UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-03970 ENVIRI CORPORATION (Exact name of registrant as specified in its charter) Delaware 23-1483991 (I.R.S. employer identification number) (State or other jurisdiction of incorp ...

Exhibit 99.1 Investor Contact Media Contact David Martin Jay Cooney +1.267.946.1407 +1.267.857.8017 dmartin@enviri.com jcooney@enviri.com FOR IMMEDIATE RELEASE ENVIRI CORPORATION REPORTS FOURTH QUARTER AND FULL YEAR 2023 RESULTS PHILADELPHIA (February 29, 2024) - Enviri Corporation (NYSE: NVRI) today reported fourth quarter 2023 results. On a U.S. GAAP ("GAAP") basis, the fourth quarter of 2023 diluted loss per share from continuing operations was $0.17, after strategic expenses and other unusual items. The ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 or 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-03970 ENVIRI CORPORATION (Exact name of registrant as specified in its charter) Delaware 23-1483991 (State or other ...

Financial Data and Key Metrics - Consolidated revenues from continuing operations increased to $520 million, up 8% compared to the prior year quarter, driven by pricing and increased demand in Clean Earth and Harsco Environmental segments [6] - Adjusted EBITDA totaled $78 million, a 58% improvement from the prior year and a 24% sequential improvement, exceeding prior guidance [7] - Net leverage decreased to 4.6x at quarter-end, with expectations to decline to near 4x by year-end before considering asset sales [8] - Free cash flow for the quarter was negative $23 million, impacted by higher cash interest and capital spending, but operating cash flow within Harsco Environmental and Clean Earth was positive [59][60] Business Segment Performance Harsco Environmental (HE) - Segment revenues totaled $290 million, up 6% excluding foreign exchange impact, with adjusted EBITDA reaching $53 million [71] - Despite lower steel production in Europe and Latin America, strength in India and Turkey partially offset the decline [13] - Full-year EBITDA for HE is expected to be modestly above last year, with higher margins and free cash flow generation near $100 million [13] - Steel output at customer sites decreased approximately 6% year-on-year, but operational improvements and other services mitigated the impact [61] Clean Earth - Segment revenues totaled $231 million, up 13% year-over-year, driven by price increases and the Stericycle settlement [72] - Adjusted EBITDA increased $30 million year-on-year, with margins reaching 15% in the quarter [73] - Clean Earth delivered its fourth consecutive quarter of ~12% EBITDA margins, with expectations to progress toward a 15% target [4] - The business is capital-light, with cash flow conversion expected to be roughly 85% of EBITDA [4] Market and Strategic Focus - The company is focusing on PFAS remediation as a significant growth opportunity, leveraging thermal desorption and oxidation technologies [56][57] - Clean Earth's soil and dredge business saw the highest bookings since acquisition, with strong volume and mix improvement potential [40] - The company is actively working on reducing overhead and improving operational efficiency in Clean Earth, targeting a 15% EBITDA margin within 18-24 months [32][33] Management Commentary on Operating Environment and Outlook - Management highlighted strong pricing initiatives and operational efficiencies as key drivers of improved performance [65] - The company raised its full-year adjusted EBITDA guidance to $270-$285 million, up from $260-$275 million, reflecting a 21% year-on-year increase at the midpoint [74] - Management expects continued improvement in cash performance for the remainder of the year [60] Other Important Information - The company initiated the process of selling its Rail segment, with expectations to complete the sale by year-end [51] - The Network Rail contract amendment reduced financial exposure and extended the delivery schedule into 2025 [85] - The Stericycle settlement contributed to the strong Q2 performance, with incremental price increases expected in 2023 and 2024 [27][82] Q&A Session Summary Question: Price Realization in Clean Earth - Management confirmed that price increases implemented in 2022 and early 2023 drove Q2 benefits, with future increases likely to be annual events [37][38] Question: Growth Opportunities in Harsco Environmental - Management highlighted non-steel production-based services as a key growth area, with lower capital requirements and better returns [26] Question: Clean Earth Margin Expansion - Drivers for margin expansion include operating leverage from volume growth, overhead reduction, and a favorable mix shift toward higher-margin soil business [32][33] Question: Stericycle Settlement Impact - The settlement contributed to Q2 performance, with incremental benefits expected in 2023 and 2024 [27][82] Question: Rail Segment Divestiture - The company is focused on reducing risks associated with long-term contracts, including the Network Rail amendment, to facilitate the Rail segment sale [51][85]

