DERR-2024-011685

July 18, 2024 Ref: 8ECA-RO-E
SENT VIA EMAIL Jeffrey Mensinger Environmental Manager US Magnesium LLC [e-mail] Michael A. Zody Parsons Behle & Latimer [e-mail] Re: Notice of Noncompliance with US Magnesium LLC Consent Decree (Case No. 2:01CV0040B) Dear Mr. Mensinger and Mr. Zody: This letter serves as a Notice of Noncompliance regarding the US Magnesium LLC (USM) Consent Decree (CD). This letter seeks your swift effort and cooperation in returning USM to compliance with requirements of the above-mentioned CD. Currently, USM is out of compliance with the CD in a number of areas: 1. As required by Paragraph 47(a)(1) and Appendix 13 of the CD, USM failed to appropriately adjust the amount of Financial Assurance for the Closure and Post-Closure of the Retrofitted Waste Pond by the April 8, 2024 deadline, and is therefore out of compliance. 2. As required by Paragraph 17 and Appendix 14 of the CD, USM failed to either cease operation of the electrolytic cells in Building 4 or retrofit with wet anode dust handling by the July 15, 2022 deadline (pursuant to an extension granted on June 30, 2022 by the EPA), and is therefore out of compliance. 3. As required by Paragraph 18 and Appendices 5 and 14 of the CD (as well as the approved Courtyard Capping Design deliverable and its attached Construction Plan and Scope of Work), USM has not properly addressed the grizzly vault adjacent to Building 3, on the west side of the Courtyard (as defined in paragraph 8.u. of the CD), by cracking, backfilling with aggregate and capping to the level of the courtyard. Pursuant to Appendix 14, this work was due to be completed by December 27, 2022. On
Re: Notice of Noncompliance with US Magnesium LLC Consent Decree (Case No. 2:01CV0040B)

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January 23, 2023, EPA approved a USM request for extension to July 28, 2023. However, the project remains uncompleted and USM is therefore out of compliance. 4. As required by Paragraph 15 and Appendices 3 and 14 of the CD, USM failed to initiate construction of the filtration system project by the June 12, 2023 deadline (pursuant to an extension granted on January 23, 2023 by the EPA), and is therefore out of compliance. Further, as required by Section VII and Appendix 12 of the CD, USM is required to perform all actions necessary to retrofit the Current Waste Pond and eliminate uncontrolled releases of hazardous substances by implementing Appendix 12. Pursuant to Paragraph 28 and 32 of the CD, USM is also required to comply with the Ground Water Discharge Permit. However, USM appears to have ceased implementation of the CERCLA Response Action as required and is in danger of late performance. On May 22, 2024, USM informed the Utah Department of Environmental Quality that scheduled construction of the Retrofitted Waste Pond would not proceed on schedule. In addition, Appendix 4(A) of the CD requires that “[w]ithin sixty (60) Days of the Effective Date of the Consent Decree, US Mag will execute the USEPA-accepted Conditional Partial Assignment and Grant of Rights….In an Event of Default as defined in Appendix G, it is the intent of the Parties to ensure that USEPA will have access to the necessary resources to implement the Salt Cap Closure Plan….” Now almost three years since the Effective Date of the CD, USM has still not executed the Conditional Partial Assignment and Grant of Rights. Although USM has submitted a USM-executed conditional assignment, correspondence from the State of Utah to both EPA and USM, of August 23, 2023, makes clear that the conditional assignment – as currently drafted – would not adequately serve to ensure EPA has necessary resources to implement the Salt Cap Closure Plan, as intended and required by the CD. As long as both ready access to necessary resources and ability to implement the Salt Cap Closure Plan, in an Event of Default, remains in doubt, EPA will maintain concerns as to whether the Salt Cap Closure and Post-Closure Plan is protective of human health or the environment, as referenced in Paragraph 16(a)(2) of the CD. The EPA reserves the right to take action pursuant to Section XIV of the CD, which allows for accrual of stipulated penalties, per violation and per day, for violations of Sections VI and X of the CD. Thank you for your prompt attention to this important matter. For questions regarding this letter, please contact Annette Maxwell, at [phone] or [e-mail], or Max Greenblum at [phone] or [e-mail]. Sincerely, Suzanne J. Bohan, Director Enforcement and Compliance Assurance Division cc: Annette Maxwell, EPA Max Greenblum, EPA