Arsenic emissions | Horn foundry can reach 20 ng/m⁠3

However, “the company’s proposals are found in the action plan submitted by the foundry in February 2022 and are not in the request to renew the ministerial authority”, the Ministry of Environment and the Fight against Climate Change (MELCC) noted on Thursday.

Transmitted to Horn Foundry Press The document in question, however, does not mention a threshold of 60 ng/m³ ; This invokes a “potential concentration range” of arsenic between 20 and 64 ng/m³.

The document explains that this large difference is due to several factors: the accuracy of the atmospheric dispersion model of “plus or minus 50%”, the actual performance of the proposed solutions, the correlations between the different solutions and the “variation” of winds, which affect the measured concentrations in the air.

Calculations have been refined since the plan was drawn up, and Horn Foundry has sent a revised lower proposal to the government, but the company said it would not disclose it publicly at this time. Press Alexis Segal, a company spokesperson.

The Environment Minister’s office, Benoît Charette, argued Thursday for a 60 ng/m limit for the fight against climate change.³ “Stated as an average during work meetings with the foundry”.

Reductions… by 2027

Horn Foundry said in its action plan that its emissions reductions could materialize “by 2027,” the time to put the proposed solutions in place.

This schedule corresponds to the schedule deadline of its next ministerial authority, which should theoretically cover the period from 2022 to 2027 – this document, which makes it possible to reject the ban on pollution. Environmental Quality ActFormerly known as “Certificate of Decontamination”.

In addition to reducing arsenic emissions, the company’s action plan also outlines an expected reduction in sulfur dioxide (SO)₂), which can reach 40% and total dust emissions, up to 10%.

However, it does not propose a specific limit for other heavy metals emitted by the smelter such as mercury, nickel, lead, antimony, chromium, cadmium or beryllium.

The foundry decontamination certificate currently in force does not impose any specific limit for metals other than arsenic.

Nine solutions

The Horn smelter’s operational plan is a requirement of the company’s existing remediation certificate, the company said. Press MELCC spokesperson Sophie Gauthier.

It outlines nine solutions proposed by the smelter to reduce the concentrations of pollutants it produces, representing investments totaling $500 million.

For the most part, the PHENIX project has great potential to reduce arsenic emissions; This new process, which reduces the number of steps required for copper transformation, can reduce its own emissions by 10 to 15%.

The ongoing development of the “transition zone” between the foundry and the first residences in the Notre-Dame district will result in a 5 to 10% reduction in arsenic concentrations in the air.

The company’s acquisition of these residences allows it to remove the “legal” air sampling station from its facilities by moving it to a new boundary of its property.

The move creates a methodological problem, argues Philippe Biuzzi, a lawyer from the Quebec Center for Environmental Law.

“You can no longer compare data taken at point A to data taken at point B,” he explained.

Other proposals the company has made to reduce its emissions include increasing indoor storage of the concentrates it smelts, “reducing airborne dust entrainment”, paving traffic lanes and concentrating the unloading area, improving existing dust collectors and capturing and treating them. Air from some roof vents.