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. , , c�� � ��-t� �� �. <br /> 5. SOURCE GOMTROL Na� j0�` �.��d°�'C <br /> S�S` i <br /> This project proposes to constafet-a-new- FR-on-this-pa[cel with a driveway. Cha�ters 3- ��o� <br /> 5 of Volume IV �-Snohomish-CouMy Dreinage fV�v3�were reviewed for specific z�,Z,� <br /> BMPs required his type of land:use.–Noncfof fhe aclivilies or land uses contained in <br /> any of the chapters in Volume IV applies to this project. Therefore, no site/development <br /> specific source control BMPs are required for this project. <br /> 6. PRESERVATION OF NATURAL DRAINAGE SYSTEM <br /> The runoff irom the site improvements will be dispersed over amended or native soils on- <br /> site and flow in the north and east natural downstream direction. However by not grading <br /> or compacting the soils in the northern and eastern portions of the site a maximum amount <br /> of site runofl from the developed project will be absorbed and infiltrated into the existing <br /> on•site soils. This will mirciic the existing conditions by maintaining the existing direction <br /> and condition of flow from this site. <br /> 7. ON-SITE STOI4MWATER MANAGEMENT <br /> The soils for this project were found to be loamy sand with a maximum water table/hard <br /> pan layer at over 6' below existing grade in areas on the site by Jamie Batlerman, refer to <br /> soil information in Append�x A. Since on-site ir�filtration was not found to be viable (or this ���� <br /> project then dispersion of the NPGIS and PGIS runoH is required when possible and for � !� <br /> this project this will be done using level spreaders and transition zones. The roof runoff C f1ti/ �2 <br /> will be directed to one of t�vo level spreaders, with a mmimum ilow path of 25-feet b�ore Lg'D�`��� t L <br /> leaving the site The proposed roo( area is 2,719 which requires approximat 40L-f i � <br /> level spreader to provide �0-(eet oF spreader for each 700sf of roo(. This wil�� I. � <br /> into two locations each receiving half of the roof area. However, a note has been added to '�T�) lC <br /> the plan to direct the coniractor to modify the length of ihe trenches if conditions warrant <br /> c;uring construction to ensure the proper length spreader is provided for the actual tributary <br /> �oof area, <br /> f�or ihe approximately new PGIS, transition zones have been designed to coliect and <br /> disperse the Oows along the northwest and noRheast slde of the new driveway_.area The1 � <br /> dispersed flows from the transition zone will pass over a minim�m o( 10-(eet o�� ���tlu' <br /> landscaping with amended soils prior to leaving lhe site. This p o�ect-does�hot propose to �c^— <br /> construct more than 5,000 sf of PGIS so i s exempl from any water quality ireatment <br /> systems per Minimum Requiremenl6. <br /> Finally, any area of the site not proposed to be covered with impervious surfaces but <br /> graded or compacled will be treated to meet the criteria for BMP T 5 13 Please re(er to <br /> thr �nglneering plans for 1he locations o( the soil amendments and additional details. <br /> ChmookSFR 12013 � � <br /> .lan 2012 Page 10 / <br /> I � j�V <br /> ��,�__ <br />