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• Refer to outfall design criteria in the Manual and DCSS. Describe any outfall <br /> designs in the SSP, and include related calculations and plans to support that the <br /> outfall criteria are met. <br /> MINIMUM REQUIRMENT #S <br /> • Indicate if the LID Performance Standard or the List Approach will be used to <br /> comply with Minimum Requirement #5. <br /> • If applicable, attach modeling results for the LID Performance Standard. <br /> • For the List Approach, discuss LID BMP feasibility, in order, for each surface type. <br /> The project shall use the first feasible LID BMP for each surface type. Keep in mind <br /> that "Other Hard Surfaces" may include sidewalks, roadways, driveways, patios, etc. <br /> LID BMP feasibility shall be discussed for each of these surfaces (see Ecology <br /> clarification). <br /> • If an LID BMP is deemed infeasible, cite specific infeasibility criteria from the <br /> Manual. Refer to Map Everett for infeasibility mapping. Mapping as an infiltration <br /> infeasibility area is sufficient documentation of infeasibility for infiltration BMPs. <br /> • Describe the overflow route for LID BMPs and clearly show this on plans or a <br /> separate figure. If the LID BMP plugs or fails, overflowing runoff shall not adversely <br /> impact public safety, onsite structures, or other properties. <br /> • Verify that the LID BMP design meets Manual and DCSS requirements, and include <br /> appropriate details in the civil plans. <br /> • Include applicable specifications in the plans such as specifications for <br /> bioretention soil media, bioretention plantings, and BMP T5.13. (DCSS Standard <br /> Drawings 202 and 203 may be used for BMP T5.13.) <br /> • Attach supporting geotechnical information (e.g., pilot infiltration testing, <br /> infiltration rate calculations). Where applicable, the geotechnical report shall <br /> address whether lateral flow from an LID BMP may cause issues onsite or impact <br /> adjacent properties. <br /> • Infiltration BMPs receiving non-roof runoff shall have upstream Ecology-approved <br /> pretreatment. <br /> • Stormwater facilities which infiltrate stormwater by means of an underground <br /> facility such as an infiltration trench or vault may need to be registered as an <br /> underground injection control well (UIC) with the Washington Department of <br /> Ecology's UIC Program. If required, a copy of the UIC registration approval notice <br /> shall be attached to the SSP. These BMPs will need to meet treatment requirements <br /> for UICs as defined in the Manual. <br /> Minimum Requirement #1-9 Supplemental Guidance City of Everett <br /> Page 15 Aug 2022 <br />