Q-2, r. 4.1 - Clean Air Regulation

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SCHEDULE H
(ss. 75, 77, 87, 91, 92, 97, 153, 156 and 197)
AIR DISPERSION MODEL
Dispersion models
The dispersion models that may be used are those in the latest edition of the US-EPA Guideline on Air Quality Models (Appendix W to Part 51). A recognized alternative may be used if the operator establishes that, in the case at hand, that model performs better than the models indicated in the guideline. The choice of the alternative model must be motivated by theoretical considerations and be supported by a comparative statistical analysis of the results, following the prescriptions of the Guideline on Air Quality Models. The latest version of the model must be used.
Calculation of the concentration of a contaminant in the atmosphere
Using the model, the operator must calculate the concentration in the atmosphere of each contaminant emitted for which a limit value is prescribed by sections 75 and 153 and in Schedules G and K.
The concentration of a contaminant in the atmosphere for a single source must be calculated by modeling with one of the following methods:
(1) a simple model, called a level 1 model, for a single source; or
(2) a multi-source complex model, called a level 2 model, simulating a single source.
Modeling with a level 2 model is required if the concentration of contaminants calculated with a level 1 model is deemed significant according to the following formula:
C ≥ 4 x (LV-IC)/5
where LV and IC are, respectively, the limit value and the initial concentration provided for in Schedules G and K.
If the establishment has several emission sources, the concentrations of contaminants in the atmosphere must be calculated using a level 2 model.
Parameters
All the parameters required for the model must be presented, namely,
(1) the model used and its version;
(2) the non-default options;
(3) the choice of environment (rural/urban);
(4) the dimensions of the modeling domain;
(5) the modeling scenario or scenarios;
(6) the physical features of the emission sources; and
(7) the calculations made to obtain the emission rates.
For level 2 modeling, the following parameters must also be presented:
(1) a description of the calculation points table;
(2) the origin and period of the meteorological data;
(3) the surface characteristics required to prepare the meteorological data files.
Modeling scenarios
The modeling scenarios must make it possible to reproduce the highest projected concentrations of contaminants on the basis of the period of application of the limit value. However, those scenarios do not include contaminant emissions attributable to unplanned and unpredictable situations, such as the use of generators in an emergency.
By using the concentration obtained for the calculation with a level 1 model, the daily and annual concentrations are obtained in the following manner:
Cdaily = CMAX-H x 0.24
CAN = CMAX-H x 0.04
where Cdaily is the daily concentration, CAN is the annual concentration and CMAX-H is the highest hourly concentration calculated.
For a level 2 model, the operator must prepare meteorological data files on the basis of 5 years of complete meteorological data representative of the location of the establishment. When such files are made available by the Ministère du Développement durable, de l’Environnement et des Parcs, they must be used.
In the case of a contaminant referred to in Schedule K for which the limit value established in column 1 is over a period of less than 1 hour, the concentration is calculated using the following formula:
C(T) = CMAX-H x 0.97 T - 0.25
where T is the time in hours and CMAX-H is the maximum concentration for 1 hour.
The operator must take into account the topography and include calculation points on the property limits or the limits of the industrial zone.
The initial concentrations of contaminants in the atmosphere, without the contribution of the source or sources considered for the modeling, must be added to the concentrations calculated. The resulting concentrations must be presented to enable comparison with the limit values prescribed by Schedules G and K.
Information to be retained
The operator must retain the following information and documents for a minimum of 5 years:
(1) one or more topographic maps showing the region for which the calculations have been made, indicating the pertinent geographical, physical and human elements. Each map must include a scale and the direction of geographical North;
(2) a top view and a sectional view indicating the dimensions of the establishment’s buildings, as taken into account in the model, and the location of the sources;
(3) the physical features of each source and the operating characteristics;
(4) for each contaminant and each period for which a limit value is prescribed, a table showing the maximum annual concentrations calculated for all the calculation points and years and their locations, the initial concentrations, the sum of the maximum concentrations calculated and the initial concentrations, and the limit value. When preparing that table, the calculation points located within the property limits or the limits of the industrial zone are excluded;
(5) the input data required for the operation of the model in a form compatible with its use (model input file) for the modeling carried out;
(6) the data generated by the operation of the model in a form compatible with its use (model input file) for the modeling carried out.
For level 2 modeling, the operator must also retain the following information and documents for a minimum of 5 years:
(1) the map or maps provided for in subparagraph 1 of the first paragraph, which will show the calculation points table, the establishment, and the property limits or the limits of the industrial zone;
(2) a 16-direction wind rose obtained from the meteorological data used in the model and indicating the average wind speed, the calm wind frequency and the proportion of missing data;
(3) for the contaminant whose maximum concentration calculated is the highest for each period for which a limit value is prescribed and for each contaminant whose maximum concentration calculated is significant, maps showing the modeling calculation results in the form of isopleth curves for each calculation point, except for the points located within the property limits, and for the entire calculation period. For each map, the results presented must include the initial concentration;
(4) for each contaminant and each applicable period, maps showing the number of exceedances for each calculation point, except for the points located within the property limits, and for the entire calculation period. The number of exceedances is calculated taking into account the initial concentration;
(5) the table provided for in subparagraph 4 of the first paragraph, which will also show the maximum number of exceedances calculated at the worst calculation point for all the calculation points and years, and their locations. When preparing that table, the calculation points located within the property limits or the limits of the industrial zone are excluded.
O.C. 501-2011, Sch. H; O.C. 868-2020, s. 4.
SCHEDULE H
(ss. 75, 77, 87, 91, 92, 97, 153, 156 and 197)
AIR DISPERSION MODEL
The dispersion models that may be used are those in the latest edition of the US-EPA Guideline on Air Quality Models (Appendix W to Part 51).
Using the model, the operator must calculate the concentration in the atmosphere of each contaminant emitted for which a limit is prescribed by sections 75 and 153 and in Schedules G and K.
All the values of the parameters required for the model must be listed.
The concentration of a contaminant in the atmosphere for a single source must be calculated by modeling with one of the following methods:
(a) a simple model, called a level 1 model, for a single source; or
(b) a multi-source complex model, called a level 2 model, simulating a single source.
For the sum of the concentration of contaminants calculated with a level 1 model and of the initial concentration exceeds 80% of the limit, modeling with a level 2 model is required.
If the establishment has several emission sources, the concentrations of contaminants in the atmosphere must be calculated using a level 2 model.
By using the concentration obtained for the calculation with a level 1 model, the daily and annual concentrations are obtained in the following manner:
Cdaily = CMAX-H x 0.24
CAN = CMAX-H x 0.04
where Cdaily is the daily concentration, CAN is the annual concentration and CMAX-H is the highest hourly concentration calculated.
For a level 2 model, the operator must use
(a) 5 years of complete meteorological data representative of the location of the establishment;
(b) the overall regional meteorological data supplied by the Ministère du Développement durable, de l’Environnement et des Parcs for the region where the establishment is located; or
(c) the overall general meteorological data supplied by the Ministère du Développement durable, de l’Environnement et des Parcs if the data described in paragraph a or b above does not exist.
The operator must describe all the calculations made using the meteorological data to obtain the specific parameters that the use of the model requires.
The annual and daily concentrations for each calculation point are obtained in the following manner, according to the meteorological data used and described above:


