In a potentially significant ruling, in Burlington Northern & Santa Fe Railway v. United States, the Supreme Court limited liability for the cleanup of hazardous waste sites under the federal Superfund statute. Justice Stevens, writing for an eight justice majority (all of the justices except for Ginsburg) significantly narrowed the basis upon which companies may be held liable for cleanup costs as "arrangers" of waste disposal. It further upheld the district court below's finding that clean-up costs could be apportioned, thereby limiting the application of joint and several liability for cleanup costs. Unlike the other environmental decisions handed down this term, this one could be a biggie. I haven't had the time to fully digest the opinion yet, but here's Dan Farber's initial reaction at Legal Planet.
UPDATE: The NYT's Adam Liptak covers the case here.