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The work covered by this section consists of furnishing, installing, maintaining, and removing a water permeable filter type of fence for the purpose of removing suspended particles from the water passing through it.
The quantity of temporary silt fence to be installed will be affected by the actual conditions which occur during the construction of the project. The quantity of temporary silt fence may be increased, decreased, or eliminated entirely at the direction of the Engineer. Such variations in quantity will not be considered as alterations in the details of construction or a change in the character of the work.
(A) Posts:
Either wood posts or steel posts may be used. Wood posts shall be a minimum of 6 feet long, at least 3 inches in diameter, and straight enough to provide a fence without noticeable misalignment. Steel posts shall be at least 5 feet in length, approximately 1 3/8 inches wide measured parallel to the fence, and have a minimum weight of 1.25 lb/ft of length. The post shall be equipped with an anchor plate having a minimum area of 14.0 square inches, and shall have a means of retaining wire and fabric in the desired position without displacement.
(B) Woven Wire Fence:
Wire fence shall be at least 32 inches high, and shall have at least 5 horizontal wires. Vertical wires shall be spaced 12 inches apart. The top and bottom wires shall be at least 10 gage. All other wires shall be at the least 12 1/2 gage.
(C) Filter Fabric:
Filter fabric shall meet the requirements of Section 1056 for Type 3 engineering fabric, Class A or B.
(D) Wire Staples:
Wire staples shall be a No. 9 staple and shall be at least 1 1/2 inches long.
The Contractor shall install temporary silt fence as shown on the plans. The silt fence shall be constructed at the locations shown on the plans and at other locations directed by the Engineer.
Class B synthetic filter fabric may be used without the woven wire fence fabric backing, subject to the following conditions:
1. Post spacing is reduced to a maximum of 6 feet.
2. The proposed fabric has been approved by the Engineer as being suitable for use without the woven wire fence fabric backing.
3. Fence posts shall be inclined toward the runoff source at an angle of not more than 20 from vertical.
Posts shall be installed so that no more than 3 feet of the post shall protrude above the ground. Filter fabric shall be attached to the wire fence fabric by wire or other acceptable means. The filter fabric shall be installed in such a manner that a minimum overlap of 18 inches is provided at all splice joints.
At the time of installation, the fabric will be rejected if it has defects, rips, holes, flaws, deterioration, or damage incurred during manufacture, transportation, or storage.
1605-4 MAINTENANCE AND REMOVAL.
The Contractor shall maintain the silt fence until the project is accepted or until the fence is removed, and shall remove and dispose of silt accumulations at the silt fence when so directed by the Engineer in accordance with Section 1630. Filter fabric shall be removed and replaced whenever it has deteriorated or clogged to such extent that it reduces the effectiveness of the silt fence.
Silt fence shall remain in place unless the Engineer directs that it be removed. Silt fence which has been removed will remain the property of the Contractor and may be used at other locations provided it is in a condition acceptable to the Engineer. Upon removal of the silt fence, the Contractor shall dress the area to give a pleasing appearance, and shall seed and mulch the area in accordance with Section 1660.
The quantity of temporary silt fence, measured as provided in Article 16055, will be paid for at the contract unit price per linear foot for "Temporary Silt Fence".
The removal and disposal of silt accumulations will be paid for as provided in Section 1630.
Seeding and mulching will be paid for as provided in Section 1660.
The item of "Temporary Silt Fence" will be considered to be a minor item. However, the provisions of Article 1045 pertaining to revised contract unit prices for overrunning minor items will not apply as no revision in the contract unit price for "Temporary Silt Fence" will be made as a result of any overrun regardless of the quantity of this item actually performed.
The above prices and payments will be full compensation for all work covered by this section, including but not limited to furnishing all fence posts, fence fabric, filter fabric, hardware, and other material; installing and maintaining the silt fence; removal and disposal of silt accumulations from the silt fence; removal of the silt fence; and dressing, seeding, and mulching the disturbed area after the silt fence has been removed.
Payment will be made under:
Temporary Silt Fence Linear Foot