(a) The Secretary shall approve local ordinances or amendments to approved ordinances which conform to these regulations. The Secretary may not, however, approve an ordinance or amendment thereto which:

(1) Contains a provision that the Secretary considers adverse to the protection and development of the Seashore;

(2) Does not comply with the federal standards set out in §§28.10, 28.11, and 28.12; or

(3) Fails to provide for the variance procedures of §28.13.

(b) A zoning authority from time to time may amend its ordinance. At such time the Secretary may revoke the approval of any ordinance or portion of an ordinance which fails to conform to these regulations. Upon resubmission by the zoning authority of an amended ordinance, the Secretary shall approve the ordinance, if it conforms with the requirements of paragraph (a) of this section.

(c) Secretarial approval of a local ordinance will be withdrawn if the Secretary finds that a zoning authority is not enforcing its ordinance.