[Code of Federal Regulations]
[Title 40, Volume 14]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR75.21]

[Page 256-258]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 75--CONTINUOUS EMISSION MONITORING--Table of Contents
 
            Subpart C--Operation and Maintenance Requirements
 
Sec. 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 Sec. 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 Sec. 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 
Sec. 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 Sec. 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 Sec. 72.2 of this 
chapter) and combusts higher sulfur fuel(s) only for infrequent, non-
routine operations (e.g., 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) The quality assurance provisions of Secs. 75.11(e)(3)(i) through 
75.11(e)(3)(iv)

[[Page 257]]

shall apply to all units with SO2 monitoring systems during 
hours in which only very low sulfur fuel (as defined in Sec. 72.2 of 
this chapter) is combusted in the unit.
    (9) Provided that a unit with an SO2 monitoring system is 
not exempted from the SO2 RATA requirements of this part 
under paragraphs (a)(6) or (a)(7) of this section, any calendar quarter 
during which a unit combusts only very low sulfur fuel (as defined in 
Sec. 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 Sec. 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 Sec. 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 
Sec. 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 
Sec. 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 Sec. 75.20(a)(5) for initial certification or

[[Page 258]]

Sec. 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 other audit, the system is out-of-control. The owner or 
operator shall follow the procedures for out-of-control periods in 
Sec. 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; 67 FR 40433, June 12, 2002; 67 FR 53505, Aug. 16, 
2002]