(a) Perpetual.--An environmental covenant is perpetual unless one of the following applies: (1) It is limited by its terms to a specific duration or the occurrence of a specific event.(2) It is terminated by consent under section 6510 (relating to amendment or termination by consent).(3) It is terminated under subsection (b).(4) It is terminated by foreclosure of an interest which has priority over the environmental covenant.(5) It is terminated or modified by judicial decree in an eminent domain proceeding, but only if: (i) the agency which signed the environmental covenant consents to the judicial action;(ii) all persons identified in section 6510(a) and (b) are given notice of the pendency of the eminent domain proceeding; and(iii) the court determines, after hearing, that the termination or modification will not adversely affect human health or the environment.(b) Judicial modification.--A court, in an action in which all persons identified in section 6510(a) and (b) have been given notice, may terminate or modify the environmental covenant on the real property subject to the environmental covenant if any of the following apply: (1) The agency which signed an environmental covenant has determined that:(i) the intended benefits of the environmental covenant can no longer be realized; or(ii) changed circumstances indicate that the intended benefits can only be realized through modification of the environmental covenant.(2) A standard allowing for a reopener of a completed environmental response project under section 505 of the Land Recycling Act is met.(c) Other modifications.--Except as otherwise provided in subsection (a) or (b), an environmental covenant may not be extinguished, limited or impaired through: (1) issuance of a tax deed;(2) foreclosure of a tax lien; or(3) application of the doctrine of adverse possession, prescription, abandonment, waiver, lack of enforcement or of a similar doctrine. 2007, Dec. 18, P.L. 450, No. 68, § 1, effective in 60 days [2/19/2008].