Environmental quality. All bodies of water, wetlands, steep slopes, hilltops, ridgelines, major stands of trees, outstanding natural topography, significant geological features and other areas of scenic, ecological and historic value shall be preserved insofar as possible; soil erosion shall be prevented insofar as possible; flood hazard shall be minimized; air quality shall be well within legal limits; and all potentially ecologically disruptive elements of site preparation, such as blasting, diversion of watercourses and the like, shall be conducted according to the highest standards of professional care.