RECLAMATION

Reclamation and mine closure costs are based principally on legal and regulatory requirements. Management estimates costs associated with reclamation of mining properties. On an ongoing basis, management evaluates its estimates and assumptions, and future expenditures could differ from current estimates.

Changes to the Company’s asset retirement obligations for operating sites are as follows:



	Year ended December 31,
In thousands	2017			2016
Asset retirement obligation - Beginning	$	86,754		$	71,763
Accretion	8,769			7,030
Additions and changes in estimates	25,370			9,389
Settlements	(2,094		)	(1,428		)
Asset retirement obligation - Ending	$	118,799		$	86,754

The Company has accrued $2.0 million and $1.9 million at December 31, 2017 and December 31, 2016, respectively, for reclamation liabilities related to former mining activities, which are included in Reclamation.

The Company increased the reclamation liability at Palmarejo by $17.1 million due to the inclusion of the waste rock facility closure plan and tailings facility expansion and at Rochester by $1.2 million at December 31, 2017 due to leach pad expansion. The Company also recorded a $7.1 million reclamation liability in conjunction with the Silvertip acquisition.