Mont. Code Ann. § 75-10-415

Upon receipt of evidence that the handling, storage, treatment, transportation, or disposal of any used oil or hazardous waste may present an imminent and substantial danger to the public health or the environment, the department may commence legal proceedings to immediately restrain or enjoin any person (including any past or present generator, past or present transporter, and past or present owner or operator of a treatment, storage, or disposal facility) who has contributed to or who is contributing to the handling, storage, treatment, transportation, or disposal from engaging in these activities or order the person to take other action as may be necessary, or both. The department may also take appropriate action as may be necessary under this section, including issuing orders necessary or appropriate to protect the public health and the environment.