31 25 00 EROSION AND SEDIMENTATION CONTROL SECTION 1 - GENERAL 1.1 SUMMARY A. Erosion and sedimentation control shall be provided by the Contractor for all areas of the site denuded or otherwise disturbed during construction. The Contractor shall be responsible for all installation, materials, labor, and maintenance of erosion and sediment control devices, as well as removal of temporary erosion and sediment control devices shown on the plans or required to protect all downstream properties, natural waterways, streams, lakes, ponds, catch basins, drainage ditches, roads, gutters, natural buffer zones, and man made structures. B. Erosion and sediment control procedures and facilities shall conform to all applicable state and local codes or ordinances and Base DPW requirements, whichever is more stringent. 1.2 PERFORMANCE REQUIREMENTS A. The Contractor shall not commence with any type of earth denuding or disturbance prior to the issuance of an approved Erosion and Sedimentation Control permit as required by the State Agency having jurisdiction over Sedimentation and Erosion Control and the Base DPW. B. The Contractor shall at all times provide satisfactory means to prevent or minimize the movement and washing of large quantities of soil. The Contractor is expected to review his site grading and drainage operations periodically to determine the areas most susceptible to erosion by excessive rainfall and periodically maintain all installed measures for the project duration. The Contractor shall correct any deficiencies or problem areas as directed by the Utility, Base DPW or the State Agency within 24 hours. C. Where there are differences or conflict between this specification and those requirements outlined in an approved Erosion and Sedimentation Control Plan, the more stringent requirements shall apply. The approved plan shall be followed and supplemented as required to maintain to the conditions noted in paragraph 1.1 above. D. The Contractor shall perform all construction and erosion control activities in accordance with the State Water Quality General Permit to Discharge Stormwater under the National Pollutant Discharge Elimination System for Construction Activities. American States Utility Services 31 25 00-1 Erosion and Sedimentation Control
SECTION 2 - MATERIALS 2.1 ROCK AND STONE: A. Stone for Gravel Construction Entrance shall be 2-3 inch washed stone. B. Stone for erosion control shall conform State Agency Details and requirements 1. While no specific gradation is required, the various sizes of stone shall be equally distributed within the required size range. The size of an individual stone particle shall be determined by measuring along its long dimension. 2. Filter fabric is required under all stone placed for sedimentation ad erosion control unless otherwise noted in the plan details. 2.2 TEMPORARY SILT FENCE A. Temporary silt fence shall be a water permeable filter type fence for the purposes of removing suspended particles from the water passing through it. B. Posts: Posts shall meet the requirements of the details on the plans. C. Woven Wire Fence: Wire fence fabric shall meet the requirements of the details on the plans D. Silt Fence Filter Fabric: shall meet the requirements of ASTM D 6461 Standard Specification for Silt Fence Materials. Silt fence which incorporates filter fabric meeting the requirements of ASTM D 6461-99, but which fails to perform in an acceptable manner shall be replaced with silt fence which is capable of acceptable performance. The maximum design life of the material is 6 months, and shall be replaced prior to 6 months. E. Wire or Plastic Ties shall have a minimum tensile strength of 50 lbs. 2.3 TEMPORARY AND PERMANENT SEEDING AND MULCHING A. As specified in Section 32 92 19 Seeding and Sodding. 2.4 SODDING A. As specified in Section 32 92 19 Seeding and Sodding. SECTION 3 - EXECUTION 3.1 GENERAL REQUIREMENTS: A. The Contractor shall be responsible for conducting his site grading and drainage operations in such manner as to prevent or lessen excessive soil erosion of the construction site work areas. American States Utility Services 31 25 00-2 Erosion and Sedimentation Control
B. The Contractor shall follow the erosion control construction sequence schedule as shown on the contract drawings, except that should circumstances dictate that extra precaution be taken to prohibit erosion and sedimentation on the project, the Contractor shall, at his own expense, take preventative measures as needed. C. If applicable, the contractor shall maintain an erosion control measures self inspection program in accordance with State Agency requirements and with State Agency Water Quality General Permit to Discharge Stormwater under the National Pollutant Discharge Elimination System for Construction Activities. D. The Contractor is required to maintain all erosion and sediment control facilities to insure proper performance throughout the construction phase and until such time all disturbed areas are permanently stabilized and approved by State Agency having jurisdiction over Sedimentation and Erosion Control and/or the Base DPW. E. The Utility has prepared an "Erosion and Sediment Control Plan Narrative" in addition to the erosion control plan sheets. Additional measures may be required to facilitate particular construction techniques and methods. The Contractor shall provide for additional measures as required for the project. F. 