(a) The division shall have the right to conduct such investigations as may reasonably be necessary to carry out its duties prescribed in this part and for this purpose to enter at reasonable times any property, public or private, for the purpose of investigating the condition, withdrawal, or use of any waters, investigating water sources, or investigating the installation or operation of any well, and to require written statements or the filing of reports under oath, with respect to pertinent questions relating to the installation or operation of any well, provided that no person shall be required to disclose any secret formula, processes, or methods used in any manufacturing operation or any confidential information concerning business activities carried on by him or under his supervision.

(b) No person shall refuse entry or access to any authorized representative of the division who requests entry for the purposes of a lawful inspection and who presents appropriate credentials, nor shall any person obstruct, hamper, or interfere with any such representative while in the process of carrying out his official duties consistent with the provisions of this part.