The legislature declares that competent operation of waste treatment plants plays an important part in the protection of the environment of the state and therefore it is of vital interest to the public. In order to protect the public health and to conserve and protect the water resources of the state, it is necessary to provide for the classifying of all domestic wastewater treatment plants; to require the examination and certification of the persons responsible for the supervision and operation of such systems; and to provide for the promulgation of rules and regulations to carry out this chapter.