SW5200602_As-Built Designer Certification - Sand Filters_20220516

State Stormwater Management
Permit No. SW5200602
AS -BUILT DESIGNER'S CERTIFICATION FOR SAND FILTER PROJECT
I hereby state that I am a licensed professional and I certify by my signature and seal below, that I
have observed the construction of the project named above to the best of my abilities with all due care
and diligence, and that the project meets all of the MDC found in NCAC 02H.1056, in accordance with
the permit documents, plans and specifications on file with or provided to the Division, except as
noted on the "AS -BUILT" drawings, such that the intent of the stormwater rules and the general
statutes has been preserved.
Check here if this is a partial certification. Section/phase/SCM #?
Check here if this is part of a Fast -Track As -Built Package Submittal per .1044(3).
Check here if the Designer did not observe the construction, but is certifying the project.
Check here if pictures of the SCM are provided.
Printed Name Signature /�-•'•
NC Registration Number
SEAL:
39082 Date
Consultant's Mailing Address:
City/State/ZIP
Phone Number
Consultant's Email address:
O Circle N if the as -built value differs from the Plan/permit. If N is circled, provide an explanation on
page 2
ON/E = not evaluated (provide explanation on page 2) ON/A = not applicable to this project or SCM.
This Certification must be completed in conjunction with the General MDC certification under NCAC
02H.1050
Consultant's Certification (MDC .1056)
OAs-built
ON/EON/A
A. Two -chambers stem
1. Does the Sand Filter include a Sediment chamber and a
Y N
Sand chamber?
or
2. The storage volume in each chamber is equivalent.
Y or N
3. The incoming stormwater is evenly distributed across the
Y N
surface of the sand.
or
B. Volume / Elevations
1. The volume of water stored in the sediment chamber and on
top of the sand in the sand chamber is at least 0.75 times the
Y or N
treatment volume.
2. The elevation of the bypass device is set at or above the
Y N
ponding depth associated with the storage volume.
or
3. The ponding depth above the sand surface is six feet or less.
Y or N
C. Sand Media / Drawdown / SHWT
1. Does the sand media meet ASTM C33 or equivalent?
Y or N
2. The depth of the sand media is consistent with the approved
Y N
tans andspecs and is a minimum of 18".
or
3. The depth of the sand media over the underdrain is
consistent with the approved plans and specs and is a
Y or N
minimum of 12 inches.
4. The sand media provides a minimum drawdown of two
Y N
inches per hour at the sand surface.
or
5. Open -bottom design — the minimum separation to the SHWT
at the lowest point of the sand filter is consistent with the
Y or N
approved plans andspecs and is a minimum of 2 feet.
Page 5of8

State Stormwater Management
Permit No. SW5200602
6. Closed -bottom design — The minimum separation to the
SHWT at the lowest point of the sand filter is consistent with
Y or N
the approved plans and is a minimum of 1 foot.
7. At least one capped clean -out pipe has been provided at the
Y N
low point of each underdrain.
or
Provide an explanation for every MDC that was not met, or for every deviation from the permitted
condition below:
Page 6of8

SEDIMENTATION CHAMBER
1�\
3 MIN
INFLOW PIPE
SAND FILTER 1 BMP SUMMARY CHART-ASBUILT r
PEAK CONTROL
STORM EVENT
POST -DEVELOPMENT
RUNOFF ICFS}
POST -ROUTING
RUNOFF ICFS}
ELEVATIONr
TOP OF DAM
446.80 r
2YR
15.64
1.1
443.39 r
10 YR
28.93
2.75
444.36 r
25 YR
39.72
7.37
444.94 r
r
100 YR
60.86
43,44
445.55 r
PROVIDED
REQUIRED
ELEVATION r
DDV
1 10044 CF
8935 CF
443.10 r
---SAND FILTER----4616 -SF --- 4468 -SF __-- 442.00 _J
SAND FILTER 1 BMP SUMMARY CHART
6"
#57 WASHED 2' RIP RAP
STONE
3" GRAVEL / STONE SURFACE
EL 439.5
CLEAN -OUT
(PVC PIPE
W / GLUED CLEAN -OUT FITTINGS
AND SCREW TYPE CAP)
PEAK CONTROL
STORM EVENT
POST -DEVELOPMENT
RUNOFF (CFS)
POST -ROUTING
RUNOFF (CFS)
ELEVATION
TOP OF DAM
447.00
2YR
21.18
1.2
443.45
10 YR
28.93
3.17
444.40
25 YR
39.72
8.47
445.01
100 YR
60.86
45.75
445.57
PROVIDED
REQUIRED
ELEVATION
DDV
10267 CIF
8935 CIF
443.10
SAND FILTER
4500 S F
4468 S F
442.00
NOTE:
