(a) The interest of a holder is an interest in real property. The rights of the Department under this subchapter or under an approved environmental covenant, other than as a holder, are not interests in real property.
(b) The Department is bound by the obligations it assumes in an environmental covenant, but the Department does not assume obligations merely by approving an environmental covenant.
(c) The following rules apply to interests in real property in existence at the time an environmental covenant is created or amended:
(1) A prior interest is not affected by an environmental covenant unless the owner of the interest is a party to the covenant or subordinates its interest to the covenant.
(2) This act does not require an owner of a prior interest to subordinate that interest to an environmental covenant or to agree to be bound by the covenant.
(3) A subordination agreement may be contained in an environmental covenant covering real property or in a separate record or, if the environmental covenant covers commonly owned property in a common interest community, in a record signed by any person authorized by the governing board of the owners' association.
(4) An agreement by a person to subordinate a prior interest to an environmental covenant affects the priority of that person's interest but does not by itself impose any affirmative obligation on the person with respect to the environmental covenant.