One Rock Capital Partners Completes Sale of EnviroServe to Clean Harbors

NEW YORK, October 5, 2026 - One Rock Capital Partners, LLC (together with its affiliates, "One Rock"), a value-oriented, operationally focused private equity firm, today announced that it has completed the previously announced sale of EnviroServe Inc. and its related affiliates (collectively, "EnviroServe" or the "Company") to Clean Harbors, Inc. ("Clean Harbors") (NYSE: CLH) for $470 million.

EnviroServe is a provider of environmental and waste management services, with a service offering spanning remediation, rail services, industrial cleaning and emergency response, as well as hazardous and non-hazardous waste transportation and processing. One Rock acquired EnviroServe through a carve-out from Savage Companies and, during its ownership, expanded the Company's service capabilities through organic growth, new greenfield locations and add-on acquisitions.

"We are pleased to complete this transaction and to see EnviroServe reach this milestone," said R. Scott Spielvogel, Managing Partner at One Rock. "Working closely with the management team, we helped EnviroServe expand its service capabilities and build a highly trained, service-oriented team during our ownership. We are confident the Company is well positioned for continued success as part of Clean Harbors, and we look forward to watching it grow."

"Today marks an exciting new chapter for Clean Harbors and EnviroServe," said Mike Battles, Co-CEO of Clean Harbors. "Over the past several years, EnviroServe has expanded its capabilities and established a strong platform for growth. We look forward to building upon that success as we integrate the business and leverage our combined strengths to enhance the solutions we provide to customers across North America."