Mont. Code Ann. § 80-15-405

Notwithstanding any other provisions of this chapter, if the department finds that an emergency exists that requires immediate action to protect ground water from agricultural chemicals or to prevent use of ground water impaired or likely to be impaired by agricultural chemicals, the department may, without notice or hearing, issue necessary orders or adopt rules to protect public health, welfare, and safety. The duration of an emergency order or rule is limited to the emergency provisions of the Montana Administrative Procedure Act as specified in 2-4-303.