Three settling CERCLA defendants, termed the performing settling defendants, in relation to the release or threatened release of hazardous substances into the environment at or from operable Unit 4 of the Wells G&H Superfund site located in Woburn, Massachusetts, must perform remedial action estimated to cost approximately $19.1 million and pay 80 percent of EPA's future response costs, including costs of overseeing this cleanup work; thirteen other defendants that arranged for the disposal of hazardous substances at the operable unit must pay approximately $3.9 million into a trust fund for use by the performing settling defendants to help finance the remedial work, and EPA will make available $4.8 million from a special site account of monies obtained in prior settlements related to the site to partially fund the remedial action.