“Owner” means any person who owns:
1. An underground storage tank used to store or dispense regulated substances after November 8, 1984, or if the use of the tank was discontinued before that date, the last person to own such a tank before its use was discontinued; or
2. An aboveground storage tank used to store or dispense regulated substances after October 1, 2003, or, if the use of the tank was discontinued before that date, the last person to own such a tank before its use was discontinued.