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1 1 • • <br /> 2014 SWMMWW MINIMUM REQUIREMENTS SUMMARY <br /> MR : MINIMUM REQUIREMENT <br /> SSP : STORMWATER SITE PLAN <br /> MR#1 PREPARATION OF STORMWATER SITE PLAN: <br /> Stormwater site plan follows the 2014 Stormwater Management Manual for Western <br /> Washington& 2017 Design and Construction Standards and Specifications. <br /> MR#2 CONSTRUCTION OF STORMWATER POLLUTION PREVENTION <br /> PLAN (SWPPP): <br /> Refer to section IV for SWPPP. <br /> MR#3 SOURCE CONTROL OF POLLUTION: <br /> Onsite BMP's will be used to minimize the source pollutant sources that include <br /> parts/vehicle cleaning, spills/leaks of fuel and other liquids, replacement of liquids, outdoor <br /> storage of batteries/liquids/parts, and vehicle parking. <br /> MR#4 PRESERVATION OF NATURAL DRAINAGE SYSTEMS AND <br /> OUTFALLS: <br /> The developed site drainage will be discharged towards an existing drainage system onsite <br /> that drains to the south within a closed pipe system to follow its natural drainage path. <br /> MR#5 ONSITE STORMWATER MANAGEMENT: <br /> For onsite stormwater management full dispersion was considered first however it was <br /> deemed infeasible due to the lack of native vegetation. Downspout full infiltration was <br /> deemed infeasible due to the soils poor infiltration qualities. Bioretention was deemed <br /> infeasible due to the soils poor infiltration. Downspout dispersion system was deemed <br /> infeasible due to a lack of vegetative flow path. Perforated stub out connection was <br /> considered and deemed feasible. Onsite stormwater management for the roof area will be <br /> provided by perforated stub out connections. The overflow from the perforated stub out <br /> connection will be connected to the existing drainage system onsite that drains to the south <br /> within a closed pipe system. For other hard surfaces full dispersion was considered <br /> infeasible due to the lack of vegetation,permeable pavement and bioretention were deemed <br /> infeasible due to the soils poor infiltration. Sheet flow dispersion was deemed feasible and <br /> will be used. Pervious areas had no feasible BMPs due to the site being nearly 100% <br /> impervious <br /> Insight Engineering Co. -Stormwater Site Plan 11/16/17 <br /> -6- <br />