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Home My WebLink About12090001.9Specifications for Silt Fence (Not to Scale) I-- 10' Max. --I n n Level contour No slope ll- _ =11=11 ELEVATION II 11111 11 -- Flat slope in front ---- of barrier 16" Min. 16" Min. 6" Min. SECTION ` "Wrap geotextili around stakes before driving Joining sections of silt fence Flow 1FEE i- - - - .11= -i h to be _ _ -- --lied and compacted Specifications for Permanent Seeding Site Preparation 1. Subsoiler; plow, or other implement shall be used to reduce soil compaction and allow maximum infiltration. (Maximizing infiltration will help control both runoff rate and water quality.) Subsoiling should be done when the soil moisture is low enough to allow the soil to crack or fracture. Subsoiling shall not be done on slip -prone areas where soil preparation should be limited to what is necessary for establishing vegetation. 2. The site shall be graded as needed to permit the use of con- ventional equipment for seedbed preparation and seeding. 3. Topsoil shall be applied where needed to establish vegetation. Seedbed Preparation 1. Lime - Agricultural ground limestone shall be applied to acid soil as recommended by a soil test. In lieu of a soil test, lime shall be applied at the rate of 100 pounds per 1;000 -sq. ft. or 2 tons per acre. 2. Fertilizer - Fertilizer shall be applied as recommended by a soil test. In place of a soil test, fertilizer shall be applied at a rate of 25 pounds per 1,000 -sq, ft. or 1000 pounds per acre of a 10 -10 -10 or 12 -12 -12 analyses. 3. Tile lime and fertilizer shall be worked into the soil with a disk harrow, spring -tooth harrow; or other suitable field implement to a depth of 3 inches. On sloping land, the soil shall be worked on the contour. Seeding Dates and Sal Conditions Seeding should be done March 1 to May 31 or August 1 to September 30. If seeding occurs outside of the above - specified dates, additional mulch and irrigation may be required to ensure a minimum of 80% germination. Tillage for seedbed preparation should be done when the soil is dry enough to crumble and not form ribbons when compressed by hand. For winter seeding; see the following section on dormant seeding. Dormant Seedings 1. Seedings should not be made from October 1 through November 20. During this period, the seeds are likely to germinate but probably will not be able to survive the winter. 2. The following methods may be used for "Dormant Seeding ": • From October 1 through November 20, prepare the seedbed, add the required amounts of lime and fertilizer, then mulch and anchor. After November 20, and before March 15, broadcast the selected seed mixture. Increase the seeding rates by 50% for this type of seeding. • From November 20 through March 15, when soil condi- tions permit, prepare the seedbed, lime and fertilize, apply the selected seed mixture, mulch and anchor. Increase the seeding rates by 50% for this type of seeding. • Apply seed uniformly with a cyclone seeder, drill, cultipacker seeder, or hydro - seeder (slurry may include seed and fertil- izer) on a firm, moist seedbed. • Where feasible, except when a cultipacker type seeder is used. the seedbed should be firmed following seeding operations with a cultipacker, roller, or light drag. On sloping land, seeding operations should be on the contour where feasible. Mulching 1. Mulch material shall be applied immediately after seeding. Dormant seeding shall be mulched. 100% of the ground surface shall be covered with an approved material. 2. Materials • Straw -If straw is used it shall be unrotted small -grain straw applied at the rate of 2 tons per acre or 90 pounds (two to three bales) per 1,000 -sq. ft. The mulch shall be spread uniformly by hand or mechanically applied so the soil surface is covered. For uniform distribution of hand - spread mulch, divide area into approximately 1,000- sq. -ft. sections and spread two 45 -lb. bales of straw in each section. • Hydroseeders -If wood cellulose fiber is used, it shall be applied at 2;000 lb./ac. or 46 Ib. 111000 sq. ft. • Other -Other acceptable mulches include rolled erosion control mattings or blankets applied according to manufac- turer's recommendations orwood chips applied at 6 tons per acre. Specifications for Silt Fence 1. Silt fence shall be constructed before upslope land distur- bance begins. 