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1 <br /> I <br /> MR 5: On-site Stormwater Management <br /> Redevelopment projects are required to implement on-site stormwater management BMPs <br /> to infiltrate, disperse, and retain stormwater runoff on-site to the maximum extent feasible <br /> without causing flooding, groundwater contamination, or erosion impacts. <br /> As noted in the existing conditions section of this report, the underlying soils contain <br /> excessive fines which limits their infiltration capacity. The geotechnical engineer does not <br /> recommend infiltration to control stormwater. The building is essentially a zero lot line <br /> development which by it's nature limits the amount of surface area available for <br /> stormwater to be absorbed by the underlying soils. <br /> The project intends to use green roof(12" depth growing media), raised landscaped <br /> planters (18" depth growing media), and non-infiltrating bio retention planters to address <br /> MR considerations. <br /> Infiltration: Infiltration into the underlying soils is not recommended by the geotechnical <br /> engineer and as such is not feasible. <br /> Dispersion: Due to the urban setting of the project,there are not flow paths that meet the <br /> requirements of this BMP within the project limits. Therefore, dispersion cannot be <br /> considered for this site. <br /> Bioretention Planters: A non-infiltrating bioretention planter is shown in the plans in a <br /> very visible location near the front entry on Level 1. The plans show 50 sq.-ft. bioretention <br /> planter to which up to 900 sq.-ft. for roof area could be directed. <br /> Vegetated Roofs: Vegetated roofs are provided in visible areas to reduce stormwater <br /> demands and beautify the amenity areas that are subject to rainfall. <br /> Level 4: 188 sq.-ft. of 18" depth planters <br /> Level 2: 857 sq.-ft. of 18" depth planters; 274 sq.-ft. 12" depth intensive green roof <br /> Level 1; 337 sq.-ft. of 18" depth planters. <br /> ' Pervious Pavement: Pervious pavements are infiltration facilities and are not feasible due <br /> to the underlying infiltration capacities of the soil. <br /> MR 6: Runoff Treatment <br /> The site is located in a combined sewer basin and runoff treatment is provided at the City <br /> 1 of Everett's Water Pollution Control Facility. Drainage of the proposed covered parking <br /> garage will be routed through an oil/water separator, and FOG drainage fixtures from the <br /> kitchen will pass through a grease interceptor prior to discharge to the combined sewer. <br /> I <br /> Hopeworks II DCI Engineers Page 5 <br /> Storm Drainage Report <br />