I. Except as provided in RSA 146-A:21, II, a residential heating oil underground storage tank shall be removed, in accordance with state fire code as defined by RSA 153:1, VI-a, if a change in the heating system removes it from use or if the owner does not intend to use it in the future. II. A residential heating oil underground storage tank, required to be removed under this section, may be permanently abandoned by closure in-place, in accordance with state fire code as defined by RSA 153:1, VI-a, if removing the system would undermine the integrity of any overlying structure. III. A discharge of oil discovered during the removal or closure in-place of a residential heating oil underground storage tank is subject to RSA 146-A:4 and RSA 146-A:5.