Any powers granted to the Ohio river valley water sanitation commission under sections 6113.01 to 6113.03, inclusive, of the Revised Code, shall be regarded as in aid of and supplemental to and in no case a limitation upon any of the powers vested in said commission by other laws of the state of Ohio or by the laws of the states of Illinois, Indiana, Kentucky, New York, Pennsylvania, Tennessee, and West Virginia, or by congress or the Ohio river valley water sanitation compact.