1. SAND FILTER IS SIZED FOR DDV AND CHECKED FOR FREEBOARD.
2. PER GEO-TECHNICAL REPORT PREPARED BY TERRACON CONSULTANTS, INC. RALEIGH, NC.
THERE IS NOT ANY GROUND WATER ENCOUNTERED AT SAND FILTER 1 LOCATION.
3. CONSTRUCTION OF SAND FILTER FACILITY AND STORM STRUCTURES
COMPLY WITH NC DEQ GUIDELINES.
4. MAINTENANCE AND INSPECTION REQUIREMENT COMPLY WITH
NC DEQ GUIDELINES.
5. SAND FILTER SHALL BE INSPECTED ONCE A QUARTER AND WITHIN 24 HOURS
AFTER EVERY STORM EVENT GREATER THAN 1.0 INCHES (OR 1.5 INCHES IF IN A
COASTAL COUNTY). RECORD OF OPERATION AND MAINTENANCE WILL BE KEPT
IN A KNOWN SET LOCATION AND WILL BE AVAILABLE UPON REQUEST.
3" GRAVEL / STONE
SURFACE
EL. 444.00
RIP RAP BERM
(CLASS B)
SANFILTER MEDIA
(ASTM C-33 SAND
OR EQUIVALENT)
1.5' MEDIA
V DDV ELEV. = 443.10
ELEV. = 442.25
6'X6' OVERFLOW OUTLET
CONTROLSTRUCTURE -
RIM. ELEV 445.00
6" PERFORATED UNDER DRAIN
@ 0.5% SLOPE
\� 100 YR ELEV. = 445.57
PROFILE VIEW
3" GRAVEL / STONE
SURFACE
1.5' SAND FILTER MEDIA
(ASTM C-33 SAND OR
EQUIVALENT)
12"
2.0'xl' rec weir
EL 444.00
EL 447.00
3 MIN.
30" RCP OUTFLOW PIPE
ELEV 436.79
V GRAVEL LAYER
N.T.S NOTICE TO CONTRACTOR:
SCARIFY BOTTOM PRIOR TO
INSTALLATION OF UNDER DRAIN SYSTEM
(DO NOT COMPACT)
FII TFR
EL 442.25
Sandfilter)
ABRIC
WASHED
#57 STONE
E / GRAVEL
UNDER DRAIN SYSTEM
TYPICAL SECTION
N.T.S
SANDFILTER 1-
Environnierrrnl Envir�nn,<n,al Enviranmemol
NCDEQ Stormwater BMP Manual Qrar" NCDEQ Stormwater BMP Manual ¢""io. NCDEQ Stormwater BMP Manual Qunlr°,
Maintenance Table 9: Sample Operation and Maintenance Provisions for Sand Filters
filter bed media and replace. If
water still ponds, then consult
Sand filters shall be inspected at least once a quarter and shall be maintained as needed to I an expert.
remove surface sediment accumulation, trash, debris, and leaf litter to prevent the filter from
clogging. Sediment should be cleaned out of the forebay/sedimentation chamber when it Outlet device Clogging has occurred. Clean out the outlet device.
accumulates to a depth of more than 6 inches. During inspection, structures such as outlets Entire BMP Trash/debris is present. Remove the trash/debris. Dispose of the sediment offsite.
and flow diversions should be checked at least annually for damage or degradation. Figure 6
shows an example of a sand filter that is overdue for maintenance. Adjacent pavement (if Sediment is present on the Sweep or vacuum the sediment
applicable) pavement surface. as soon as possible. The outlet device is damaged Repair or replace the outlet
device.
