Anaconda - What’s happening at the Site?

NDEP conducted a public meeting in Yerington on December 10, 2024 to discuss the current status of the cleanup. Major tasks completed since the 2018 NPL Deferral include the completion of all remedial investigations and risk assessments for the site operable units (OUs). 

The OU-8 areas throughout the site (former Arimetco Heap Leach Operations) were the subject of the Phase 1 remediation mandated under EPA Record of Decision 1 (ROD 1; 2017) and NDEP ROD 1A (2021). The bulk of construction activities associated with Phase 1 remediation have been completed, including the construction of five new, double-lined heap leach drain down fluid evaporation ponds, and the regrading and capping of the copper heap leach pads that were operated by Arimetco from 1989–1999.  Closure of Pond A, which has been out of service due to the amount of solid build up in that pond, was completed in March 2025.  The remaining component of the Phase 1/1A remedial action includes the installation of a new sewer system for the Weed Heights community before the old sewer system can be decommissioned and final stormwater conveyance and containment can be built.  Construction of the new sewer system began in April 2025.  Ongoing activities include site maintenance and security, including daily oversight by Atlantic Richfield of the heap leach pad fluid management system.

Phase 2 of the Site cleanup will be implemented pursuant to ROD 2 for the remainder of the OUs.  The feasibility study (FS) process to assess remedial alternatives for the remainder of the OUs has been initiated and a draft document is expected in November 2025. The FS is expected to be final in spring 2026, with the proposed plan release scheduled for June 2026.  A final draft of ROD 2 supporting complete site cleanup is slated for completion by NDEP in August 2026 and is expected to be final in February 2027. Unforeseen circumstances may require adjustment of these milestones.  The fact sheet below outlines the FS process for ROD 2.

Click the link to access the Anaconda Fact Sheet — December 2023 [pdf, 423KB]

Operable Units Map and List

Closure Schedule