Va. Code § 44-146.20
If two or more political subdivisions find that disaster operation plans and programs would be better served by interjurisdictional arrangements in planning for, preventing, or responding to disaster in that area, then direct steps may be taken as necessary, including creation of an interjurisdictional relationship, a joint emergency operations plan, mutual aid, or such other activities as necessary for planning and services. Any political subdivision may provide or receive assistance in the event of a disaster or emergency, pursuant to this chapter, under the provisions of any local mutual aid agreement or by the Statewide Mutual Aid program if agreed to by resolution of the governing body. The action of the governing body may include terms and conditions deemed necessary by the governing body for participation in the program. The governing body may withdraw from participation in the Statewide Mutual Aid program by adoption of a resolution or ordinance upon a finding that participation is no longer in the public interest. The locality shall immediately notify the State Coordinator of Emergency Services of the adoption of a participation or withdrawal resolution.
Va. Code § 44-146.20