The Sewer Inspector and other duly authorized employees or representatives of the municipality, and of any contracting municipality, bearing proper credentials and identification shall be permitted to enter all properties for the purposes of inspection, observation, measurement, sampling, and testing in accordance with the provisions of the law, all the foregoing not to be carried out beyond a point having a direct bearing on the kind and source of discharge to the sewers or waterways or facilities for waste treatment. The foregoing shall also apply for the purposes of but not limited to inspection, observation, measurement, sampling, repair, and maintenance of any portion of the sewage works lying within any duly negotiated easements between the municipality and any private property owner. NYSDEC and USEPA officials shall have the same powers and authority of inspection enjoyed by the Sewer Inspector or other duly authorized employees or representatives of the municipality as pertains to commercial or industrial discharges to the system.