Recent CERCLA Decision Allows Divisibility of Comingled Groundwater Plume

In Burlington Northern, when the United States Supreme Court decided that joint and several liability under section 107 of CERCLA could be ameliorated in cases where the harm was theoretically capable of apportionment, potentially responsible parties (PRPs) hailed the decision outlining the test for divisibility as a great breakthrough. In practice, however, the availability of the divisibility defense that PRPs hoped would flow from the Burlington Northern decision has been limited, particularly in complex, comingled groundwater plume cases. In March 2020, however, the District Court in Von Duprin LLC v. Moran Electric Service, Inc. et al. (United States District Court, Southern District of Indiana – Indianapolis Division. Case No. 1:16-cv-01942-TWP-DML) issued the first CERCLA decision finding that a comingled groundwater plume was capable of apportionment because there was a reasonable basis to divide the harm. The District Court relied on the findings of one of the technical experts, who analyzed substantial groundwater monitoring results from four different source areas and demonstrated that the magnitude of the concentrations and chemical characteristics of the Chlorinated Volatile Organic Compounds (CVOCs) were different in the four source areas. The Von Duprin case involved the release of hazardous substances at four properties located in Indianapolis,...