Figure 6: Sand Filter Overdue for Maintenance
Perimeter of sand filter Areas of bare soil and/or Regrade soil if necessary to
Clogged Sediment Chamber Clogged Sand Chamber erosive gullies have formed. remove the gully, and then Receiving water Erosion or other signs of Contact the NC Division of
99 99 anamer plant a ground cover and water damage have occurred at the Water Resources.
until it is established. Provide outlet.
lime and a one-time fertilizer
application.
Vegetation is too short or too Maintain vegetation at an
long. appropriate hei ht.
9
` Flow diversion structure The structure is clogged. Unclog the conveyance and
dispose of any sediment offsite.
The structure is damaged. Make any necessary repairs or
replace if damage is too large
for repair.
Forebay or pretreatment area Sediment has accumulated to a Search for the source of the
depth of greater than six sediment and remedy the
inches. problem if possible. Remove
the sediment and stabilize or
Important maintenance procedures for a sand filter include: dispose of it in a location where
it will not cause impacts to
1. Manage the drainage area to reduce the sediment load to the sand filter. streams or the BMP.
2. Clean out the sedimentation chamber or forebay whenever sediment depth exceeds six Erosion has occurred. Provide additional erosion
inches. protection such as reinforced
turf matting or riprap if needed
3. At least once a year, skim the sand media. to prevent future erosion
problems.
4. Replace the sand filter media whenever it fails to function properly after maintenance.
Weeds are present. Remove the weeds, preferably
5. Inspect the sand filter at least quarterly. Any problems that are found shall be repaired by hand. If a pesticide is used,
immediately. wipe it on the plants rather than
spraying.
Maintain operation and maintenance records in a known set location. Operation and
maintenance records will be available upon request. Filter bed and underdrain Water is ponding on the surface Check to see if the collector
collection system for more than 24 hours after a system is clogged and flush if
storm. necessary. If water still ponds,
remove the top few inches of
TOP OF SAN
BOTTOM C
BOTTOM OF
POND 1 / SANDFILTER - OUTLET STRUCTURE DETAIL
N.T.S.
NOTE:
GRATING SECTION SHALL BE FASTENED TO THE SUPPORTS WITH A
MINIMUM OF FOUR (4) SADDLE CLIP ANCHORS DESIGNED TO FIT OVER
TWO (2) BEARING BARS WITH STUD BOLTS, WASHERS AND NUTS.
ALUMINUM RIVETED GRATIN
(1-1/8" X 7")
ALUMINUM ANGLE 3" x
2" x 3/8", LLV
1/2"6 S.S. EXP. ANCHORS
@ 2'-0" O.C. 3 1/2" MIN.
EMBEDMENT
INSIDE FACE OF CONIC. BOX
GRATING DETAIL
NOT TO SCALE
CARRY RIP RAP UP
SIDES OF SPILLWAY
� 1-SILT FENCE
CLASS 1 OR 2
x RIP RAP
DRIP RAP APRON
OUT�FT F�
/4"
3'
SP/LLW.4 Y LENGTH S DEVSLOPES
12"
F� (5' MIN.)
ELEVATION OF POND SPILLWAY
NOT TO SCALE
POND
SPILLWAY
SPILLWAY CREST
SPILLWAY CREST
ID
BOTTOM
LENGTH
ELEV.
NUMBER
WIDTH
(L)
(H)
SF 1
10'MIN.
1 10'
446.00
NOTE: CONTRACTOR TO REMOVE SILT FENCING
AFTER POST -CONSTRUCTION ACTIVITIES HAVE BEEN
COMPLETED, AND POND SLOPES HAVE BEEN STABILIZED.
C-6. Sand Filter 7 Revised: 1-3-2017 C-6. Sand Filter 8 Revised: 1-3-2017 C-6. Sand Filter 9 Revised: 1-3-2017
POND 1 /SANDFILTER OVERFLOW EMERGENCY SPILLWAY
N.T.S.
#5 WASHED STONE ON
OUTER SURFACE OF
BERM ACROSS SPILLWAY
NO STONE THRU BERM
C
m
. (E
i
a r c h i t e c t s
ARCHITECT:
16150 Main Circle Drive, Suite 100
St. Louis, MO 63017
[phone] / fax [phone]
CONSULTANTS:
CIVII:
Stantec
801 Jones Franklin Road, Suite 300
Raleigh, NC 27606
MEP/FP:
SSC Engineering, Inc.
18207 Edison Ave.
Chesterfield, MO 63005
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COOPERATIVE
DBUILDING SOLUTIONS
PA RIC
EXPERIENCE. EXCELLENCE.
DESCRIPTION
DATE
ADDENDUM #2
07/10/2020
ERC/STRM COMMENTS
08/14/2020
PROFESSIONAL RECORD
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08/14/202
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DATE
07-10-2020
PROJECT NUMBER
19.025
TITLE
SANDFILTER 1
DETAILS
SHEET

SEDIMENTATION CHAMBER
1�\
3 MIN
INFLOW PIPE
SAND FILTER 2 BMP SUMMARY CHART ASBUILT
PEAK CONTROL
STORM EVENT
POST -DEVELOPMENT
RUNOFF (CFS)
POST -ROUTING
RUNOFF (CFS)
ELEVATION
TOP OF DAN'.
450,00
2YR
6,61
0,99
447,10
10 Y R
11.63
1,24
447.71
25 YR
1.5.59
1.98
448,13
100 YR
23.25
10,61
448,64
PROVIDED
REQUIRED
ELEVATION
DDV
7320 CF
1 2559 C=
446,80
SAND FILTER
1608 SF
1200 S=
446.D0
SAND FILTER 2 BMP SUMMARY CHART
6"
#57 WASHED 2' RIP RAP
STONE
3" GRAVEL / STONE SURFACE
EL 443.5
CLEAN -OUT
(PVC PIPE
W / GLUED CLEAN -OUT FITTINGS
AND SCREW TYPE CAP)
PEAK CONTROL
STORM EVENT
POST -DEVELOPMENT
RUNOFF (CFS)
POST -ROUTING
RUNOFF (CFS)
ELEVATION
TOP OF DAM
450.00
2YR
5.8
0.89
446.88
111
10.6
1.14
447.46
25 YR
14.48
1.31
447.93
100 YR
22.07
5.30
448.56
PROVIDED
REQUIRED
ELEVATION
DDV
6713 CF
2559 CF
446.70
SAND FILTER
1500 SF
1200 SF
446.00
NOTE:
1. SAND FILTER IS SIZED FOR DDV AND CHECKED FOR FREEBOARD.
2. PER GEO-TECHNICAL REPORT PREPARED BY TERRACON CONSULTANTS, INC. RALEIGH, NC.
THERE IS NOT ANY GROUND WATER ENCOUNTERED AT SAND FILTER 1 LOCATION.
3. CONSTRUCTION OF SAND FILTER FACILITY AND STORM STRUCTURES
COMPLY WITH NC DEQ GUIDELINES.
4. MAINTENANCE AND INSPECTION REQUIREMENT COMPLY WITH
NC DEQ GUIDELINES.
5. SAND FILTER SHALL BE INSPECTED ONCE A QUARTER AND WITHIN 24 HOURS
AFTER EVERY STORM EVENT GREATER THAN 1.0 INCHES (OR 1.5 INCHES IF IN A
COASTAL COUNTY). RECORD OF OPERATION AND MAINTENANCE WILL BE KEPT
IN A KNOWN SET LOCATION AND WILL BE AVAILABLE UPON REQUEST.
NCDEQ Stormwater BMP Manual
Maintenance
Sand filters shall be inspected at least once a quarter and shall be maintained as needed to
remove surface sediment accumulation, trash, debris, and leaf litter to prevent the filter from
clogging. Sediment should be cleaned out of the fore bay/sed i me ntatio n chamber when it
accumulates to a depth of more than 6 inches. During inspection, structures such as outlets
and flow diversions should be checked at least annually for damage or degradation. Figure 6
shows an example of a sand filter that is overdue for maintenance.
Figure 6: Sand Filter Overdue for Maintenance
Clogged Sediment Chamber Clogged Sand Chamber
Iwo
Important maintenance procedures for a sand filter include:
1. Manage the drainage area to reduce the sediment load to the sand filter.
2. Clean out the sedimentation chamber or forebay whenever sediment depth exceeds six
inches.
3. At least once a year, skim the sand media.
4. Replace the sand filter media whenever it fails to function properly after maintenance.
5. Inspect the sand filter at least quarterly. Any problems that are found shall be repaired
immediately.
Maintain operation and maintenance records in a known set location. Operation and
maintenance records will be available upon request.
C-6. Sand Filter
7
Revised: 1-3-2017
NCDEQ Stormwater BMP Manual
Table 9: Sample Operation and Maintenance Provisions for Sand Filters
3" GRAVEL / STONE
SURFACE
EL. 448.00
RIP RAP BERM
(CLASS B)
SANFILTER MEDIA
(ASTM C-33 SAND
OR EQUIVALENT)
1.5' MEDIA
DDV ELEV. = 446.70
ELEV. = 446.25
4'X4' OVERFLOW OUTLET
CONTROLSTRUCTURE -
RIM. ELEV 448.50
6" PERFORATED UNDER DRAIN
@ 0.5% SLOPE
Entire BMP
Trash/debris is present.
Remove the trash/debris.
Adjacent pavement (if
Sediment is present on the
Sweep or vacuum the sediment
applicable)
pavement surface.
as soon as possible.
Perimeter of sand filter
Areas of bare soil and/or
Regrade soil if necessary to
erosive gullies have formed.
remove the gully, and then
plant a ground cover and water
until it is established. Provide
lime and a one-time fertilizer
application.
Vegetation is too short or too
Maintain vegetation at an
long.
appropriate height.
Flow diversion structure
The structure is clogged.
Unclog the conveyance and
dispose of any sediment offsite.
The structure is damaged.
Make any necessary repairs or
replace if damage is too large
for repair.
Forebay or pretreatment area
Sediment has accumulated to a
Search for the source of the
depth of greater than six
sediment and remedy the
inches.
problem if possible. Remove
the sediment and stabilize or
dispose of it in a location where
it will not cause impacts to
streams or the BMP.
Erosion has occurred.
Provide additional erosion
protection such as reinforced
turf matting or riprap if needed
to prevent future erosion
problems.
Weeds are present.
Remove the weeds, preferably
by hand. If a pesticide is used,
wipe it on the plants rather than
spraying.
Filter bed and underdrain
Water is ponding on the surface
Check to see if the collector
collection system
for more than 24 hours after a
system is clogged and flush if
storm.
necessary. If water still ponds,
remove the top few inches of
C-6. Sand Filter
8
Revised: 1-3-2017
100 YR ELEV. = 448.56
2.0'W x 0.5'H rec weir
PROFILE VIEW
N.T.S
3" GRAVEL / STONE
SURFACE
1.5' SAND FILTER MEDIA
(ASTM C-33 SAND OR
EQUIVALENT)
DO
FILTER FABRIC
EL 450.00
3 MIN.
1 Fj
18" RCP OUTFLOW PIPE
ELEV 443.5
V GRAVEL LAYER
NOTICE TO CONTRACTOR:
SCARIFY BOTTOM PRIOR TO
INSTALLATION OF UNDER DRAIN SYSTEM
(DO NOT COMPACT)
EL 446.25
EL 446.00 (Top Sandfilter)
FILTER FABRIC
EL 444.5
WASHED
#57 STONE
EL 443.5
6" PERFORATED PIPE / GRAVEL
UNDER DRAIN SYSTEM
TYPICAL SECTION
N.T.S
SANDFILTER 2
Stormwater BMP Manual
filter bed media and replace. If
water still ponds, then consult
an expert.
Outlet device Clogging has occurred. Clean out the outlet device.
Dispose of the sediment offsite.
The outlet device is damaged Repair or replace the outlet
device.
Receiving water Erosion or other signs of Contact the NC Division of
damage have occurred at the Water Resources.
outlet.
C-6. Sand Filter
9
Revised: 1-3-2017
AV
I
X X�X
POND 1 / SANDFILTER - OUTLET STRUCTURE DETAIL
N.T.S.
NOTE:
GRATING SECTION SHALL BE FASTENED TO THE SUPPORTS WITH A
MINIMUM OF FOUR (4) SADDLE CLIP ANCHORS DESIGNED TO FIT OVER
TWO (2) BEARING BARS WITH STUD BOLTS, WASHERS AND NUTS.
ALUMINUM RIVETED GRATIN
(1-1/8" X 7")
/4"
ALUMINUM ANGLE 3" x
2" x 3/8", LLV
1/2"0 S.S. EXP. ANCHORS
@ 2'-0" O.C. 3 1/2" MIN.
EMBEDMENT
INSIDE FACE OF CONC. BOX
GRATING DETAIL
NOT TO SCALE
CARRY RIP RAP UP
SIDES OF SPILLWAY
\X
� 1�SILT FENCE
CLASS 1 OR 2
X RIP RAP
--RIP RAP APRON
3'
SPILL WA Y LENG
Fr-
12"
(5" MIN.)
ELEVATION OF POND SPILLWAY
NOT TO SCALE
POND
SPILLWAY
SPILLWAY CREST
SPILLWAY CREST
ID
BOTTOM
LENGTH
ELEV.
NUMBER
WIDTH
(L)
(H)
SF 2
10'MIN.
1 10'
1 449.00
NOTE: CONTRACTOR TO REMOVE SILT FENCING
AFTER POST -CONSTRUCTION ACTIVITIES HAVE BEEN
COMPLETED, AND POND SLOPES HAVE BEEN STABILIZED.
POND 1 / SANDFILTER OVERFLOW EMERGENCY SPILLWAY
N.T.S.
4H:1 V
SIDE SLOPES
#5 WASHED STONE ON
OUTER SURFACE OF
BERM ACROSS SPILLWAY
NO STONE THRU BERM
C
m
.E
a r c h i t e c t s
ARCHITECT:
16150 Main Circle Drive, Suite 100
St. Louis, MO 63017
[phone] / fax [phone]
CONSULTANTS:
CIVII:
Stantec
801 Jones Franklin Road, Suite 300
Raleigh, NC 27606
MEP/FP:
SSC Engineering, Inc.
18207 Edison Ave.
Chesterfield, MO 63005
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COOPERATIVE
DBUILDING SOLUTIONS
PA RIC
EXPERIENCE. EXCELLENCE.
DESCRIPTION
DATE
ADDENDUM #2
07/10/2020
ERC/STRM COMMENTS
08/14/2020
PROFESSIONAL RECORD
yv,CARo
_ ❑82
08/14/202
�'' ��G 1 IyE�'. •' �
rr�r �'�R�f • A �R�,'`�
,`fflfillll ON\
DATE
07-10-2020
PROJECT NUMBER
19.025
TITLE
SANDFILTER 2
DETAILS
SHEET
305