Except as provided in subsection (b) of this section, any person, as defined in this subtitle, who has an interest that is or may be adversely affected may commence a civil action on his own behalf to compel compliance with this subtitle: Against the Department if there is alleged a failure of the Department to perform any act or duty under this subtitle that is not discretionary; or Against any other person who is alleged to be in violation of any rule, regulation, order, or permit issued under this subtitle. An action may not be commenced under subsection (a) of this section: Prior to 60 days after the plaintiff has given notice in writing of the alleged violation to the Department, the Attorney General, and to any alleged violator; provided that, the action may be brought immediately if the alleged violation constitutes an imminent threat to the health or safety of the plaintiff, or would immediately affect a legal interest of the plaintiff; or If the Department or the State has commenced and is diligently prosecuting a civil action to require compliance under this subtitle, but any person may intervene in the action as a matter of right. The Secretary of the United States Department of Interior may intervene as a matter of right in any action brought under this subtitle. This section is intended to be read in conjunction with and to supplement the provisions of Subtitle 5 of Title 1 of the Natural Resources Article (Environmental Standing Act), but in the event of any conflict, the requirements of this section shall prevail.