Notwithstanding any other provision of law, upon any district in the Lake Tahoe Basin providing in any area of the district a sewer system and treatment facilities sufficient to handle and treat any resultant waste and transportation facilities sufficient to transport any resultant effluent outside the Lake Tahoe Basin, the further maintenance or use of cesspools or other means of waste disposal in such area is a public nuisance and the district shall require all buildings from which waste is discharged to be connected with the sewer system within a period of not less than 90 days from the completion of such system and facilities.