(1) The department encourages qualified cities, towns, and other municipal corporations to apply for a grant of authority to conduct and operate a permit system for the regulation of commercial and industrial waste discharges into their sewerage systems in accordance with RCW 90.48.165.

(2) The department is committed to the policy of maintaining the highest possible standards of water quality within the state in compliance with the basic aims expressed in RCW 90.48.010 and national policies and goals expressed by the Federal Water Pollution Control Act Amendments of 1972, (FWPCAA). The implementation of a permit issuance program by any city, town, or municipal corporation shall be continuously evaluated by the department for compliance with these policies, aims, and goals.

(3) In compliance with the requirements of the National Pollutant Discharge Elimination System (NPDES), as provided for in the FWPCAA, the department shall maintain its enforcement of compliance of effluent limitation standards upon publicly owned or operated treatment works under their NPDES permits. Under such permit, any municipality granted authority hereunder to administer a permit program as hereinafter defined shall continue to be primarily responsible for its effluent quality according to the terms of such NPDES permit.