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8.2 Environmental Effects Assessment

In Newfoundland, acceptable air quality is determined against the criteria set out in Schedule A of the Newfoundland Air Pollution Control Regulations. This Schedule provides the limits for various contaminants that should not be exceeded in order to maintain satisfactory air quality (Table 8.1). In addition to these standards, the Canadian Environmental Protection Act (CEPA) contains Ambient Air Quality Objectives. These objectives have been set at three levels: tolerable, acceptable and desirable, they range from protection of basic human health (tolerable) to "providing a long term goal for air quality that provides a basis for an anti-degradation policy for unpolluted parts of the country and for the continuing development of control technology" (desirable) (Table 8.1).

The Project will affect the microclimate in areas of direct physical disturbance. Project-related CO2 emissions may contribute to climate changes in all phases, although these emissions are relatively small.

The principal air emissions that may affect air quality during the construction phase will be TSP, resulting from construction activities. There will also be power generation and vehicular and equipment emissions during this phase, which will have only a small contribution to TSP, NOx, and SO2.


During both open pit and underground operations, there will be a number of sources of emissions that may affect air quality. The principal sources of TSP are open pit operation, the rock crusher, vehicular movement, wind blown dust from non-mineralized mine rock and overburden storage and, potentially, fugitive dust during vessel loading. The principal sources of SO2 and NOx during this phase are the electric power generators and incinerator, with some contribution from vehicular and equipment emissions, particularly NOx from heavy equipment.

Haulage from the mine and mill site to the port will cause particulate emissions from road dust.

During decommissioning, emissions may include TSP, NOx, and SO2, but to a lesser extent than is expected to occur in construction and operation. These effects will be dependent upon meteorological conditions, which will determine how contaminants are dispersed in the surrounding airshed. Potential environmental effects are summarized in Table 8.10. The environmental effects synthesis is in Appendix 8A.

Table 8.10 Potential Environmental Effects


Potential Environmental Effects
Project Phase
Activities
Microclimate change
All
 physical disturbance
climate change
All
 CO2 emissions from power generation, vehicles, and equipment
air quality (TSP, CO, NOx, SO2) change
All
 construction, material handling, power generation, vehicles, and equipment
Visibility
All
 vehicle movement, open pit mining


8.2.1 Microclimate Change

The Project will affect only the microclimate in those areas of direct physical disturbance, such as the open pit, the mill site and other areas cleared during the Project. In the cleared areas, there may be changes in temperature and relative humidity due to changes in the surface energy and water balances. These changes will be confined within the immediate area of the disturbance, as in, for example, the increased heating of the air along and adjacent to a dry road. The use of water to control dust on the roads will cause a small increase in relative humidity along the road right-of-way (cleared area), but it would be imperceptible only a few metres away. Upon decommissioning, a reclamation program will be undertaken.


8.2.2 Climate Change

Climate change is currently a topic of international discussion. The international community is examining the commitments by all countries to reduce CO2, and other greenhouse gas emissions, and this could have implications for emission controls in the future. There are currently no established emission or ambient air quality standards for CO2. and this is likely to change. Nevertheless, in the absence of regulation, Canada's emission inventories can be used to establish the relative contribution of anticipated emissions from the Project. In 1994, Canada's contribution to the global emissions of CO2 wais approximately 450 million tonnes (Mt) per year, 2 percent of the estimated global total. Newfoundland's contribution is about 17 Mt/y, or 4 percent of the Canadian total. The maximum annual Project contribution (when underground operation is at maximum production) is 0.205 Mt/y (JWEL 1996).

Thus, the emissions of CO2 from the Project are small relative to the Canadian emissions totals. The use of waste heat where possiblein different process areas and space heating will reduce the amount of fossil fuel consumed by the Project and help to reduce the emissions of CO2. The emissions of CO2 from the Project will cause no immediate or discernible environmental effect on climate change.


8.2.3 Air Quality

An analysis of source contributions (JWEL 1997b) showed that the diesel generators and heavy equipment will be the greatest contributors to gaseous contaminants. Transportation and material handling will be the major contributors to particulate emissions from the Project.

The air quality within the open pit, the underground mine, and the processing areas is subject to the regulations governing occupational health and safety.

Open pit activities that may affect air quality include diesel-fuelled vehicle emissions, fugitive dust caused by vehicle traffic, ore transferring operations, and blasting. The contaminants of concern are TSP and NO2, which arise from diesel fuel use, truck movement, and pit development activities.


