Earlier this year, we reported on a case that seemed to breathe new life into the divisibility defense under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).  Under CERCLA, a party that causes or contributes to contamination, or even just owns contaminated property, can be held liable for the entire cleanup.  In May 2015, a federal court in Wisconsin became one of the very few courts to hold that a party’s harm could be divisible under CERCLA – such that the party would only be liable for its fair share of the harm.  But on October 19, 2015, the court took it all back.

In its May ruling, the court relied on expert estimates regarding certain parties’ contributions of contaminants to the Lower Fox River to determine a percentage share of the harm and, ultimately, the costs.  In the wake of the court’s May 2015 ruling, a number of parties asked the court to reconsider its findings.  The judge reevaluated the expert estimates and determined they were not as reliable as he had originally thought.

One of the court’s main criticisms of the expert estimates is that they contradict facts already found by the court.  This appears to be a common theme in unsuccessful divisibility cases – a recent CERCLA case in Rhode Island had the same criticism of a party’s attempt to prove divisibility.  It seems that when there is an imperfect factual record and significant disagreement on the underlying facts of a particular case, divisibility can be very difficult, if not impossible, to prove.

Despite these rulings, divisibility remains an important tool for potentially responsible parties in any CERCLA case.  The hammer of CERCLA is hard, and parties need any opportunity to reduce costs by attempting to tie liability to the actual harm created.  It may be hard to prove, but it is an important and viable defense for any potentially responsible party under CERCLA.