We are minimizing our environmental impacts in our operations through a proactive reclamation program. We clean up affected areas during the life of our projects, and reclaim disturbed areas after our work has been completed.
In 2011, Canadian Natural abandoned the greatest number of wells and received the most reclamation certificates of any operator in Western Canada from our regulator. We accounted for 39 per cent of all wells abandoned and 24 per cent of all reclamation certificates received in Western Canada.
In 2012, 622 inactive wells were abandoned and more than 3,500 wells have been abandoned since 2009. We submitted 374 reclamation certificates in 2012. There were 590 hectares of land reclamation certified in 2012 which is equivalent to 880 soccer fields or 1,774 hectares that were certified between 2009 and 2012.
Since the beginning of the Horizon project in 2008, we have reclaimed 160 hectares of the 5,500 hectares of land we have disturbed through our mining operations.We also reduced our footprint in the oil sands region through our Oil Sands Exploration (OSE) lease reclamation program, which evaluates the potential oil sands resource base on our leased lands. Through the OSE program we have certified 342 sites in 2012. Since 2009 we have submitted over 100 sites for reclamation closure for approximately 537 hectares.
Important steps in our ongoing reclamation work at Horizon are reforestation and soil salvage programs. Since the beginning of Horizon reclamation in 2008, we have reclaimed 160 hectares of the 5,500 hectares of land we have disturbed through our mining operations. We are also monitoring the progress of 120,000 spruce seedlings planted throughout these years.