(a) For the purpose of preserving and promoting the public health and welfare, the Commission may create sanitary districts without regard for county, township or municipal lines. However, no municipal corporation or any part of the territory in a municipal corporation shall be included in a sanitary district except at the request of the governing board of the municipal corporation. If the municipal corporation has not levied any tax nor performed any official act nor held any elections within a period of four years preceding the date of the petition for the sanitary district, a request of the governing board shall not be required.
(b) For the purposes of this Part, the term "Department" means the Department of Environmental Quality, and the term "Secretary" means the Secretary of Environmental Quality.