This excerpt taken from the SU 6-K filed Jan 28, 2005.
2. Asset Retirement Obligations
On January 1, 2004, the company retroactively adopted the new Canadian accounting standard related to Asset Retirement Obligations (ARO). Under the new standard a liability is recognized for the future retirement obligations associated with the companys property, plant and equipment. The fair value of the ARO is recorded on a discounted basis. This amount is capitalized as part of the cost of the related asset and amortized to expense over its useful life. The liability accretes until the company settles the obligation. The 2003 and estimated 2004 impact of adopting this standard compared to the previous standard is: