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4L <br /> A6 <br /> surface waters, preserve hydrologic conditions that closely resemble pre-development <br /> conditions, reduce or prevent flooding by managing the peak discharges and volumes of runoff, <br /> minimize erosion and sedimentation, not result in significant degradation of groundwater, <br /> reduce suspended solids, nitrogen, volatile organics and Ether pollutants to improve water <br /> quality and provide increased protection of sensitive natural resources. <br /> These standards may.be met using the following or similar best management-practices: <br /> (1) For lots occupied, or proposed to be occupied, by .single or two-family residences, <br /> recharge shall be attained through site design that incorporates natural drainage patterns <br /> and vegetation in order to maintain pre-development stormwater patterns and water <br /> quality to the greatest extent possible, stormwater runoff from rooftops, driveways and <br /> other impervious surfaces shall be muted through grassed water quality swales, as sheet <br /> flow over lawn areas or to constructed stormwater wetlands, sand filters, organic filters <br /> and/or similar systems capable of removing nitrogen from stormwater. <br /> (2) For lots occupied or proposed to be occupied by other uses, a stormwater management <br /> plan shall be developed which 1 utilizes site planning techniques to minimize runoff, 2) <br /> utilizes nonstructural techniques, including pollution prevention and source reduction, to <br /> minimize the type of treatment needed for stormwater and provides for the artificial <br /> recharge of precipitation to groundwater through site design that incorporates natural <br /> drainage patterns and vegetation and through the use of constructed stormwater <br /> wetland , wet (retention) ponds, water quality sales, sand filters, organic filters or <br /> similar site.appropriate best management practices capable of removing nitrogen and <br /> other contaminants from stormwater and otherwise meeting the stormwater Management _ <br /> Standards and technical guidance contained in the Massachusetts Department of <br /> Environme. al Protection`s Stormwater Management Handbook, Volumes 1 and 2, dated <br /> March 1997, for the type of use proposed and the soil types present on the site. Such <br /> runoff shall not be discharged directly to rivers, streams, other surface water bodies, <br /> wetlands or vernal pools. Dry wells small be prohibited. Except when used for roof runoff <br /> from non-galvanized roofs, all such wetlands, ponds, swales or other infiltration facilities <br /> shall be preceded by oil, grease and sediment traps or other best management practices <br /> to facilitate control of hazardous materials spills and removal of contamination and to <br /> avoid sedimentation of treatment and leaching facilities. Al such artificial recharge <br /> systems shall be maintained in full working order by the owners under the provisions of <br /> an operations and maintenance plan approved by the Board to ensure that systems <br /> function as designed. Infiltration systems greater than three feet deep shall be <br /> located at least one hundred 10 feet from drinking water wells. Any infiltration basins <br /> or trenches shall be constructed with a three foot minimum separation between the <br /> bottom of the structure and maximum groundwater elevation. <br /> ar <br /> The Applicant shall submit sufficient plans and specifications to demonstrate the operation and <br /> effectiveness of the proposed stormwater management facilities and practices and shall require <br /> - their implementation and maintenance, including provisions for deed restrictions and other <br /> implementing provisions, as a condition of approval of the proposed project. No permit may be <br /> approved for a project unless. the Board determines that the proposed system of stormwater <br /> management and artificial recharge will achieve the purposes described above. <br /> 3 <br />