180 SECTION 261
261.01 Description
This work consists of furnishing, installing, maintaining and removing fiber rolls.
261.02 Equipment
Reserved.
261.03 Materials.
Provide fiber rolls that are composed of degradable netting that contains compressed: − Hay or straw that is seed free and free of noxious weeds; or − Wood excelsior.
261.04 Construction Requirements
A.Maintenance. Remove sediment when it reaches 1/3 of the exposed height of any section of the fiber roll, or as directed by the Engineer. The Engineer may direct the installation of a second fiber roll if removing the sediment deposit is not possible. Inspect the fiber rolls within 24 hours of each rainfall greater than 0.25 inches and at least daily during prolonged rainfall. Submit a fiber rolls inspecti on report within 24 hours of each inspection. Perform and submit a daily review of the location of fiber rolls and check for effectiveness. Remove and replace fiber rolls when necessary.
B.Removal. Do not remove the fiber roll without the Engineers approval. Level, smooth, seed, and mulch the removal area to match surrounding conditions.
261.05 Method of Measurement
The Engineer will measure as specified in Section 109.01, “Measurement of Quantities” and as follows: The Engineer will not measure overlaps.
261.06 Basis of Payment
Pay Item Pay Unit Fiber Roll __IN Linear Foot Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified. 181 The Department will pay for the cleaning of sediment deposits as specified in Section 109.03 C, “PS-1 Price” . The Department will pay for the removal of pre-existing fiber rolls as specified in Section 109.03, “Compensation for Contract Revision” . Section 262 182 SECTION 262 FLOTATION SILT CURTAIN
262.01 Description
This work consists of furnishing, installing, maintaining, and removing flotation silt curtain.
262.02 Equipment
Reserved.
262.03 Materials
Material Property Requirement Curtain Fabric Impermeable vinyl -coated nylon Grab Tensile Strength 500 lb Floatation 8 inch diameter Marine quality expanded polystyrene Net Buoyancy per Foot 20 lb Top Load Carrying Components Fabric plus 5∕16 inch galvanized steel cable 9,800 lb min break strength Ballast (min) 5∕16 inch galvanized chain Connections Between Sections Aluminum collar reinforced quick disconnects
262.04 Construction Requirements
A.Installation. Attach anchor lines to the flotation device.
1.Still Water. Secure both ends of the curtain on land using the anchor points. Use anchor buoys if bottom anchors are used. Tow out the curtain in the furled condition and attach to the anchor points. Set additional anchor points as necessary and attach them firmly to the curtain to maintain the desired location of the curtain. Release the furling lines to let the curtain skirt drop.
2.Moving Water. Set all anchor points. Ensure the anchor points keep the curtain in the desired location. Use anchor buoys on all anchor points. Start securing the furled curtain to the anchor points on the upstream side and work downstream. Make any necessary adjustments.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 215–216 of 550.