MARINE SANITATION DEVICES.

SEC. 311. MARINE SANITATION DEVICES. (a) State Regulation of Houseboats.— Section 312(f)(1) is amended by striking out “After” and inserting in lieu thereof “(A) Except as provided in subparagraph (B), after and by adding at the end thereof the following: “(B) A State may adopt and enforce a statute or regulation with respect to the design, manufacture, or installation or use of any marine sanitation device on a houseboat, if such statute or regulation is more stringent than the standards and regulations promulgated under this section. For purposes of this paragraph, the term ‘houseboat’ means a vessel which, for a period of time determined by the State in which the vessel is located, is used primarily as a residence and is not used primarily as a means of transportation.”. (b) State Enforcement.—Section 312(k) is amended by adding at the end the following: “The provisions of this section may also be enforced by a State.”.