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1 <br /> BMP C105: Stabilized Construction Entrance <br /> Purpose Construction entrances are stabilized to reduce the amount of sediment <br /> transported onto paved roads by vehicles or equipment by constructing a <br /> stabilized pad of quarry spalls at entrances to construction sites. <br /> Conditions of Use Construction entrances shall be stabilized wherever traffic will be leaving <br /> a construction site and traveling on paved roads or other paved areas <br /> within 1,000 feet of the site. <br /> On large commercial,highway, and road projects,the designer should <br /> include enough extra materials in the contract to allow for additional <br /> ' stabilized entrances not shown in the initial Construction SWPPP. It is <br /> difficult to determine exactly where access to these projects will take <br /> place; additional materials will enable the contractor to install them where <br /> ' needed. <br /> Design and • See Figure 4.2 for details.Note:the 100'minimum length of the <br /> Installation entrance shall be reduced to the maximum practicable size when the <br /> Specifications size or configuration of the site does not allow the full length(100'). <br /> • A separation geotextile shall be placed under the spalls to prevent <br /> fine sediment from pumping up into the rock pad. The geotextile <br /> shall meet the following standards: <br /> Grab Tensile Strength (ASTM D4751) 200 psi min. <br /> Grab Tensile Elongation (ASTM D4632) 30%max. <br /> Mullen Burst Strength (ASTM D3786-80a) 400 psi min. <br /> ' AOS(ASTM D4751) 20-45 (U.S.standard sieve size) <br /> • Consider early installation of the first lift of asphalt in areas that will <br /> ' paved;this can be used as a stabilized entrance. Also consider the <br /> installation of excess concrete as a stabilized entrance. During large <br /> concrete pours, excess concrete is often available for this purpose. <br /> • Hog fuel(wood-based mulch)may be substituted for or combined with <br /> quarry spalls in areas that will not be used for permanent roads.Hog <br /> fuel is generally less effective at stabilizing construction entrances and <br /> ' should be used only at sites where the amount of traffic is very limited. <br /> Hog fuel is not recommended for entrance stabilization in urban areas. <br /> The effectiveness of hog fuel is highly variable and it generally <br /> arequires more maintenance than quarry spalls. The inspector may at <br /> any time require the use of quarry spalls if the hog fuel is not <br /> preventing sediment from being tracked onto pavement or if the hog <br /> fuel is being carried onto pavement. Hog fuel is prohibited in <br /> permanent roadbeds because organics in the subgrade soils cause <br /> degradation of the subgrade support over time. <br /> • Fencing(see BMPs C103 and C104) shall be installed as necessary to <br /> restrict traffic to the construction entrance. <br /> I <br /> 4-8 Volume►►—Construction Stormwater Pollution Prevention February 2005 <br />