Financial Performance - Total revenues for Q2 2023 reached $520.2 million, a 8.1% increase from $481.1 million in Q2 2022[132] - Harsco Environmental segment revenues increased to $289.6 million in Q2 2023, up from $277.6 million in Q2 2022, driven by higher service pricing and operational improvements[132] - Clean Earth segment revenues rose to $230.6 million in Q2 2023, compared to $203.5 million in Q2 2022, primarily due to price increases and operational enhancements[132] - Consolidated operating income for Q2 2023 was $24.3 million, a significant recovery from an operating loss of $97.0 million in Q2 2022[132] - Revenues for the three months ended June 30, 2023 increased by $39.1 million, or 8.1%, compared to the same period in 2022, while revenues for the six months increased by $82.0 million, or 8.8%[142] Operating Margins - Harsco Environmental's operating margin decreased to 4.4% in Q2 2023 from 8.5% in Q2 2022, while Clean Earth's operating margin improved to 10.0% from a loss of 54.9%[132] - The Company anticipates Clean Earth segment operating results to improve meaningfully in 2023 due to higher service pricing and operational improvements[131] Impairment Charges - A net gain of $3.0 million was recognized in Q2 2023 related to a lease modification for a site relocation in the U.S.[135] - The Company recorded an impairment charge of $14.1 million in Q2 2023 related to abandoned equipment at an HE site in China[135] - The company recorded a goodwill impairment charge of $104.6 million in the CE segment during the second quarter of 2022, which did not recur in 2023[146] - An impairment charge of $14.1 million was recorded in the HE segment for the three months ended June 30, 2023[147] Expenses - Cost of sales for the three months ended June 30, 2023 increased by $3.4 million, or 0.8%, and for the six months, it increased by $27.1 million, or 3.5%[144] - Selling, general and administrative expenses (SG&A) for the three months ended June 30, 2023 rose by $8.9 million, or 13.1%, and for the six months, it increased by $11.7 million, or 8.5%[145] - Interest expense increased by $9.0 million for the three months and by $18.3 million for the six months ended June 30, 2023, primarily due to higher interest rates on Senior Secured Credit Facilities[149] - Defined benefit pension expense for the three and six months ended June 30, 2023 was $5.4 million and $10.7 million, respectively, compared to income of $2.2 million and $4.7 million in the same periods of 2022[152] - Income tax expense from continuing operations was $10.3 million and $17.2 million for the three and six months ended June 30, 2023, compared to benefits of $3.1 million and $1.9 million in 2022[153] Losses and Income - Loss from continuing operations was $18.6 million for the three months and $27.2 million for the six months ended June 30, 2023, an improvement from losses of $105.6 million and $111.8 million in the same periods of 2022[154] - Total other comprehensive income was $14.4 million and $21.6 million for the three and six months ended June 30, 2023, compared to losses of $29.1 million and $17.1 million in 2022[156] Cash Flow and Debt - Net cash used by investing activities in the first six months of 2023 was $56.4 million, an increase of $12.7 million from the same period in 2022[159] - Net cash provided by financing activities in the first six months of 2023 was $34.3 million, compared to net cash used of $(54.6) million in the first half of 2022, primarily due to increased net borrowings of $33.9 million[160] - The total outstanding balance of Senior Secured Credit Facilities as of June 30, 2023, was $1,375.0 million, an increase from $1,337.5 million at the end of 2022[162] - The consolidated net debt to Consolidated Adjusted EBITDA ratio was 4.63x as of June 30, 2023, remaining compliant with the covenant limit of 5.50x[164] - The Company could increase net debt by $248.7 million while remaining compliant with debt covenants as of June 30, 2023[164] Corporate Changes - The Company changed its corporate name from Harsco Corporation to Enviri Corporation on June 5, 2023, reflecting its transformation into an environmental solutions provider[129] Liquidity and Market Risks - The Company expects to continue utilizing its sources of liquidity, including cash from operations and borrowings, to meet future cash requirements for operations and growth initiatives[161] - Approximately 17.8% of the Company's consolidated cash and cash equivalents had regulatory restrictions as of June 30, 2023[167] - The required coverage of consolidated interest charges is set at a minimum of 2.75x through the end of 2024[163] - Market risks have not changed significantly from those disclosed in the Company's Annual Report for the fiscal year ended December 31, 2022[169]

