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Iq:I <br /> Consulting <br /> Engineers <br /> Page 9 of 13 <br /> - ADT count equal or greater than 100 vehicles per 1,000SF of gross building area <br /> - 300 total trip ends per day <br /> - Storage or maintenance of 25 or more vehicles greater than 20 tons gross weight(including heavy <br /> equipment) <br /> Minimum Requirement#7: Flow Control: <br /> The Norton Terminal is flow control exempt because it has direct discharge to Port Gardner Bay through <br /> Outfalls A and M. <br /> Minimum Requirement#8: Wetland Protection: <br /> There are no wetlands within the project limits and no on-site stormwater discharges into a wetland area. <br /> Minimum Requirement#9: Operation and Maintenance: <br /> Maintenance and inspection guidelines for drainage facilities are provided in Appendix D. <br /> 5.0 Drainage Calculations <br /> 5.1 General <br /> New stormwater collection and conveyance systems will be installed to accommodate the <br /> redevelopment of the site. The proposed stormwater collection and conveyance system includes <br /> trench drains, concrete gutters, catch basins, and manholes to convey stormwater runoff from the <br /> site to Port Gardner Bay. Existing downspouts collecting the warehouse roof at the south end of the <br /> site will be maintained and tied into the new and replaced Outfall A. <br /> Additional stormwater system improvements for basin M, that encompasses the majority of the <br /> terminal, include installing a high-flow bypass structure with an integrated stormwater lift station to <br /> pump the water quality flow rate to the Chitosan Enhanced Sand Filtration (CESF)system. Higher flows <br /> that exceed the water quality flow rate will bypass the lift station and flow into Port Gardner Bay via <br /> the new Outfall M. <br /> The new stormwater conveyance system will also include the replacement and upsizing of existing <br /> outfalls. Outfall A will be upsized from a 10 inch ductile iron pipe to an 18 inch HDPE pipe. Outfall M <br /> will be upsized from a 12 inch PVC pipe to a 36 inch HDPE pipe. <br /> 5.2 Drainage Basin Summary <br /> Basin A drainage area is roughly 4.24 acres in size and includes the existing warehouse roof area, <br /> which is approximately 3.11 acres.The remainder of the basin will be completely paved with asphalt <br />