OCR Text |
Show Measurement and Monitoring The working group devoted considerable effort to the assessment of verification needs, frequency and methods. The objective was to be less arbitrary than the up-front application of verification requirements to all boilers and heaters, as commonly seen in existing emission standards. It was postulated that a statistical approach could be developed that would determine the verification requirements for any individual unit based on the magnitude and variability of its emissions. This would provide a certain level of confidence that emissions were being maintained at or below the guideline emission limit by assigning more strict verification requirements to units having higher and more variable N O x emissions and less strict requirements to units having lower and more consistent emissions. This would provide the incentive of reduced monitoring costs if improved N O x control performance was demonstrated. Although the statistical approach was agreed to have merit, it was ultimately felt to be too complex. Instead, it w a s agreed to assign straightforward verification requirements in the Guideline based on simplicity and the following considerations: • the stringency of verification requirements should be based on the capacity (and thus the potential magnitude of emissions) of the boiler or heater; • for lower capacity units, the cost of continuous verification or even regular periodic monitoring may not be justified by the resulting improvement in emission control; • for continuous verification, there should be flexibility in selection of potentially less costly verification methods. The results of these deliberations are outlined in the following table. Table 9 - N O , Emission Verification Capacity (GJ/hr) (MMBtu/hr) 10.5-105 ! 10-100 i | 105-264 ! 100-250 i j > 264 > 250 i » Verification Requirement An initial verification test to be conducted at the time the new boiler or heater is commissioned. Initial verification test plus an annual test of compliance with emission limits. Initial verification test plus an annual test of compliance with emission limits plus some form of continuous verification. 10 |