HomeMy WebLinkAbout214.001.CONDITIONS OF USE
1.1.SILT FENCE MAY BE USED DOWNSLOPE OF ALL DISTURBED AREAS.
1.2.SILT FENCE IS NOT INTENDED TO TREAT CONCENTRATED FLOWS, NOR IS IT INTENDED TO TREAT SUBSTANTIAL AMOUNTS OF OVERLAND FLOW. ANY CONCENTRATED
FLOW MUST BE CONVEYED THROUGH THE DRAINAGE SYSTEM TO A SEDIMENT TRAP OR POND.
2.DESIGN AND INSTALLATION SPECIFICATIONS
2.1.THE GEOTEXTILE USED MUST MEET THE STANDARD LISTED BELLOW. A COPY OF THE MANUFACTURER'S FABRIC SPECIFICATIONS MUST BE AVAILABLE ON SITE.
2.2.STANDARD STRENGTH FABRIC REQUIRES WIRE BACKING TO INCREASE THE STRENGTH OF THE FENCE. WIRE BACKING OR CLOSER POST SPACING MAY BE REQUIRED
FOR EXTRA STRENGTH FABRIC IF FIELD PERFORMANCE WARRANTS A STRONGER FENCE.
2.3.WHERE THE FENCE IS INSTALLED, THE SLOPE SHALL NOT BE STEEPER THAN 2H:1V
2.4.IF A TYPICAL SILT FENCE IS USED, THE STANDARD 4"X4" TRENCH MAY BE REDUCED AS LONG AS THE BOTTOM 8 INCHES OF THE SILT FENCE FABRIC IS WELL BURIED AND
SECURE IN A TRENCH THAT STABILIZES THE FENCE AND DOES NOT ALLOW WATER TO BYPASS OR UNDERMINE THE SILT FENCE.
2.5.FILTER FABRIC FENCES SHALL BE INSTALLED ALONG CONTOURS WHENEVER POSSIBLE.
3.MAINTENANCE STANDARDS
3.1.ANY DAMAGE SHALL BE REPAIRED IMMEDIATELY.
3.2.IF CONCENTRATED FLOWS ARE EVIDENT UPHILL OF THE FENCE, THEY MUST BE INTERCEPTED AND CONVEYED TO A SEDIMENT TRAP OR POND.
3.3.IT IS IMPORTANT TO CHECK THE UPHILL SIDE OF THE FENCE FOR SIGNS OF THE FENCE CLOGGING AND ACTING AS A BARRIER TO FLOW AND THEN CAUSING
CHANNELIZATION OF FLOWS PARALLEL TO THE FENCE. IF THIS OCCURS, REPLACE THE FENCE OR REMOVE THE TRAPPED SEDIMENT.
3.4.SEDIMENT MUST BE REMOVED WHEN SEDIMENT IS 6 INCHES HIGH.
3.5.IF THE FILTER FABRIC (GEOTEXTILE) HAS DETERIORATED DUE TO ULTRAVIOLET BREAKDOWN, IT SHALL BE REPLACED.
NOTES:
JOINTS IN FILTER FABRIC SHALL BE SPLICED AT
POSTS. USE STAPLES, WIRE RINGS, OR
EQUIVALENT TO ATTACH FABRIC TO POSTS
2"x2" 14 GAUGE WIRE, OR
EQUIVALENT, IF STANDARD
STRENGTH FABRIC USED
FILTER FABRIC 2' MIN.
12" MIN.
4"x4" MIN. TRENCH
BACKFILL TRENCH WITH NATIVE SOIL
OR 3/4" TO 1-1/2" WASHED GRAVEL
2"x4" WOOD POSTS, STEEL FENCE POSTS, OR EQUIVALENT (TYP.)
6' MAX.
POST SPACING MAY BE INCREASED
TO 8' IF WIRE BACKING IS USED
AOS (ASTM D4751)30-100 SIEVE SIZE (0.60-0.15mm) FOR SILT FILM
50-100 SIEVE SIZE (0.30-0.15mm) FOR OTHER FABRICS
WATER PERMITTIVITY (ASTM D4491)0.02 SEC-1 MINIMUM
GRAB TENSILE STRENGTH (ASTM D4632)180 LBS. MIN. FOR EXTRA STRENGTH FABRIC
100 LBS. MIN. FOR STANDARD STRENGTH FABRIC
GRAB TENSILE ELONGATION (ASTM D4632)30% MAX. (WOVEN)
ULTRAVIOLET RESISTANCE (ASTM D4355)70% MIN.
SILT FENCE
STD. PLAN - 214.00
PUBLIC WORKS
DEPARTMENT
APPROVED:
DATEGregg Zimmerman
Public Works Administrator
UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE (NTS)
DocuSign Envelope ID: 6EECF5B6-602A-4E4A-B436-A317AA638878
9/28/2018 | 9:45 AM PDT