No grant which the Administrator is authorized to make to any applicant for construction of sewage treatment works in any area in any State may be withheld, conditioned, or restricted by the Administrator on the basis of any requirement of this chapter except as provided in subsection (b).
Nothing in this section shall be construed to amend or alter any provision of the National Environmental Policy Act [42 U.S.C. 4321 et seq.] or to affect any determination as to whether or not the requirements of such Act have been met in the case of the construction of any sewage treatment works.