§  75.21 Quality assurance and quality control requirements.

(a) Continuous emission monitoring systems. The owner or operator of an affected unit shall operate, calibrate and maintain each continuous emission monitoring system used to report emission data under the Acid Rain Program as follows:

(1) The owner or operator shall operate, calibrate and maintain each primary and redundant backup continuous emission monitoring system according to the quality assurance and quality control procedures in appendix B of this part.

(2) The owner or operator shall ensure that each non-redundant backup CEMS meets the quality assurance requirements of §  75.20(d) for each day and quarter that the system is used to report data.

(3) The owner or operator shall perform quality assurance upon a reference method backup monitoring system according to the requirements of method 2, 6C, 7E, or 3A in appendix A of part 60 of this chapter (supplemented, as necessary, by guidance from the Administrator), instead of the procedures specified in appendix B of this part.

(4) The owner or operator of a unit with an SO2 continuous emission monitoring system is not required to perform the daily or quarterly assessments of the SO2 monitoring system under appendix B to this part on any day or in any calendar quarter in which only gaseous fuel is combusted in the unit if, during those days and calendar quarters, SO2 emissions are determined in accordance with §  75.11(e)(1) or (e)(2). However, such assessments are permissible, and if any daily calibration error test or linearity test of the SO2 monitoring system is failed while the unit is combusting only gaseous fuel, the SO2 monitoring system shall be considered out-of-control. The length of the out-of-control period shall be determined in accordance with the applicable procedures in section 2.1.4 or 2.2.3 of appendix B to this part.

(5) For a unit with an SO2 continuous monitoring system, in which gaseous fuel that is very low sulfur fuel (as defined in §  72.2 of this chapter) is sometimes burned as a primary or backup fuel and in which higher-sulfur fuel(s) such as oil or coal are, at other times, burned as primary or backup fuel(s), the owner shall perform the relative accuracy test audits of the SO2 monitoring system (as required by section 6.5 of appendix A to this part and section 2.3.1 of appendix B to this part) only when the higher-sulfur fuel is combusted in the unit and shall not perform SO2 relative accuracy test audits when the very low sulfur gaseous fuel is the only fuel being combusted.

(6) If the designated representative certifies that a unit with an SO2 monitoring system burns only very low sulfur fuel (as defined in §  72.2 of this chapter), the SO2 monitoring system is exempted from the relative accuracy test audit requirements in appendices A and B to this part.

(7) If the designated representative certifies that a particular unit with an SO2 monitoring system combusts primarily fuel(s) that are very low sulfur fuel(s) (as defined in §  72.2 of this chapter), and combusts higher sulfur fuel (s) only as emergency backup fuel(s) or for short-term testing, the SO2 monitoring system shall be exempted from the RATA requirements of appendices A and B to this part in any calendar year that the unit combusts the higher-sulfur fuel(s) for no more than 480 hours. If, in a particular calendar year, the higher-sulfur fuel usage exceeds 480 hours, the owner or operator shall perform a RATA of the SO2 monitor (while combusting the higher-sulfur fuel) either by the end of the calendar quarter in which the exceedance occurs or by the end of a 720 unit (or stack) operating hour grace period (under section 2.3.3 of appendix B to this part) following the quarter in which the exceedance occurs.

(8) On and after April 1, 2000, the quality assurance provisions of §§  75.11(e)(3)(i) through 75.11(e)(3)(iv) shall apply to all units with SO2 monitoring systems during hours in which only very low sulfur fuel (as defined in §  72.2 of this chapter) is combusted in the unit.

(9) Provided that a unit with an SO2 monitoring system is not exempted under paragraphs (a)(6) or (a)(7) of this section from the SO2 RATA requirements of this part, any calendar quarter during which a unit combusts only very low sulfur fuel (as defined in §  72.2 of this chapter) shall be excluded in determining the quarter in which the next relative accuracy test audit must be performed for the SO2 monitoring system. However, no more than eight successive calendar quarters shall elapse after a relative accuracy test audit of an SO2 monitoring system, without a subsequent relative accuracy test audit having been performed. The owner or operator shall ensure that a relative accuracy test audit is performed, in accordance with paragraph (a)(5) of this section, either by the end of the eighth successive elapsed calendar quarter since the last RATA or by the end of a 720 unit (or stack) operating hour grace period, as provided in section 2.3.3 of appendix B to this part.

(10) The owner or operator who, in accordance with §  75.11(e)(1), uses a certified flow monitor and a certified diluent monitor and Equation F-23 in appendix F to this part to calculate SO2 emissions during hours in which a unit combusts only natural gas or pipeline natural gas (as defined in §  72.2 of this chapter) shall meet all quality control and quality assurance requirements in appendix B to this part for the flow monitor and the diluent monitor.

(b) Continuous opacity monitoring systems. The owner or operator of an affected unit shall operate, calibrate, and maintain each continuous opacity monitoring system used under the Acid Rain Program according to the procedures specified for State Implementation Plans, pursuant to part 51, appendix M of this chapter.

(c) Calibration gases. The owner or operator shall ensure that all calibration gases used to quality assure the operation of the instrumentation required by this part shall meet the definition in §  72.2 of this chapter.

(d) Notification for periodic relative accuracy test audits. The owner or operator or the designated representative shall submit a written notice of the dates of relative accuracy testing as specified in §  75.61.

(e) Consequences of audits. The owner or operator shall invalidate data from a continuous emission monitoring system or continuous opacity monitoring system upon failure of an audit under appendix B to this part or any other audit, beginning with the unit operating hour of completion of a failed audit as determined by the Administrator. The owner or operator shall not use invalidated data for reporting either emissions or heat input, nor for calculating monitor data availability.

(1) Audit decertification. Whenever both an audit of a continuous emission or opacity monitoring system (or component thereof, including the data acquisition and handling system), of any excepted monitoring system under appendix D or E to this part, or of any alternative monitoring system under subpart E of this part, and a review of the initial certification application or of a recertification application, reveal that any system or component should not have been certified or recertified because it did not meet a particular performance specification or other requirement of this part, both at the time of the initial certification or recertification application submission and at the time of the audit, the Administrator will issue a notice of disapproval of the certification status of such system or component. For the purposes of this paragraph, an audit shall be either a field audit of the facility or an audit of any information submitted to EPA or the State agency regarding the facility. By issuing the notice of disapproval, the certification status is revoked prospectively by the Administrator. The data measured and recorded by each system shall not be considered valid quality-assured data from the date of issuance of the notification of the revoked certification status until the date and time that the owner or operator completes subsequently approved initial certification or recertification tests. The owner or operator shall follow the procedures in §  75.20(a)(5) for initial certification or §  75.20(b)(5) for recertification to replace, prospectively, all of the invalid, non-quality-assured data for each disapproved system.

(2) Out-of-control period. Whenever a continuous emission monitoring system or continuous opacity monitoring system fails a quality assurance audit or any another audit, the system is out-of-control. The owner or operator shall follow the procedures for out-of-control periods in §  75.24.

[58 FR 3701, Jan. 11, 1993, as amended at 60 FR 26527, 26566, May 17, 1995; 61 FR 25582, May 22, 1996; 61 FR 59159, Nov. 20, 1996; 64 FR 28599, May 26, 1999]