under this subsection not later than July 1 of the year in which the adjustment is made. (3) Applicability A fee adjustment under this subsection shall begin to apply the calendar year following the calendar year in which it is made. 503. Inspection and monitoring (a) Inspections (1) In general The Secretary concerned shall conduct inspections of mineral activities so as to ensure compliance with the requirements of this Act. (2) Frequency (A) In general The Secretary concerned shall establish a frequency of inspections for mineral activities conducted under a permit issued under title III, but in no event shall such inspection frequency be less than 1 complete inspection per calendar quarter or, in the case of a permit for which the Secretary concerned approves an application under section 304(f), 2 per calendar quarter. (B) Frequency after revegetation After revegetation has been completed in accordance with a reclamation plan, the Secretary concerned shall conduct 2 complete inspections annually. (C) Seasonal mineral activities The Secretary concerned may modify the inspection frequency for mineral activities that are conducted on a seasonal basis. (D) Termination Inspections shall continue under this subsection until final release of financial assurance. (3) By request (A) In general Any person that has reason to believe such person is or may be adversely affected by mineral activities due to any violation of the requirements of a permit approved under this Act may request an inspection under this section of such mineral activities. (B) Review period Not later than 30 business days after the date the Secretary concerned receives a request under subparagraph (A), the Secretary concerned shall determine whether the request states a reason to believe that a violation exists. (C) Imminent threat If, in a request submitted under subparagraph (A), a person alleges and provides reason to believe that an imminent threat to the environment or danger to the health or safety of the public exists, subparagraph (B) shall