENTS:
Q
1. RIPRAP LINED OUTLET PROTECTION SHALL BE INSTALLED IN CUT WITH CLASS II
FILTER FABRIC UNDERLAYMENT LOCATED IMMEDIATELY UPLAND OF THE
FLOODPLAIN.
2. OUTLET PROTECTION FOR THE DRY DETENTION CELL SHALL BE 15' LONG & BE
FLAT WITH A 0% GRADE. WIDTH AT BEGINNING OF OUTLET PROTECTION=10',
WIDTH AT END OF OUTLET PROTECTION=14'.
3. CONTRACTOR SHALL INSTALL A CLASS II FILTER FABRIC UNDERLAYMENT. FILTER
FABRIC SHALL BE KEYED INTO THE EXISTING GROUND A MINIMUM OF 12" AT ITS ENDS
& ALONG THE ENTIRE PERIMETER.
4. A 6" LAYER OF #57 STONE SHALL BE PLACED OVER THE FILTER FABRIC FOR ITS
PROTECTION BEFORE THE VDOT STD. TYPE I RIPRAP IS INSTALLED.
5. PLACEMENT OF FILTER FABRIC SHALL BE DONE IMMEDIATELY AFTER OUTLET
PROTECTION PREPARATION. EDGES OF THE FILTER SHEETS SHALL OVERLAP AT LEAST
9".
6. STONE PLACEMENT SHALL FOLLOW IMMEDIATELY AFTER PLACEMENT OF THE FILTER
FABRIC & #57 STONE. RIPRAP SHALL BE PLACED SO THAT IT PRODUCES A DENSE
WELL -GRADED MASS OF STONE WITH MINIMAL VOIDS. THE FINISHED SLOPE SHALL BE
FREE OF POCKETS OF SMALL STONE OR CLUSTERS OF LARGE STONES.
7. OUTLET PROTECTION SHALL TIE INTO EXISTING GROUND IN CUT AT A
MAXIMUM SLOPE OF 3:1.
8. CONTRACTOR SHALL SCHEDULE A MEETING WITH AN ENGINEERING DEPARTMENT
INSPECTOR AT LEAST 24 HOURS IN ADVANCE OF THE OUTLET PROTECTION
CONSTRUCTION. TICKETS FROM THE QUARRY SHALL BE AVAILABLE FOR REVIEW
BEFORE STONE PLACEMENT TO ENSURE CORRECT STONE SIZES. STONE GRADATIONS
SHALL MEET MINIMUM CURRENT VDOT ROAD AND BRIDGE SPECIFICATIONS.
APPROVED
by the Albemarle County
Community Development Department
Date 10/30/2020
File WP0201800027, Amendment #1
DRY DETENTION CELL SECTION
TT/R. Cl -L]
No. 35791
10/30/20
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DRY DETENTION
ELL RISER
FOUNDATION
NOTE:
TO REDUCE
THE
ISK OF
LOATAT
ON, RISER
BASE
BARREL
CONNECTION
SHALL
BE FIRMLY
EMBEDDED
6" INTO
N 18"
THICK REINFORCED
CON
FETE FOUNDATION
THAT I
8'x8' &
BURIED
UTSIDE
THE LIM
TS OFT
E EXCAVATION.
370
370
'
MH-1
WITH A
IM ELEVATION
O
'cam.22'
357.50'
A TRASHRACK
SHALLBE
INSTALLED
EXISTINGOVERTHE
MH
1's UPP
R 24"
PENING
GRADE
INS
EAD OF
MH-1
RAME &
OVER.
RISER
TO INCLUDE
A
" 2 " LOW
-FLOW
365
0
IFICE WITH
AN I
VERT=3
2.00'
365
ER
APPRO
ED 10'
IDE TOP
OF DAM
ELEV.
360'.
360
PROP
SED GRADING
WITH
360
AMENDMENT.
DRY
DETEL
ITION C
LL's VOL
ME
CON
FACTOR
SHALL
HA
BEEN ENLARGED.
_
INSTAL
A CO
PACTE
s
CLAY
CORE
w/ A
EMBANKMENT
0 BE IN
7�
a
ACCORDANCE
w/ THE
355
N
DESI
N SHo
N ON
355
ul
'I
LbL
BASIN
BOTTOM
SHALL
HAVE P
SITIVE SLOPE
TO
350
THE RISER
IN ALL
PLACES
350
0
LN
0�
345
N
1
1
345
PROPOSED
024"
HOPE
BARREL
(95.33'
@ 8.300
, INV. I
=350.0
',
INV. OU
=342.0
')
w0
340
0E-
340
PROPO
3ED VD
ST
EW-1
CONTRACTOR
TO
INSTAL
335
ATf
STRAT CSO
O
335
Ti'THEIBOTTOM
OFLTHE
ANHOL
PROP
SED 02
" HOPE
ARREL
(51.50'
@ 2.140/,
INV. I
=335.10,
330
INV. OU
=334.0
')
330
RELOCATED
PROPOSED
FLAT
0%) 18'
LONG, 1.5'
DEEP
DOT STD.
CL. AI
RIPRAP LINED
OUTLET
PROTECTION.
WIDTF
AT FLO
DPLAIN
14', WIDTH
AT PIPE
OUTF
LL=10'.
325
SEE THIS
SHEET 17OR
ADDITIONAL
NOTES &
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172131
SCALE
AS SHOWN
SHEET NO.
8
0+50 0+75
0+50 1+00 1+50 2+00 2+50 3+00 3+50