(1) It is the purpose of this chapter to provide:
(a) additional and cumulative remedies to prevent, abate, and control the pollution of the waters of the state; and
(b) sufficient authority to allow the state to meet federal requirements for the state's assumption of primacy under the federal Water Pollution Control Act, as amended by the Water Quality Act of 1987, 33 U.S.C. Section 1251 et seq.
(2) Nothing in this chapter:
(a) abridges or alters rights of action or remedies in equity or under common or statutory law, criminal or civil; or
(b) estops the state or any municipality or person, as riparian owners or otherwise, in the exercise of their rights in equity or under common or statutory law to suppress nuisances or to abate pollution.