A summary chart showing each quality assurance test and the frequency at which each test is required is located at the end of this Exhibit in Figure 1.
2.1 Daily Assessments Perform the following daily assessments to quality-assure the hourly data recorded by the monitoring systems during each period of unit operation, or, for a bypass stack or duct, each period in which emissions pass through the bypass stack or duct. These requirements are effective as of the date when the monitor or continuous emission monitoring system completes certification testing.
2.1.1 Calibration Error Test Except as provided in Section 2.1.1.2 of this Exhibit, perform the daily calibration error test of each gas monitoring system (including moisture monitoring systems consisting of wet- and dry-basis O2 analyzers) according to the procedures in Section 6.3.1 of Exhibit A to Appendix B, and perform the daily calibration error test of each flow monitoring system according to the procedure in Section 6.3.2 of Exhibit A to Appendix B. When two measurement ranges (low and high) are required for a particular parameter, perform sufficient calibration error tests on each range to validate the data recorded on that range, according to the criteria in Section 2.1.5 of this Exhibit.
For units with add-on emission controls and dual-span or auto-ranging monitors, and other units that use the maximum expected concentration to determine calibration gas values, perform the daily calibration error tests on each scale that has been used since the previous calibration error test. For example, if the pollutant concentration has not exceeded the low-scale value (based on the maximum expected concentration) since the previous calibration error test, the calibration error test may be performed on the low-scale only. If, however, the concentration has exceeded the low-scale span value for one hour or longer since the previous calibration error test, perform the calibration error test on both the low- and high-scales.
2.1.1.1 On-line Daily Calibration Error Tests Except as provided in Section 2.1.1.2 of this Exhibit, all daily calibration error tests must be performed while the unit is in operation at normal, stable conditions (i.e., "on-line").
2.1.1.2 Off-line Daily Calibration Error Tests Daily calibrations may be performed while the unit is not operating (i.e., "off-line") and may be used to validate data for a monitoring system that meets the following conditions:
1) An initial demonstration test of the monitoring system is successfully completed and the results are reported in the quarterly report required under 40 CFR 75.64, incorporated by reference in Section 225.140. The initial demonstration test, hereafter called the "off-line calibration demonstration", consists of an off-line calibration error test followed by an on-line calibration error test. Both the off-line and on-line portions of the off-line calibration demonstration must meet the calibration error performance specification in Section 3.1 of Exhibit A to Appendix B. Upon completion of the off-line portion of the demonstration, the zero and upscale monitor responses may be adjusted, but only toward the true values of the calibration gases or reference signals used to perform the test and only in accordance with the routine calibration adjustment procedures specified in the quality control program required under Section 1 of this Exhibit. Once these adjustments are made, no further adjustments may be made to the monitoring system until after completion of the on-line portion of the off-line calibration demonstration. Within 26 clock hours after the completion hour of the off-line portion of the demonstration, the monitoring system must successfully complete the first attempted calibration error test, i.e., the on-line portion of the demonstration.2) For each monitoring system that has passed the off-line calibration demonstration, off-line calibration error tests may be used on a limited basis to validate data, in accordance with subsection (2) in Section 2.1.5.1 of this Exhibit.2.1.2 Daily Flow Interference Check Perform the daily flow monitor interference checks specified in Section 2.2.2.2 of Exhibit A to Appendix B while the unit is in operation at normal, stable conditions.
2.1.3 Additional Calibration Error Tests and Calibration Adjustmentsa) In addition to the daily calibration error tests required under Section 2.1.1 of this Exhibit, a calibration error test of a monitor must be performed in accordance with Section 2.1.1 of this Exhibit, as follows: whenever a daily calibration error test is failed; whenever a monitoring system is returned to service following repair or corrective maintenance that could affect the monitor's ability to accurately measure and record emissions data; or after making certain calibration adjustments, as described in this Section. Except in the case of the routine calibration adjustments described in this Section, data from the monitor are considered invalid until the required additional calibration error test has been successfully completed.b) Routine calibration adjustments of a monitor are permitted after any successful calibration error test. These routine adjustments must be made so as to bring the monitor readings as close as practicable to the known values of the calibration gases or to the actual value of the flow monitor reference signals. An additional calibration error test is required following routine calibration adjustments where the monitor's calibration has been physically adjusted (e.g., by turning a potentiometer) to verify that the adjustments have been made properly. An additional calibration error test is not required, however, if the routine calibration adjustments are made by means of a mathematical algorithm programmed into the data acquisition and handling system. It is recommended that routine calibration adjustments be made, at a minimum, whenever the daily calibration error exceeds the limits of the applicable performance specification in Exhibit A to Appendix B for the pollutant concentration monitor, CO2 or O2 monitor, or flow monitor.c) Additional (non-routine) calibration adjustments of a monitor are permitted prior to (but not during) linearity checks and RATAs and at other times, provided that an appropriate technical justification is included in the quality control program required under Section 1 of this Exhibit. The allowable non-routine adjustments are as follows. The owner or operator may physically adjust the calibration of a monitor (e.g., by means of a potentiometer), provided that the post-adjustment zero and upscale responses of the monitor are within the performance specifications of the instrument given in Section 3.1 of Exhibit A to Appendix B. An additional calibration error test is required following such adjustments to verify that the monitor is operating within the performance specifications at both the zero and upscale calibration levels.2.1.4 Data Validation a) An out-of-control period occurs when the calibration error of a CO2 or O2 monitor (including O2 monitors used to measure CO2 emissions or percent moisture) exceeds 1.0 percent CO2 or O2, or when the calibration error of a flow monitor or a moisture sensor exceeds 6.0 percent of the span value, which is twice the applicable specification of Exhibit A to this Appendix. Notwithstanding, a differential pressure-type flow monitor for which the calibration error exceeds 6.0 percent of the span value will not be considered out-of-control if Click here to view image
