(2) The department may require any person in control of an air contamination source to provide necessary holes in stacks or ducts and proper sampling and testing facilities, as may be necessary and reasonable for the accurate determination of the nature, extent, quantity and degree of air contaminants which are emitted as the result of operation of the source.
(3) All sampling and testing shall be conducted in accordance with methods used by the department or equivalent methods of measurement acceptable to the department.
(4) All sampling and testing performed under this section shall be conducted in accordance with applicable safety rules and procedures established by law. [Formerly 449.702 and then 468.340]