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MINIMUM REQUIREMENT#3: SOURCE CONTROL OF POLLUTANTS <br /> The O&M Manual for this project will contain specific directions that the parking areas <br /> around the building addition shall be swept regularly and shall not be hosed down. It <br /> should be noted the Rodland Toyota complex already contains an automated car wash <br /> so no vehicle washing is performed in the parking areas for this business. This is not <br /> considered a "high-use site" so no further BMPs are necessary, refer to the water quality <br /> section of this report for further detail. <br /> MINIMUM REQUIREMENT#4: PRESERVATION OF NATURAL DRAINAGE SYSTEMS <br /> AND OUTFALLS <br /> All of the runoff from the existing site is tributary to the existing conveyance system within <br /> the Madison St and Evergreen Way R.O.W.s and that will remain the case after this <br /> project is completed. <br /> MINIMUM REQUIREMENT#5: ON-SITE STORMWATER MANAGEMENT <br /> Due to the developed nature of this existing parcel and the lack of any landscaping in this <br /> zone there is no area available for constructing on-site stormwater management BMPs. <br /> In addition, this site had previously contained a structure and has been graded so the <br /> potential for infiltration in the Alderwood type soils is not a viable option. <br /> MINIMUM REQUIREMENT#6: RUNOFF TREATMENT <br /> Since this project does propose to construct more than 5,000 sf of new/replaced PGIS <br /> runoff treatment is required. In reviewing the definitions of"high-use sites"this project <br /> does not generate more than 100 ADT per 1,000 sf of gross building area and none of <br /> the other three definitions apply to this project. As noted above, infiltration is not viable <br /> on this site so it cannot be used for treatment. Therefore, since this is a commercial <br /> project Enhance treatment is required. For this site a Contech Stormfilter catch basin has <br /> been selected to provided the necessary level of treatment. <br /> MINIMUM REQUIREMENT#7: FLOW CONTROL <br /> Since the existing conditions for this project are roof and pavement and the proposed <br /> conditions are roof and pavement there is not net change in the runoff characteristics for <br /> this project. Therefore, no additional flow control facilities are required. <br /> MINIMUM REQUIREMENT#8: WETLAND PROTECTION <br /> No wetlands exist in the downstream system for this project. <br /> MINIMUM REQUIREMENT#9: BASIN/WATERSHED PLANNING <br /> No existing Basin or Watershed plans were found that affect the area around this project. <br /> Rodland Toyota 12-0412 <br /> May 2012 Page-11 <br />