Financial Data and Key Metrics Changes - Harsco's consolidated revenues from continuing operations increased to $496 million, up 9% year-over-year, driven by pricing and increased demand for environmental services [17] - Adjusted EBITDA totaled $63 million, representing a 28% improvement from the prior year [17] - Free cash flow for the quarter was $12 million, an improvement both year-on-year and sequentially [18] - The company expects full year adjusted EBITDA to be within a range of $260 million to $275 million, up 17% year-on-year [47] Business Line Data and Key Metrics Changes - Harsco Environmental segment revenues totaled $273 million, with adjusted EBITDA of $44 million; revenues increased year-on-year due to higher services pricing and demand, while adjusted EBITDA decreased by $4 million year-on-year [19] - Clean Earth segment revenues totaled $222 million, with adjusted EBITDA of $27 million, representing a 17% increase in revenues year-on-year, primarily driven by price increases [20] - Clean Earth's adjusted EBITDA increased by $17 million year-on-year, with margins improving approximately 700 basis points to over 12% [21] Market Data and Key Metrics Changes - Overall steel output at customer sites decreased approximately 1% year-on-year, with production performance varying by region [45] - Hazardous materials revenues reached $186 million, up 17% year-over-year, led by industrial markets [46] - Soil and dredge revenues totaled $36 million for the quarter, representing a 15% increase over the prior year [46] Company Strategy and Development Direction - The company plans to initiate the sale of its Rail business later this year, with expectations of a successful divestiture [5][40] - Harsco aims to limit growth capital in Harsco Environmental to opportunities that provide strong risk-adjusted returns [13] - The company is focused on improving operational performance, including service levels, logistics, safety, and labor efficiency [39] Management's Comments on Operating Environment and Future Outlook - Management noted that the external environment appears stable, and they are lifting their outlook for the year [12] - The company expects free cash flow conversion to grow from 55% last year to over 80% this year [39] - Management expressed confidence in achieving the 15% EBITDA margin target for Clean Earth, although the timing remains uncertain [55] Other Important Information - The company welcomed Jeff Beswick as the new President of Clean Earth, highlighting his experience in the hazardous waste industry [7] - Corporate governance updates include the addition of Tim Laurion to the Board of Directors, bringing extensive industry knowledge [41] Q&A Session Summary Question: Guidance clarification regarding Clean Earth - Management acknowledged a strong start to the year but indicated that guidance reflects current outlook and uncertainty in the economy [50] Question: Labor issues in Clean Earth - Management confirmed improvements in staffing and operational performance, leading to increased volumes [27] Question: Pricing initiatives - Management stated that pricing initiatives have been effective, with cumulative price increases now exceeding inflation [28] Question: Soil business performance - Management noted that the soil business remains below previous peaks but is showing positive trends [66] Question: PFAS opportunity - Management indicated that while there are challenges with specific projects, the overall PFAS strategic model is robust [76] Question: Rail business sale timeline - Management expects to process the sale of the Rail business in the latter half of the year [62]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 or 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-03970 HARSCO CORPORATION (Exact name of registrant as specified in its charter) Delaware 23-1483991 (State or other jur ...

HARSCO CORPORATION UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-03970 (Exact name of registrant as specified in its charter) Delaware 23-1483991 (State or other jurisdiction of incorporation or organization) (I.R.S. employe ...

Harsco Corporation (HSC) Q4 2022 Earnings Conference Call February 27, 2023 9:00 AM ET Company Participants David Martin - Vice President of Investor Relations Nick Grasberger - Chairman and Chief Executive Officer Pete Minan - Senior Vice President and Chief Financial Officer Conference Call Participants Michael Hoffman - Stifel Larry Solow - CJS Securities Rob Brown - Lake Street Capital Markets Operator Good morning. My name is Rocco, and I will be your conference facilitator. Welcome everyone to the Har ...

(a) Excludes Harsco Rail Segment. (b) Does not total due to rounding. RECONCILIATION OF ADJUSTED EBITDA BY SEGMENT TO OPERATING INCOME (LOSS) AS REPORTED BY SEGMENT (Unaudited) RECONCILIATION OF NON-GAAP MEASURES © 2023 Harsco Corporation. All Rights Reserved. This document and the information set forth herein are the property of Harsco Corporation. HARSCO CORPORATION Harsco Harsco Consolidated 19 RECONCILIATION OF NON-GAAP MEASURES (In thousands) Harsco Environmental Harsco Clean Earth (a) Corporate Consol ...