, the absolute value of the difference between the monitor response and the reference value in Equation A-6 of Exhibit A to Appendix B, is < 0.02 inches of water. For a mercury monitor, an out-of-control period occurs when the calibration error exceeds 5.0% of the span value. Notwithstanding, the mercury monitor will not be considered out-of-control if Click here to view image
in Equation A-5 does not exceed 1.0 µg/scm. The out-of-control period begins upon failure of the calibration error test and ends upon completion of a successful calibration error test. Note, that if a failed calibration, corrective action, and successful calibration error test occur within the same hour, emission data for that hour recorded by the monitor after the successful calibration error test may be used for reporting purposes, provided that two or more valid readings are obtained as required by Section 1.2 of Appendix B. Emission data must not be reported from an out-of-control monitor.b) An out-of-control period also occurs whenever interference of a flow monitor is identified. The out-of-control period begins with the hour of completion of the failed interference check and ends with the hour of completion of an interference check that is passed.2.1.5 Quality Assurance of Data With Respect to Daily Assessments When a monitoring system passes a daily assessment (i.e., daily calibration error test or daily flow interference check), data from that monitoring system are prospectively validated for 26 clock hours (i.e., 24 hours plus a 2-hour grace period) beginning with the hour in which the test is passed, unless another assessment (i.e., a daily calibration error test, an interference check of a flow monitor, a quarterly linearity check, a quarterly leak check, or a relative accuracy test audit) is failed within the 26-hour period.
2.1.5.1 Data Invalidation with Respect to Daily Assessments The following specific rules apply to the invalidation of data with respect to daily assessments:
1) Data from a monitoring system are invalid, beginning with the first hour following the expiration of a 26-hour data validation period or beginning with the first hour following the expiration of an 8-hour start-up grace period (as provided under Section 2.1.5.2 of this Exhibit), if the required subsequent daily assessment has not been conducted.2) For a monitor that has passed the off-line calibration demonstration, a combination of on-line and off-line calibration error tests may be used to validate data from the monitor, as follows. For a particular unit (or stack) operating hour, data from a monitor may be validated using a successful off-line calibration error test if: a) An on-line calibration error test has been passed within the previous 26 unit (or stack) operating hours; andb) the 26 clock hour data validation window for the off-line calibration error test has not expired. If either of these conditions is not met, then the data from the monitor are invalid with respect to the daily calibration error test requirement. Data from the monitor must remain invalid until the appropriate on-line or off-line calibration error test is successfully completed so that both conditions in subsections (a) and (b) are met.3) For units with two measurement ranges (low and high) for a particular parameter, when separate analyzers are used for the low and high ranges, a failed or expired calibration on one of the ranges does not affect the quality-assured data status on the other range. For a dual-range analyzer (i.e., a single analyzer with two measurement scales), a failed calibration error test on either the low or high scale results in an out-of-control period for the monitor. Data from the monitor remain invalid until corrective actions are taken and "hands-off" calibration error tests have been passed on both ranges. However, if the most recent calibration error test on the high scale was passed but has expired, while the low scale is up-to-date on its calibration error test requirements (or vice-versa), the expired calibration error test does not affect the quality-assured status of the data recorded on the other scale.2.1.5.2 Daily Assessment Start-Up Grace Period For the purpose of quality assuring data with respect to a daily assessment (i.e., a daily calibration error test or a flow interference check), a start-up grace period may apply when a unit begins to operate after a period of non-operation. The start-up grace period for a daily calibration error test is independent of the start-up grace period for a daily flow interference check. To qualify for a start-up grace period for a daily assessment, there are two requirements:
1) The unit must have resumed operation after being in outage for 1 or more hours (i.e., the unit must be in a start-up condition) as evidenced by a change in unit operating time from zero in one clock hour to an operating time greater than zero in the next clock hour.2) For the monitoring system to be used to validate data during the grace period, the previous daily assessment of the same kind must have been passed on-line within 26 clock hours prior to the last hour in which the unit operated before the outage. In addition, the monitoring system must be in-control with respect to quarterly and semi-annual or annual assessments. If both of the above conditions are met, then a start-up grace period of up to 8 clock hours applies, beginning with the first hour of unit operation following the outage. During the start-up grace period, data generated by the monitoring system are considered quality-assured. For each monitoring system, a start-up grace period for a calibration error test or flow interference check ends when either:
(1) a daily assessment of the same kind (i.e., calibration error test or flow interference check) is performed; or (2) 8 clock hours have elapsed (starting with the first hour of unit operation following the outage), whichever occurs first.2.1.6 Data Recording Record and tabulate all calibration error test data according to month, day, clock-hour, and magnitude in either ppm, percent volume, or scfh. Program monitors that automatically adjust data to the corrected calibration values (e.g., microprocessor control) to record either:
(1) the unadjusted concentration or flow rate measured in the calibration error test prior to resetting the calibration, or (2) the magnitude of any adjustment. Record the following applicable flow monitor interference check data: (1) sample line/sensing port pluggage, and (2) malfunction of each RTD, transceiver, or equivalent.2.2 Quarterly Assessments For each primary and redundant backup monitor or monitoring system, perform the following quarterly assessments. This requirement applies as of the calendar quarter following the calendar quarter in which the monitor or continuous emission monitoring system is provisionally certified.
