Environmental Impact
THREE KIDS MINE

Recent Environmental Assessments and Reports

Overall Environmental Scope: An extensive environmental investigation was completed including the collection of over 900 samples.

The main contaminants at the site are from tailings — mine residue from the milling process. These tailings are planned to be placed in one central pit and capped with a polymer liner with a minimum half-life of almost 500 years, guaranteeing long-term containment. The groundwater in the area is hundreds of feet below the pit floor, so water pollution through leaching will not be an issue. Homes will not be built on this pit and it will eventually be a community park.

Asbestos also has been dumped on the site over many years. The tailings and asbestos will be cleaned up first, and then the balance of the disturbed dirt that was moved to reach the manganese will be placed in the pits in phases as development occurs.

NDEP issued a Record of Decision for the cleanup plan. This document is the basis for the governing Remedial Design document and drawings. This document was approved in March 2024 to prepare for the start of site work. 

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Remedial Design Report, Revision 1

This Remedial Design details the selected alternative as described in the Record of Decision (ROD) and presents engineering drawings for remediation and reclamation of the Site.

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Remedial Investigation Report, Revision 2

The Remedial Investigation (RI) Report establishes the nature and extent of mining related impacts on the site after an extensive characterization process.

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Corrective Action Plan – Soil and Mine Wastes, R1

The CAP describes the preferred alternative as selected in the Focused Feasibility Study (FFS) Report and is based on results presented in the Remedial Investigation (RI) Report.

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Remedial Design to Implement Corrective Action Plan
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Record of Decision

The selected alternative in this ROD is intended to remediate historical contaminant releases; treat the land to return it to a safe, stable condition that is protective of public health and the environment and is consistent with its established and intended productive post-response action use.

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Screening Level Ecological Risk Assessment, Revision 1

This report assesses exposure to contaminants of ecological concern to at-risk plants or animals in disturbed portions of the site.

More Environmental Documents

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Focused Feasibility Study Report – Soil and Mine Wastes

The FFS report proposes remedial action alternatives, defines remediation goals, evaluates remedial alternatives for the site, and recommends a preferred alternative.

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Background Soil Report, Revision 1

This report establishes naturally occurring levels of contaminants at the site and considers which soil is suitable for clean cover over mine waste.

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Asbestos Survey Report – Revision 2

This report provides the results of a bulk material asbestos survey performed on the property

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Phase I Environmental Site Assessment

The purpose of this assessment was to preliminarily identify environmental conditions on the property.

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Leaching Analysis Report, Revision 1

This report evaluates whether site related chemicals including metals, organic compounds, and semi volatile organic compounds in soils, rock, and mining waste at the project site could potentially mobilize in meteoric water and impact groundwater.

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