EMISSION MEASUREMENT CENTER GUIDELINE DOCUMENT 40 CFR PART 60 APPENDIX B, PERFORMANCE SPECIFICATION 2 DEFINITION OF NORMAL LOAD INTRODUCTION Paragraph 8.4.1, Relative Accuracy (RA) Test Period, of Performance Specification 2 (PS-2) states that the RA test is to be conducted "while the affected facility is operating at more than 50 percent of normal load..." The specification of "more than 50 percent of normal load" was intended to ensure that the certification of the continuous emission monitoring system (CEMS) occurred under a representative operating condition and emission concentration when tested. A new source operating at 50 percent of permitted capacity or greater would be expected to produce pollutant and diluent levels in a range that would effectively test the CEMS performance. Operation of the source at 50 percent or greater than the permitted operating level may not be appropriate in some cases. For example, during the initial testing of a source, specifically a New Source Performance Standard facility, the operating capacity of the process will be much less than its permitted capacity. The following guidance describes alternative operating condition criteria. GUIDELINE The objectives of the calibration drift and RA tests of Sections 8.3 and 8.4 of PS-2 are to evaluate whether the CEMS conforms to the performance and equipment specifications of PS-2. In order to demonstrate conformance the monitored source must be in operation. Two conditions of the certification test must be determined prior to certification testing: 1. representative operations, and; 2. normal load. 1. Representative Operations. The CEMS must be certified when flow rates and emission concentrations are at the levels of normal operating conditions. If "normal" operation consists of variable loads, e.g., gas turbines used for electrical peaking-plants, the CEMS should be tested under these variable conditions. This includes startup, shutdown, and operational periods denoted as malfunctions. However, requiring certification under all of these conditions, although representative, may not be reasonable. The reviewing Agency and the source should agree to the operating conditions suitable for testing the CEMS. 2. Normal Load. Normal load means the permitted operating capacity of the facility. However, if a facility operates at less than 50 percent of their permitted capacity and does not anticipate a significant increase, it may not be necessary to increase the system load to 50 percent of the Prepared by Kim Garnett, EMC EMC, OAQPS, EPA EMC GD-017 April 20, 2020 ------- EMC GD-017 EMTIC GUIDELINE DOCUMENT PAGE 2 permitted capacity for certification testing of the CEMS. The reviewing agency needs to confirm that the load, or capacity of the operation, provides an emission level for sufficient evaluation of the monitor's performance and intended use. The objective of the certification test is to ensure that the CEMS data is reliable. The reviewing agency should ensure, within practical bounds, that the test is conducted during representative conditions. Prepared by Kim Garnett, EMC EMC, OAQPS, EPA EMC GD-017 April 20, 2020 ------- |