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Table 5. Soil Infiltration Rates. <br />HSG Soil <br />Texture* <br />Corresponding Unified Soil <br />Classification** <br />Infiltration <br />Rate [in/hr] <br />A <br />Gravel <br />Sandy <br />Gravel <br />Silty Gravel <br />GW Well-graded gravels, sandy gravels <br />1.63GPGap-graded or uniform gravels, <br />sandy gravels <br />GM Silty gravels, silty sandy gravels <br />SW Well-graded gravelly sands <br />Sand <br />Loamy <br />Sand <br />Sandy <br />Loam <br />SP Gap-graded or uniform sands, <br />gravelly sands 0.8 <br />B Loam <br />Silt Loam <br />SM Silty sands, silty gravelly sands 0.45 <br />MH Micaceous silts, diatomaceous <br />silts, volcanic ash 0.3 <br />C Sandy Clay <br />Loam ML Silts, very fine sands, silty or <br />clayey fine sands 0.2 <br />D <br />Clay Loam <br />Silty Clay <br />Loam <br />Sandy Clay <br />Silty Clay <br />Clay <br />GC Clayey gravels, clayey sandy <br />gravels <br />0.06 <br />SC Clayey sands, clayey sandy <br />gravels <br />CL Low plasticity clays, sandy or silty <br />clays <br />OL Organic silts and clays of low <br />plasticity <br />CH Highly plastic clays and sandy <br />clays <br />OH Organic silts and clays of high <br />plasticity <br />Source: Adapted from the "Design Infiltration Rates" table from the Minnesota <br />Stormwater Manual, MPCA (January 2014). <br />* U.S. Department of Agriculture, Natural Resources Conservation Service, <br />2005. National Soil Survey Handbook, title 430-VI. (Online) Available: <br />http://soils.usda.gov/technical/handbook/. <br />** ASTM standard D2487-00 <br /> <br /> 3. A minimum of three feet of separation from the seasonal high water table. <br /> 4. Design and placement in accordance with the 2007 Minnesota Department of Health guidance <br />Evaluating Proposed Stormwater Infiltration Projects in Vulnerable Wellhead Protection Areas. <br /> (b) Water reuse. Water reuse BMPs must be designed to provide: <br /> 1. A maximum irrigation rate of one-inch per week over the irrigated lawn/turf grass area(s); <br /> 2. No greater than a 26 week (April 15 to October 15) growing season; and