This unilateral administrative order is issued with respect to operable unit one of the Site, to address contamination of soil at certain residential properties, as well as contaminated dust in the interior of a subset of the properties, which together present conditions that constitute an imminent and substantial endangerment to public health, welfare or the environment. The unilateral administrative order requires the three respondents to perform the remedial design and remedial action for operable unit one selected in the Record of Decision, which involves excavating and disposing off-site of PCB contaminated soil, and cleaning the interiors of properties where PCB are present above EPA's remediation goal. Four properties are known to be in need of remediation, but during the remedial design phase the respondents must investigate additional properties to determine if those other properties also require remediation.