4 Va. Admin. Code § 25-101-40
If the drilling of a vertical ventilation hole has not commenced within two years of the date of the issuance of the permit, the permit shall expire.
§§ 45.1-161.3, 45.1-161.106, 45.1-161.121, 45.1-161.254 and 45.1-161.292 of the Code of Virginia.
Derived from Virginia Register Volume 17, Issue 20, eff. July 18, 2001.