Maryland Code, Environment § 9-330

(1) False or inaccurate information was contained in the application;

(2) Conditions or requirements of the discharge permit have been or are about to be violated;

(3) Substantial deviation from plans, specifications, or requirements has occurred;

(4) The Department has been refused entry to the premises for the purpose of inspecting to insure compliance with the conditions of the discharge permit;

(5) A change in conditions exists that requires temporary or permanent reduction or elimination of the permitted discharge;

(6) Any State or federal water quality stream standard or effluent standard has been or is threatened to be violated; or

(7) Any other good cause exists for revoking the discharge permit.