10-21-4: EXCEPTIONS TO PERMIT REQUIREMENT:
Although prior written notification of any site work shall be given to the Director of Public Works by any person performing site work, a permit shall not be required for any of the following:
   A.   Development Less Than One Acre: Development of a site of one acre or less for residential use, or of one acre or less for commercial or industrial use; provided, that the person responsible for any such development shall implement necessary soil erosion and sediment control measures to satisfy the principles set forth in this chapter;
   B.   Single-Family Residence: Excavation below final grade for the foundation of a single-family residence and appurtenant structures on a site one acre or less for which a building permit has been issued by the City; provided, that the person responsible for any such development shall implement necessary soil erosion and sediment control measures to satisfy the principles set forth in this chapter;
   C.   Agricultural Use: Agricultural use of land;
   D.   Septic System For Existing: Installation, renovation or replacement of a septic system to serve an existing dwelling or structure.
(1987 Code § 18.50-4)