8.2.3.1 Modelling

The results of the dispersion modelling study have been mapped for the Assessment Area (Appendix 8B). The main results of the modelling may be summarized as follows:
  • the Newfoundland Air Quality Standards for point of impingement (Schedule B) are met for all contaminants and for all time periods at and beyond the VBNC Claim Block boundary;


  • the air quality outside of the VBNC Claim Block will meet the federal desirable air quality criterion; and


  • within the VBNC Claim Block, the air quality will remain within the federal desirable air quality criteria and the Newfoundland criteria except for short-term (1-hour) particulate matter. During open pit mining, particulate matter may exceed 80 µg/m3 within 2-3 km of the open pit.


    • The maps illustrate the strong effects of topography on the air quality within the VBNC Claim Block. Maximum levels are associated with elevated terrain. The concentrations are well within occupational health and safety limits, and these maximum levels are infrequent and confined to the high terrain where human or animal presence is infrequent. Therefore, the air emissions from the Project within the VBNC Claim Block will be very low except in the immediate vicinity of physical disturbances or sources of emissions.


    8.2.3.2 Sources of Air Emissions

    Sources of air emissions were identified for three scenarios representative situations of maximum air emissions during construction and operation. Scenario One models maximum emissions during construction, which could occur at anytime in the year. Scenario Two models the maximum emissions that could occur when the open pit is in production and construction is proceeding on the underground mine facilities. Scenario Three models maximum emissions when the underground mine is in year-round production at peak capacity and the open pit mine is no longer in operation.

    The rates of emissions for each identified source for each scenario were estimated. For much of the activity, the information was obtained from the US EPA (1993, 1995). For the diesel generators, a manufacturer provided detailed emission information and exhaust stack parameters for the units proposed for the Project.

    The combinations of sources for each scenario and the related emission rates are indicated in Tables 8.11 and 8.12. Emission rates vary for some sources based on levels of Project activity. The detailed derivation of the emissions from these sources is provided in the Air Quality Modelling Report (JWEL 1997b).


    Table 8.11 Source and Equipment Air Emissions During Construction (Scenario One)

    Sources TSP (g/s) SO2 (g/s) NO2 (g/s) CO (g/s)
    Plant Site Generator 0.380 0.780 0.21 0.680
    Underground Shaft Generator 0.230 0.470 0.13 0.410
    Incinerator 0.035 1.25E-05 4.5E-6 5.00E-05
    Boilers 5.000 1.08 0.157 0.462
    Road Grading and Construction Negligible Negligible Negligible Negligible
    Open Pit 34.822 0.692 2.96 1.00
    Crusher Plant ( includes Conveyors) 0.110      
    Non-Mineralized Mine Rock Storage 1.169      
    North Overburden Storage 0.851      
    South Overburden Storage 0.851      


    Table 8.12 Source and Equipment Air Emissions During Operations (Scenario Two and Scenario Three)

    Sources TSP (g/s) SO2 (g/s) NO2 (g/s) CO (g/s)
    Scenario Two: Open Pit Mining/ underground construction        
    Plant Site Generator 2.260 4.680 1.26 4.080
    Underground Shaft Generator 0.750 1.560 0.42 1.360
    Incinerator 0.035 1.25E-05 4.5E-6 5.00E-05
    Boilers 5.000 1.08 0.157 0.462
    Open Pit (blasting addressed separately) 35.54 0.900 3.277 1.132
    Crusher Plant ( includes Conveyors) 0.145      
    Non-Mineralized Mine Rock Storage 1.169      
    North Overburden Storage 0.851      
    South Overburden Storage 0.851      
    Concentrate Haulage (empty) 8.824 0.137 0.442 0.430
    Concentrate Haulage (full) 16.536 0.274 0.844 0.860
    Shipping Loadout 0.090      
    Underground Mine Vent 0.150      
    Scenario Three: Underground Mining
    Plant Site Generatora 4.900 10.140 2.72 8.840
    Incinerator 0.035 1.25E-05 4.5E-6 5.00E-05
    Boilers 5.000 1.08 0.157 0.462
    Crusher Plant ( includes Conveyors) 0.212      
    Concentrate Haulage (empty) 8.824 0.137 0.442 0.430
    Concentrate Haulage (full) 16.536 0.274 0.844 0.860
    Shipping Loadout 0.090      
    Underground Mine Vent 0.15      
    a Although the size of the plant generator has not been determined, this value is an assumed source for the underground mine.

