In addition to all of the other powers conferred upon it in this chapter, an authority may do all things necessary and convenient to carry out the powers expressly given in this part. No authority shall have or exercise any governmental powers or authority other than those specifically granted in this chapter. No authority shall have any taxing powers, any right or authority to pledge, encumber or obligate the general credit of any of its creating or participating municipalities for its bonds or debts, nor any power of eminent domain or condemnation.