Environmental Compliance Monitoring
Output Monitoring
Alcan B.C.’s multi-media environmental permit (see Pollution Prevention Planning) requires it to report continually on several key parameters. Brief context relating to each of these parameters is provided below. Click on the name of the parameter to see current results and relevant permit limits. Further context – with respect to recent performance and improvement initiatives – is available in Alcan B.C.’s annual performance report.
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Permit Section
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Parameter
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Description
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3.1 B Lagoon and
3.2 D Lagoon *
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Dissolved fluoride originates mainly from the leaching of an on-site landfill, as well as from raw-material losses and fallout from uncaptured fluoride emissions. (The landfill is no longer used, and ongoing storm water diversion work will reduce leaching from it.)
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Dissolved aluminum originates when alumina comes into contact with precipitation, and also through uncaptured “scrubbed alumina” in emissions (alumina used in a process to control fluoride emissions).
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Both dissolved fluoride and dissolved aluminum can be toxic to marine life at high enough levels.
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4.1 Potline Secondary Emissions
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Materials and process deficiencies (anode cracking and anode effects) result in some gaseous fluoride bypassing collection systems. Fluoride emissions can impact vegetation health.
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These air-borne solids are composed mainly of alumina, and the relevant contributing factors closely parallel those for gaseous fluoride.
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PAHs are a large family of chemical compounds, and originate in emissions mainly as a byproduct of anode manufacturing and consumption.
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4.2 SO2 Emissions
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S02 originates from the coke (a byproduct of petroleum refining) used to manufacture anodes, and is released both during coke calcining and as anodes are consumed during aluminum production.
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4.3.3 Casting
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Chlorine is used during casting to ensure the purity of alloys. Consumption is monitored given the potential impacts of chlorine gas on vegetation in the immediately surrounding area. (A replacement for chlorine gas is currently under assessment.)
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* The diversion of D-Lagoon to B-Lagoon was completed in March, 2002, and the outfall is now used only in the event of overflow conditions. Reporting specific to D-Lagoon was discontinued at that point.
Impact Monitoring
In addition to meeting permit requirements to monitor specific outputs within its emissions and effluents, Alcan B.C. engages in various monitoring initiatives designed to assess any potential impacts of its activities on the surrounding environment.
Since 1970, Alcan B.C. has commissioned broad-scale annual sampling of hemlock in the Kitimat Valley, which is analyzed for fluoride and sulphur content. A qualitative assessment of the findings is commissioned every other year, with the most recent one concluding that vegetation conditions in the area are generally healthy and improving.
Alcan B.C. was also a partner in a major recent study of the impact of PAH on fish in Douglas Channel. This study confirmed that the primary contributing factors to PAHs have been eliminated at the smelter, and that impacts on marine organisms have generally been lower than expected.
Permit Amendments
Alcan has requested formal amendments to its P2 multi-media environmental permit, to reflect operational changes since the permit was issued and various minor amendments already informally agreed to by the province.
Two major requested amendments are:
- increase in the maximum daily discharge from the B-Lagoon – this reflects the fact that there is one point of discharge rather than two and will not affect the total discharge; and
- authorization for use of up of 40 kg/year of sulphur hexafluoride (SF6) in the casting process.
Various minor requested amendments relate to administrative and technical matters. The amendment requests are fully outlined in an application (632KB pdf) submitted to the B.C. government.