It is the purpose of this article to facilitate the orderly development of structures which are needed to provide wireless telecommunications services, to encourage strongly the joint use of new and existing towers and minimize the total number of towers throughout Shenandoah County, and to encourage the configuration of towers and antennas in such a way that minimizes their visual impact. Furthermore, it is the purpose of this article to treat providers of functionally equivalent services in a reasonably like manner and to provide adequate sites for the provision of telecommunications services throughout Shenandoah County with minimal negative impact on the County. In enacting this article, no attempt has been made to address the environmental effects of radio frequency emissions. The siting of new telecommunications towers shall occur through the special use permit process, except that telecommunications facilities that locate on existing structures and towers shall be exempt from the special use permit requirement. The siting of telecommunications towers is permitted, provided that they are sited to minimize negative impact on residential properties, land use patterns, scenic areas, public lands and properties of significant historic value.