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8. BOUNCE AND INUNDATION PERIOD. (a) The project must meet the hydroperiod standards found in Table C4 with respect to all down -gradient wetlands. (b) Wetland Susceptibility Class is determined based on wetland type, as follows: (1) Highly susceptible wetland types include: sedge meadows, bogs, coniferous bogs, open bogs, calcareous fens, low prairies, coniferous swamps, lowland hardwood forests, and seasonally flooded waterbasins. (2) Moderately susceptible wetland types include: shrub-carrs, alder thickets, fresh (wet) meadows, and shallow & deep marshes. (3) Slightly susceptible wetland types include: floodplain forests and fresh wet meadows or shallow marshes dominated by cattail giant reed, reed canary grass or purple loosestrife. (4) Least susceptible wetland includes severely degraded wetlands. Examples of this condition include cultivated hydric soils, dredge/fill disposal sites and some gravel pits. 9. DESIGN CRITERIA. (a) Infiltration BMPs must be designed to provide: (1) Adequate pretreatment measures to remove sediment before runoff enters the primary infiltration area; (2) Drawdown within 48 -hours or 72 -hours from the end of a storm event, for surface or sub -surface features, respectively. Soil infiltration rates shall be based on the appropriate HSG classification and associated infiltration rates (see Table C5). The least permeable layer of the soil boring column must be utilized in BMP calculations (see Design Criteria (e). Alternate infiltration rates based on a recommendation and certified measurement testing from a licensed geotechnical engineer or licensed soil scientist will be considered. Infiltration area will be limited to horizontal areas subject to prolonged wetting; (3) A minimum of three feet of separation from the Seasonal High Water Table; and (4) Consideration of the Minnesota Department of Health guidance document Evaluating Proposed Stormwater Infiltration Projects in Vulnerable Wellhead Protection Areas. Documentation shall be submitted to support implementation of this guidance document and will be accepted at the discretion of the District Engineer. (b) Water Reuse BMPs must conform to the following: (1) Design for no increase in stormwater runoff from the irrigated area or project site. (2) Required design submittal packages for water reuse BMPs must include: (i) An analysis using Metropolitan Council Stormwater Reuse Guide `Water Balance Tool Irrigation Constant Demand' spreadsheet for irrigation practices or `Water Balance Too Non -Irrigation Constant Demand' Spreadsheet for non - irrigation practices. The tools are available for download at: http:/twww.metrocouncii.org/wastewater-water/planning/water-supply- planning/studies-projects-workgroups-M/completed-studies- projects/stormwater-reuse-g u ide.asp x; 20