((a)) Nothing in this chapter shall be interpreted to adversely affect existing State regulatory or enforcement power which has been granted to any State through the Clean Water Act [ et seq.] or Coastal Zone Management Act of 1972 [ et seq.].
((b)) Nothing in this chapter shall be interpreted to expand the regulatory or enforcement power of the Federal Government which has been delegated to any State through the Clean Water Act or Coastal Zone Management Act of 1972.