After settling with EPA and having its settlement upheld in court, a potentially responsible party (PRP) is free from liability to all other PRPs given notice of that proposed settlement under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA, or Superfund). This principle, long recognized as key to CERCLA's successful performance, was recently affirmed by the United States Court of Appeals for the Eighth Circuit in its ASARCO, LLC v. Union Pacific Railroad Company decision.
Though the Endangered Species Act has very strong prohibitory language, in practice its bark is sometimes much worse than its bite. The U.S. Court of Appeals for the Fifth Circuit's recent decision in The Aranas Project v. Shaw, et al. has preserved the statute's status as a mere "paper tiger" by reversing a district court ruling which had the potential to preserve the dwindling wild whooping crane population.