2. All silt fence shall be placed as close to the contour as possible so that water will not concentrate at low points in the fence and so that small swales or depressions that may carry small concentrated flows to the silt fence are dissipated along its length. 3. Ends of the silt fences shall be brought upslope slightly so that water ponded by the silt fence will be prevented from flowing around the ends. 4. Silt fence shall be placed on the flattest area available 5. Where possible, vegetation shall be preserved for 5 feet or as much as possible) upslope from the silt fence. If 1 P ) P Pe vegetation is removed, ft shall be reestablished within 7 days from the installation of the silt fence. 6. The height of the silt fence shall be a minimum of 16 inches above the original ground surface. 7. The silt fence shall be placed in an excavated or sliced trench cut a minimum of 6 inches deep. The trench shall be made with a trencher, cable laying machine, slicing machine, or other suitable device that will ensure an adequately uniform trench depth. 8. The silt fence shall be placed with the stakes on the downslope side of the geotextile. A minimum of 8 inches of geotextile must be below the ground surface. Excess material shall lay on the bottom of the 6 -inch deep trench. The trench shall be backfilled and compacted on both sides of the fabric. 9. Seams between sections of silt fence shall be spliced together only at a support post with a minimum 6 -in. overlap prior to driving into the ground, (see details). 10. Maintenance -Silt fence shall allow runoff to pass only as diffuse flow through the geotextile. If runoff over - tops the silt fence, flows under the fabric or around the fence ends, or in any other way allows a concentrated flow discharge, one of the following shall be performed, as appropriate: 1) the layout of the silt fence shall be changed, 2) accumulated sediment shall be removed, or 3) other practices shall be installed. Sediment deposits shall be routinely removed when the deposit reaches approximately one -half of the height of the sift fence. Silt fences shall be inspected after each rainfall and at least daily during a prolonged rainfall. The location of existing sift fence shall be reviewed daily to ensure its proper location and effectiveness. If damaged, the silt fence shall be repaired immediately. Criteria for sift fence materials 1. Fence post -The length shall be a minimum of 32 inches. Wood posts will be 2- by -2 -in. nominal dimensioned hardwood of sound quality. They shall be free of knots, splits and other visible imperfections, that will weaken the posts. The maximum spacing between posts shall be 10 ft. Posts shall be driven a minimum 16 inches into the ground, where possible. If not possible, the posts shall be adequately secured to prevent overturning of the fence due to sediment /water loading. 2. Sift fence fabric - See chart below. Table 6.3.2 Minimum criteria for Silt Fence Fabric (ODOT, 2002) FABRIC PROPERTIES VALUES TEST METHOD Minimum Tensile Strength 120 lbs. (535 N) ASTM D 4632 Maximum Elongation at 60 Ibs 50° ASTM D 4632 Minimum Puncture Strength 50 Ibs (220 N) ASTM D 4833 Minimum Tear Strength 40 Ibs (180 N) ASTM D 4533 Apparent Opening Size _ 0.84 mm ASTM D 4751 Minimum Permittivity 1X10 -2 sec. -1 ASTM D 4491 UV Exposure Strength Retention 70%„ ASTM G 4355 3. Straw and Mulch Anchoring Methods Straw mulch shall be anchored immediately to minimize loss by wind or water. • Mechanical -A disk, crimper, or similar type tool shall be set straight to punch or anchor the mulch material into the soil. Straw mechanically anchored shall not be finely