    The modelling results for the three scenarios are mapped in Appendix 8B. The only predicted exceedance is for the one-hour maximum TSP for Scenario Two (open pit mining concurrent with underground construction). These predicted 1-hour maximums are associated with calm wind events, which occur relatively infrequently according to meteorological records. The modelling indicates the provincial 1-hour point-of-impingement standard is exceeded within about 2-3 km of the open pit mine, which is within the VBNC Claim Block boundary.

    "Animals that eat vegetation, like caribou that eat moss, that must be the reason why animals is not healthy because they eat what fall from the industry." Mary Mae Rich, Panel scoping meeting in Sheshatshiu, May 15, 1997.

    Water will be applied on the haul roads in the open pit on a routine basis. A more frequent water application to unpaved surfaces will occur during times of extremely dry conditions, when traffic-generated dust is high. A dust reducing agent such as magnesium chloride may be employed to suppress dust from vehicle movement along unpaved surfaces. Because the area of maximum particulate emission is also the working area of the mine, the mitigation of the air pollution will be essential to the maintenance of the working environment. This improves the potential success of the mitigation program so that air quality criteria are attained.


    8.2.4 Visibility

    The only potential effect on visibility will be from localized particulate matter generated by the open pit mining activities, the thermal plume from the heated exhaust of the generators, and individual vehicles and equipment. The extent of the effect will vary with meteorological conditions and the amount of mitigation. The maintenance of visibility and dust control in the open pit will ensure that environmental effects outside of the pit are very unlikely. The dust plumes generated by vehicles on the port access road will be very infrequent, short-lived, and localized.


    8.2.5 Accidental Events

    Spills of concentrate, petroleum, hazardous materials, as well as on-site fires and forest fires, could result in atmospheric emissions. Spills of concentrate would likely be short-term events where small quantities of concentrate particles would be emitted into the air near the concentrate handling equipment. Spills of petroleum and hazardous materials would be short-term events which could cause the release of petroleum vapours, solvent vapours, and sodium hypochlorite. Forest fires generate smoke consisting mainly of fine particulate matter, including organic material.

    In all cases, the response will be coordinated according to procedures outlined in the Emergency Response Plan, which is described in Chapter 4. The procedures are designed to reduce the quantity of the release and to contain released material so that releases associated with spills would likely be short-term, with only localized environmental effects.


    8.2.6 Cumulative Environmental Effects

    Other activities are ongoing or proposed in the Landscape Region. The air quality effects due to the Project are generally localized and unlikely to result in any cumulative environmental effects on the atmospheric environment.

    Ongoing exploration within and outside of the VBNC Claim Block is likely to continue. The effects of drilling, helicopter transportation, and other minor sources of air emissions are very limited spatially. No detectable cumulative environmental effects are anticipated.

    An anorthosite quarry is currently operated by the Labrador Inuit Development Corporation, approximately 8 km from Nain in Ten Mile Bay, and at least two other quarries are being considered. Dust generated by the quarries is generally limited to within a few hundred metres beyond the quarry limits.

    The Project and all other activities in the area will generate relatively small quantities of greenhouse gases, which will contribute to the cumulative effects on climate. However, these are insufficient to cause any detectable contribution to global climate change to provide any substantial contribution to global climate change.


    8.2.7 Environmental Design, Mitigation and Optimization

    The features incorporated into the Project design (as described in Chapter 4) include:

  • a focus on efficient power generation, which will reduce the contribution of greenhouse gases to the atmosphere and the potential contribution of the Project to anthropogenic climate change;


  • development of a proactive mitigation management plan including routine application of water and dust reducing agents, such as magnesium chloride, to haul roads to reduce dust from vehicle movements;


  • the use of fabric filter dust collectors at strategic locations in the milling process to reduce dust releases to atmosphere;


  • use of scrubbers to remove dust from the off-gas from the rotary kilns used to dry concentrate;


  • closed conveyors and transfer points;


  • appropriatelarge stack heights on generators with individual flues to maintain acceptable dispersion of emitted contaminantsexhaust momentum; and


  • re-vegetation and surface stabilization to reduce wind erosion.



