Exhibit 99.1 Investor Contact Media Contact David Martin Maura Pfeiffer +1.267.946.1407 +1.267.964.1868 dmartin@enviri.com mpfeiffer@enviri.com FOR IMMEDIATE RELEASE ENVIRI CORPORATION REPORTS FIRST QUARTER 2024 RESULTS • Harsco Rail Now Reported Within Continuing Operations As Sales Process is Paused • First Quarter Revenues Totaled $600 Million, an Increase of 7 Percent Over the Prior-Year Quarter • Q1 GAAP Operating Income of$26 Million • Adjusted EBITDA in Q1 Totaled $78 million, an Increase of 19 Perc ...