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5. SOURCE CONTROL <br /> This project proposes to construct a new SFR on this parcel with a driveway. Per Volume <br /> 1 of the City of Everett 2010 Stormwater Management Manual residential development <br /> does not require source control. <br /> 6. PRESERVATION OF NATURAL DRAINAGE SYSTEM <br /> The runoff from the site improvements will be infiltrated or dispersed into/over amended <br /> soils on-site and flow in the norther natural downstream direction. However by not grading <br /> or compacting the soils around the site a maximum amount of site runoff from the <br /> developed project will be absorbed and infiltrated into the existing on-site soils. This will <br /> mimic the existing conditions by maintaining the existing direction and condition of flow <br /> from this site. <br /> 7. ON-SITE STORMWATER MANAGEMENT <br /> The soils for this project were found to be Alderwood sandy loam. Since on-site <br /> dispersion and soil management will be used the existing disturbed soils on the site will be <br /> treated to meet the City requirements for amended soils. The roof runoff will be directed to <br /> one of four splash blocks that will drain to either shallow swale located east or west of the <br /> SFR. The swale bottom will be treated with amended soils and graded to drain north and <br /> discharge along the back of sidewalk in the 95th Ct SE R.O.W. The swale is propose to be <br /> approximately 6-inches deep with side slopes no greater then 5:1 with a minimum of 12" of <br /> amended soils beneath the swale. <br /> For the new PGIS a transition zone has been designed to collect and disperse the flows <br /> along the east side of the new driveway area. The dispersed flows from the transition <br /> zone will pass over a minimum of 10-feet of landscaping with amended soils prior to <br /> leaving the site. This project does not propose to construct more than 5,000 sf of PGIS so <br /> it is exempt from any water quality treatment systems per Minimum Requirement 6. <br /> Finally, any area of the site not proposed to be covered with impervious surfaces but <br /> graded or compacted will be treated to meet the criteria for DOE BMP T.5.13. Please <br /> refer to the engineering plans for the locations of the soil amendments and additional <br /> details. <br /> Fordham SFR 12-0906 <br /> Oct. 2012 Page 9 <br />