Subject to the provisions of Section 3, no contractor shall drill a water well or engage in the occupation of a water well contractor unless he holds a valid license as a water well contractor issued by the Department under this Act. Subject to the provisions of Section 3, after January 1, 1972, no person shall drill a water well, install or repair a water well pump or equipment, or engage in the occupation of a Water Well and Pump Installation Contractor unless he holds a valid license as a Water Well and Pump Installation Contractor issued under this Act.
     Provided, however, that nothing in this Section or any other statute or regulation of this State prohibits any person from making a water well pump installation or engaging in the business of connecting water pressure tanks to the water supply systems of buildings or to pumps or pumping units, so long as such person possesses either a valid license as a water well pump installation contractor or a water well and pump installation contractor issued under this Act. Any person holding a valid license under the Illinois Plumbing License Act may apply and receive, without examination or fee, a water well pump installation contractor license provided that all other requirements of this Act are met.