Maryland Code, Environment § 14-114

(a) Except in an emergency, a rule, regulation, order, or amendment may not be made by the Department without a public hearing upon at least ten days' notice. The public hearing shall be held at the time and place prescribed by the Department. Any interested person is entitled to be heard by the Department.

(b) When an emergency requiring immediate action exists, the Department is authorized to issue an emergency order without notice or hearing. An emergency order takes effect upon promulgation. An emergency order may not remain effective for more than 15 days.

(c) All rules, regulations, and orders issued by the Department shall be in writing, entered and indexed in books kept by the Department as public documents open for inspection during normal office hours. A copy of any rule, regulation, or order certified by the Secretary of the Department or the Secretary’s designee shall be received in evidence in all courts with the same effect as the original.

(d) The Department may act either upon its own motion or the petition of any interested person. On the filing of a petition concerning any matter within its jurisdiction, it shall promptly fix a date for a hearing and cause notice of the hearing to be given. The hearing shall be held promptly after the filing of the petition. If the hearing relates to the issuance of a permit for or with respect to a specific well, it shall be held in the county or municipal corporation where the well is located. The Department shall enter its order within ten days after the hearing.