1502 WALL ST IMAGINE CHILDRENS MUSEUM 2022-08-25

Maintenance Standards If the fence has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. BMP C105: Stabilized Construction Access Purpose Stabilized construction accesses are established to reduce the amount of sediment transported onto paved roads outside the project site by vehicles or equipment.This is done by constructing a sta- bilized pad of quarry spalls at entrances and exits for project sites. Conditions of Use Construction accesses shall be stabilized wherever traffic will be entering or leaving a construction site if paved roads or other paved areas are within 1,000 feet of the site. For residential subdivision construction sites, provide a stabilized construction access for each res- idence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient length/width to provide vehicle access/parking, based on lot size and configuration. On large commercial, highway, and road projects,the designer should include enough extra mater- ials in the contract to allow for additional stabilized accesses 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 Installation Specifications See Figure 11-3.1: Stabilized Construction Access for details. Note:the 100' minimum length of the access shall be reduced to the maximum practicable size when the size or configuration of the site does not allow the full length(100'). Construct stabilized construction accesses with a 12-inch thick pad of 4-inch to 8-inch quarry spalls, a 4-inch course of asphalt treated base(ATB), or use existing pavement. Do not use crushed con- crete, cement, or calcium chloride for construction access stabilization because these products raise pH levels in stormwater and concrete discharge to waters of the State is prohibited. 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 standards listed in Table 11-3.2: Stabilized Con- struction Access Geotextile Standards. Table 11-3.2: Stabilized Construction Access Geotextile Standards Geotextile Property Required Value Grab Tensile Strength(ASTM D4751) 200 psi min. 2019 Stormwater Management Manual for Western Washington Volume ll-Chapter 3-Page 275