Speaker, Strafford, "Arguing Apportionment Versus Allocation in CERCLA Litigation in Federal Court"


September 7, 2023

The U.S. Supreme Court’s Burlington Northern & Santa Fe Railway Co. v. U.S. ruling on divisibility under CERCLA led to optimism on the use of this defense to joint and several liability. However, there is no bright-line test for determining divisibility, and several recent court decisions have shown that defining and distinguishing harm at a site may continue to be difficult.

In court decisions involving the Fox River in Wisconsin, the Upper Columbia River in Washington state, and from Rhode Island and South Carolina, judges and parties wrestle with the threshold question for divisibility: is the harm “theoretically capable of apportionment”?

Divisibility is a potential defense to joint and several liability under CERCLA that divides the harm caused by each party (apportionment), so if the court’s answer to this question is “yes,” then the party seeking to limit its liability may succeed. In contrast, equitable allocation is designed to assign relative responsibility among liable parties to arrive at a “fair share” – without strict divisibility of the harm among the parties. In a cost recovery suit, if the divisibility defense is not available, then a party may be found jointly and severally liable and must bring contribution claims to shift responsibility to others under an equitable allocation approach.

Listen as the panel examines the Burlington Northern decision and its progeny concerning divisibility and apportionment versus equitable allocation. The panel will also review recent cases addressing this legal theory and offer practice pointers on which circumstances lend themselves to a divisibility defense, the main technical approaches available, and options on how to present this defense.


I. Understanding the divisibility defense versus equitable allocation under CERCLA

  • Section 113 equitable contribution vs. apportionment as a defense to a Section 107 claim
  • What the Burlington Northern decision means for divisibility and whether it has altered the landscape

II. Technical approaches to divisibility and equitable allocation

  • Overlap between the two
  • Unique elements of each

III. Lessons learned from recent decisions
IV. Best practices

  • Evidentiary issues and practical pointers for establishing support of each approach


The panel will discuss these and other relevant issues:

  • How are the federal courts applying the Burlington Northern decision in divisibility cases?
  • When and which parties should consider divisibility as opposed to equitable allocation?
  • What circumstances lend themselves to a divisibility defense versus an equitable allocation?
  • What steps can counsel take to overcome the challenging issues involved in proving divisibility?
  • Lessons learned from court decisions on divisibility and apportionment