    • 8.3 Residual Environmental Effects

    The definitions for the rating of residual environmental effects on the atmospheric environment are based on the Newfoundland Air Pollution Control Regulations (Schedule B) and the CEPA Ambient Air Quality Objectives(CEPA. As defined under CEPA, the air quality guidelines of tolerable, acceptable and desirable will be used. The maximum tolerable level denotes a concentration beyond which appropriate action is required to protect the health of the general population; it is intended to provide protection against effects on soil, water, vegetation, visibility and human and animal well-being. The maximum desirable level is the long-term goal for air quality.

    A major (significant) residual environmental effect is one which produces long-term or continuous changes to air quality that extend beyond the property boundaries of the VBNC Claim Block (Atmospheric Environment Assessment Area) at levels that reduce air quality from an acceptable level to a tolerable level (as per the federal ambient air quality objectives), as well as exceeding the Newfoundland regulations (Schedule B), and for CO2 (a greenhouse gas), would result in a detectable effect on global climate.

    A moderate (significant) residual environmental effect is one which causes air quality within the VBNC Claim Block (Atmospheric Environment Assessment Area), on a long-term or continuous basis, to exceed the Newfoundland regulations (Schedule B) and where the federal acceptable level is exceeded and for CO2 (a greenhouse gas), would result in a detectable effect on global climate.

    A minor (not significant) residual environmental effect is one which is generally confined to the VBNC Claim Block (Atmospheric Environment Assessment Area), may be of short duration, does not exceed the Newfoundland regulations (Schedule B), and would be predicted not to change the air quality from within the limits of federal standards of acceptable or desirable ranges and for CO2 (a greenhouse gas), would not result in a detectable effect on global climate.

    A negligible (not significant) residual environmental effect is one where the environmental effects are within both the limits of the Newfoundland regulations (Schedule B) and the federal desirable level, and for CO2 (a greenhouse gas), would not result in a detectable effect on global climate.

    The residual environmental effects remaining after the application of mitigation, and including consideration of cumulative environmental effects, are presented in Table 8.13.


    Table 8.13 Summary of Residual Environmental Effects


    Project Phase
    Residual Environmental
    Effect
    Significance
    Likelihooda
     
    Sustainable Use (Capacity) of Renewable Resourcesa
    Construction NOx and TSP above background, release of greenhouse gases contributing to climate change
    minor
    (not significant)
    high n/a
    n/a
    Operation NOx and particulate matter elevated within VBNC Claim Block; SO2 elevated within VBNC Claim Block, release of greenhouse gases contributing to climate change
    minor
    (not significant)
    n/a
    n/a
    Decommissioning localized elevated TSP, release of greenhouse gases contributing to climate change
    negligible
    (not significant)
    high n/a
    n/a
    Post-Decommissioning
    n/a*
    n/a
    high n/a
    n/a
    Accidental Events TSP above background
    negligible
    (not significant)
    high n/a
    n/a
    a likelihood and sustainable use of renewable resources are only defined for environmental effects that are significant (moderate or major) (CEAA: 1994: 84, 187).
    * n/a = not applicable


    8.3.1 Construction

    Although there will be elevated levels of suspended particulate matter during preparation of the open pit, the environmental effect is rated minor (not significant). The construction of access roads within the VBNC Claim Block will result in very localized and short-term TSP emissions which can be controlled by application of water to the road surface.

    There will be some contribution of greenhouse gases, but the result and residual environmental effect on climate change is rated negligible (not significant).


    8.3.2 Operation

    The result of the dispersion modelling indicates that concentrations of SO2, CO, and NO2 will remain within the ambient air standards (NF Regulation 957/96) both outside of and within the VBNC Claim Block. and therefore will not be of concern except in the case of very sensitive receptors. Lichens may be in this category and should be monitored to determine if that is the case

    The predicted hourly concentrations of TSP meets the provincial standards outside of the VBNC Claim Block. Within the VBNC Claim Block, the criteria levels are met (NF Regulation 957/96) except for the predicted maximum 1-hour value. Without mitigation, the criterion might be exceeded up to 4 km from the mine site; however, the application of a proactive mitigation program could reduce the range to the immediate perimeter of the mine site.

    The predicted 24-hour concentrations of TSP and NO2 meet the provincial (NF Regulation 957/96) and federal (CEPA) standards in all cases.

    Local visibility will be reduced by the occurrence of a dust plume behind a vehicle on an unpaved road. Given the infrequency of vehicle movements along the road to the port (one passing every 10 to 15 minutes), the hourly average concentration of TSP is predicted to be within regulatory limits. At the side of the road, however, there will be a visible, short-lived plume. This may in fact provide some warning to wildlife of the approach of the haulage vehicles.

