- 692 - SECTION 815 -- SILT TRAP
815.01 Description
1.This work consists of the cons truction, maintenance and removal of silt traps. A silt trap is a shallow exca vation constructed in a drainage path to dissipate energy, induce sediment deposition and provide temporary storage.
815.02 Construction Methods
1.The silt trap shall be approximat ely 1 foot deep and of varying width and length. The shape should be rectangular with the longer dimension parallel to the flow of water. The size , shape and location of the silt trap shall be as shown in the contract or as directed by the Engineer.
2.Construction of the silt trap s hall be accomplished by methods and equipment suitable for the purpose and acceptable to the Engineer.
3.The initial excavated material fr om the construction of the silt trap shall be incorporated into the grade or placed as directed by the Engineer.
4.The silt trap shall be cleaned when at 50% capacity by removal and disposal of the silt to maintain functi onality. Sediment removed from the silt trap shall be deposited in an upland location.
5.The silt trap shall be removed w hen it is deemed of no further use by filling the area with soil and shaping to blend with the adjacent natural ground.
815.03 Method of Measurement
1.Silt trap construction will be measured based on equipment rental.
2.Silt removal will be meas ured based on equipment rental.
3.Silt trap removal will be measured based on equipment rental.
815.04 Basis of Payment
1.P a y I t e m P a y U n i t Rental of Skid Loader, Hour Fully Operated Rental of Loader, Hour Fully Operated Rental of Crawler Mounted Hour Hydraulic Excavator, Fully Operated Rental of Dump Truck, Hour Fully Operated Rental of Backhoe, Hour Fully Operated
2.Payment is full compensation for all work described in this Section. - 693 - SECTION 816 -- SILT FENCE
816.01 Description
1.This work consists of installing the silt fence at locations shown in the contract and at locations as appr oved or determined by the Engineer. The installation shall be in accordance with the contract.
816.02 Material Requirements
1.All silt fence material shal l be selected from the Department’s Approved Products List.
a.Low Porosity Silt Fence is typically used for perimeter control. b. High Porosity Silt Fence is used for velocity control.
c.Low Profile Silt Fence is us ed for perimeter control and inlet protection
d.Coir Silt Fence is used for perimeter control of wetlands and locations specified to use a biodegradable silt fence.
e.Temporary Silt Fence shall be any product from the silt fence category of the Department ’s Approved Products List with a use appropriate to the situation.
2.Silt Fence Posts a. The silt fence posts shall be Studded “T” Steel Posts with a minimum weight of 1.25 lbs/foot (37 Kg/m).
b.Used Studded “T” St eel Posts are acceptable.
c.Coir Silt Fence wooden posts shall be derived from hardwood tree species.
3.Zip ties shall be UV stabilized, black with a 50 lb (22 Kg) minimum tensile strength.
816.03 Construction Methods
1.The silt fence shall be install ed and in good working condition prior any grading or excavation operations and as needed throughout the construction process. The silt fence installation shall not exceed the amount required for the current construction season.
2.Silt Fence may be installed in the ground by either of the two methods listed below.
a.Trenching Method
1.The Contractor shall excavate a trench to the depth, width, and length shown in the contract.
2.The Contractor shall place the silt fence in the trench and pin it as shown in the contract.
3.Wire staples shall be us ed for anchoring the silt fence.
4.The Contractor shall ba ckfill the trench, compact the soil, and attach the fabric to the posts as shown in the contract. The posts shall be driven until firm.
b.Slicing Method (1) The Contractor shall inst all silt fence by mechanically slicing the material into the soil.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 726–726 of 1,048.