Va. Code § 5.1-2.18
The Board may, to the extent permitted by law, enter into agreements with agencies or authorities in this Commonwealth or from adjoining states or with an agency or authority of the United States for joint action pursuant to the provisions of this chapter. Each such agreement shall specify its duration, the proportionate interest which each participating authority or agency shall have in the property, facilities, and privileges of the joint undertaking; the apportionment of the costs of the undertaking among the participating authorities or agencies; the disposition of all property, facilities, and privileges jointly owned upon termination of such agreement or any renewal thereof; the payment or assumption of any indebtedness arising out of such joint operation which remains unpaid upon the disposal of all assets or upon the termination of the agreement or any renewal thereof; and such other provisions as may be necessary to insure efficient operation of the joint undertaking.
Va. Code § 5.1-2.18