2.2.1 Linearity Check Perform a linearity check, in accordance with the procedures in Section 6.2 of Exhibit A to Appendix B, for each primary and redundant backup, mercury monitor and each primary and redundant backup CO2 or O2 monitor (including O2 monitors used to measure CO2 emissions or to continuously monitor moisture) at least once during each QA operating quarter, as defined in 40 CFR 72.2, incorporated by reference in Section 225.140. For mercury monitors, perform the linearity checks using elemental mercury standards. Alternatively, you may perform 3-level system integrity checks at the same three calibration gas levels (i.e., low, mid, and high), using a NIST-traceable source of oxidized mercury. If you choose this option, the performance specification in Section 3.2(c) of Exhibit A to Exhibit B must be met at each gas level. For units using both a low and high span value, a linearity check is required only on the ranges used to record and report emission data during the QA operating quarter. Conduct the linearity checks no less than 30 days apart, to the extent practicable. The data validation procedures in Section 2.2.3(e) of this Exhibit must be followed.
2.2.2 Leak Check For differential pressure flow monitors, perform a leak check of all sample lines (a manual check is acceptable) at least once during each QA operating quarter. For this test, the unit does not have to be in operation. Conduct the leak checks no less than 30 days apart, to the extent practicable. If a leak check is failed, follow the applicable data validation procedures in Section 2.2.3(g) of this Exhibit.
2.2.3 Data Validation a) A linearity check must not be commenced if the monitoring system is operating out-of-control with respect to any of the daily or semiannual quality assurance assessments required by Sections 2.1 and 2.3 of this Exhibit or with respect to the additional calibration error test requirements in Section 2.1.3 of this Exhibit.b) Each required linearity check must be done according to subsection (b)(1), (b)(2) or (b)(3) of this Section: 1) The linearity check may be done "cold", i.e., with no corrective maintenance, repair, calibration adjustments, re-linearization or reprogramming of the monitor prior to the test.2) The linearity check may be done after performing only the routine or non-routine calibration adjustments described in Section 2.1.3 of this Exhibit at the various calibration gas levels (zero, low, mid or high), but no other corrective maintenance, repair, re-linearization or reprogramming of the monitor. Trial gas injection runs may be performed after the calibration adjustments and additional adjustments within the allowable limits in Section 2.1.3 of this Exhibit may be made prior to the linearity check, as necessary, to optimize the performance of the monitor. The trial gas injections need not be reported, provided that they meet the specification for trial gas injections in Section 1.4(b)(3)(G)(v) of Appendix B. However, if, for any trial injection, the specification in Section 1.4(b)(3)(G)(v) is not met, the trial injection must be counted as an aborted linearity check.3) The linearity check may be done after repair, corrective maintenance or reprogramming of the monitor. In this case, the monitor must be considered out-of-control from the hour in which the repair, corrective maintenance or reprogramming is commenced until the linearity check has been passed. Alternatively, the data validation procedures and associated timelines in Sections 1.4(b)(3)(B) through (I) of Appendix B may be followed upon completion of the necessary repair, corrective maintenance, or reprogramming. If the procedures in Section 1.4(b)(3) are used, the words "quality assurance" apply instead of the word "recertification".c) Once a linearity check has been commenced, the test must be done hands-off. That is, no adjustments of the monitor are permitted during the linearity test period, other than the routine calibration adjustments following daily calibration error tests, as described in Section 2.1.3 of this Exhibit. If a routine daily calibration error test is performed and passed just prior to a linearity test (or during a linearity test period) and a mathematical correction factor is automatically applied by the DAHS, the correction factor must be applied to all subsequent data recorded by the monitor, including the linearity test data.d) If a daily calibration error test is failed during a linearity test period, prior to completing the test, the linearity test must be repeated. Data from the monitor are invalidated prospectively from the hour of the failed calibration error test until the hour of completion of a subsequent successful calibration error test. The linearity test must not be commenced until the monitor has successfully completed a calibration error test.e) An out-of-control period occurs when a linearity test is failed (i.e., when the error in linearity at any of the three concentrations in the quarterly linearity check (or any of the six concentrations, when both ranges of a single analyzer with a dual range are tested) exceeds the applicable specification in Section 3.2 of Exhibit A to Appendix B) or when a linearity test is aborted due to a problem with the monitor or monitoring system. The out-of-control period begins with the hour of the failed or aborted linearity check and ends with the hour of completion of a satisfactory linearity check following corrective action and/or monitor repair, unless the option in subsection (b)(3) of this Section to use the data validation procedures and associated timelines in Section 1.4(b)(3)(B) through (I) of this Appendix has been selected, in which case the beginning and end of the out-of-control period must be determined in accordance with Sections 1.4(b)(3)(G)(i) and (ii). For a dual-range analyzer, "hands-off" linearity checks must be passed on both measurement scales to end the out-of-control period.f) No more than four successive calendar quarters must elapse after the quarter in which a linearity check of a monitor or monitoring system (or range of a monitor or monitoring system) was last performed without a subsequent linearity test having been conducted. If a linearity test has not been completed by the end of the fourth calendar quarter since the last linearity test, then the linearity test must be completed within a 168 unit operating hour or stack operating hour "grace period" (as provided in Section 2.2.4 of this Exhibit) following the end of the fourth successive elapsed calendar quarter, or data from the CEMS (or range) will become invalid.g) An out-of-control period also occurs when a flow monitor sample line leak is detected. The out-of-control period begins with the hour of the failed leak check and ends with the hour of a satisfactory leak check following corrective action.h) For each monitoring system, report the results of all completed and partial linearity tests that affect data validation (i.e., all completed, passed linearity checks; all completed, failed linearity checks; and all linearity checks aborted due to a problem with the monitor, including trial gas injections counted as failed test attempts under subsection (b)(2) of this Section or under Section 1.4(b)(3)(G)(vi) of Appendix B), in the quarterly report required under 40 CFR 75.64, incorporated by reference in Section 225.140. Note that linearity attempts that are aborted or invalidated due to problems with the reference calibration gases or due to operational problems with the affected units need not be reported. Such partial tests do not affect the validation status of emission data recorded by the monitor. A record of all linearity tests, trial gas injections and test attempts (whether reported or not) must be kept on-site as part of the official test log for each monitoring system.2.2.4 Linearity and Leak Check Grace Perioda) When a required linearity test or flow monitor leak check has not been completed by the end of the QA operating quarter in which it is due or if, due to infrequent operation of a unit or infrequent use of a required high range of a monitor or monitoring system, four successive calendar quarters have elapsed after the quarter in which a linearity check of a monitor or monitoring system (or range) was last performed without a subsequent linearity test having been done, the owner or operator has a grace period of 168 consecutive unit operating hours, as defined in 40 CFR 72.2, incorporated by reference in Section 225.140 (or, for monitors installed on common stacks or bypass stacks, 168 consecutive stack operating hours, as defined in 40 CFR 72.2) in which to perform a linearity test or leak check of that monitor or monitoring system (or range). The grace period begins with the first unit or stack operating hour following the calendar quarter in which the linearity test was due. Data validation during a linearity or leak check grace period must be done in accordance with the applicable provisions in Section 2.2.3 of this Exhibit.b) If, at the end of the 168 unit (or stack) operating hour grace period, the required linearity testor leak check has not been completed, data from the monitoring system (or range) will be invalid, beginning with the first unit operating hour following the expiration of the grace period. Data from the monitoring system (or range) remain invalid until the hour of completion of a subsequent successful hands-off linearity test or leak check of the monitor or monitoring system (or range). Note that when a linearity test or a leak check is conducted within a grace period for the purpose of satisfying the linearity test or leak check requirement from a previous QA operating quarter, the results of that linearity test or leak check may only be used to meet the linearity check or leak check requirement of the previous quarter, not the quarter in which the missed linearity test or leak check is completed.2.2.5 Flow-to-Load Ratio or Gross Heat Rate Evaluation a) Applicability and Methodology. Unless exempted from the flow-to-load ratio test under Section 7.6 of Exhibit A to Appendix B, the owner or operator must, for each flow rate monitoring system installed on each unit, common stack or multiple stack, evaluate the flow-to-load ratio quarterly, i.e., for each QA operating quarter (as defined in 40 CFR 72.2, incorporated by reference in Section 225.140). At the end of each QA operating quarter, the owner or operator must use Equation B-1 to calculate the flow-to-load ratio for every hour during the quarter in which: the unit (or combination of units, for a common stack) operated within ± 10.0 percent of Lavg, the average load during the most recent normal-load flow RATA; and a quality assured hourly average flow rate was obtained with a certified flow rate monitor. Alternatively, for the reasons stated in subsections (c)(1) through (6) of this Section, the owner or operator may exclude from the data analysis certain hours within ± 10.0 percent of Rh and may calculate Rh values for only the remaining hours. Click here to view image
