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Provisions and contingent liabilities | 12 Months Ended
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Dec. 31, 2018
Disclosure of provisions [Line Items] |
Disclosure of provisions [text block] |
| 15. | Provisions and contingent liabilities
| (a) | This caption is made up as follows:
|  | 2018 |  |  | 2017 |
|  | US$(000) |  |  | US$(000) |
Provision for closure of mining units and exploration projects (b) |  |  | 225,877 |  |  |  | 200,183 |
Provision for bonus to employees and officers |  |  | 18,620 |  |  |  | 2,331 |
Provision for obligations with communities (c) |  |  | 5,878 |  |  |  | 19,376 |
Provision for safety contingencies |  |  | 4,877 |  |  |  | 3,898 |
Provision for labor contingencies |  |  | 4,042 |  |  |  | 2,963 |
Provision for environmental liabilities |  |  | 3,768 |  |  |  | 5,534 |
Board of Directors’ participation |  |  | 2,108 |  |  |  | 1,273 |
Workers’ profit sharing payable |  |  | 1,772 |  |  |  | 3,569 |
Provision for environmental contingencies |  |  | 234 |  |  |  | 1,233 |
Other provisions |  |  | 758 |  |  |  | 1,364 |
|  |  | 267,934 |  |  |  | 241,724 |
Classification by maturity: |  |  |  |  |  |  |  |
Current portion |  |  | 68,172 |  |  |  | 76,847 |
Non-current portion |  |  | 199,762 |  |  |  | 164,877 |
|  |  | 267,934 |  |  |  | 241,724 |
| (b) | Provision for closure of mining units and exploration projects -
The table below presents the movement of the provision for closure of mining units and exploration projects:
|  | 2018 |  |  | 2017 |
|  | US$(000) |  |  | US$(000) |
Beginning balance |  |  | 200,183 |  |  |  | 206,462 |
Changes (additions and deductions) in estimates |  |  |  |  |  |  |  |
Continuing mining units, note 11(a) |  |  | 42,874 |  |  |  | 10,594 |
Discontinued mining units, note 1(e) |  |  | 6,013 |  |  |  | 12,701 |
Exploration projects, note 26(a) |  |  | (2,433 | ) |  |  | 891 |
Accretion expense: |  |  |  |  |  |  |  |
Continuing mining units, note 27(a) |  |  | 4,911 |  |  |  | 4,360 |
Exploration projects, note 27(a) |  |  | 71 |  |  |  | 22 |
Discontinued mining units, note 1(e) |  |  | 54 |  |  |  | 215 |
Disbursements |  |  | (25,796 | ) |  |  | (23,292 | )
Sale of mining units, note 1(e) |  |  | - |  |  |  | (11,770 | )
Final balance |  |  | 225,877 |  |  |  | 200,183 |
Classification by maturity: |  |  |  |  |  |  |  |
Current portion |  |  | 30,524 |  |  |  | 39,826 |
Non-current portion |  |  | 195,353 |  |  |  | 160,357 |
|  |  | 225,877 |  |  |  | 200,183 |
The provision for closure of mining units and exploration projects represents the present value of the closure costs that are expected to be incurred between the years 2019 and 2041. These estimates are based on studies prepared by independent advisers that meet the environmental regulations in effect. The provision for closure of mining units and exploration projects corresponds mostly to activities that must be carried out for restoring the mining units and areas affected by operation and production activities. The principal works to be performed correspond to earthworks, re-vegetation efforts and dismantling of the plants. Closure budgets are reviewed regularly to take into account any significant change in the studies conducted. Nevertheless, the closure costs of mining units will depend on the market prices for the closure works required, which would reflect future economic conditions. Also, the time when the disbursements will be made depends on the useful life of the mine, which will be based on future metals prices. As of December 31, 2018, the future value of the provision for closure of mining units and exploration projects was US$280.3 million, which has been discounted using annual risk-free rates from minimums of 1.98 and 4.74 to a maximum of 4.74 percent in periods of 1 to 23 years. The Group believes that this liability is sufficient to meet the current environmental protection laws approved by the Ministry of Energy and Mines. As of December 31, 2018, the Group has constituted letters of credit in favor of the Ministry of Energy and Mines for US$119.7 million (US$109.6 million as of December 31, 2017) to secure current mine closure plans of its mining units and exploration projects up to date.
| (c) | The provisions for obligations with the communities decrease mainly due to the negotiations made by the Company in its operating units, which begin and were recorded in 2017.
