Permits & Development - Encroachment(EP)/Driveway(DW) Permits - 2007_EP-07-301 thru EP-07-400_ - EP-07-352

Home Browse Search

10-1.06 TEMPORARY DRAINAGE INLET PROTECTION Temporary drainage inlet protection shall be constructed, maintained, and removed at the locations shown on the approved Water Pollution Control Program (WPCP) in accordance with "Water Pollution Control' of these special provisions,and in accordance with the details shown on the plans and these special provisions. Temporary drainage inlet protection shall be one of the water pollution control practices for sediment control. The WPCP shall include the use of temporary drainage inlet protection. The Contractor shall select the appropriate drainage inlet protection in accordance with the details to meet the conditions around the drainage inlet. Throughout the duration of the contract, the Contractor shall provide protection to meet the changing conditions around the drainage inlet. Temporary drainage inlet protection shall be Type 5. MATERIALS Silt Fence At the Contractor's option, temporary silt fence shall be prefabricated or constructed with silt fence fabric, posts, and fasteners. Silt fence fabric shall conform to the following requirements: Specification Requirements Width,mm,min. 900 Grab tensile strength(25-mm grip),kilonewtons,minimum.in each direction 0.55 ASTM Designation: D 4632 or appropriate test method forspecific polymer Elongation,percent minimum in each direction 15 ASTM Designation: D 4632 or appropriate test method forspecific polymer Permittivity, 1/sec.,minimum. 1.5 ASTM Designation: D 4491 Flow rate,liters per minute per square meter,minimum. 400 ASTM Designation: D 4491 Ultraviolet stability,percent tensile strength retained after 500 hours,minimum. 70 ASTM Designation: D 4355 xenon-arc lamp and waterspray weathering method Silt fence fabric shall be geotextile manufactured from woven polypropylene or polymer material. Silt fence fabric may be made of recycled materials. No materials shall contain biodegradable filler materials that can degrade the physical or chemical characteristics of the finished fabric. The Engineer may order tests to confirm the absence of biodegradable filler materials in conformance to the requirements in ASTM Designation: E 204. Posts for temporary silt fences shall be one of the following: A. Posts shall be untreated fir,redwood,cedar,or pine,shall be cut from sound timber,and shall be straight and free of loose or unsound knots and other defects which would render them unfit for the purpose intended. Wood post shall be a minimum of 34 mm x 40 mm in size,and 4 feet in length. The end of the post to be embedded in the soil shall be pointed. B. Posts shall be steel and have a"U," "T," "L," or other cross sectional shape that can resist failure from lateral loads. The steel posts shall have a minimum mass per length of 1.1 kg/m and a minimum length of 1.2 m. One end of the steel posts shall be pointed and the other end shall be capped with an orange or red plastic safety cap which fits snugly to the steel post. The Contractor shall submit to the Engineer for approval a sample of the capped steel post before installation. Fasteners for attaching silt fence fabric to posts shall be as follows: A. When prefabricated silt fence is used,posts shall be inserted into sewn pockets. B. Silt fence fabric shall be attached to wooden posts with nails or staples as shown on the plans or as recommended by the manufacturer or supplier. Tie wire or locking plastic fasteners shall be used to fasten the silt fence fabric to steel posts. Maximum spacing of fasteners shall be 200 mm along the length of the steel post. Sediment Filter Bag Sediment filter bag fabric shall be geotextile manufactured from woven polypropylene or polymer material. Sediment filter bag fabric may be made from recycled polymer materials. Polymer materials shall not contain biodegradable filler materials and shall conform to the requirements in ASTM Designation: E 204. Contract No. 10-OM7104 146