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  1. Home
  2. Bonita Peak Mining District
  3. Current Activities

Cleanup Progress

On this page:

  • Site Milestones
  • Cleanup Schedule by Operable Unit

Cleaning up Superfund sites is a complex, multi-phase process. Learn more:

  • Superfund Cleanup Process
  • A community guide to EPA's Superfund program (PDF)(12 pp, 454 KB)

Site Milestones

MilestoneDate(s)
Initial Assessment Completed03/26/1998
Proposed to the National Priorities List04/07/2016
Finalized on the National Priorities List09/09/2016
Remedial Investigation Started05/19/2016
Remedy Selected05/20/2019
Remedial Action Started09/20/2019
Construction CompletedNot Yet Achieved
Deleted from National Priorities ListNot Yet Achieved
Most Recent Five-Year Review10/08/2024
Achieved Sitewide Ready for Anticipated ReuseNot Yet Achieved

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Cleanup Schedule by Operable Unit

During cleanup, a site can be divided into a number of distinct areas depending on its complexity. These areas, called operable units (OUs), may address geographic areas, specific problems, or areas where a specific action is required. Examples of typical operable units include construction of a groundwater pump and treatment system or construction of a cap over a landfill.

MilestoneStart DateCompletion Date
OU 00 - SITEWIDE
Consent Decree 09/13/2019
Unilateral Administrative Order 01/06/2021
Removal01/12/2017 
Removal08/14/201708/01/2024
Removal08/01/202307/23/2024
Five-Year Review (EPA Performed) 10/08/2024
OU 01 - Sitewide - Remedial
Removal (EPA Performed)07/17/202310/02/2023
Removal07/17/2023 10/02/2023
Removal07/08/2024 10/04/2024
Removal07/24/2024 10/09/2024
Removal09/03/2024 12/12/2024
Removal09/01/2025 Estimated Sep - Nov 2026
RemovalEstimated Jun - Aug 2026 Estimated Sep - Nov 2026
Combined Remedial Investigation/Feasibility Study (EPA Performed)05/19/2016 05/20/2019
Combined Remedial Investigation/Feasibility Study09/20/2019 04/30/2021
Combined Remedial Investigation/Feasibility Study07/14/2022 Estimated Mar - May 2027
Combined Remedial Investigation/Feasibility Study09/08/2022 Estimated Mar - May 2028
Combined Remedial Investigation/Feasibility Study09/08/2022 
Combined Remedial Investigation/Feasibility Study02/16/2023 
Combined Remedial Investigation/Feasibility StudyEstimated Mar - May 2028 
Record of Decision (EPA Performed) 05/20/2019
Record of Decision 04/30/2021
Record of Decision Estimated Mar - May 2027
Record of Decision Estimated Mar - May 2028
Remedial Design (EPA Performed)06/01/2020 09/30/2022
Remedial DesignEstimated Jun - Aug 2026 Estimated Mar - May 2028
Remedial DesignEstimated Mar - May 2027 Estimated Sep - Nov 2028
Remedial DesignEstimated Jun - Aug 2028 
Remedial Action (EPA Performed)09/20/2019 03/31/2026
Remedial Action 09/14/2021 Estimated Dec 2026 - Feb 2027
Remedial Action 12/18/2024 
Remedial Action Estimated Mar - May 2028 
Remedial Action Estimated Sep - Nov 2028 
Operation and Maintenance11/06/2025 
OU 02 - Mayflower
Administrative Order of Consent (EPA Performed) 05/10/2017
Administrative Order of Consent 09/03/2020
Consent Decree 04/28/2022
Remedial Investigation05/10/2017 06/27/2022
Combined Remedial Investigation/Feasibility Study06/27/2022Estimated Mar - May 2028
Record of Decision Estimated Mar - May 2028
Remedial DesignEstimated Mar - May 2028 
OU 3- Groundwater System
Unilateral Administrative Order 03/15/2018
Removal (EPA Performed)Estimated Mar - May 2028 
Remedial Investigation (EPA Oversight)04/11/2018 07/26/2019
Remedial Investigation7/26/2019 
Combined Remedial Investigation/Feasibility Study (EPA Performed)04/09/2019 
Administrative Order of Consent  08/15/2019
Removal

09/14/2019

04/10/2025

Administrative Order of Consent 

08/23/2021

Removal09/13/2021 Estimated Mar - May 2027

*NOTE: This date may not reflect the actual start or actual completion of the milestone. Either the lead for this activity changed, the project was phased, or the project did not fit the normal definitions of activities tracked in this table.

NOTE: Dates and estimated dates will not display for all milestones. Estimated dates only display for milestones planned within the next three fiscal years. Estimated dates and start dates will not display for the following enforcement milestones: Administrative Order of Consent, Consent Decree and Unilateral Administrative Order. Start dates will not display for the following document milestones: Five-Year Review, Record of Decision, Record of Decision Amendment, Explanation of Significant Differences and Partial NPL Deletion.

DISCLAIMER: The data on this page are derived from the Superfund Enterprise Management System and are solely for informational purposes. The data cannot be relied upon to create any substantive or procedural rights or requirements enforceable by any party in litigation with any member of the public, states, tribes, the United States or any federal agency. EPA reserves the right to change these data at any time without public notice.

Bonita Peak Mining District

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Contact Us About the Bonita Peak Mining District
Contact Us About the Bonita Peak Mining District to ask a question, provide feedback, or report a problem.
Last updated on April 21, 2026
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