Mo. Rev. Stat. § 249.430
249.430 Definitions.
249.430. Definitions. — For the purpose of sections 249.430 to 249.660 , the following definitions will apply:
(1) "Lateral sewer district" shall mean all of the area served by a lateral area;
(2) "Main sewer district" shall include all of the area in, and including the watershed, and including the area of any submain and lateral sewer districts served by the main sewer;
(3) "Submain sewer district" shall mean all of the area served by a submain sewer district and shall include the area of any lateral sewer district served by a submain sewer.
(L. 1941 p. 557 § 2)