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 all other locations necessary to prevent sediment transport. G. The Contractor shall furnish, install, maintain, and remove temporary gravel construction entrance/exits. The entrance/exit shall be located at points where vehicles enter and exit the project and as indicated on the plans to limit sediment "tracked" off the site. H. The Contractor shall install the inlet protection as shown on the detail drawing and at the locations indicated. The Contractor shall install inlet protection when storm drain inlets are to be made operational before permanent stabilization of the disturbed drainage area. The inlet protection applies to areas of heavy runoff and provides for overflow capacity to prevent excessive ponding; however, shallow temporary flooding should be anticipated. I. Provisions for establishing Ground Cover 1. Soil stabilization shall be achieved on any area of a site where landdisturbing activities have temporarily or permanently ceased according to the following schedule: a. All perimeter dikes, swales, ditches, perimeter slopes and all slopes steeper than 3 horizontal to 1 vertical (3:1) shall be provided temporary or permanent stabilization with ground cover as soon as practicable but in any event within 7 calendar days from the last land-disturbinf activity. American States Utility Services 31 25 00-3 Erosion and Sedimentation Control
b. All other disturbed areas shall be provided temporary or permanent stabilization with ground cover as soon as practicable, but in any event within 14 calendar days from the last landdisturbing activity. J. If any earthwork is to be suspended for any reason whatsoever for longer than 15 days, the disturbed areas shall be seeded with temporary vegetative cover or otherwise protected against excessive erosion during the suspended period as specified in Section 32 92 19 Seeding and Sodding. Suspension of work in any area of operation does not relieve the Contractor of the responsibility for the erosion control and temporary measures shall not be considered cause for a change in the price bid. 3.2 TEMPORARY SILT FENCE INSTALLATION A. 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 silt fence shall be constructed at the locations shown on the plans and at other locations directed by the Utility. The quantity of temporary silt fence may be increased, decreased, or eliminated entirely at the direction of the Utility. Such variations in quantity shall not be considered as alterations in the details of construction or a change in the character of the work. B. Post spacing is reduced to a maximum of 6 feet. C. The proposed fabric has been approved by the Utility as being suitable for use without the woven wire fence fabric backing. D. Fence posts shall be inclined toward the runoff source at an angle of not more than 20 from vertical. E. Posts shall be installed so that no more than 3 feet of the post shall protrude above the ground. F. Filter fabric shall be attached to the wire fence fabric by wire or other acceptable means. The fabric shall be continual in length. The fabric shall extend into an 8- inch x 4-inch trench along the uphill side of the fence. The trench shall be backfilled and compacted. G. Where possible, the filter fabric from a continuous roll cut to the length of the barrier shall be used to avoid joints. When joints are necessary, securely fasten the filter cloth only at a support post with overlap to the next post. At the time of installation, the fabric shall be rejected if it has defects, rips, holes, flaws, deterioration, or damage incurred during manufacture, transportation, or storage. American States Utility Services 31 25 00-4 Erosion and Sedimentation Control
3.3 PLACEMENT OF STONE FOR EROSION CONTROL A. A geotextile liner shall be placed under all stone installation as indicated in the plans or as directed by the Utility. B. Unless otherwise directed by the Utility, the stone shall be placed on slopes less than the angle of repose of the material and to the line, grade and slope as indicated on the plans. The stone shall be placed so that the smaller stones are uniformly distributed throughout the mass. All stone shall be placed in a neat, uniform layer with an even surface meeting the approval of the Utility. C. At locations where stone is required for channel changes and drainage ditches, the stone shall be placed prior to diverting the water into the channel changes and drainage ditches. D. At locations where stone is required at the outlet of pipe culverts, the stone shall be placed immediately after completion of the pipe culvert installation. 3.4 GRAVEL CONSTRUCTION ENTRANCE/EXIT A. The area to receive the stone shall be cleared of all vegetation, roots and other objectionable materials. The subgrade shall be graded and properly compacted. B. Area shall be covered with engineering fabric. The stone shall be placed, graded and compacted to a minimum depth of 8 inches and as shown on the plans. C. The minimum construction entrance dimensions shall be 50 feet in length and 12 feet in width. D. The construction entrance/exit shall be maintained and the stone supplemented throughout the life of the project and shall be removed upon stabilization and disposed of off-site. E. Contractor shall remove all objectionable materials spilled, washed or tracked onto public roadways. END OF SECTION 31 25 00 American States Utility Services 31 25 00-5 Erosion and Sedimentation Control