Minera Yanacocha SRL and subsidiary [Member] |
Disclosure of provisions [Line Items] |
Disclosure of provisions [text block] |
| 12. | Provisions
| (a) | This caption is made up as follows:
|  | 2018 |  |  | 2017 |
|  | US$(000) |  |  | US$(000) |
Provision for closure of mining units and exploration projects (b) |  |  | 1,294,464 |  |  |  | 1,234,731 |
Provision of social responsibility (c) |  |  | 18,010 |  |  |  | 21,689 |
Accrual of operating costs (d) |  |  | 11,442 |  |  |  | 15,064 |
Workers’ profit sharing payable (e) |  |  | 3,920 |  |  |  | 1,733 |
Accrual of capital expenditure |  |  | 3,682 |  |  |  | 1,840 |
Other provisions |  |  | 2,785 |  |  |  | 1,403 |
|  |  | 1,334,303 |  |  |  | 1,276,460 |
Classification by maturity: |  |  |  |  |  |  |  |
Current portion |  |  | 41,154 |  |  |  | 39,495 |
Non-current portion |  |  | 1,293,149 |  |  |  | 1,236,965 |
|  |  | 1,334,303 |  |  |  | 1,276,460 |
| (b) | Provision for closure of mining units and explorations projects -
The Company's mining and exploration activities are subject to various laws and regulations governing the protection of the environment. These laws and regulations are continually changing and are generally becoming more restrictive. The Company conducts its operations so as to protect the public health and environment and believes its operations are in compliance with all applicable laws and regulations in all material respects. The Company has made, and expects to make in the future, expenditures to comply with such laws and regulations, but cannot predict the amount of such future expenditures. Estimated future reclamation costs are based principally on legal and regulatory requirements. The liability for reclamation or the Asset retirement obligation (“ARO”) comprises activities to be carried out by the Company in the restoration of mines and adjacent areas in the completion stage of the gold extraction process. Such activities include the restoration of mining locations, water treatment plant operations, as well as reforestation and land treatments. The movement of the ARO for 2018, 2017 and 2016 is broken down as follows:
|  | 2018 |  |  | 2017 |  |  | 2016 |
|  | US$(000) |  |  | US$(000) |  |  | US$(000) |
Opening balance |  |  | 1,234,731 |  |  |  | 1,012,888 |  |  |  | 578,959 |
Additional provisions |  |  | 43,560 |  |  |  | 221,450 |  |  |  | 430,292 |
Payments |  |  | (19,842 | ) |  |  | (21,376 | ) |  |  | (10,467 | )
Unwinding of discount, note 20 |  |  | 36,015 |  |  |  | 21,769 |  |  |  | 14,104 |
Final balance |  |  | 1,294,464 |  |  |  | 1,234,731 |  |  |  | 1,012,888 |
Classification by maturity |  |  |  |  |  |  |  |  |  |  |  |
Current portion |  |  | 19,325 |  |  |  | 19,455 |  |  |  | 15,636 |
Non-current portion |  |  | 1,275,139 |  |  |  | 1,215,276 |  |  |  | 997,252 |
|  |  | 1,294,464 |  |  |  | 1,234,731 |  |  |  | 1,012,888 |
There were minimal changes to the updated closure plan in 2017 prior to submitting to Peruvian regulators in September 2017. The regulators completed their review and approved the updated closure plan in November 2017. As of December 31, 2018, the Company recorded an increase to the reclamation liability of US$44 million (US$206 million in 2017). The increase to the reclamation obligation resulted in an increase to the recorded asset retirement cost asset of US$27.2 million (US$97 million in 2017) related to the producing portions of the mine and a non-cash charge to reclamation expense for the year ended December 31, 2018 of US$16.3 million (US$109 million as December 31, 2017) related to the areas of Carachugo, Yanacocha, Maqui Maqui and Cerro Negro operations no longer in production. The increase of the 2018 reclamation obligation is mainly due to new disturbance from the Quecher Main development project and changes in the labor cost estimate. The increase to the 2017 reclamation obligation is mainly due to a decrease in the market-based discount rate compared to the prior year. The discount rates used in the calculation of the provision as December 31, 2018 and December 31, 2017 were between 0.3% and 2.9%.
| (c) | Provision of social responsibility -
The provision of social responsibility relates to community commitments to develop projects near the mine site, including training and support for other activities such as building infrastructure and donations.
| (d) | Accrual of operating cost -
The accrual of operating cost relates to the provisional valuation of services received by the Company as part of its operations that were pending to be invoiced such as power, maintenance, contractors and others.
| (e) | Workers' profit sharing -
In accordance with Peruvian legislation, the Company maintains an employee profit sharing plan equal to 8% of annual taxable income. Distributions to employees under the plan are based 50% on the number of days that each employee worked during the preceding year and 50% on proportionate annual salary levels.
