825 N BROADWAY 2017-01-13 - Laserfiche WebLink

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