1) In Equation B-1, the owner or operator may use either bias-adjusted flow rates or unadjusted flow rates, provided that all of the ratios are calculated the same way. For a common stack, Lh will be the sum of the hourly operating loads of all units that discharge through the stack. For a unit that discharges its emissions through multiple stacks or that monitors its emissions in multiple breechings, Qh will be either the combined hourly volumetric flow rate for all of the stacks or ducts (if the test is done on a unit basis) or the hourly flow rate through each stack individually (if the test is performed separately for each stack). For a unit with a multiple stack discharge configuration consisting of a main stack and a bypass stack, each of which has a certified flow monitor (e.g., a unit with a wet SO2 scrubber), calculate the hourly flow-to-load ratios separately for each stack. Round off each value of Rh to two decimal places.2) Alternatively, the owner or operator may calculate the hourly gross heat rates (GHR) in lieu of the hourly flow-to-load ratios. The hourly GHR must be determined only for those hours in which quality assured flow rate data and diluent gas (CO2 or O2) concentration data are both available from a certified monitor or monitoring system or reference method. If this option is selected, calculate each hourly GHR value as follows: Click here to view image
3) In Equation B-1a, the owner or operator may either use bias-adjusted flow rates or unadjusted flow rates in the calculation of (HeatInput)h, provided that all of the heat input values are determined in the same manner. 4) The owner or operator must evaluate the calculated hourly flow-to-load ratios (or gross heat rates) as follows. A separate data analysis must be performed for each primary and each redundant backup flow rate monitor used to record and report data during the quarter. Each analysis must be based on a minimum of 168 acceptable recorded hourly average flow rates (i.e., at loads within ± 10 percent of Lavg). When two RATA load levels are designated as normal, the analysis must be performed at the higher load level, unless there are fewer than 168 acceptable data points available at that load level, in which case the analysis must be performed at the lower load level. If, for a particular flow monitor, fewer than 168 acceptable hourly flow-to-load ratios (or GHR values) are available at any of the load levels designated as normal, a flow-to-load (or GHR) evaluation is not required for that monitor for that calendar quarter.5) For each flow monitor, use Equation B-2 in this Exhibit to calculate Eh, the absolute percentage difference between each hourly Rh value and Rref, the reference value of the flow-to-load ratio, as determined in accordance with Section 7.5 of Exhibit A to Appendix B. Note that Rref must always be based upon the most recent normal-load RATA, even if that RATA was performed in the calendar quarter being evaluated. Click here to view image
6) Equation B-2 must be used in a consistent manner. That is, use Rref and Rh if the flow-to-load ratio is being evaluated, and use (GHR)ref and (GHR)h if the gross heat rate is being evaluated. Finally, calculate Ef, the arithmetic average of all of the hourly Eh values. The owner or operator must report the results of each quarterly flow-to-load (or gross heat rate) evaluation, as determined from Equation B-2, in the electronic quarterly report required under 40 CFR 75.64, incorporated by reference in Section 225.140.b) Acceptable Results. The results of a quarterly flow-to-load (or gross heat rate) evaluation are acceptable, and no further action is required, if the calculated value of Efis less than or equal to: (1) 15.0 percent, if Lavg for the most recent normal-load flow RATA is [GREATER THAN OR EQUAL TO] 60 megawatts (or [GREATER THAN OR EQUAL TO] 500 klb/hr of steam) and if unadjusted flow rates were used in the calculations; or (2) 10.0 percent, if Lavg for the most recent normal-load flow RATA is [GREATER THAN OR EQUAL TO] 60 megawatts (or [GREATER THAN OR EQUAL TO] 500 klb/hr of steam) and if bias-adjusted flow rates were used in the calculations; or (3) 20.0 percent, if Lavg for the most recent normal-load flow RATA is < 60 megawatts (or < 500 klb/hr of steam) and if unadjusted flow rates were used in the calculations; or (4) 15.0 percent, if Lavg for the most recent normal-load flow RATA is < 60 megawatts (or < 500 klb/hr of steam) and if bias-adjusted flow rates were used in the calculations. If Ef is above these limits, the owner or operator must either: implement Option 1 in Section 2.2.5.1 of this Exhibit; or perform a RATA in accordance with Option 2 in Section 2.2.5.2 of this Exhibit; or re-examine the hourly data used for the flow-to-load or GHR analysis and recalculate Ef, after excluding all non-representative hourly flow rates. If Ef is above these limits, the owner or operator must either: implement Option 1 in Section 2.2.5.1 of this Exhibit; perform a RATA in accordance with Option 2 in Section 2.2.5.2 of this Exhibit; or (if applicable) re-examine the hourly data used for the flow-to-load or GHR analysis and recalculate Ef, after excluding all non-representative hourly flow rates, as provided in subsection (c) of this Section. c) Recalculation of Ef. If the owner or operator did not exclude any hours within ± 10 percent of Lavg from the original data analysis and chooses to recalculate Ef, the flow rates for the following hours are considered non-representative and may be excluded from the data analysis: 1) Any hour in which the type of fuel combusted was different from the fuel burned during the most recent normal-load RATA. For purposes of this determination, the type of fuel is different if the fuel is in a different state of matter (i.e., solid, liquid, or