Michigan Compiled Laws, Chapter 324. Natural Resources and Environmental Protection § 324.5538

Sec. 5538. Any variance granted pursuant to sections 5535, 5536, and 5537  1 shall be granted for a period of time, that does not exceed 1 year, as is specified by the department at the time of granting it, but any variance may be continued from year to year. Any variance granted by the department may be granted on the condition that the person receiving it shall report to the department periodically, as the department specifies, as to the progress which the person has made toward compliance with the rule of the department.