Final rule · 2026-12544

No-Migration Variance From Land Disposal Restrictions for Clean Harbors Grassy Mountain, Utah

The Environmental Protection Agency (EPA) is approving with conditions, no-migration variances for four categories/groups of wastes, containing up to a combined 250 temporary disposal units ("put piles") at any one time, from the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions (LDR) standards at Clean Harbors' Grassy Mountain (Clean Harbors) commercial treatment, storage and disposal facility (TSDF) in Tooele County, Utah. These variances will allow Clean Harbors to temporarily store treated hazardous wastes that are awaiting LDR compliance verification in put piles within its Subtitle C (hazardous waste) landfill. The petitioner demonstrated, to a reasonable degree of certainty, that there will be no migration of hazardous constituents from the put piles for as long as the wastes remain hazardous. Additionally, once LDR compliance is verified, the put piles will be disposed within the onsite RCRA hazardous waste landfill cell and will be subject to the conditions set out in the Compliance Monitoring Plan section of this document.