Table 1-Missing Data Procedure for SO2 CEMS, CO2 CEMS, Moisture CEMS, and Diluent (CO2 or O2) Monitors for Heat Input Determination
Trigger conditions | Calculation routines | ||
Monitor data availability (percent) | Duration (N) of CEMS outage (hours)2 | Method | Lookback period |
95 or more | N [LESS THAN EQUAL TO]24 | Average | HB/HA. |
N [GREATER THAN]24 | For SO2, CO2, and H2O **, the greater of: | ||
Average | HB/HA. | ||
90th percentile | 720 hours. * | ||
For O2 and H2OX, the lesser of: | HB/HA. | ||
10th percentile | 720 hours. * | ||
90 or more, but below 95 | N [LESS THAN EQUAL TO]8 | Average | HB/HA. |
N [GREATER THAN]8 | For SO2, CO2, and H2O **, the greater of: | ||
Average | HB/HA. | ||
95th percentile | 720 hours. * | ||
For O2 and H2OX, the lesser of: | |||
Average | HB/HA. | ||
5th Percentile | 720 hours. * | ||
80 or more, but below 90 | N [GREATER THAN]0 | For SO2, CO2, and H2O **, | |
Maximum value1 | 720 hours. * | ||
For O2 and H2OX: | |||
Minimum value1 | 720 hours. * | ||
Below 80 | N [GREATER THAN]0 | Maximum potential concentration3 or % (for SO2, CO2, and H2O**) or | |
Minimum potential concentration or % (for O2 and H2OX) | None. |
HB/HA = hour before and hour after the CEMS outage.
* Quality-assured, monitor operating hours, during unit operation. May be either fuel-specific or non-fuel-specific. For units that report data only for the ozone season, include only quality assured monitor operating hours within the ozone season in the lookback period. Use data from no earlier than 3 years prior to the missing data period.
1 Where a unit with add-on SO2 emission controls can demonstrate that the controls are operating properly during the missing data period, as provided in § 75.34 , the unit may use the maximum controlled concentration from the previous 720 quality-assured monitor operating hours.
2 During unit operating hours.
3 Where a unit with add-on SO2 emission controls can demonstrate that the controls are operating properly during the missing data period, the unit may report the greater of: (a) the maximum expected SO2 concentration or (b) 1.25 times the maximum controlled value from the previous 720 quality-assured monitor operating hours (see § 75.34 ).
X Use this algorithm for moisture except when Equation 19-3, 19-4 or 19-8 in Method 19 in appendix A-7 to part 60 of this chapter is used for NOX emission rate.
** Use this algorithm for moisture only when Equation 19-3, 19-4 or 19-8 in Method 19 in appendix A-7 to part 60 of this chapter is used for NOX emission rate.
Table 2-Load-Based Missing Data Procedure for NOX-Diluent CEMS, NOX Concentration CEMS and Flow Rate CEMS
Trigger conditions | Calculation routines | |||
Monitor data availability (percent) | Duration (N) of CEMS outage (hours)2 | Method | Lookback period | Load ranges |
95 or more | N [LESS THAN EQUAL TO]24 | Average | 2,160 hours * | Yes. |
N [GREATER THAN]24 | The greater of: | |||
Average | HB/HA | No. | ||
90th percentile | 2,160 hours * | Yes. | ||
90 or more, but below 95 | N [LESS THAN EQUAL TO]8 | Average | 2,160 hours * | Yes. |
N [GREATER THAN]8 | The greater of: | |||
Average | HB/HA | No. | ||
95th percentile | 2,160 hours * | Yes. | ||
80 or more, but below 90 | N [GREATER THAN]0 | Maximum value1 | 2,160 hours * | Yes. |
Below 80 | N [GREATER THAN]0 | Maximum potential NOX emission rate3; or maximum potential NOX concentration3; or maximum potential flow rate | None | No. |
HB/HA = hour before and hour after the CEMS outage.
* Quality-assured, monitor operating hours, using data at the corresponding load range ("load bin") for each hour of the missing data period. May be either fuel-specific or non-fuel-specific. For units that report data only for the ozone season, include only quality assured monitor operating hours within the ozone season in the lookback period. Use data from no earlier than three years prior to the missing data period.