gas) than is the fuel burned during the RATA or if the fuel is a different classification of coal (e.g., bituminous versus sub-bituminous). Also, for units that co-fire different types of fuels, if the reference RATA was done while co-firing, then hours in which a single fuel was combusted may be excluded from the data analysis as different fuel hours (and vice-versa for co-fired hours, if the reference RATA was done while combusting only one type of fuel);2) For a unit that is equipped with an SO2 scrubber and that always discharges its flue gases to the atmosphere through a single stack, any hour in which the SO2 scrubber was bypassed; 3) Any hour in which "ramping" occurred, i.e., the hourly load differed by more than ± 15.0 percent from the load during the preceding hour or the subsequent hour;4) For a unit with a multiple stack discharge configuration consisting of a main stack and a bypass stack, any hour in which the flue gases were discharged through both stacks;5) If a normal-load flow RATA was performed and passed during the quarter being analyzed, any hour prior to completion of that RATA; and6) If a problem with the accuracy of the flow monitor was discovered during the quarter and was corrected (as evidenced by passing the abbreviated flow-to-load test in Section 2.2.5.3 of this Exhibit), any hour prior to completion of the abbreviated flow-to-load test.7) After identifying and excluding all non-representative hourly data in accordance with subsections (c)(1) through (6) of this Section, the owner or operator may analyze the remaining data a second time. At least 168 representative hourly ratios or GHR values must be available to perform the analysis; otherwise, the flow-to-load (or GHR) analysis is not required for that monitor for that calendar quarter.8) If, after re-analyzing the data, Ef meets the applicable limit in subsection (b)(1), (b)(2), (b)(3), or (b)(4) of this Section, no further action is required. If, however, Ef is still above the applicable limit, data from the monitor will be declared out-of-control, beginning with the first unit operating hour following the quarter in which Ef exceeded the applicable limit. Alternatively, if a probationary calibration error test is performed and passed according to Section 1.4(b)(3)(B) of Appendix B, data from the monitor may be declared conditionally valid following the quarter in which Ef exceeded the applicable limit. The owner or operator must then either implement Option 1 in Section 2.2.5.1 of this Exhibit or Option 2 in Section 2.2.5.2 of this Exhibit.2.2.5.1 Option 1 Within 14 unit operating days of the end of the calendar quarter for which the Ef value is above the applicable limit, investigate and troubleshoot the applicable flow monitors. Evaluate the results of each investigation as follows:
a) If the investigation fails to uncover a problem with the flow monitor, a RATA must be performed in accordance with Option 2 in Section 2.2.5.2 of this Exhibit.b) If a problem with the flow monitor is identified through the investigation (including the need to re-linearize the monitor by changing the polynomial coefficients or K factors), data from the monitor are considered invalid back to the first unit operating hour after the end of the calendar quarter for which Ef was above the applicable limit. If the option to use conditional data validation was selected under Section 2.2.5(c)(8) of this Exhibit, all conditionally valid data will be invalidated, back to the first unit operating hour after the end of the calendar quarter for which Ef was above the applicable limit. Corrective actions must be taken. All corrective actions (e.g., non-routine maintenance, repairs, major component replacements, re-linearization of the monitor, etc.) must be documented in the operation and maintenance records for the monitor. The owner or operator then must either complete the abbreviated flow-to-load test in Section 2.2.5.3 of this Exhibit, or, if the corrective action taken has required relinearization of the flow monitor, must perform a 3-load RATA. The conditional data validation procedures in Section 1.4(b)(3) of Appendix B may be applied to the 3-load RATA.2.2.5.2 Option 2 Perform a single-load RATA (at a load designated as normal under Section 6.5.2.1 of Exhibit A to Appendix B) of each flow monitor for which Ef is outside of the applicable limit. If the RATA is passed hands-off, in accordance with Section 2.3.2(c) of this Exhibit, no further action is required and the out-of-control period for the monitor ends at the date and hour of completion of a successful RATA, unless the option to use conditional data validation was selected under Section 2.2.5(c)(8) of this Exhibit. In that case, all conditionally valid data from the monitor are considered to be quality-assured, back to the first unit operating hour following the end of the calendar quarter for which the Ef value was above the applicable limit. If the RATA is failed, all data from the monitor will be invalidated, back to the first unit operating hour following the end of the calendar quarter for which the Ef value was above the applicable limit. Data from the monitor remain invalid until the required RATA has been passed. Alternatively, following a failed RATA and corrective actions, the conditional data validation procedures of Section 1.4(b)(3) of Appendix B may be used until the RATA has been passed. If the corrective actions taken following the failed RATA included adjustment of the polynomial coefficients or K factors of the flow monitor, a 3-level RATA is required, except as otherwise specified in Section 2.3.1.3 of this Exhibit.
