SW6120301_Details_20120323

Y
Exl GRADE
ANY FILL MATERIAL
USED TO CONSTRUCT
INFILTRATION BASINS
MUST BE CLEAN SAND
WITH LESS THAN 7%
PASSING 200 SIEVE.
ExI`ING GRADE
ANY FILL MATERIAL
USED TO CONSTRUCT
INFILTRATION BASINS
MUST BE CLEAN SAND
WITH LESS THAN 7%
PASSING 200 SIEVE.
TOP OF BASIN = 372.00'
CONCRETE CONTROL STRUCTURE (TOP OF RISER = 370.80)
UTILIZE NEENAH GRATE TYPE 4884—A OR APPROVED EQUAL
25--YEAR WSEL = 370.92'
s� 10—YEAR WSEL= 370.66'
1—YEAR WSEL= 369.40'
. -- GEOTEXTILE FILTER FABRIC
INLET PIPE
ELEV: 368.0SEDIMENT CLEANOUT ELEV: 368.15
0
4" LAYER CLEAN SAND
INLET PIPE
v _ SHWT >10' BELOW EXISTING GRADE
INFILTRATION BASIN BMP #1
N.T.S.
EXISTING
ANY FILL MATERIAL
USED TO CONSTRUCT
INFILTRATION BASINS
MUST BE CLEAN SAND
WITH LESS THAN 7%
PASSING 200 SIEVE.
RCP OUTFALL (REFER TO GRADING
PLAN FOR PROPOSED ELEVATIONS)
TOP OF BASIN = 371.00'
CONCRETE CONTROL STRUCTURE (TOP OF RISER = 370.35)
UTILIZE NEENAH GRATE TYPE 4884—A OR APPROVED EQUAL
25-YEAR WSEL = 370.40'
�^ 10-YEAR WSEL= 370.14'
ELEV: 368.00
4" LAYER CLEAN SAND
1-YEAR WSEL= 369.12'
GEOTEXTILE FILTER FABRIC
SEDIMENT CLEANOUT ELEV: 368.15
�^ SHWT > 10' BELOW EXISTING GRADE -
INFILTRATION BASIN BMP 2
N.T.S.
�X,sTtG GRADE
Q� '-ANY FILL MATERIAL
USED TO CONSTRUCT
11
INFILTRATION BASINS
^^ MUST BE CLEAN SAND
WITH LESS THAN 7%
PASSING 200 SIEVE.
RCP OUTFALL (REFER TO GRADING
PLAN FOR PROPOSED ELEVATIONS)
CONSIRUCTION NOTES
CARE SHOULD BE USED DURING INSTALLATION TO MINIMIZE COMPACTION OF SOIL ON THE BOTTOM AND WALLS OF INFILTRATION DEVICES SINCE THIS WILL REDUCE THE PERMEABILITY AT THE SOIL INTERFACE. TO AVOID
COMPACTING THE DRAINAGE MEDIA, LIGHT EQUIPMENT AND CONSTRUCTION TECHNIQUES THAT MINIMIZE COMPACTION SHOULD BE USED.
RUNOFF SHALL NOT BE DIRECTED INTO AN INFILTRATION DEVICE UNTIL THE DRAINAGE AREA IS STABILIZED. A CONSTRUCTION SEQUENCE MUST BE FOLLOWED THAT REFLECTS THE NEED TO STABILIZE THE INFILTRATION DEVICE,
THE LONGEVITY OF INFILTRATION DEVICES IS STRONGLY INFLUENCED BY THE CARE TAKEN DURING CONSTRUCTION.
A MINIMUM OF ONE OBSERVATION WELL SHALL BE INCLUDED IN THE DESIGN OF AN INFILTRATION SYSTEM TO PERIODICALLY VERIFY THAT THE DRAINAGE MEDIA IS FULLY DRAINING. THE MONITORING WELL SHALL CONSIST OF A
4-INCH TO 6-INCH DIAMETER, PERFORATED POLYVINYL CHLORIDE (PVC) PIPE WITH A LOCKING CAP. THE WELL SHOULD BE PLACED NEAR THE CENTER OF THE FACILITY OR IN THE GENERAL LOCATION OF THE LOWEST POINT
WITHIN THE FACILITY, WITH THE INVERT AT THE EXCAVATED BOTTOM OF THE FACILITY.
MAINaNANC (MOTES
PLEASE REFER TO SECTION 7.0 OF THE NCDENR STORMWATER BMP MANUAL, GENERAL BMP MAINTENANCE, FOR INFORMATION ON TYPES OF MAINTENANCE, TYPICAL FREQUENCY, AND SPECIFIC MAINTENANCE TASKS THAT ARE
COMMON TO ALL BMPS. THE FOLLOWING INFORMATION IS MAINTENANCE THAT IS SPECIFIC TO INFILTRATION DEVICES.
FOR THE FIRST YEAR OF OPERATION, INSTALLATIONS SHOULD BE INSPECTED MONTHLY AND AFTER EACH MAJOR STORM. AFTER THE FIRST YEAR, QUARTERLY INSPECTIONS, PREFERABLY CONDUCTED AFTER A STORM, ARE
RECOMMENDED.
