3400 RIVERFRONT BLVD BASE FILE 2020-07-15

Storm water Pollution Prevention Plan • Design the project to fit the existing topography, soils, and drainage patterns. • Emphasize erosion control rather than sediment control. • Minimize the extent and duration of the area exposed. • Keep runoff velocities low. • Retain sediment on site. • Thoroughly monitor site and maintain all ESC measures. • Schedule major earthwork during the dry season. In addition,project management will incorporate the key components listed below: As this project site is located west of the Cascade Mountain Crest,the project will be managed according to the following key project components: Phasing of Construction • The construction project is being phased to the extent practicable in order to prevent soil erosion, and,to the maximum extent possible, the transport of sediment from the site during construction. • Revegetation of exposed areas and maintenance of that vegetation shall be an integral part of the clearing activities during each phase of construction, per the Scheduling BMP (C 162). Seasonal Work Limitations • From October 1 through April 30, clearing, grading, and other soil disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority that silt-laden runoff will be prevented from leaving the site through a combination of the following: ❑ Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters; and ❑ Limitations on activities and the extent of disturbed areas; and ❑ Proposed erosion and sediment control measures. 17