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, Indiana, including property previously owned by Von Duprin (the “Von Duprin Facility”) and three upgradient properties. The four properties were identified as (1) the Von Duprin Property, (2) the Moran Property, (3) the Ertel Property, and (4) the Zimmer Paper Property. All three of the upgradient sites and the Von Duprin Facility were once owned and operated by manufacturers who released chlorinated solvents into nearby groundwater, which comingled into a plume extending beyond the sites. Plaintiff Von Duprin, which had engaged in remediation of the Von Duprin property and down-gradient off-site properties, brought suit against other PRPs under Section 107 of CERCLA, seeking past and future costs. The Court had to determine relative responsibility for the groundwater plume along with the parties’ respective financial responsibility for cleanup. Defendant Moran raised divisibility as a defense to CERCLA liability.
The Court found defendant Moran’s technical expert, Dr. Adam Love, credibly demonstrated a reasonable basis for apportionment of the harm based on a database he created from 30 environmental reports that monitored groundwater on the four properties at issue. Dr. Love determined that the contamination emanated from four geographically distinct areas and the chemical characteristics of those CVOCs were different at each source. Dr. Love also distinguished the CVOCs at the Von Duprin Property as dramatically different from the magnitude and chemical characteristics of the compounds at the three upgradient properties using the ratio of TCE to PCE in the soil and groundwater samples taken from each individual property to determine how much each property contributed to the comingled plume.
The findings of defendant Moran’s expert were used as the basis for the Court’s ruling that the harm in this case is divisible and, thus, a reasonable basis for its apportionment amongst the parties existed. While this case touches on a number of other CERCLA issues, it provides useful guidance to CERCLA defendants in comingled plume cases. Use of a credible expert and extensive data are key factors that may persuade courts in such suits.