Surface. Parking facilities shall be designed to prevent dust, erosion, and excessive water flow across streets or adjoining property. Parking facilities shall be graded for proper drainage and shall be improved with a durable and dustless surface, such as concrete or bituminous concrete surface, unless an alternative material and/or design as part of a readily accepted stormwater BMP, in accordance with the most-recent version of the Lancaster Township Subdivision, Land Development and Stormwater Management Ordinance, as amended.