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volume reduction BMPs. All computations, calculations, and modeling used to determine BMP design shall be <br />submitted for review including plans showing detailed dimensions and size of the BMPs. Table D and E shall be <br />completed for surface infiltration basins /rain gardens (Table D) and subsurface storage and infiltration BMPs (Table E). <br />For all other BMPs, calculations, computations, or modeling must be submitted justifying the volume reduction <br />proposed. <br />Table D. Surface Infiltration and Rain Garden Volume Calculation Table <br />Volume Reduction <br />BMP ID <br />Area (sq. ft.) <br />Infiltration <br />Rate (in /hr) <br />Multiplier <br />Volume <br />Reduction* <br />(cu. ft.) <br />If Using <br />Filtration, <br />70% Credit <br />Example: Rain Garden <br />200 <br />0.6 <br />4 <br />480 <br />336 <br />Dry Basin <br />2962 <br />0.8 <br />4 <br />Triton <br />2 <br />184.0 <br />1829.5 <br />4 <br />43.8 <br />21.9 <br />3 <br />1.0 <br />0.8 <br />4 <br />494.6 <br />0.5 <br />4 <br />5.2 <br />3 <br />4 <br />1 Y <br />� �'�'t <br />�z S <br />rg 4 <br />5 <br />4 <br />rim a� sru <br />*Volume reduction = Area x infiltration Rate x 4 <br />Total = <br />pary �ru v� <br />9$ < 5`,F.._i <br />Table E. Subsurface Storage and Infiltration Volume Calculation Table <br />Volume <br />Reduction <br />BMP <br />Pipe <br />Diameter <br />(Ft.) <br />Pipe X- <br />section area <br />(Sq. Ft.) <br />Pipe Length <br />(Ft.)* <br />Pipe Storage <br />(Cu. Ft.) <br />Rock <br />depth, <br />below <br />outlet <br />(Ft.) ** <br />Trench <br />width (Ft.) <br />Trench X- <br />section area <br />(Sq. Ft.) <br />Example <br />3.0 <br />7.1 <br />125.0 <br />883.1 <br />4.5 <br />4.5 <br />20.3 <br />Triton <br />9S <br />184.0 <br />1829.5 <br />0.5 <br />43.8 <br />21.9 <br />Tree Trench <br />1.0 <br />0.8 <br />630.0 <br />494.6 <br />0.5 <br />10.3 <br />5.2 <br />3 <br />4 <br />5 <br />Volume <br />Reduction <br />BMP <br />Trench area - <br />Pipe area <br />(Sq.Ft.) <br />Trench <br />Length <br />(Ft.)* <br />Trench <br />Rock <br />Porosity, <br />n ( %) <br />Trench Rock <br />Storage (Cu. <br />Ft.) <br />Total BMP <br />Volume <br />Reduction <br />(Cu. Ft.) <br />Table E Continued... <br />Example <br />13.2 <br />125.0 <br />0.4 <br />659.3 <br />1542.4 <br />* Pipe length and trench length mus <br />* *Rock depth below outlet shall not <br />Triton <br />12.0 <br />184.0 <br />0.4 <br />8804 <br />Tree Trench <br />44 <br />630.0 <br />04 <br />1100.0 <br />t5s <br />4 <br />sx�v <br />t <br />be equal. <br />be greater than the maximum water depth found in Table B. <br />TOTAL <br />J � <br />Summary of Total Qnsite Volume Reduction = Subtotal from Table D + Subtotal from Table E <br />;`box (d) <br />Table D Table E Other BMPs* Total Volume Reduction <br />* Calculations and /or modeling must be submitted justifying the volume reduction proposed for other BMPs. <br />39 <br />