chopped but, generally, be left longer than 6 inches. • Mulch Netting - Netting shall be used according to the manufacturer's recommendations. Netting may be neces- sary to hold mulch in place in areas of concentrated runoff and on critical slopes. • Asphalt Emulsion - Asphalt shall be applied as recom- mended by the manufacture or at the rate of 160 gallons per acre. Table 7.10.2 Permanent Seeding • Synthetic Binders - Synthetic binders such as Acrylic DLR (Agri -Tac), DCA -70, Petroset, Terra Tack or equivalent may be used at rates specified by the manufacturer. • Wood Cellulose Fiber -Wood cellulose fiber shall be applied at a net dry weight of 750 pounds per acre. The wood cellulose fiber shall be mixed with water with the mixture containing a maximum of 50 pounds cellulose per 100 gal- lons of water. Irrigation Permanent seeding shall include irrigation to establish vegeta- tion during dry weather or on adverse site conditions, which require adequate moisture for seed germination and plant growth. Irrigation rates shall be monitored to prevent erosion and dam- age to seeded areas from excessive runoff. - - - - -- - - -- Seed Mix Seeding Rate _ -- - - - - -- - -..._ Notes: Lbs. /acre Lbs.A,000 Sq. Feet General Use Creeping Red Fescue Domestic Ryegrass Kentucky Bluegrass 20 -40 10 -20 20 -40 12 -1 1/4 -1/2 12 -1 For close mowing & for waterways with <2.0 ft/sec velocity Tall Fescue 40 -50 1 -1 1/4 1 Turf-type (dwarf) Fescue 90 21/4 1 Steep Banks or Cut Slopes Tall Fescue 40 -50 1 -1 1/4 40 Crown Vetch Tall Fescue 10 -20 20 -30 1%4 -112 12 -314 Do not seed later than August Flat Pea Tall Fescue 20 -25 20 -30 12 -3/4 1,2 -3/4 Do not seed later than August Road Ditches and Swales Tall Fescue 40 -50 1 -11/4 Turf-type (Dwarf) Fescue Kentucky Bluegrass 90 5 2114 0.1 Lawns Kentucky Bluegrass Perennial Ryegrass 100 -120 2 2 Oats Kentucky Bluegrass Creeping Red Fescue 100 -120 2 1 -1/2 For shaded areas Note. Other approved seed species may be substimted. Specifications for Mulching 1. Mulch and other appropriate vegetative practices shall be applied to disturbed areas within 7 days of grading if the area is to remain dormant (undisturbed) for more than 21 days or on areas and portions of the site which can be brought to final grade. 2. Mulch shall consist of one of the following: • Straw - Straw shall be unrotted small grain straw applied at the rate of 2 tons /ac. or 90 Ib. /1000 sq. ft. (two to three bales). The straw mulch small be spread uniformly by hand or mechanically so the soil surface is covered. For uniform distribution of hand- spread mulch, divide area into approximately 1,000 sq.ft. sections and place two 45 -lb. bales of straw in each section. • Hydroseeders - Wood cellulose fiber should be used at 2,000 lb./ac. or 46 Ib. 1'1,000 sq, ft. • Other - Acceptable mulches include mulch mattings and rolled erosion control products applied according to manufacturer's recommendations or wood rnulch /chips applied at 10 -20 tons /ac. 3. Mulch Anchoring - Mulch shall be anchored immediately to minimize loss by wind or runoff. The following are acceptable methods for anchoring mulch. • Mechanical - Use a disk, crimper, or similar type tool set straight to punch or anchor the mulch material into the soil. Straw mechanically anchored shall not be finely chopped but be left generally longer than 6 inches. • Mulch Nettings - Use according to the manufacturer's recommendations, following all placement and anchoring requirements. Use in areas of water concentration and steep slopes to hold mulch in place. • Synthetic Binders - For straw mulch, synthetic binders such as Acrylic DLR (Agri -Tac), DCA -70, Petroset, Terra Tack or equal may be used at rates recommended by the manufacturer. All applications of Sythetic Binders must be conducted in such a manner where there is no contact with waters of the state. • Wood Cellulose Fiber - Wood cellulose fiber may be used for anchoring straw. The fiber binder shall be applied at a net dry weight of 750 lb./acre. The wood cellulose fiber shall be mixed with water and the mixture shall contain a maximum of 50 lb./100 gal. of wood cellulose fiber. Specifications for Temporary Seeding Table 7.8.1 Temporary Seeding Species Selection Seeding Dates Species Lb. 1 1000 ft2 Lb /Acre March 1 to August 15 Oats 3 128 (4 Bushel) Tall Fescue 1 40 Annual Ryegrass 1 40 Perennial Ryegrass 1 40 Tall Fescue 1 40 Annual Ryegrass 1 40 Annual Ryegrass 1.25 55 Perennial Ryegrass 3.25 142 Creeping Red Fescue 0.4 17 Kentucky Bluegrass 0.4 17 Oats 3 128 (3 bushel) Tall Fescue 1 40 Annual Ryegrass 1 40 August 16th to November Rye 3 112 (2 bushel) Tall Fescue 1 40 Annual Ryegrass 1 40 Wheat 3 120 (2 bushel) Tall Fescue 1 40 Annual Ryegrass 1 40 Perennial Rye 1 40 Tall Fescue 1 40 Annual Ryegrass 1 40 Annual Ryegrass 1.25 40 Perennial Ryegrass 3.25 40 Creeping Red Fescue 0.4 40 Kentucky Bluegrass 0.4 November 1 to Feb. 29 Use mulch only or dormant seeding Note: Other approved species may be substituted. 1. Structural erosion and sediment control practices such as diversions and sediment traps shall be installed and stabilized with temporary seeding prior to grading the rest of the construction site. 2. Temporary seed shall be applied between construction operations on soil that will not be graded or reworked for 21 days or greater. These idle areas shall be seeded within 7 days after grading. 3. The seedbed should be pulverized and loose to ensure the success of establishing vegetation. Temporary seeding should not be postponed if ideal seedbed preparation is not possible. 4. Soil Amendments - Temporary vegetation seeding rates shall establish adequate stands of vegetation, which may require the use of soil amendments. Base rates for lime and fertilizer shall be used. 5, Seeding Method -Seed shall be applied uniformly with a cyclone spreader, drill, cultipacker seeder, or hydroseeder. When feasible, seed that has been broadcast shall be covered by raking or dragging and then lightly tamped into plane using a roller or cultipacker. If hydroseeding is used, the seed and fertilizer will be mixed on -site and the seeding shall be done immediately and without interruption. Specifications for Temporary Seeding Mulching Temporary Seeding 1. Applications of temporary seeding shall include mulch, which shall be applied during or immediately after seeding. Seedings made during optimum seeding dates on favor- able, very flat soil conditions may not need mulch to achieve adequate stabilization. 2. Materials: • Straw -If straw is used, it shall be unrotted small -grain straw applied at a rate of 2 tons per acre or 90 lbs./ 1,000 sq, ft. (2 -3 bales) • Hydroseeders -If wood cellulose fiber is used; it shall be used at 2000 lbs./ ac. or 46 Ib./ 1,000- sq. -ft. • Other -Other acceptable mulches include mulch mattings applied according to manufacturer's recommendations or wood chips applied at 6 ton / ac. 3. Straw Mulch shall be anchored immediately to minimize loss by wind or water Anchoring methods: • Mechanical -A disk, crimper, or similar type tool shall be set straight to punch or anchor the mulch material into the soil. Straw mechanically anchored shall not be finely chopped but left to a length of approximately 6 inches. • Mulch Netting- Netting shall be used according to the manufacturers recommendations. Netting may be neces- sary to hold mulch in place in areas of concentrated runoff and on critical slopes. • Synthetic Binders - Synthetic binders such as Acrylic DLR (Agri -Tac); DCA -70, Petroset, Terra Track or equivalent may be used at rates recommended by the manufacturer. • Wood- Cellulose Fiber -Wood- cellulose fiber binder shall be applied at a net dry wt. of 750 lb./ac, The wood- cellulose fiber shall be mixed with water and the mixture shall contain a maximum of 50 lb, 1100 gal. J Q H W D>. 06 CO W � F- U 0Z Z Q a a U) a Z Q W U) Z W Z> V) F- U W F-- _ V) Uaf �0 • W to W � LU Z C� Z LU SCALE: AS NOTED DATE: OCTOBER 201 JOB NO.: 44; DESIGN: YJ DRAWN: JE CHECKED: YJ SHEET NO. nl= �