The U.S. Department of Justice said a new law in Washington state expanding the number of Hanford nuclear reservation workers covered by a presumption doesn’t eliminate the need for the nation’s top court to determine whether the presumption violates principles of intergovernmental immunity.

The U.S. Supreme Court is scheduled to hold oral arguments in U.S. v. Washington on April 18. Washington State Attorney General Robert Ferguson in a March 15 court filing said the dispute is moot because Gov. Jay Inslee enacted new legislation expanding the scope of the Hanford presumption.

The governor in March signed S.B. 5890, which gives all workers at the nuclear reservation the presumption that several diseases are compensable when experienced within 72 hours of exposure to fumes or chemicals. The bill repealed statutory language from the 2018 measure that created the presumption, H.B. 1723, which limited its application to only U.S. Department of Energy workers.

The Justice Department told the high court that S.B. 5890 alters the category of workers covered by the presumption but preserves the “novel and burdensome features” of the original law.

“H.B. 1723 was in force for nearly four years before the state enacted S.B. 5890,” the department argued in court filings. “During that time, more than 200 claims were allowed… making the United States liable to pay tens of millions of federal taxpayer dollars. The validity of H.B. 1723 is directly relevant to the disposition of those claims, many of which are still on appeal. The question presented is accordingly not moot.”

The Justice Department is arguing that the presumption is precluded by the principles of federal intergovernmental immunity. If the high court agrees, the department argues that it would have the option to recover payments already made.

While attorneys representing Washington state argue that every claim approved under H.B. 1723 would also be approved under S.B. 5890, the Justice Department said coverage provisions under the two bills are different.

H.B. 1723 applies to any person working directly or indirectly for the federal government at the 500 square-mile Hanford site. S.B. 5890 applies to workers at any radiological hazardous waste facility, which is defined to mean “any structure and its lands” where specific forms of dangerous waste are stored. The federal government argues that some office and administrative buildings, for example, do not appear to fit within the coverage area defined by S.B. 5890.

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