(a) Except for monitor malfunctions, associated repairs, and required quality assurance or quality control activities (including, as applicable, calibration checks and required zero and span adjustments of the monitoring system), you must conduct all monitoring at all times the other solid waste incineration unit is operating.(b) You must obtain valid monitoring data for at least 75 percent of the operating hours per day for at least 90 percent of the operating days per calendar quarter. An operating day is any day the unit combusts any municipal or institutional solid waste.(c) If you do not obtain the minimum data required in subsections (a) and (b) of this section, you have deviated from the data collection requirement regardless of the operating parameter level monitored.(d) Do not use data recorded during monitor malfunctions, associated repairs, and required quality assurance or quality control activities for meeting the requirements of this division, including data averages and calculations. You must use all the data collected during all other periods in assessing compliance with the operating limits.