2.2.5.3 Abbreviated Flow-to-Load Testa) The following abbreviated flow-to-load test may be performed after any documented repair, component replacement, or other corrective maintenance to a flow monitor (except for changes affecting the linearity of the flow monitor, such as adjusting the flow monitor coefficients or K factors) to demonstrate that the repair, replacement, or other maintenance has not significantly affected the monitor's ability to accurately measure the stack gas volumetric flow rate. Data from the monitoring system are considered invalid from the hour of commencement of the repair, replacement, or maintenance until either the hour in which the abbreviated flow-to-load test is passed, or the hour in which a probationary calibration error test is passed following completion of the repair, replacement, or maintenance and any associated adjustments to the monitor. If the latter option is selected, the abbreviated flow-to-load test must be completed within 168 unit operating hours of the probationary calibration error test (or, for peaking units, within 30 unit operating days, if that is less restrictive). Data from the monitor are considered to be conditionally valid (as defined in 40 CFR 72.2, incorporated by reference in Section 225.140), beginning with the hour of the probationary calibration error test. b) Operate the units in such a way as to reproduce, as closely as practicable, the exact conditions at the time of the most recent normal-load flow RATA. To achieve this, it is recommended that the load be held constant to within ± 10.0 percent of the average load during the RATA and that the diluent gas (CO2 or O2) concentration be maintained within ± 0.5 percent CO2 or O2 of the average diluent concentration during the RATA. For common stacks, to the extent practicable, use the same combination of units and load levels that were used during the RATA. When the process parameters have been set, record a minimum of six and a maximum of 12 consecutive hourly average flow rates, using the flow monitors for which Ef was outside the applicable limit. For peaking units, a minimum of three and a maximum of 12 consecutive hourly average flow rates are required. Also record the corresponding hourly load values and, if applicable, the hourly diluent gas concentrations. Calculate the flow-to-load ratio (or GHR) for each hour in the test hour period, using Equation B-1 or B-1a. Determine Eh for each hourly flow-to-load ratio (or GHR), using Equation B-2 of this Exhibit and then calculate Ef, the arithmetic average of the Eh values.c) The results of the abbreviated flow-to-load test will be considered acceptable, and no further action is required if the value of Eh does not exceed the applicable limit specified in Section 2.2.5 of this Exhibit. All conditionally valid data recorded by the flow monitor will be considered quality assured, beginning with the hour of the probationary calibration error test that preceded the abbreviated flow-to-load test (if applicable). However, if Ef is outside the applicable limit, all conditionally valid data recorded by the flow monitor (if applicable) will be considered invalid back to the hour of the probationary calibration error test that preceded the abbreviated flow-to-load test, and a single-load RATA is required in accordance with Section 2.2.5.2 of this Exhibit. If the flow monitor must be re-linearized, however, a 3-load RATA is required.2.6 System Integrity Checks for Mercury Monitors For each mercury concentration monitoring system (except for a mercury monitor that does not have a converter), perform a single-point system integrity check weekly, i.e., at least once every 168 unit or stack operating hours, using a NIST-traceable source of oxidized mercury. Perform this check using a mid- or high-level gas concentration, as defined in Section 5.2 of Exhibit A to Appendix B. The performance specifications in subsection (3) of Section 3.2 of Exhibit A to Appendix B must be met, otherwise the monitoring system is considered out-of-control, from the hour of the failed check until a subsequent system integrity check is passed. If a required system integrity check is not performed and passed within 168 unit or stack operating hours of last successful check, the monitoring system will also be considered out of control, beginning with the 169th unit or stack operating hour after the last successful check, and continuing until a subsequent system integrity check is passed. This weekly check is not required if the daily calibration assessments in Section 2.1.1 of this Exhibit are performed using a NIST-traceable source of oxidized mercury.
