(a) Discharge of untreated sewage is prohibited in all waters of this state.
(b) Recreational vessels with no installed marine sanitation device or approved sewage disposal system and residence boats are prohibited from discharging sewage in all state waters. Notwithstanding any provision of this chapter to the contrary, this chapter shall not be construed as prohibiting the disposal of sewage by a vessel or residence boat into a sewage disposal system constructed and operated according to law and approved by the Department of Public Health.