Md. Code, Environment § 1–807

(a) (1) An environmental covenant and any amendment or termination of the covenant must be recorded in every county in which any portion of the real property subject to the covenant is located.

(2) For purposes of indexing, a holder shall be treated as a grantee.

(b) Except as otherwise provided under § 1-808(c) of this subtitle, an environmental covenant is subject to the laws of the state governing recording and priority of interests in real property.