On December 3, the U.S. Supreme Court heard oral argument on a case to determine if PRPs at a superfund site can pursue state causes of action while the EPA is actively pursuing remediation under federal superfund law. Copper smelting operations by Atlantic Richfield Co. were responsible for contaminating approximately 100 landowners’ property in Opportunity, Montana. Atlantic Richfield and the EPA have spent more than 30 years cleaning up the 300 square mile Anaconda Smelter Superfund Site, but the landowners claim that harmful amounts of heavy metals remain. The landowners went to state court to force Atlantic Richfield to pay for additional cleanup work and Atlantic Richfield countered that the state law claims are barred by the federal action. The landowners site the “savings clause” in the text of CERCLA which states that CERCLA does not interfere with state law leaving them free to bring cleanup related claims in state court. Atlantic Richfield, in turn, notes that the landowners themselves are PRPs by virtue of owning contaminated property and that PRPs are prevented from performing cleanup work without the EPA’s approval. If the Supreme Court sides with the landowners, it could have the potential side effect of making PRPs wary of entering into an agreement with the U.S. EPA as the EPA settlements would offer no finality to possible claims associated with the site.