MAINTENANCE IS VERY IMPORTANT FOR INFILTRATION DEVICES. PROPERTY OWNERS SHOULD BE EDUCATED IN THE FUNCTION AND MAINTENANCE REQUIREMENTS OF INFILTRATION DEVICES. ESPECIALLY IMPORTANT IS THE
MAINTENANCE OF VEGETATED AREAS THAT DRAIN TO THE INFILTRATION SYSTEM. AREAS THAT ARE ALLOWED TO BECOME BARE AND UNVEGETATED WILL CONTRIBUTE EXCESS SEDIMENT TO THE INFILTRATION SYSTEM AND HASTEN
ITS FAILURE. ANY SEDIMENT DEPOSITS IN PRETREATMENT DEVICES SHOULD BE REMOVED AT LEAST ANNUALLY.
THE SURFACE OF INFILTRATION SYSTEMS MUST BE KEPT IN GOOD CONDITION. COLONIZATION BY GRASS OR OTHER PLANTS SHOULD BE DISCOURAGED, SINCE THIS CAN LEAD TO REDUCED SURFACE INFILTRATION RATES. IN
MANY INSTANCES, IT IS CONVENIENT TO COVER INFILTRATION TRENCHES WITH CONCRETE GRID PAVERS OR SIMILAR PERMEABLE PAVING SYSTEMS THAT CAN BE REMOVED EASILY AND REPLACED AS NECESSARY TO SERVICE THE
TRENCH.
IN ORDER TO MONITOR PERFORMANCE OF THE INFILTRATION DEVICE, OBSERVATIONS SHOULD BE CONDUCTED TO DETERMINE HOW LONG IT TAKES RETAINED WATER TO INFILTRATE INTO THE SOIL AFTER A STORM EVENT, THE
DETERMINATION CAN BE MADE IN TWO WAYS. THE MOST INFORMATIVE WAY IS TO READ THE WATER LEVEL SEVERAL TIMES OVER A PERIOD OF DAYS AFTER A LARGE STORM. THE ALTERNATIVE IS A "ONE -STOP' METHOD, WHERE
A SINGLE READING IS TAKEN AND COMPARED WITH THE LOCAL RAINFALL RECORD. ALTHOUGH LESS ACCURATE THAN THE MULTIPLE READING METHOD, THE ONE -STOP METHOD WILL STILL ALLOW SIGNIFICANT DETERIORATION IN
PERFORMANCE TO BE RECOGNIZED.
THE TOP SEVERAL INCHES OF DRAINAGE MEDIA AND THE FILTER CLOTH ALONG THE TOP OF THE DRAINAGE MEDIA SHOULD BE REPLACED ANNUALLY OR AT LEAST WHEN THE DEWATERING TIME IS LONGER THAN 5 DAYS. IF
AFTER REPLACING THE TOP MEDIA THE INFILTRATION RATE IS STILL NOT IN THE ACCEPTABLE RANGE, THE ENTIRE FACILITY MUST BE DISMANTLED AND RECONSTRUCTED.
PROPER DISPOSAL OF THE MATERIALS REMOVED IS NECESSARY, THE AGGREGATE AND CLOTH SHOULD BE APPROPRIATELY PACKAGED AND DELIVERED TO THE LOCAL LANDFILL, IF THE OPERATING AUTHORITY APPROVES THE
DISPOSAL.
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THICK
)NCRETE
aLL.S
;ATE
SECTI JN A--- A
15 RCP OU 1; -,1
Ca) 1- 40%
IN V= 368.00
25-YR WSEL-=370.92
1.3-YR V5-EL=370.65
TOP OF RISER
ELEV. = 370.80
RATE
15" RCP OU f LE r
0 1.40%
I N V= 368.00
CROUND L:IEVATION = 368.00
SEC -DON B---B
INFILTRATION BASIN #1 PONCE CONTROL STRUCTURE CS-09
NOT SCALE
THICK
iNCRETE
\LLS
ATE
T-
SECTION A. —A
15" RCP DUTEEi
9 2,007,
ENV=367 00
25-YR '�VS�'L-370.40
10-- YR WSEL_=370.14
INFILTRATION BASIN 2 POND CONTROL STRUCTURE CS-04
NOT jO SCAL
TOP OF RISER
ELEV.-370 35
GRATE
I"' RCP OO LET
Q 2.00%
INV�=36/ (�O
GROUND ELEVA TkON == 368.00
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CONSULTANT:
KIMLEY—HORN AND ASSOC.
333 FAYETTEVILLE STREET,
SUITE 600
RALEIGH, NC 27601
TEL [phone]
FAX [phone]
SEAL.
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CONSTRUCTION DRAWINGS
STORE NUMBER:10157
HWY 24/87 & H M CAGLE DR.
HARNETT COUNTY, NC 28326
OWNER/DEVELOPER:
REDDLANDS, INC.
116-103 WILSON PIKE CIRCLE
BRENTWOOD, TN 37027
PH [phone]
FAX [phone]
REVISIONS:
LAYOUT COORD: COB
PLANNING MGR. COB
DRAWING BY: WJB
DATE: 03/05/2012
JOB NUMBER: 012426052
TI TLE:
STORMWATER
DETAILS
SHEET NUMBER:
C-14
COMMENTS: