SWA000065_(5)Scanned _1/27/2020

Construction 1. dear, grub, and strip the area under the embankment of all vegetation and
Specifications root mat. Remove all surface soil containing high amounts of organic matter
and stockpile or dispose of it properly. Haul all objectionable material to the
designated disposal area. Place temporary sediment control measures below
basin as needed
2. Ensure that fill material for the embankment is free of roots, woody
SCHEDULE 40 vegetation, organic matter, and other objectionable material. Place the fill in
PVC END PVC VENT PVC PIPE lifts not to exceed 9 inches, and machine compact it. Over fill the embankment
CAP PVC ELBOW PIPE / 6 inches to allow for settlement.
ff 3. Shape the basin to the specified dimensions. Prevent the skimming device
WATER SURFACE o — from settling into the mud by excavating a shallow pit under the skimmer or
providing a low support under the skimmer of stone or timber.
• • • , _ PVC END ° 4. Place the barrel (typically 4-inch Schedule 40 PVC pipe) on a firm, smooth
.. .. CAP SC VC PIPE4 �``.
foundation of impervious soil. Do not use pervious material such as sand,
ORIFICE gravel, or crushed stone as backfill around the pipe. Place the fill material
PVC TEE FLEXIBLE PLATE around the pipe spillway in 4-inch layers and compact it under and around
PVC PIPE HOSE PVC TEE the pipe to at least the same density as the adjacent embankment, Care must
1/2" HOLES IN RIP -RAP PAD be taken not to raise the pipe from the firm contact with its foundation when
UNDERSIDE REQUIRED compacting under the pipe haunches.
UNDER SKIMMER
Place a minimum depth of 2 feet of compacted backfill over the pipe spillway
before crossing it with construction equipment. In no case should the pipe
BOTTOM SURFACE conduit be installed by cutting a trench through the dam after the embankment
END VIEW FRONT VIEW is complete.
5. Assemble the skimmer following the manufacturers instructions, or as
designed.
6. Lay the assembled skimmer on the bottom of the basin with the flexible
joint at the inlet of the barrel pipe. Attach the flexible joint to the barrel pipe
and position the skimmer over the excavated pit or support. Be sure to attach
a rope to the skimmer and anchor it to the side of the basin. This will be used
ARM ASSEMBLY a to pull the skimmer to the side for maintenance.
0 7. Earthen spillways --Install the spillway in undisturbed soil to the greatest
extent possible. The achievement of planned elevations, grade, design width,
-- - -- °`C"' ENCL®SURE and entrance and exit channel slopes are critical to the successful operation
of the spillway. The spillway should be lined with laminated plastic or
impermeable geotextile fabric. The fabric must be wide and long enough to
cover the bottom and sides and extend onto the top of the dam for anchoring
°o in a trench. The edges may be secured with 8-inch staples or pins. The fabric
PERSPECTIVE VIEW ° WATER ENTRY must be long enough to extend down the slope and exit onto stable ground.
UNIT The width of the fabric must be one piece, not joined or spliced; otherwise
NOTE: SKIMMER TO BE TETHERED water can get under the fabric. If the length of the fabric is insufficient for the
SKIMMER entire length of the spillway, multiple sections, spanning the complete width,
may be used. The upper section(s) should. overlap the lower section(s) so
that water cannot flow under the fabric. Secure the upper edge and sides
of the fabric in a trench with staples or pins. (Adapted from "A Manual for
SEE N.C. DENR EROSION and SEDIMENT Designing, Installing and Maintaining Skimmer Sediment Basins." February,
CONTROL PLANNING and DESIGN MANUAL 1999. J. W. Fairclotb & Son.).
FOR CONDITIONS WHERE PRACTICE APPLIES; 8. Inlets —Discharge water into the basin in a manner to prevent erosion. Use
PLANNING CONSIDERATION & DESIGN CRITERIA. temporary slope drains or diversions with outlet protection to divert sediment -
laden water to the upper end of the pool area to improve basin trap efficiency
(References: Runoff Control Measures and Outlet Protection).
V. Erosion controi----uonstruct the structure so chat me alsu roea area is
minimized. Divert surface water away from bare areas. Complete the
DESIGN CRITERIA embankment before the area is cleared. Stabilize the emergency spillway
SUMMARY: SKIMMER SEDIMENT BASIN �+ �ro embankment and all other disturbed areas above the crest of the principal
PRIMARY SPILLWAY: TRAPEZOIDAL SPILLWAY WITH IMPERMEABLE MEMBRANE PERSPECTIVE VIEW spillway immediately after construction (References: Surface Stabilization).
MAXIMUM DRAINAGE AREA: 10 ACRES Gp
MINIMUM VOLUME: 1800 CUBIC FEET PER ACRE OF DISTURBED AREA � �0�1� 10. Install porous baffles as specified in Practice 6.65, Porous Baffles.
MINIMUM
LtW RATIO; 2:1 SURFACE AREA: 2:1 SQUARE FEET PER CFS OF O25 PEAK INFLOW
MItiC1Q Q11. After all the sediment -producing areas have been permanently stabilized,
MAXIMUM L1W RATIO: 6:1 BAFFLE (TYP.) remove the structure and all the unstable sediment. Smooth the area to
MINIMUM DEPTH: 2 FEET blend with the adjoining areas and stabilize properly (References: Surface
DEWATERING MECHANISM: SKIMMER
MINIMUM DEWATERING TIME: 2 DAYS Stabilization).
DESIGN BASIN LIFE: 3 YEARS OR LESS
DAM HEIGHT: 5 FEEL' MAXIMUM -
BAFFLES REQUIRED: -fc 3 BAFFLES
STABLE TRANSITION Maintenance Inspect skimmer sediment basins at least weekly and after each significant
REQUIRED TO THE one-half inch or eater rainfall event and re immediate) Remove
BASE OF THE SLOPE' ( greater) pair y�
SEE NC EROSION AND SEDIMENT CONTROL sediment and restore the basin to its original dimensions when sediment
PLANNING AND DESIGN MANUAL, accumulates to one-half the height of the first bathe. Pull the skimmer to
NOTE: BASINS LESS THAN 20' IN LENGTH MAY one side so that the sediment underneath it can be excavated. Excavate the
USE 2 BAFFLES. sediment from the entire basin, not just around the skimmer or the first cell.
Make sure vegetation growing in. the bottom of the basin does not hold down
the skimmer.
INLET ZONE 25%
STONE WIFABRIC OF SURFACE AREA Repair the baffles if they are damaged. Re -anchor the baffles if water is
flowing underneath or around them.
SKIMMER
FIRST CHAMBER
yiP't 25% OF SURFACE AREA If the skimmer is clogged with trash and there is water in the basin, usually
�Q��V jerking on the rope will make the skimmer bob up and down and dislodge
GSECOND CHAMBER the debris and restore flow. If this does not work, pull the skimmer over to
EAR 25% OF SURFACE AREA the side of the basin and remove the debris. Also check the orifice inside the
skimmer to see if it is clogged-, if so remove the debris.
EXTEND BAFFLES UP SIDES AS If the skimmer arm or barrel pipe is clogged, the orifice can be removed and
TO NOT ALLOW FLOW AROUND the obstruction cleared with a plumber's snake or by flushing with water. Be
THE ENDS.
�Qq TETHER sure and replace the orifice before repositioning the skimmer.
STONE ENERGY i(<2 OUTLET ZONE 25% OF SURFACE AREA Check the fabric lined spillway for damage and make any required repairs
Sediment basin shall be maintained DISSIPATOR �— f/� with fabric that spans the full width of the spillway. Check the embankment,
and silt removed when basin is 1/2 full
NOTES:
1. LOCATE SEDIMENT INFLOW TO THE BASIN AWAY
FROM THE DAM TO PREVENT SHORT CIRCUITS
FROM INLETS TO OUTLETS.
2. BASIN MUST BE STABILIZED IMMEDIATELY
UPON CONSTRUCTION AND PRIOR TO SITE
INSPECTION APPROVAL
SKIMMER SEDIMENT BASIN
spillways, and outlet for erosion damage, and inspect the embankment for
BAFFLE DETAIL piping and settlement. Make all necessary repairs immediately. Remove all
trash and other debris from the skimmer and pool areas.
SUPPORT ROPE SUPPORT POST
TO WIRE TO 24" INTO BOTTOM Freezing weather can result in ,ice forming in the basin. Some special
PREVENT SAGGING OR SIDES
STAKE TO precautions should be taken in the winter to prevent the skimmer from
4'
'M-AX SUPPORT WIRE -� plugging with ice.
V11 MIN
COIR MESH OR JUTE, TRENCHED
DESIGN LIFE OF FABRIC INTO BOTTOM AND SIDE
IS 6-12 MONTHS _
SPECIFICATION
SKIMMER SEDIMENT BASIN
1. INSTALL METER AT R/W
2- "TWO (2)-3/4" SERVICE LINES MUST BE INSTALLED
INSIDE A 2 SLEEVE j
3- "TWO (2)-1" SERVICE LINES MUST BE INSTALLED
INSIDE A 3" SLEEVE."
4. SLEEVES SHOULD BE SCHEDULE 40 PVC PIP£-
& SEE DETAIL FOR SERVICE MATERIAL AND METER
SETTING
6. SERVICE LINE SHALL BE 3' BELOW FINISHED GRADE
OF DITCHES-
7. CONDUIT MUST EXILND PAST PRFPOSFD SIDEWALK.
-2" PVC SLEEVE W/ 3/4" CARRIER
I
10115 M!�
12" MIN
II SINGLE 3/4" SERVICES
INSTALLED 3' OFF � � W
PROPERTY LINE a z
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IL
TYPICAL DOMESTIC WATER SERVICE INSTALLATION DETAIL
NO SCALE
EXISTING I AS NOTED ON PLANS
ROAD
ROAD SHOULDER
I
z BACIfI7l.L AS ��
� INDICATED
o �? %D
I N�2 ro�
M
45 SEND
NEW WATER LINE SERVICE LINE TO
CORPORATION METER CONNECTION
COCK—A.Y. MCDONALD OR EQUAL
SERVICE SADDLE — A.Y. MCDONALD OR EQUAL
STYLE HINGED 3691 FOR 3/4-
SERVICE SADDLE — A.Y. MCDONALD OR EQUAL
TRENCH WIDTH
PIPE O.D. + 18' FOR PIPES UNDER 33' O.D.
NOTL: PIPE Q.D. + 24" FOR PIPES OVER 33" O.D.
1. "SERVICE CONNECTION" IN PROPOSAL TO INCLUDE SERVICE SADDLE,
45' BEND, CORPORATION COCK AND ALL LABOR INVOLVED IN
MAKING A COMPLETE SERVICE CONNECTION. ,
2. SERVICE PIPING TO BE 3/4" SDR-9 PE TUBING
3. ALL BRASS FITTINGS SHALL BE COMPRESSION TYPE
TYPICAL WATER SERVICE CONNECTION
USING TAPPING SADDLE DETAIL r Y��
NO SCALE
3
1' FROM EDGE OF ROW �
METER BOX LID. CAST, IRON . a
1
9
7
0
U
SERVICE LINE �
FROM STREET �
METER SETTER
CENTERED
IN BOX METER TO BE INSTALLED
BRICK SUPPORT
V;3
Ills
;
" X 18" �ci c, j ,,. ;, r
SS NIPPLE I ".-10,'. r R"
METER SETTER WfTH
DOUBLE CHECK VALVE
1. METER AND PRIVATE SERVICE LINE NOT IN CONTRACT UNLESS SPECIFIED (BACKFLOW PREVENTER)
2. INCLUDE STONE IN PRICE OF METER BOX.
3. METER SETTER SIZE AS NOTED ON PLANS.
4- ALL BRASS FITTINGS SHALL BE COMPRESSION TYPE.
-TYPICAL 3/4"' METER SETTER INSTALLATION DETAIL
No SCALE
PLAN
I as"
ELEVATION [ A 1
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16 314'
IRON
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ISOMETRIE
TYPICAL METER BOX DETAIL FOR 3/4"' SERVIC;F
NO SCALE
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