Last week, a federal appeals court vacated a $926 million judgment against Rockwell International  and Dow Chemical over alleged plutonium contamination. See Cook v. Rockwell International Corp., No. 08-1224 (10th Cir., 9/3/10).

The owners of properties near the former Rocky Flats Nuclear Weapons Plant (“Rocky Flats”) filed a proposed class action against the facility’s operators under the Price-Anderson Act, alleging trespass and nuisance claims arising from the alleged release of plutonium particles onto their properties. Rocky Flats, located near Denver, Colorado, was established by the US in the 1950s to produce nuclear weapon components. The government contracted with Dow to operate the facility from 1952 to 1975, and then with Rockwell from 1975 to 1989.

Some radiation cases seem to last longer than the half-life of uranium.  The complaint here was filed in 1990.  A class was certified in 1993. After over fifteen years of litigation, the district court conducted a jury trial between October, 2005 and January, 2006, resulting in a jury verdict in favor of the plaintiff class, which numbered about 15,000.

This appeal ensued, and a main issue was the jury instructions (we leave for another day the preemption and PAA statutory issues). In accordance with the district court’s construction of Colorado law, the jury instructions did not require plaintiffs to establish either an actual injury to their properties or a loss of use of their properties. With respect to the nuisance claims, the district court instructed the jury that plaintiffs could establish defendants’ conduct interfered with the use and enjoyment of the class properties by proving defendants’ conduct exposed plaintiffs to “some increased risk of health problems” or caused conditions “that pose a demonstrable risk of future harm” to their property area.  As to plaintiffs’ trespass claims, the district court instructed the jury that plaintiffs were not required to show that plutonium is present on the class members’ properties at any particular level or concentration, that they suffered any bodily harm because of the plutonium, or that the presence of plutonium damaged these properties in some other way.

First, the nuisance theory. Under Colorado law, a plaintiff asserting a nuisance claim must establish an interference with the use and enjoyment of his property that is both “substantial” and “unreasonable.”  A jury may find the presence of radioactive contamination creates an actual risk to health and thereby interferes with a plaintiff’s use or enjoyment of his land if the contamination disturbs the plaintiff’s comfort and convenience, including his peace of mind, with respect to his continued use of the land.  But, said the court,  a scientifically unfounded risk cannot rise to the level of an unreasonable and substantial interference. To the extent plaintiffs here relied on anxiety from an increased risk to their health as an interference with the use and enjoyment of their properties, that anxiety must arise from scientifically verifiable evidence regarding the risk and cannot be wholly irrational. No reasonable jury could find that irrational anxiety about a risk that cannot be scientifically verified tips this balance so as to render the interference “unreasonable.”  So the charge was wrong to the extent it permitted any subjective anxiety to suffice for an unreasonable interference.

The court of appeals then turned to the trespass theory.  And here, the issue turned on whether the plaintiffs’ claim was a traditional trespass theory or a so-called “intangible trespass.”  The parties agreed that to prevail under a traditional trespass claim, a plaintiff must establish only a physical intrusion upon the property of another without the proper permission from the person legally entitled to possession. A plaintiff need not establish any injury to his legally protected interest in the land or damage to the land itself.  Unlike a traditional trespass claim, however, the court made clear that an intangible trespass claim requires an aggrieved party to prove physical damage to the property  caused by such intangible intrusion.

So is the invasion of plutonium particles onto real property a traditional or intangible trespass claim?  The cases suggest that “intangible” is something that is impalpable, or incapable of being felt by touch. Noise intrusion and electromagnetic fields emitted by power lines are examples of the intangible. Neither can be perceived by any of the senses.   Here,  plaintiffs had to concede that the plutonium particles allegedly present on their properties are impalpable and imperceptible by the senses. Although the particles in question have mass and are “physically present” on the land, because the particles are impalpable, the trespass alleged here must be tried as an intangible trespass.

Consequently, the instructions on this point were also in error, and on remand, plaintiffs will be required to prove the plutonium contamination caused “physical damage to the property” in order to prevail on their trespass claims.

Interestingly, because the district court’s class certification analysis failed to consider whether
plaintiffs could establish various elements of their claims, properly defined, the 10th Circuit also reversed the district court’s class certification ruling. Upon remand, the district court will have to  revisit the class certification question to determine whether plaintiffs can establish the proper elements of their claims on a class-wide basis.  Obviously, the need to show unreasonable interference and physical damage may each create predominating individual issues.