Town Hall Address 100 Mountain Ave. Springfield, NJ 07081-1702 United States- Union County Website http://www.springfield-nj.us County Clerk 973-912-2201 100 Mountain Ave. Springfield, NJ 07081-1702 United States County Admin 973-912-2202 Springfield, NJ 07081-1702 United States Assessor 973-912-2204 100 Mountain Ave. Springfield, NJ 07081-1702 United States Tax Collector 973-912-2204 100 Mountain Ave. Springfield, NJ 07081-1702 United States Attorney 973-912-2200 100 Mountain Ave. Springfield, NJ 07081-1702 United States Mayor 973-912-2201 100 Mountain Ave. Springfield, NJ 07081-1702 United States Municipal Court 973-912-2213 100 Mountain Ave. Springfield, NJ 07081-1702 United States County Union