Standards and criteria.

A. In granting a permit under this article, the standards and criteria that shall be utilized shall include but not be limited to the following:(1) Drainage, erosion and sediment control measures and facilities shall be designed and constructed in accordance with accepted engineering standards and guidelines as outlined in the document Guidelines for Erosion and Sediment Control in Urban Areas of New York State, available from the Monroe County Soil Conservation District. The Best Management Practices for Stormwater Runoff Management, prepared by the Irondequoit Bay Coordinating Committee, shall also be used as a reference document.(2) Among the acceptable range of options that can be utilized by a developer to control drainage, erosion and sedimentation on the work site both during and after project construction are those outlined and labeled as Best Management Practices for Stormwater Runoff Management, prepared by the Irondequoit Bay Coordinating Committee.(3) The applicant shall ensure that the release rate and, if soil conditions permit, the volume of stormwater runoff leaving a construction site will not exceed that which occurred from the area in its undeveloped state for intensities and durations of rainfall associated with storms having a twenty-five-year frequency.(4) The applicant must demonstrate the water quality, erosion and sedimentation impacts on the downstream watershed for any activity requiring a permit.(5) Runoff with suspended soil solids shall be retained on site for a sufficient length of time so as to ensure that such runoff is at least 90% free of settleable soil solids when it leaves the development site.(6) Excavation, grading, filling and stripping shall be permitted to be undertaken only in such locations and in such a manner as to minimize the potential of erosion and sedimentation and the threat to the health, safety and general welfare of neighboring property owners and the general public.(7) The control of erosion and sediment shall be a continuous process undertaken prior to, during and after site preparation and construction, to include any grading, clearing, filling, road construction, utility construction or building construction.(8) The smallest practical area of land shall be exposed by site preparation at any given time.(9) The exposure of areas by site preparation shall be kept to the shortest practical period of time prior to the construction of structures or improvements or the restoration of the exposed areas to an attractive natural condition.(10) Mulching or temporary vegetation suitable to the site shall be used where necessary to protect areas exposed by site preparation, and permanent vegetation which is well adapted to the site shall be installed as soon as practical.(11) Where slopes are to be revegetated in areas exposed by site preparation, the slopes shall not be of such steepness that vegetation cannot be readily established or that problems of erosion or sedimentation may result.(12) Site preparation and construction shall not adversely affect the free flow of water by encroaching on, blocking or restricting watercourses.(13) All fill material shall be of a composition suitable for the ultimate use of the fill, free of rubbish and carefully restricted in its content of brush, stumps, tree debris, rocks, frozen material and soft or easily compressible material.(14) Fill material shall be compacted sufficiently to prevent problems of erosion, and where the material is to support structures, it shall be compacted to a minimum of 90% of standard proctor with proper moisture control.(15) All topsoil which is excavated from a site shall be stockpiled and used for the restoration of the site and such stockpiles, where necessary, shall be seeded or otherwise treated to minimize the effects of erosion.(16) Prior to, during and after site preparation and construction, an integrated drainage system shall be provided which at all times minimizes erosion, sediment, hazards of slope instability and adverse effects on neighboring property owners.(17) The natural drainage system shall generally be preserved in preference to modifications of this system, excepting where such modifications are necessary to reduce levels of erosion and sediment and adverse effects on neighboring property owners.(18) All drainage systems shall be designed to handle adequately anticipated flows both from within the site and from the entire upstream drainage basin.(19) Sufficient grades and drainage facilities shall be provided to prevent the ponding of water, unless such ponding is proposed within site plans, in which event there shall be sufficient water flow to maintain proposed water levels and avoid stagnation.(20) There shall be provided, wherever necessary to minimize erosion and sediment on the site as well as downstream, within the drainage basin such measures as benches, berms, terraces, diversions, swales, riprap catch basins, slope drains, sediment filters and traps and sediment, debris and retention basins.(21) Drainage systems, plantings and other erosion or sediment control devices shall be maintained as frequently as necessary to provide adequate protection against erosion and sediment and to ensure that the free flow of water is not obstructed by the accumulation of silt, debris or other material or by structural damage.(22) If temporary sediment basins are used, the detention storage shall be calculated on the basis of the twenty-five-year frequency rainfall for the affected area.

If permanent sediment basins or storage facilities are used, the retention volume shall be able to handle the runoff of a one-hundred-year rainfall for any and all durations from the proposed development site.(23) The developer shall be responsible for minimizing the tracking of mud onto existing roads. Roads shall be scraped and broomed clear of mud, if at all feasible, at the end of each working day, as required. The Town of Webster reserves the right to include in any required guaranty of performance or letter of credit an allowance to cover the estimated costs of such dust and mud control activities.(24) The drainage system being developed within the proposed development site shall have the capacity to handle flows from upstream areas through the site based on the following guidelines:(a) For those major watercourses with a tributary drainage area in excess of seven square miles, the ultimate channel shall be designed for an average recurrence interval of 100 years.(b) For those major watercourses with a tributary drainage area between seven square miles and four square miles, the final channel shall be designed for an average recurrence interval of 50 years.(c) Secondary watercourses, defined as those with a tributary drainage area of between one and four square miles, shall have the final channel designed for an average recurrence interval of 25 years.(d) Minor watercourses, defined as those with a tributary drainage area of one square mile or less, shall have the final channel designed for an average recurrence interval of 10 years.(25) Intermittent (runoff event) discharges from development sites to streams shall meet applicable federal, state and county standards relating to pollution control.