has refused to expand the marketable title doctrine to make the presence of hazardous waste an encumbrance on title,” and opined that a buyer’s remedy in situations where environmental cleanup is required “would have been to include an environmental contingency clause in the contract or to insist on warranties against such conditions.” See also Donahey v. Bogle, 987 F.2d 1250, 1254 (6th Cir.1993), vacated on other grounds, 512 U.S. 1201, 114 S.Ct. 2668, 129 L.Ed.2d 805 (1994) (“[A]n ‘encumbrance’ is ... something ... that diminishes the value of the title to the property; environmental contaminants may diminish the value of the realty, but they do not constitute an encumbrance because they do not affect title.”); Cameron v. Martin Marietta Corp., 729 F.Supp. 1529, 1532 (E.D.N.C. 1990) (<HOLDING>); United States v. Allied Chem. Corp., 587
holding that a declaratoryjudgment action against the state that would affect property in which the state had an interest was barred by  14 holding that state law claim regarding breach of settlement agreement was preempted by federal labor law holding that although defendant transferred property which was contaminated by chemicals in violation of state and federal regulations plaintiffs failed to state a claim for breach of warranty against encumbrances recognizing state laws can be preempted by federal regulations as well as by federal legislation holding that a breach of contract claim against one defendant related back to interference with contract claim against that defendant and breach of contract claim against second defendant because it was based on same set of operative facts