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Only be allowed on sites where: <br />a. The total area disturbed is 5 acres or less <br />b. The discharge rate from the BIVIl' will have negligible <br />hydrologic impacts to received waters as described in <br />Chapter 1128.09.C.6.b. <br />c. Prior written approval is given by the Village Engineer; and <br />d. For sites greater than five (5) acres or less than five (5) <br />acres but part of a larger common plan of development or <br />sale which will disturb five (5) or more acres, prior written <br />approval has been given by the Ohio EPA. <br />2. Be designed to slow and filter runoff flowing through the turf <br />grasses with a maximum depth of flow no greater than 3 inches. <br />Be designed to have a minimum hydraulic residence time of 5 <br />minutes. <br />d. Concentrated runoff shall be converted to sheet flow, or a diffuse flow <br />usiug a pluuge pool, flow diffuser or level spreader, before <br />entering an extended conveyance facility designed according to the flow through <br />drain time. <br />5. Additional criteria for extended detention facilities: <br />a. The outlet shall be designed to not release more than the first half of the water <br />quality volume in less than 1/3`a of the drain time. A valve shall be <br />provided to drain any permanent pool volume for removal of accumulated <br />sediments. The outlet shall be designed to minimize clogging, vandalism, <br />maintenance, and promote the capture of floatable pollutants. <br />b. The basin design shall incorporate the following features to maximize <br />multiple uses, aesthetics, safety, and maintainability: <br />(1) Basin side slopes above the permanent pool shall have a run to rise <br />ratio of 4:1 or flatter. <br />(2) The perimeter of all permanent pool areas deeper than 4 feet shall <br />be surrounded by an aquatic bench that extends at least 8 feet and <br />no more than 15 feet outward from the normal water edge. The 8 <br />feet wide portion of the aquatic bench closest to the shoreline shall <br />have an average depth of 6 inches below the permanent pool to <br />promote the growth of aquatic vegetation. The remainder of the <br />aquatic bench shall be no more than 15 inches below the <br />permanent pool to minimize drowning risk to individuals who <br />accidentally or intentionally enter the basin, and to limit growth of <br />dense vegetation in a manner that allows waves and mosquito <br />predators to pass through the vegetation. The maximum slope of <br />the aquatic bench shall be 10 (IT) to 1 (V). The aquatic bench shall <br />be planted with hearty plants comparable to wetland vegetation that <br />are able to withstand prolonged inundation. <br />