It is recognized that, due to variable factors, no single standard of quality and purity of the environment is applicable to all ambient air, land or waters of the State. In order to attain the objectives of this chapter, the Department, after proper study and after conducting a public hearing upon due notice, shall adopt rules and regulations and classification standards. The classification and the standards of quality and purity of the environment shall be adopted by the Department in relation to the public use or benefit to which such air, land or waters are or may, in the future, be put. Such classification and standards may from time to time be altered or modified by the Department.

The adoption of a classification of the waters and the standards of quality and purity of the environment shall be made by the Department only after public hearing on due notice as provided by this chapter.