Except as expressly provided in §§ 12–305, 12–307, and 12–503(b) of this title, this title does not apply to Baltimore County. Except as expressly provided in §§ 12–305, 12–307, and 12–503(b) of this title, this title does not apply to areas of Montgomery and Prince George’s counties that are under the jurisdiction of the Washington Suburban Sanitary Commission.