If any provision of this Act is held invalid such provision shall be deemed to be excised from this Act and the invalidity thereof shall not affect any of the other provisions of this Act. If the application of any provision of this Act to any person or circumstance is held invalid it shall not affect the application of such persons or circumstances other than those as to which it is invalid. The provisions of this Act shall not be considered as impairing, altering, modifying, repealing or superseding any of the jurisdiction or powers of the Illinois Commission or of the Department of Natural Resources under the Rivers, Lakes, and Streams Act. This Act shall be construed broadly and liberally to effectuate its purpose of improving the prosperity of the Port District by facilitating the removal and marketing of its raw materials and the development of industrial, mining and transportation employment.