7407 EVERGREEN WAY BOSTON CHICKEN 2018-01-01 MF Import

1.0 SCOPE OF WORI: — Our work includes the following tasls: • Iden6fy jusdfication for not providing detention. Delineate Vibutary drainage basin via topographic analysis. • Assess off-sitc vibutary contribufions and bypass areas. • Sile inspecuon to visually observe exisGng runoff conditions. • Desgn treatment facilipes for quality control. — 2.0 GGIVERAL INFORMATION The proposed project lies in a portion of Ihe southwest quarter of Secuon 7, Township 28 North, __ Range 5 East of ihe R'illamette Meridian, within the City of Everett. Based upon a more localized description, the property address is 7407 Evergreen Way. A viciniry mxp is located within the appendix of ihis report. The project site Las a trapezoidal shape wit}� an approximate area of 34,450 syuare feeL The site is currently developed and occupied by an existing restaurant (Mr. Bill's). Tlie topography of the site is relatively flat with a fill slope (6 to 8 feet high) along the east property line. The proposed project is to demolish the existi�g on-site improvements and to consvuct a single- srory, wood-frame Boston Chicken restaurant. 1'he restaurant facility will be near Uie property frcntage with Evergreen Way and surrounded by appropriate parking and landscaping. Since the project is the re-development of lhis property and will not cause an increase in the impervious surface area, consequently causing no increase in srormwater r,moff, deten:ion is not required. Supporting calculations are included herewith (see Appendix). In consideradon of water quality, treatment of srormwater will be provided. As stated �vithin the City response to the Environmental Checklist (SEPA), treatment via a baffled oil/w�ter separator _ in �eries with a bioswale is proposed. 3.0 STORNiVVATER OUANTITY CONTROL As mentioned above, since ihis project is the redevelopment of the subject properry and this developmznt will not iucrease the impervious surface area or increase the srormwater runoff, — detention is not required. Within the appendix of this report, we have supporting calculaticns that identify a net decrease in stormwater runoff as caused by the pervious surface areas ihat will be provided in the form of perimeler landscaping. However, to enhance �he stonmvater treatment, — lhe storm drain:ige system for thi: nroject includes a restrictor manhole ihat will control Flows during mild rainfall intensities to limit the runoff to the downstream oil/wa!�r separator and biofiltration swale. During heavy rainfall, an overflow pipe has been designed ro bypa.,s the water _ yuality control feamres of the proposed srorm system. Burghauscn Considting Enginccrs, Inc. PegO � Of � 518-0.ffJ'_ �15GIps/sdc