Press Release EXHIBIT 99.1 Clean Harbors Announces Second-Quarter 2025 Financial Results NORWELL, Mass. – July 30, 2025 – Clean Harbors, Inc. ("Clean Harbors" or the "Company") (NYSE: CLH), the leading provider of environmental and industrial services throughout North America, today announced financial results for the second quarter ended June 30, 2025. "Our second-quarter results reflect the consistent profitable growth of our Environmental Services (ES) segment, where we experienced strong demand for our ...