MGWA Shop MGWA Sustaining Membership 2024 $90.00 Minnesota Ground Water Association Membership. Sustaining Rate. This membership rate supports the lower dues rate for Students and Retired members. Join or renew at any time. Includes sign-up to to MGWA newsletter emails and web access to the membership directory. MGWA Professional Membership 2024 $60.00 Minnesota Ground Water Association Membership. Join or renew at any time. Includes sign-up to to MGWA newsletter emails and web access to the membership directory. MGWA Retired Membership 2024 $30.00 Minnesota Ground Water Association Membership. Full-time Retired Rate. Join or renew at any time. Includes sign-up to to MGWA newsletter emails and web access to the membership directory. MGWA Student Membership 2024 $20.00 Minnesota Ground Water Association Membership. Full-time Student Rate. Join or renew at any time. Includes sign-up to to MGWA newsletter emails and web access to the membership directory.