Q851. My aggregation of units/common pipe configuration only contains a few units with a maximum rated heat input capacity ≥ 10 million British thermal units per hour (mmbtu/hr).  What should be entered for cumulative maximum rated heat input capacity of the aggregated units?  If I only enter the heat input capacity for those units ≥ 10, I receive a data validation error regarding potential-to-emit.

A851. You should sum only the capacity for those units with a maximum rated heat input capacity ≥ 10 and enter the summation as the cumulative maximum rated heat input capacity for the aggregation/common pipe configuration.

For example, if a facility reports an aggregation of units configuration containing 60 units, but only two of the 60 units have a maximum rated heat input capacity ≥ 10 mmbtu/hr (e.g., 10 and 12 mmbtu/hr), then the cumulative maximum rated heat input capacity for the configuration would be the sum of those two values (i.e., 22 mmbtu/hr). In this instance, it is possible to incorrectly trigger a potential-to-emit validation error because a significant amount of heat input capacity (i.e., emissions) exists within the small (<10 mmbtu/hr) units and that is not accounted for in the cumulative maximum rated heat input capacity reported.

If you receive potential-to-emit validation errors, you should first confirm that the entered data are correct.  As these checks specifically evaluate the potential-to-emit of the configuration using the cumulative maximum rated heat input capacity reported, it should be confirmed that this value has been reported accurately and is in the correct units of measure (mmbtu/hr).  If you have confirmed that the reported value is accurate and you believe that your configuration is triggering these potential-to-emit validation checks in error due to the small (<10 mmbtu/hr) unit exemption, you should proceed to submit and certify your report with these validation errors. You may also provide optional comments to explain validation errors while submitting your annual report.