In addition to all other powers and duties of the air quality board, environmental quality board and surface mine board as prescribed in this chapter or elsewhere by law, the boards created or continued pursuant to the provisions of this chapter have and may exercise the following powers and authority and shall perform the following duties:

(1) To consider appeals, subpoena witnesses, administer oaths, make investigations and hold hearings relevant to matters properly pending before a board;

(2) On any matter properly pending before it whenever the parties achieve agreement that a person will cease and desist in any act resulting in the discharge or emission of pollutants or do any act to reduce or eliminate such discharge or emission, or do any act to achieve compliance with this chapter or chapter twenty-two or rules promulgated thereunder or do any act to resolve an issue pending before a board, such agreement, upon approval of the board, shall be embodied in an order and entered as, and has the same effect as, an order entered after a hearing as provided in section seven of this article;

(3) To enter and inspect any property, premise or place on or at which a source or activity is located or is being constructed, installed or established at any reasonable time for the purpose of ascertaining the state of compliance with this chapter or chapter twenty-two and the rules promulgated thereunder: Provided, That nothing contained in this section eliminates any obligation to follow any process that may be required by law; and

(4) To perform any and all acts within the appropriate jurisdiction of each board to secure for the benefit of the state participation in appropriate federally delegated programs.