Meteorological Annual Daily
data concentration concentration



Complete and Average of the Average of the 24 hourly
representative of the 8,760 concentrations concentrations calculated
location of the calculated, for for every day of
establishment for each year every year
5 years


Overall regional Average of the Average of the 24 hourly
meteorological data 8,760 concentrations concentrations calculated
supplied by the calculated for every day
Ministère du
Développement durable,
de l’Environnement
et des Parcs


Overall general From the highest hourly From the highest hourly
meteorological data concentration calculated: concentration calculated:
supplied by the CAN = CMAX-H x 0.04, Cdaily = CMAX-H x 0.24
Ministère du where CAN is the annual where Cdaily is the daily
Développement durable, concentration and CMAX-H concentration and CMAX-H
de l’Environnement is the highest hourly is the highest hourly
et des Parcs if the concentration calculated concentration calculated
data described above
does not exist


In the case of a contaminant for which column 1 of Schedule K provides that the limit is established over a period of less than 1 hour, the concentration is calculated using the following formula:
C(T) = CMAX-H x 0.97 T - 0.25
where T is the time in hours and CMAX-H is the maximum concentration for 1 hour.
The operator must take into account the topography if the difference in altitude between the highest and the lowest points of the region for which the calculations are made is equal to or greater than 10 m.
The initial concentrations of contaminants into the atmosphere, without the contribution of the source or sources considered for the modeling, must be added to the concentrations calculated. The resulting concentrations must be presented to enable comparison with the limit values prescribed by Schedules G and K.
The operator must retain the following information for a minimum of 5 years:
(a) one or more maps showing the region for which the calculations have been made, indicating the calculation points and their altitude, the establishment and its property limits, and the pertinent geographical, physical and human elements. Each map must include a scale and the direction of geographical North;
(b) a top view and a sectional view of the establishment’s buildings and the location of the sources;
(c) the physical features of each source and the operating characteristics;
(d) for each contaminant, maps showing the modeling calculation results in the form of isopleth curves for each year of calculation;
(e) for each contaminant, a table showing the location of each calculation point and the concentrations modelized, for each year of calculation;
(f) for each contaminant, a table showing the maximum annual concentrations calculated for all the calculation points and years and their locations; the initial concentrations and the sum of the maximum concentrations calculated and the initial concentrations; and
(g) the input data required for the operation of the model in a form compatible with its use (model input file) for the modeling carried out.
O.C. 501-2011, Sch. H.