    The visible plume from the open pit mine would likely be confined to a few hundred metres at most (based on observations of other mines), and could be confined to within 100 m of operating equipment.

    In full operation of the mine, the contribution to global greenhouse gas emissions will be 1.2 percent of the current provincial total and 0.046 percent of the Canadian total from fuel combustion. The potential environmental effects on climate are rated negligible (not significant)

    The residual environmental effects of elevated concentrations of particulate matter and NO2 are considered to be minor ( not significant).


    8.3.3 Decommissioning

    There will be small amounts of dust created by infrastructure removal and re-contouring of the site. These episodes will be of short duration and confined to a small area. The residual environmental effect is rated negligible (not significant).

    There are no global climatic change effects. Re-vegetation of the previously disturbed areas will restore the microclimate in these areas.


    8.3.4 Post-Decommissioning

    Provided that the Since re-vegetation and stabilization of surfaces occurs will be carried out during decommissioning, there is not likely to be any extended wind-induced dust generation or microclimatic residual environmental effects at the Project.

    8.3.5 Accidental Events

    A spill of concentrate will generate only short-term and small amounts of concentrate dispersed into the air. The residual environmental effects rating is negligible (not significant).

    A widespread forest fire could produce short-term residual environmental effects on the atmospheric environment and longer-term residual environmental effects on the microclimate of the area. These are rated negligible (not significant).


    8.3.6 Monitoring and Follow-up

    The process for monitoring and follow-up is outlined in Chapter 4.



    8.4 References

    AES (Atmospheric Environment Service). 1983. Canadian Climate Normals 1951-1980, Temperature and Precipitation, Atlantic Provinces. Minister of Supply and Services Canada, Ottawa, ON.

    AES (Atmospheric Environment Service). 1990. The Climates of Canada. Minister of Supply and Services Canada, Ottawa, ON.

    Bluestein, H. B. 1992. Synoptic-Dynamic Meteorology in Midlatitudes Volume II Observations and Theory of Weather Systems. Oxford University Press. New York, NY

    CEAA (Canadian Environmental Assessment Agency). 1994. Responsible Authority's Guide.

    (CEPA) Canadian Environmental Protection Act. 1990. Clean Air Act, Ambient Air Quality Objectives, Schedule 1.

    Clark, P.U. and W. W. Fitzhugh. 1991. Postglacial relative sea level history of the Labrador coast and interpretation of the archaeological record. Pp: 189-213. In L.L. Johnson (ed.) Paleoshorelines and prehistory: and investigation method.

    Consolidated Newfoundland Regulation 957/96, Air Pollution Control Regulations Under the Environment Act (OC 96-246), 1996, Schedules A and B.

    Environment Canada. 1990. SOE Report No. 90-1: A State of the Environment Report. September, 53 p.

    Environment Canada. 1993. Newfoundland and Labrador Marine Weather Guide. Minister of Supply and Services. Ottawa, ON.

    EPS (Environmental Protection Services). 1991. National Air Pollution Surveillance Annual Summary (EPS 7/AP/24). Environment Canada, Ottawa, ON.

    Gullett, D. W. and W. R. Skinner, 1992: The State of Canada's Climate: Temperature Change in Canada 1895-1991. A State of the Environment Report, SOE Rep. No. 92-2., Atmospheric Environment Service, Environment Canada. 36 p.

    Houghton, J.T., L.G. Meira Filho, B.A. Callander, N. Harris, A. Kattenberg, and K. Maskell (eds). 1995. Climate Change 1995. Contribution of WG1 to the Second Assessment Report of the Intergovernmental Panel on Climate Change Intergovernmental Panel on climate, Cambridge University Press, 572 p.

    JWEL (Jacques Whitford Environment). 1996. Northeast Regional Air Quality Committee Project Report. Prepared for the Northeast Regional Air Quality Committee (NRAQC).

    JWEL (Jacques Whitford Environment Limited). 1997a. Voisey's Bay 1996 Environmental Baseline Technical Data Report: Air Quality. Voisey's Bay Nickel Company Limited. St. John's, NF.

    JWEL (Jacques Whitford Environment Limited). 1997b. Voisey's Bay Mine/Mill Project Air Quality Modelling Report. Voisey's Bay Nickel Company Limited, St. John's, NF.