Sociedad Minera Cerro Verde S.A.A. [Member] |
Disclosure of provisions [Line Items] |
Disclosure of provisions [text block] |
| 11. | Provisions
This item is made up as follows:
|  | December 31, 2018 |  |  | December 31, 2017 |
|  | US$(000) |  |  | US$(000) |
Current: |  |  |  |  |  |  |  |
Provisions related to services and freight not invoiced |  |  | 11,823 |  |  |  | 14,513 |
Provision for social commitments (a) |  |  | 1,815 |  |  |  | 2,767 |
Provision for legal contingencies |  |  | 1,719 |  |  |  | 1,232 |
Provision for remediation and mine closure (b) |  |  | - |  |  |  | 690 |
Total current |  |  | 15,357 |  |  |  | 19,202 |
Non–current: |  |  |  |  |  |  |  |
Provision for royalties and mining tax (c) |  |  | 191,299 |  |  |  | 133,376 |
Provision for remediation and mine closure (b) |  |  | 131,888 |  |  |  | 156,169 |
Other long-term liabilities (d) |  |  | 11,033 |  |  |  | 15,889 |
Provision for social commitments (a) |  |  | 8,111 |  |  |  | 8,229 |
Total non-current |  |  | 342,331 |  |  |  | 313,663 |
| (a) | The provision for social commitments as of December 31, 2018, is associated with an irrigation project in La Joya (US$4.5 million) and repaving Alata-Congata Road (US$5.4 million).
| (b) | The Company’s mineral exploitation activities are subject to environmental protection standards. In order to comply with these standards, the Company has obtained the approval for the Environment Adequacy Program (PAMA) and for the Environmental Impact Studies (EIA), required for the operation of Cerro Verde’s production unit.
On October 14, 2003, Law N° 28090 was enacted, which regulates the commitments and procedures that entities involved in mining activities must follow in order to prepare, file and implement a mine site closing plan, as well as the respective environmental guarantees that assure compliance with the plan in accordance with protection, conservation and restoration of the environment. On August 15, 2005, the regulations regarding this law were approved. During 2006, in compliance with the mentioned law, the Company completed the closure plans for its mine site, and presented it to the Ministry of Energy and Mines. The closure plans for its mine site was approved by Resolution No 302-2009 MEM-AAM and its modifications were approved by Resolution No 207-2012 MEM-AAM, Resolution No 186-2014 MEM-DGAAM and its last modification, Resolution No 032-2018 MEM-DGAAM. As of December 31, 2018, pursuant to legal requirements, the Company has issued a letter of credit to the Ministry of Energy and Mines totaling US$42.7 million to secure mine closure plans. The estimate of remediation and mine closure costs is based on studies prepared by independent consultants and based on current environmental regulations. This provision corresponds mainly to the activities to be performed in order to restore the areas affected by mining activities. The main tasks to be performed include ground removal, soil recovery, and dismantling of plant and equipment. The table below presents the changes in the provision for remediation and mine closure:
|  | 2018 |  |  | 2017 |  |  | 2016 |
|  | US$(000) |  |  | US$(000) |  |  | US$(000) |
Beginning balance |  |  | 156,859 |  |  |  | 153,313 |  |  |  | 161,270 |
Accretion expense |  |  | 4,322 |  |  |  | 4,595 |  |  |  | 4,391 |
Changes in estimates, Note 7 |  |  | (32,017 | ) |  |  | (3,710 | ) |  |  | (16,091 | )
Additions, Note 7 |  |  | 2,724 |  |  |  | 2,661 |  |  |  | 3,743 |
Final balance |  |  | 131,888 |  |  |  | 156,859 |  |  |  | 153,313 |
As of December 31, 2018, the Company’s provision for remediation and mine closure was US$131.9 million (reflecting the future value of the provision for remediation and mine closure of US$374.4 million, discounted using an annual risk-free rate of 2.99%). As of December 31, 2017, the Company’s provision for remediation and mine closure was US$156.9 million (reflecting the future value of the provision for remediation and mine closure of US$374.4 million, discounted using an annual risk-free rate of 2.73%). As of December 31, 2016, the Company’s provision for remediation and mine closure was US $153.3 million (reflecting the future value of the provision for remediation and mine closure of US $368.8 million, discounted using an annual risk-free rate of 2.97%) The Company considers this liability sufficient to meet the current environmental protection laws approved by the Ministry of Energy and Mines (MEM). As of December 31, 2018, changes in estimates (US$32.0 million) are mainly due to changes in the escalation ratio.
| (c) | As of December 31, 2018, represents the non-current portion of net assets tax (ITAN) for the years 2010, 2011 and 2013 of US$19.6 million and interest and penalties of (i) disputed mining royalties for the period October 2011 through December 2013 of US$70.0 million, (ii) special mining tax for the year 2011 through the year 2013 of US$50.8 million, (iii) income tax related to disputed mining royalties for the year 2010 of US$41.1 million and (iv) ITAN for the years 2010, 2011 and 2013 of US$9.8 million.
As of December 31, 2017, represents the non-current portion of disputed mining royalties for the period January 2009 through September 2011 of US$113.8 million, ITAN for the years 2010, 2011 and 2013 of US$19.6 million.
| (d) | Primarily represents SUNAT assessments for prior years related to income and non-income tax contingencies in which the Company expects to obtain an unfavorable result of US$6.2 million as of December 31, 2018 (US$11.4 million as of December 31, 2017).

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