This act states the rules and regulations to prevent and control pollution of waters in the state. It is unlawful for any person to discharge any pollutant unless the discharge conforms with a valid New Jersey Pollutant Discharge Elimination System permit that has been issued by the commissioner. It is also unlawful for any person to build, install, modify or operate any facility for the collection, treatment or discharge of any pollutant, except after approval by the department pursuant to regulations adopted by the commissioner. All permits issued under this act shall be for fixed terms not to exceed five years. Any permittee who wishes to continue discharging after the expiration date of his permit must file for a new permit at least 180 days prior to that date.