Md. Code, Environment § 2–602

(a) The Department may issue a show–cause order or a corrective order under this section if the Department has reasonable grounds to believe that the person to whom the order is directed has violated:

(1) This title;

(2) Any rule or regulation adopted under this title;

(3) Any plan for compliance issued under this title; or

(4) Any permit or registration issued under § 2–401 of this title.

(b) The Department is not required to issue a show–cause order or a corrective order before enforcing this title by injunction or civil penalty under this subtitle.