ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS |
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| Environmental Remediation Obligations [Abstract] | Ìý | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Environmental Loss Contingency And Mine Closure Obligation Disclosure [Text Block] |
NOTE 11 - ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS
The following is a summary of our environmental and mine closure obligations:
Environmental
Our mining and exploration activities are subject to various laws and regulations governing the protection of the environment. We conduct our operations to protect the public health and environment and believe our operations are in compliance with applicable laws and regulations in all material respects. Our environmental liabilities include obligations for known environmental remediation exposures at various active and closed mining operations and other sites, and have been recognized based on the estimated cost of investigation and remediation at each site. If the cost can only be estimated as a range of possible amounts with no specific amount being more likely, the minimum of the range is accrued. Future expenditures are not discounted unless the amount and timing of the cash disbursements are readily known. Potential insurance recoveries have not been reflected. Additional environmental obligations could be incurred, the extent of which cannot be assessed.
Mine Closure
The accrued closure obligation for our mining operations provides for contractual and legal obligations associated with the eventual closure of the mining operations. We performed a detailed assessment of our asset retirement obligations related to our active mining locations in accordance with our accounting policy, under which we perform an in-depth evaluation of the liability every three years in addition to routine annual assessments. In 2017, we employed a third-party specialist to assist in the triennial in-depth evaluation.
For the assessments performed, we determined the obligations based on detailed estimates adjusted for factors that a market participant would consider (e.g., inflation, overhead and profit) and then discounted the obligation using the current credit-adjusted risk-free interest rate based on the corresponding life of mine. The estimate also incorporates incremental increases in the closure cost estimates and changes in estimates of mine lives. The closure date for each of our active operating mine sites was determined based on the exhaustion date of the remaining iron ore reserves. The closure date and expected timing of the capital requirements to meet our obligations for our indefinitely idled or closed mines, is determined based on the unique circumstances of each property. For indefinitely idled or closed mines, the accretion of the liability is recognized over the anticipated timing of remediation. The amortization of the related asset and accretion of the liability is recognized over the estimated mine lives for our active operations.
The following represents a roll forward of our asset retirement obligation liability for the years ended:
For the year ended DecemberÌý31, 2017, the revision of estimated cash flows relates primarily to updates to our estimates resulting from our three-year in-depth review of our closure obligations for each of our U.S. mines. The primary driver of the decrease in estimated cash flows was the Empire mine, as the mine closure obligation was reduced $26.2 million as a result of the refinement of the cash flows required for reclamation, remediation and structural removal. Prior estimates were based on RS Means (a common costing methodology used in the construction and demolition industry) average costing data while the current estimate was compiled using a more detailed cost build-up approach.
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