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ASSET RETIREMENT OBLIGATIONS (Tables)
 6 Months Ended
Jun. 30, 2019
ASSET RETIREMENT OBLIGATION  
Summary of Asset Retirement Obligation

The following table summarizes the changes in the reserve for future restoration and reclamation costs on the balance sheet:

 

 

 

 

 

 

 

 

 

    

June 30, 

    

December 31, 

(thousands of dollars)

 

2019

 

2018

Balance, beginning of period

 

$

6,203

 

$

5,731

Liabilities settled

 

 

(320)

 

 

(521)

Liabilities disposed

 

 

(13)

 

 

 —

Accretion expense

 

 

156

 

 

993

Balance, end of period

 

 

6,026

 

 

6,203

Less: Current portion

 

 

(881)

 

 

(708)

Non-current portion

 

$

5,145

 

$

5,495