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An PAC4"4"*E1*) <br /> SECTION 6 — Minimum Requirement #5 <br /> 6.1 On-site Stormwater Management <br /> To satisfy Minimum Requirement#5, the stormwater generated onsite a Stormwater Site <br /> Plan has been completed in accordance with Volume III, Chapter 12 of the City of <br /> Everett Stormwater Management Manual. An evaluation of the applicable BMPs follows <br /> below. <br /> BMP 12.10 Vegetation Protection Areas <br /> The setting aside of vegetation protection areas can greatly mitigate the impacts of <br /> development on the site's hydrological cycle. The amount of impervious areas on a site <br /> is directly reduced as a result of the protection areas. In addition vegetation protection <br /> areas can often be located to receive sheet flow from necessary parking areas, <br /> driveways, etc., which turns these surfaces into ineffective impervious surfaces for the <br /> purpose of determining the applicability of the minimum requirements. <br /> Vegetation protection areas are not feasible for this project due to site layout and <br /> grading proposed which encompasses the entire project site. <br /> BMP 12.20 Post-Construction Soil Quality and Depth <br /> Naturally occurring (undisturbed) soil and vegetation provide important stormwater <br /> functions including: water infiltration; nutrient, sediment, and pollutant adsorption; <br /> sediment and pollutant biofiltration; water interflow storage and transmission; and <br /> pollutant decomposition. These functions are largely lost when development strips away <br /> native soil and vegetation and replaces it with minimal topsoil and sod. Not only are <br /> these important stormwater functions lost, but such landscapes themselves become <br /> pollution-generating pervious surfaces due to increased use of pesticides, fertilizers and <br /> other landscaping and household/industrial chemicals, the concentration of pet wastes, <br /> and pollutants that accompany roadside litter. <br /> BMP 12.20 for soil amendments has been proposed for all new planting areas on site. <br /> BMP 12.30 On-site Infiltration Areas <br /> On-site infiltration areas are small on-site depressions or infiltration trenches. Only runoff <br /> from non-pollutant generating impervious and pervious surfaces may be discharged to <br /> on-site infiltration areas designed per this volume. Infiltration for stormwater treatment is <br /> covered in Chapter 9. <br /> BMP 12.30 is not feasible for this project. Please refer to page 6 of the attached soils <br /> report in Appendix B. <br /> BMP 12.40 Raingardens <br /> In this manual, raingardens are small bioretention areas used as on-site stormwater <br /> management BMPs. Raingardens may be used to receive runoff from pollutant <br /> generating pervious and impervious surfaces, as well as areas where infiltration facilities <br /> are not feasible. Raingardens may be integrated into the landscaped areas of the lot. <br /> Starbucks Page 6 <br /> Broadway and 10th Store <br /> Drainage Report <br /> May 2014 <br />