Potash sector emission estimate codes

This page will provide guidance to potash-producing facilities on which National Pollutant Release Inventory (NPRI) emission estimation codes to use when reporting.

General guidance on the use of emission estimation codes for the potash industry

There are four emission quantification methods (and the associated National Pollutant Release Inventory (NPRI) emission estimation codes) commonly used by potash-producing facilities when they report to the NPRI:

• Source testing (M3)
• Site-specific emission factors (E1)
• Published emission factors (E2)
• Engineering estimates (O)

Source testing (M3)

You should select this emission quantification code if you use one set of source sampling results to calculate the concentration of one or more substances (in this case, TPM, PM₁₀, PM_2.5). This sampling is normally conducted to demonstrate compliance with a regulatory requirement or as a result of guidance provided by regulatory authorities.

To use this method, once you have conducted your source sampling test, you multiply the concentration of each substance by the volumetric flow rate to determine the quantity of each substance released over time. That quantity can be divided by throughput to calculate an emission per unit production or it can be multiplied by hours of operations to calculate an annual emission.

Site-specific emission factors (E1)

You should select this estimation code if you perform the source sampling tests many times for the same source and develop your own site-specific emission factors. Those factors can then be used to relate the quantity of substance(s) released from that source to some common activity (for example, the volume of product produced in a defined period).

Published emission factors (E2)

You should select this estimation code when you use emission factors that have already been developed and published by industry associations or government agencies for use by the industry sector or in particular jurisdictions. These factors are based many source testing results from one or more facilities in the same industry sector or from the same type of process equipment (for example, fuel combustion equipment).

Engineering estimates (O)

To use this method you must have knowledge of the physical and chemical processes, equipment design properties, and engineering principles that allows you to calculate pollutant releases from an emission source. This approach should be used with caution since the resulting data are usually an approximation, however, it can be used when no other estimation method is available to you. Any quantities derived using this method should be refined should better information become available in the future.  

The following table provides guidance on which emission estimation methods are currently being used by potash-producing facilities categorized by source as well as the methods recommended by NPRI.