The US Supreme Court ruled Monday in Guam v. United States that a case against the US for causing toxic waste pollution in Guam may proceed.

This case originated from a lawsuit by Guam against the US accusing the Navy of causing the contamination at the Ordot Dump. Guam alleged that the US was responsible for the costs of closing and remediating the landfill under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

The Ordot Dump was built and operated by the Navy in the 1940s as a site for disposing of municipal and military waste. Guam alleges that this waste included munitions and chemicals such as DDT and Agent Orange for decades without environmental safeguards. The contaminants leaked into the Lonfit River and ultimately flowed into the Pacific Ocean.

In the early 2000s, the US Environmental Protection Agency sued Guam under the Clean Water Act to gain a court order compelling Guam to address the dump. Guam subsequently paid a civil penalty, closed the dump, and created a cover system. The dump was closed in 2011, and Guam initiated its lawsuit against the US in 2017.

The Supreme Court unanimously ruled in favor of Guam. The Navy had argued that Guam was responsible for the costs because it took “response actions,” which, under CECLA, would trigger the statute of limitations to toll. If the statute of limitations began to run, it would be more than six years passed, thus making it too late for Guam to bring this claim.

The court disagreed: “[R]elying on that functional overlap to reinterpret the phrase ‘resolved its liability … for some or all of a response action’ to mean ‘settled an environmental liability that might have been actionable under CERCLA’ would stretch the statute beyond Congress’ actual language.” The court thus held that, for an action to be considered a CERCLA response to toll the statute of limitations, CERCLA-specific liability must have been found.

The holding allows the case against the US to proceed.