Va. Code § 33.2-2114
The district shall be enlarged by resolution of the governing body upon the petitions of the district commission and the owners of at least 51 percent of either the land area or the assessed value of real property of the district and of at least 51 percent of either the land area or assessed value of real property located within the territory sought to be added to the district. However, any such territory shall be contiguous to the existing district. The petition shall present the information required by § 33.2-2101. Upon receipt of such a petition, the county shall use the standards and procedures provided in § 33.2-2101, except that the residents and owners of both the existing district and the area proposed for the enlargement shall have the right to appear and show cause why any property should not be included in the proposed district. If the proposed enlargement of the district encompasses any portion of a town, then such standards and procedures shall include the requirement to obtain a resolution from the town council in the manner set forth in § 33.2-2101, which shall have the same effect as set forth in that section.
If the governing body finds the enlargement of a local district would be in accordance with the applicable comprehensive plan for the development of the area, in the best interests of the residents and owners of the property within the proposed district, and in furtherance of the public health, safety, and general welfare, and if the governing body finds that enlargement of the district does not limit or adversely affect the rights and interests of any party that has contracted with the district, the governing body may pass a resolution providing for the enlargement of the district.
Va. Code § 33.2-2114