[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: 40CFR75.30]

[Page 260-261]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 75--CONTINUOUS EMISSION MONITORING--Table of Contents
 
             Subpart D--Missing Data Substitution Procedures
 
Sec. 75.30  General provisions.


    (a) Except as provided in Sec. 75.34, the owner or operator shall 
provide substitute data for each affected unit using a continuous 
emission monitoring system according to the missing data procedures in 
this subpart whenever the unit combusts any fuel and:
    (1) A valid, quality-assured hour of SO2 concentration 
data (in ppm) has not been measured and recorded for an affected unit by 
a certified SO2 pollutant concentration monitor, or by an 
approved alternative monitoring method under subpart E of this part, 
except as provided in paragraph (d) of this section; or
    (2) A valid, quality-assured hour of flow data (in scfh) has not 
been measured and recorded for an affected unit from a certified flow 
monitor, or by an approved alternative monitoring system under subpart E 
of this part; or
    (3) A valid, quality-assured hour of NOX emission rate 
data (in lb/mmBtu) has not been measured or recorded for an affected 
unit, either by a certified NOX-diluent continuous emission 
monitoring system or by an approved alternative monitoring system under 
subpart E of this part; or
    (4) A valid, quality-assured hour of CO2 concentration 
data (in percent CO2, or percent O2 converted to 
percent CO2 using the procedures in appendix F to this part) 
has not been measured and recorded for an affected unit, either by a 
certified CO2 continuous emission monitoring system or by an 
approved alternative monitoring method under subpart E of this part; or
    (5) A valid, quality-assured hour of NOX concentration 
data (in ppm) has not been measured or recorded for an affected unit, 
either by a certified NOX concentration monitoring system 
used to determine NOX mass emissions, as defined in 
Sec. 75.71(a)(2), or by an approved alternative monitoring system under 
subpart E of this part; or
    (6) A valid, quality-assured hour of CO2 or O2 
concentration data (in percent CO2, or percent O2) 
used for the determination of heat input has not been measured and 
recorded for an affected unit, either by a certified CO2 or 
O2 diluent monitor, or by an approved alternative monitoring 
method under subpart E of this part; or
    (7) A valid, quality-assured hour of moisture data (in percent 
H2O) has not been measured or recorded for an affected unit, 
either by a certified moisture monitoring system or an approved 
alternative monitoring method under subpart E of this part. This 
requirement does not apply when a default percent moisture value, as 
provided in Secs. 75.11(b) or 75.12(b), is used to account for the 
hourly moisture content of the stack gas; or
    (8) A valid, quality-assured hour of heat input rate data (in mmBtu/
hr) has not been measured and recorded for a unit from a certified flow 
monitor and a certified diluent (CO2 or O2) 
monitor or by an approved alternative monitoring system under subpart E 
of this part.
    (b) However, the owner or operator shall have no need to provide 
substitute data according to the missing data procedures in this subpart 
if the owner or operator uses SO2, CO2, 
NOX, or O2 concentration, flow rate, percent 
moisture, or NOX emission rate data recorded from either a 
certified redundant or regular non-redundant backup CEMS, a like-kind 
replacement non-redundant backup analyzer, or a backup reference method 
monitoring system when the certified primary monitor is not operating or 
is out-of-control. A redundant or non-redundant backup continuous 
emission monitoring system must have been certified according to the 
procedures in Sec. 75.20 prior to the missing data period. Non-redundant 
backup continuous emission monitoring system must pass a linearity check 
(for pollutant concentration monitors) or a calibration error test (for 
flow monitors) prior to each period of use of the certified backup 
monitor for recording and reporting emissions. Use of a certified backup 
monitoring system or backup reference method monitoring system is 
optional and at the discretion of the owner or operator.

[[Page 261]]

    (c) When the certified primary monitor is not operating or out-of-
control, then data recorded for an affected unit from a certified backup 
continuous emission monitor or backup reference method monitoring system 
are used, as if such data were from the certified primary monitor, to 
calculate monitor data availability in Sec. 75.32, and to provide the 
quality-assured data used in the missing data procedures in Secs. 75.31 
and 75.33, such as the ``hour after'' value.
    (d) The owner or operator shall comply with the applicable 
provisions of this paragraph during hours in which a unit with an 
SO2 continuous emission monitoring system combusts only 
gaseous fuel.
    (1) Whenever a unit with an SO2 CEMS combusts only 
natural gas or pipeline natural gas (as defined in Sec. 72.2 of this 
chapter) and the owner or operator is using the procedures in section 7 
of appendix F to this part to determine SO2 mass emissions 
pursuant to Sec. 75.11(e)(1), the owner or operator shall, for purposes 
of reporting heat input data under Sec. 75.57(b)(5), and for the 
calculation of SO2 mass emissions using Equation F-23 in 
section 7 of appendix F to this part, substitute for missing data from a 
flow monitoring system, CO2 diluent monitor or O2 
diluent monitor using the missing data substitution procedures in 
Sec. 75.36.
    (2) Whenever a unit with an SO2 CEMS combusts gaseous 
fuel and the owner or operator uses the gas sampling and analysis and 
fuel flow procedures in appendix D to this part to determine 
SO2 mass emissions pursuant to Sec. 75.11(e)(2), the owner or 
operator shall substitute for missing total sulfur content, gross 
calorific value, and fuel flowmeter data using the missing data 
procedures in appendix D to this part and shall also, for purposes of 
reporting heat input data under Sec. 75.54(b)(5) or Sec. 75.57(b)(5), as 
applicable, substitute for missing data from a flow monitoring system, 
CO2 diluent monitor, or O2 diluent monitor using 
the missing data substitution procedures in Sec. 75.36.
    (3) The owner or operator of a unit with an SO2 
monitoring system shall not include hours when the unit combusts only 
gaseous fuel in the SO2 data availability calculations in 
Sec. 75.32 or in the calculations of substitute SO2 data 
using the procedures of either Sec. 75.31 or Sec. 75.33, for hours when 
SO2 emissions are determined in accordance with 
Sec. 75.11(e)(1) or (e)(2). For the purpose of the missing data and 
availability procedures for SO2 pollutant concentration 
monitors in Secs. 75.31 and 75.33 only, all hours during which the unit 
combusts only gaseous fuel shall be excluded from the definition of 
``monitor operating hour,'' ``quality-assured monitor operating hour,'' 
``unit operating hour,'' and ``unit operating day,'' when SO2 
emissions are determined in accordance with Sec. 75.11(e)(1) or (e)(2).
    (4) During all hours in which a unit with an SO2 
continuous emission monitoring system combusts only gaseous fuel and the 
owner or operator uses the SO2 monitoring system to determine 
SO2 mass emissions pursuant to Sec. 75.11(e)(3), the owner or 
operator shall determine the percent monitor data availability for 
SO2 in accordance with Sec. 75.32 and shall use the standard 
SO2 missing data procedures of Sec. 75.33.

[60 FR 26528, 26566, May 17, 1995, as amended at 61 FR 59160, Nov. 20, 
1996; 64 FR 28600, May 26, 1999; 67 FR 40433, June 12, 2002]