7. Property, Plant and Equipment
| 20071 | ||||||
| Cost | Accumulated Depreciation and Amortization |
Net Book Value |
||||
| Land and improvements | $ | 248.9 | $ | 53.9 | $ | 195.0 |
| Buildings and improvements | 647.9 | 220.5 | 427.4 | |||
| Machinery and equipment | 5,074.5 | 1,937.3 | 3,137.2 | |||
| Mine development costs | 196.8 | 69.0 | 127.8 | |||
| $ | 6,168.1 | $ | 2,280.7 | $ | 3,887.4 | |
| 2006 | ||||||
| Cost | Accumulated Depreciation and Amortization |
Net Book Value |
||||
| Land and improvements | $ | 233.3 | $ | 51.9 | $ | 181.4 |
| Buildings and improvements | 547.9 | 206.4 | 341.5 | |||
| Machinery and equipment | 4,618.0 | 1,750.4 | 2,867.6 | |||
| Mine development costs | 200.4 | 65.1 | 135.3 | |||
| $ | 5,599.6 | $ | 2,073.8 | $ | 3,525.8 | |
Depreciation and amortization of property, plant and equipment included in cost of goods sold and in selling and administrative expenses was $279.8 (2006 – $226.3; 2005 – $227.4). The net carrying amount of property, plant and equipment not being amortized at December 31, 2007 because it was under construction or development was $608.8 (2006 – $381.6).
During the year, the company recorded an impairment charge of $NIL (2006 – $6.3; 2005 – $NIL) relating to certain assets. As at December 31, 2007, the company determined that there were no triggering events requiring impairment analysis. Interest capitalized to property, plant and equipment during the year was $21.8 (2006 – $19.1; 2005 – $5.7).
The opening balance of pre-stripping costs at January 1, 2007 was $28.5, additions during 2007 were $24.8 and amortization was $19.9, for a balance at December 31, 2007 of $33.4.
Acquiring or constructing property, plant and equipment by incurring a liability does not result in a cash outflow for the company until the liability is paid. In the period the related liability is incurred, the change in operating accounts payable on the Consolidated Statements of Cash Flow is typically reduced by such amount. In the period the liability is paid, the amount is reflected as a cash outflow for investing activities. The applicable net change in operating accounts payable that was reclassified from (to) investing activities on the Consolidated Statements of Cash Flow in 2007 was $59.8 (2006 – $(2.6), 2005 – $26.0).