    Oke, T.R. 1987. Boundary Layer Climates. Methuen & Co. Ltd.

    Petrie, B. 1996. Climate Variability in the Waters on the Scotian Shelf and the Gulf of Maine. In R.W. Shaw (ed), Climate Change and Climate Variability in Atlantic Canada. Workshop Proceedings, Halifax, Nova Scotia. December 3 to 6, 1996. Environment Canada-Atlantic Region Occasional Report No. 9.

    Pocklington, R. and M. R. Morgan. 1996. Cooling in the North Atlantic Region in Relation to Secular Climate Change. Pp. 329-348. In R.W. Shaw (ed.), Climate Change and Climate Variability in Atlantic Canada. Workshop Proceedings, Halifax, Nova Scotia. December 3 to 6, 1996. Environment Canada-Atlantic Region Occasional Report No. 9.

    Rich, M.M. 1997. Environmental Assessment Panel for the Voisey's Bay Mine/Mill Project. Transcript of Proceedings of the Scoping Sessions, May 15, Sheshatshiu.

    Swail, V.R. 1996. Analysis of Climate Variability in Ocean Waves In the Northwest Atlantic Ocean. Pp. 313-318. In R.W. Shaw (ed.), Climate Change and Climate Variability in Atlantic Canada. Workshop Proceedings, Halifax, Nova Scotia. December 3 to 6, 1996. Environment Canada-Atlantic Region Occasional Report No. 9.

    US EPA. 1993. Emission Factor Documentation for AP-42 Section 3.4: Large Stationary Diesel and All Stationary Dual Fuel Engines.

    US EPA. 1995. Compilation of Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources. Fifth Edition as in Air Chief (EPA-454/C-95-001).

    Williamson, T. 1997. From Sina to Sikujaluk: Our Footprint. Mapping Inuit Environmental Knowledge in the Nain District of Northern Labrador. Prepared for the Labrador Inuit Association.


    Appendix 8A

    Environmental Effects Assessment Summary: Air Quality

    Appendix 8B

    Air Quality Modelling Results




    Scenario One




    Figure 8B.1 Mine/Mill Construction Scenario
    One Hour Maximum Concentration Carbon Monoxide (micrograms/cubic metre)


    Figure 8B.2 Mine/Mill Construction Scenario
    One Hour Maximum Concentration Nitrogen Dioxides (micrograms/cubic metre)


    Figure 8B.3 Mine/Mill Construction Scenario
    One Hour Maximum Concentration Total Suspended Particulates (micrograms/cubic metre)




    Figure 8B.4 Mine/Mill Construction Scenario
    One Hour Maximum Concentration Total Particulate Matter (micrograms/cubic metre)


    Figure 8B.5 Mine/Mill Construction Scenario
    One Hour Maximum Concentration Sulphur Dioxide (micrograms/cubic metre)


    Scenario Two




    Figure 8B.6 Mine/Mill Open Pit Scenario
    One Hour Maximum Concentration Carbon Monoxide (micrograms/cubic metre)




    Figure 8B.7 Mine/Mill Open Pit Scenario
    One Hour Maximum Concentration Nitrogen Dioxides (micrograms/cubic metre)


    Figure 8B.8 Mine/Mill Open Pit Scenario
    One Hour Maximum Concentration Total Suspended Particulate (micrograms/cubic metre)




    Figure 8B.9 Mine/Mill Open Pit Scenario
    Annual Average Maximum Concentration Total Particulate Matter(micrograms/cubic metre)


    Figure 8B.10 Mine/Mill Open Pit Scenario
    One Hour Maximum Concentration Sulphur Dioxide (micrograms/cubic metre)


    Scenario Three


    Figure 8B.11 Mine/Mill Underground Scenario
    One Hour Maximum Concentration Carbon Monoxide (micrograms/cubic metre)


    Figure 8B.12 Mine/Mill Underground Scenario
    One Hour Maximum Concentration Nitrogen Dioxides (micrograms/cubic metre)


    Figure 8B.13 Mine/Mill Underground Scenario
    One Hour Maximum Concentration Total Suspended Particulate (micrograms/cubic metre)




    Figure 8B.14 Mine/Mill Underground Scenario
    One Hour Maximum Concentration Total Particulate Matter (micrograms/cubic metre)


    Figure 8B.15 Mine/Mill Underground Scenario
    One Hour Maximum Concentration Sulphur Dioxide (micrograms/cubic metre)


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