Mich. Admin. Code R. 323.2128
Rule 2128. Upon determination by the department that public disclosure of information contained on any NPDES form, except information concerning effluent data or information from the files and records of the department not otherwise entitled to protection against disclosure by previous action of the department or of EPA, would divulge information entitled to protection as trade secrets of the applicant, the department shall label and otherwise handle the information as confidential, and shall notify and forward the information to the regional administrator. In making its determination of entitlement to protection as a trade secret, the department shall consider evidence submitted by the applicant. If the department denies entitlement to protection as a trade secret, the applicant, upon notification thereof, shall have 30 days in which to appeal the decision to the department. If the department determines, following appeal, that the information is not entitled to trade secret status, then the department, not less than 30 days after the applicant is notified of the decision, shall release the information for inspection or copying pursuant to R 323.2127. Where EPA has previously accorded trade secret status to information of an applicant, the department shall accept that finding as entitlement to trade secret status for the purpose of this rule. Unless otherwise determined by the regional administrator or the department, all information labeled by the department as confidential shall not be available to the public for inspection or copying pursuant to R 323.2127, except that the information shall be made available at any time to the regional administrator or other authorized representative of the United States concerned with carrying out part 31 of the act or the federal act, upon written request therefore.
Mich. Admin. Code R. 323.2128