A CERCLA § 107(r) “windfall lien” is a CERCLA statutory lien on a property for the increase in the fair market valueof that property attributable to EPA’s cleanup efforts. Unlike a CERCLA § 107(l) lien, it is not a lien for all of EPA’s unrecovered response costs. The windfall lien is limited to the lesser of EPA’s unrecovered response costs or the increase in fair market value attributable to EPA’s cleanup.
Attached is a document with more frequently asked questions and answers about windfall liens.
EPA's Windfall Lien FAQ can also be found at: (http://www.epa.gov/compliance/resources/policies/cleanup/superfund/interim-windfall-lien-faq.pdf)