Md. Code, Environment § 1-808

(a) An environmental covenant is perpetual unless it is:

(1) By its terms, limited to a specific duration or terminated by the occurrence of a specific event;

(2) Terminated by consent as provided under § 1-809 of this subtitle;

(3) Terminated under subsection (b) of this section;

(4) Terminated by foreclosure of an interest that has priority over the environmental covenant; or

(5) Terminated or modified in an eminent domain proceeding, if:

(i) The Agency that signed the covenant is a party to the proceeding;

(ii) Each person identified in § 1-809(a) and (b) of this subtitle is given notice of the pendency of the proceeding; and

(iii) The court determines, after a hearing, that the termination or modification will not adversely affect human health or the environment.

(b) (1) If the Agency that signed an environmental covenant has determined that the intended benefits of the covenant can no longer be realized, a court, under the doctrine of changed circumstances, in an action in which all persons identified in § 1-809(a) and (b) of this subtitle have been given notice, may terminate the covenant or reduce its burden on the real property subject to the covenant.

(2) The Agency’s determination or its failure to make a determination upon request is subject to review in accordance with the Administrative Procedure Act.

(c) Except as otherwise provided in subsections (a) and (b) of this section, an environmental covenant may not be extinguished, limited, or impaired through issuance of a tax deed, foreclosure of a tax lien, or application of the doctrine of adverse possession, prescription, abandonment, waiver, lack of enforcement, or acquiescence, or a similar doctrine.