Particulate emissions at the potrooms increased, most notably at the Deschambault Smelter, where more frequent interventions (involving opening the pot hoods) were required due to coal dust issues in the pots.
The results reported at the roof vents comprise the emissions measures taken during a three-part sampling. They are considered fairly stable, except in Bécancour, where the test was conducted at a fume treatment centre at which one of the filtration units needed new dry bags. A leak, which was fixed between two samplings, explains the significant increase in 2012.
Particulate emissions – Söderberg potrooms
Particulate emissions at the Söderberg potrooms rose significantly in 2012 due to operational issues related primarily to the poor quality of the raw materials received at the beginning of the year.
The recorded value, however, meets the target established in the performance agreement with the Ministère du Développement durable, de l’Environnement, de la Faune et des Parcs, which became regulation in 2011.