Except as provided in subsection (b) of this section, to qualify for an “on–sale” Class B license, Class C license, or Class D license, the licensed premises shall be equipped with public restrooms with: a minimum of one restroom for each sex; and a connection to a public or private water and waste system that is approved by the health department. If the Board finds that the requirements of this section will impose an undue hardship on the applicant, the Board may waive the requirements.