1 Where a unit with add-on NOX emission controls can demonstrate that the controls are operating properly during the missing data period, as provided in § 75.34 , the unit may use the maximum controlled NOX concentration or emission rate from the previous 2,160 quality-assured monitor operating hours. Units with add-on controls that report NOX mass emissions on a year-round basis under subpart H of this part may use separate ozone season and non-ozone season data pools to provide substitute data values, as described in § 75.34(a)(2) .
2 During unit operating hours.
3 Alternatively, where a unit with add-on NOX emission controls can demonstrate that the controls are operating properly during the missing data period, as provided in § 75.34 , the unit may report the greater of: (a) the maximum expected NOX concentration (or maximum controlled NOX emission rate, as applicable); or (b) 1.25 times the maximum controlled value at the corresponding load bin, from the previous 2,160 quality-assured monitor operating hours.
Table 3-Non-load-based Missing Data Procedure for NOX-Diluent CEMS and NOX Concentration CEMS
Trigger conditions | Calculation routines | ||
Monitor data availability (percent) | Duration (N) of CEMS outage (hours)1 | Method | Lookback period |
95 or more | N [LESS THAN EQUAL TO]24 | Average | 2,160 hours. * |
N [GREATER THAN]24 | 90th percentile | 2,160 hours. * | |
90 or more, but below 95 | N [LESS THAN EQUAL TO]8 | Average | 2,160 hours. * |
N [GREATER THAN]8 | 95th percentile | 2,160 hours. * | |
80 or more, but below 90 | N [GREATER THAN]0 | Maximum value3 | 2,160 hours. * |
Below 80, or operational bin indeterminable | N [GREATER THAN]0 | Maximum potential NOX emission rate2 or maximum potential NOX concentration2 | None. |
* If operational bins are used, the lookback period is 2,160 quality-assured, monitor operating hours, and data at the corresponding operational bin are used to provide substitute data values. If operational bins are not used, the lookback period is the previous 2,160 quality-assured monitor operating hours. For units that report data only for the ozone season, include only quality-assured monitor operating hours within the ozone season in the lookback period. Use data from no earlier than three years prior to the missing data period.
1 During unit operation.
2 Alternatively, where a unit with add-on NOX emission controls can demonstrate that the controls are operating properly, as provided in § 75.34 , the unit may report the greater of: (a) the maximum expected NOX concentration, (or maximum controlled NOX emission rate, as applicable); or (b) 1.25 times the maximum controlled value at the corresponding operational bin (if applicable), from the previous 2,160 quality-assured monitor operating hours.
3 Where a unit with add-on NOX emission controls can demonstrate that the controls are operating properly during the missing data period, as provided in § 75.34 , the unit may use the maximum controlled NOX concentration or emission rate from the previous 2,160 quality-assured monitor operating hours. Units with add-on controls that report NOX mass emissions on a year-round basis under subpart H of this part may use separate ozone season and non-ozone season data pools to provide substitute data values, as described in § 75.34(a)(2) .
Table 4-Non-load-based Missing Data Procedure for Flow Rate CEMS
Trigger conditions | Calculation routines | ||
Monitor data availability (percent) | Duration (N) of CEMS outage (hours)1 | Method | Lookback period |
95 or more | N [LESS THAN EQUAL TO]24 | Average | 2160 hours* |
N [GREATER THAN]24 | The greater of: Average 90th percentile | HB/HA 2160 hours* | |
90 or more, but below 95 | N [LESS THAN EQUAL TO]8 | Average | 2160 hours* |
N [GREATER THAN]8 | The greater of: Average 95th percentile HB/HA 2160 hours* | ||
80 or more, but below 90 | N [GREATER THAN]0 | Maximum value | 2160 hours* |
Below 80, or operational bin indeterminable | N [GREATER THAN]0 | Maximum potential flow rate | None |
* If operational bins are used, the lookback period is the previous 2,160 quality-assured, monitor operating hours and data at the corresponding operational bin are used to provide substitute data values. If operational bins are not used, the lookback period is the previous 2,160 quality-assured, monitor operating hours. For units that report data only for the ozone season, include only quality-assured monitor operating hours within the ozone season in the lookback period. Use data from no earlier than three years prior to the missing data period.
1 During unit operation.
40 C.F.R. §75.33