[Note: The following TABLE/FORM is too wide to be displayed on one screen. You must print it for a meaningful review of its contents. The table has been divided into multiple pieces with each piece containing information to help you assemble a printout of the table. The information for each piece includes:
(1) a three line message preceding the tabular data showing by line # and character # the position of the upper left-hand corner of the piece and the position of the piece within the entire table; and (2) a numeric scale following the tabular data displaying the character positions.] Figure 1 for Exhibit B of Appendix B - Quality Assurance Test Requirements
Test | Basic QA test frequency requirements [FN*] |
| Daily [FN*] | Weekly | Quarterly [FN*] | Semiannual [FN*] | Annual |
Calibration Error Test (2 pt.) | / | | | | |
Interference Check (flow) | / | | | | |
Flow-to-Load Ratio | | | / | | |
Leak Check (DP flow monitors) | | | / | | |
Linearity Check or System Integrity Check [FN**] (3 pt.) | | | / | | |
Single-point System Integrity Check [FN**] | | / | | | |
RATA (SO2, NOx, CO2, O2, H2O) [FN1] | | | | / | |
RATA (All Hg monitoring systems) | | | | | / |
RATA (flow) [FN1] [FN2] | | | | / | |
[FN*] "Daily" means operating days, only. "Weekly" means once every 168 unit or stack operating hours. "Quarterly" means once every QA operating quarter. "Semiannual" means once every two QA operating quarters. "Annual" means once every four QA operating quarters. [FN**] The system integrity check applies only to Hg monitors with converters. The single-point weekly system integrity check is not required if daily calibrations are performed using a NIST-traceable source of oxidized Hg. The 3-point quarterly system integrity check is not required if a linearity check is performed.
[FN1] Conduct RATA annually (i.e., once every four QA operating quarters), if monitor meets accuracy requirements to qualify for less frequent testing. [FN2] For flow monitors installed on peaking units, bypass stacks conduct all RATAs at a single, normal load (or operating level). For other flow monitors, conduct annual RATAs at two load levels (or operating levels). Alternating single-load and 2-load (or single-level and 2-level) RATAs may be done if a monitor is on a semiannual frequency. A single-load (or single-level) RATA may be done in lieu of a 2-load (or 2-level) RATA if, since the last annual flow RATA, the unit has operated at one load level (or operating level) for [GREATER THAN OR EQUAL TO] 85.0 percent of the time. A 3-level RATA is required at least once every five calendar years and whenever a flow monitor is re-linearized, except for flow monitors exempted from 3-level RATA testing under Section 6.5.2(b) of Exhibit A to Appendix B.
Figure 2 for Exhibit B of Appendix B - Relative Accuracy Test Frequency Incentive System
RATA | Semiannual [FNW] (percent) | Annual [FNW] |
SO2 or NOX [FNY] | 7.5% < RA [LESS THAN OR EQUAL TO] 10.0% or ± 15.0 ppm [FNX] | RA [LESS THAN OR EQUAL TO] 7.5% or ± 12.0 ppm [FNX] |
SO2-diluent | 7.5% < RA [LESS THAN OR EQUAL TO] 10.0% or ± 0.030 lb/mmBtu [FNX] | RA [LESS THAN OR EQUAL TO] 7.5% or ± 0.025 lb/mmBtu =G5X |
NOX-diluent | 7.5% < RA [LESS THAN OR EQUAL TO] 10.0% or ± 0.020 lb/mmBtu [FNX] | RA [LESS THAN OR EQUAL TO] 7.5% or ± 0. 015 lb/mmBtu [FNX] |
Flow | 7.5% < RA [LESS THAN OR EQUAL TO] 10.0% or ± 2.0 fps [FNX] | RA [LESS THAN OR EQUAL TO] 7.5% or ± 1.5 fps [FNX] |
CO2 or O2 | 7.5% < RA [LESS THAN OR EQUAL TO] 10.0% or ± 1.0 CO2/O2 [FNX] | RA [LESS THAN OR EQUAL TO] 7.5% or ± 0.7% CO2/O2 [FNX] |
Hg [FNX] µg/scm | N/A | RA < 20.0% or ± 1.0 [FNX] |
Moisture | 7.5% < RA [LESS THAN OR EQUAL TO] 10.0% or ± 1.5% H2O [FNX] | RA [LESS THAN OR EQUAL TO] 7.5% or ± 1.0% H2O [FNX] |
[FNW] The deadline for the next RATA is the end of the second (if semiannual) or fourth (if annual) successive QA operating quarter following the quarter in which the CEMS was last tested. Exclude calendar quarters with fewer than 168 unit operating hours (or, for common stacks and bypass stacks, exclude quarters with fewer than 168 stack operating hours) in determining the RATA deadline. For SO2 monitors, QA operating quarters in which only very low sulfur fuel as defined in 40 CFR 72.2, incorporated by reference in Section 225.140, is combusted may also be excluded. However, the exclusion of calendar quarters is limited as follows: the deadline for the next RATA will be no more than 8 calendar quarters after the quarter in which a RATA was last performed.
[FNX] The difference between monitor and reference method mean values applies to moisture monitors, CO2 and O2 monitors, low emitters of SO2, NOX, or Hg, or and low flow, only. The specifications for Hg monitors also apply to sorbent trap monitoring systems.
[FNY] A NOX concentration monitoring system used to determine NOX mass emissions under 40 CFR 75.71, incorporated by reference in Section 225.140.