Franklin Township, Adams County

"Stormwater management. [1] Stormwater runoff from an ASES shall be managed in accordance with the requirements of the Franklin Township Stormwater Management Ordinance. [2] Where solar panels are mounted above the ground surface allowing for vegetation below the panels, the horizontal area of the panel may be considered a disconnected impervious area ("DIA") and therefore, will have no increase from the predevelopment to post-development runoff coefficient. The horizontal area of the panel can only be considered a DR if the following conditions apply: [a] Where natural vegetative cover is preserved and/or restored utilizing low-impact construction techniques from the Pennsylvania Department of Environmental Protection Stormwater Best Management Practices Manual, including, but not limited to the following: minimizing the total disturbed area, minimizing soil compaction in disturbed areas, and revegetating and reforesting disturbed areas using native species. [b] Where the vegetative cover has a minimum uniform 90% perennial vegetative cover with a density capable of resisting accelerated erosion and sedimentation. [i] For panels located on slopes of 0% to 5%, a minimum four-inch height of vegetative cover shall be maintained. [ii] For panels located on slopes between 5% and 10%, a meadow condition shall be maintained. [iii] Panels located on slopes between 10% and 15% cannot be considered DIA. [iv] Solar panels located on slopes over 15% are not permitted. [v] Vegetated areas shall not be subject to chemical fertilization or herbicide/pesticide application, except for those applications necessary to establish the vegetative cover or to prevent invasive species and in accordance with an approved erosion and sediment control plan. [vi] Agrivoltaics, the codevelopment of the same area of land for both solar photovoltaic power and conventional agriculture, may be used, provided that: [A] Only shade-tolerant crops may be used; [B] Crops must be no tilled in; [C] A written erosion and sediment control plan must be developed for agricultural plowing or tilling activities, or a portion of the overall farm conservation plan must identify BMPs used; [D] Any cutting or mowing of the agricultural crop is limited to a height of no less than four inches; [E] Application of chemical fertilization or herbicides/pesticides is limited to the agronomic needs to the crop(s). [c] Where the solar panels within a solar array are arranged in a fashion that: [i] Allows the passage of runoff between each solar panel, thereby minimizing the creation of concentrated runoff. [ii] Allows for the growth of vegetation beneath the panel and between the solar arrays. [d] Where the length of the receiving, overland, vegetated area, downhill of each solar arrays is equal to or greater than the contributing, maximum, combined, horizontal length of the solar arrays. The grass area below each solar array shall not be considered in the length of the receiving, overland, vegetated area. [e] Where the contribution flow path or total combined horizontal length of a solar array is less than 75 feet. [f] Where less than 5% of the horizontal area of the solar panels themselves are disturbed and/or covered by the ground-mounted support structures or foundation. [g] Where the lowest vertical clearance along the drip edge or drip line of all solar panels within a solar array is 10 feet or less from the surface of the ground but an adequate height to promote vegetative growth below the solar array. [h] Where the drip edge or drip line of the solar panels is mounted level to promote sheet flow discharge unless no more than 500 square feet of contributing surface will discharge to any one point, in which case a spreading device is required for the concentrated discharges. [3] The horizontal area of any solar panel or solar array that cannot meet all the conditions to be considered DIA shall be treated as impervious area. These areas shall be included in the predevelopment to post-development runoff analysis as impervious area to determine the need for post-construction stormwater management ("PCSM") best management practices. [a] Use of gravel is permissible under a panel or in the receiving downhill flow path; however, the use of gravel would not allow the horizontal area of the solar panel or solar array to be considered as a DIA. [b] All impervious areas associated with the ASES such as roadways and support buildings cannot be considered a DIA and shall follow normal protocols when performing the PCSM stormwater analysis."