Allocation of environmental cleanup costs among responsible parties is a key component of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund. Indeed, the United States Supreme Court has expressly acknowledged its importance and twice within the past three terms has grappled with how responsible parties may bring CERCLA claims, for contribution or otherwise, to force other responsible parties to share responsibility for cleanup costs at contaminated sites. While some questions remain to be answered around the edges, it is once again fairly clear that a responsible party who is subject to joint and several liability for cleanup costs has a statutory claim under CERCLA by which he can require other responsible parties to bear their equitable shares of the cleanup burden. Thus, because a CERCLA defendant can bring actions for contribution or cost recovery, he may not have to shoulder the entire cleanup burden himself, while other responsible parties avoid liability entirely, just because he had the misfortune of being the one responsible party sued. In addition to providing a whiff of fairness in the Superfund program, the availability of contribution and cost recovery claims by responsible parties is widely credited with promoting settlements and encouraging cleanups of contaminated sites by private parties while preserving governmental resources.

The "imminent hazard" provisions of the Resource Conservation and Recovery Act (RCRA), like CERCLA, are used to force responsible parties to bear the costs of cleaning up contaminated sites. Sections 7003 and 7002(a)(1)(B) authorize the United States and citizens, respectively, to require responsible parties to clean up wastes which may present an "imminent and substantial endangerment" to health or the environment. Defendants in RCRA imminent hazard cases, like CERCLA defendants, generally are subject to strict, retroactive and joint and several liability. But unlike in CERCLA cases, virtually without exception courts have ruled that defendants in RCRA imminent hazard cases do not have a claim under RCRA, for contribution or otherwise, by which they can seek to force other responsible parties to share the cleanup responsibility.