Appendix P to Part 51 - Minimum Emission Monitoring Requirements
40:2.0.1.1.2.25.11.20.33 : Appendix P
Appendix P to Part 51 - Minimum Emission Monitoring Requirements
1.0 Purpose. This appendix P sets forth the minimum
requirements for continuous emission monitoring and recording that
each State Implementation Plan must include in order to be approved
under the provisions of 40 CFR 51.214. These requirements include
the source categories to be affected; emission monitoring,
recording, and reporting requirements for those sources;
performance specifications for accuracy, reliability, and
durability of acceptable monitoring systems; and techniques to
convert emission data to units of the applicable State emission
standard. Such data must be reported to the State as an indication
of whether proper maintenance and operating procedures are being
utilized by source operators to maintain emission levels at or
below emission standards. Such data may be used directly or
indirectly for compliance determination or any other purpose deemed
appropriate by the State. Though the monitoring requirements are
specified in detail, States are given some flexibility to resolve
difficulties that may arise during the implementation of these
regulations.
1.1 Applicability. The State plan shall require the owner
or operator of an emission source in a category listed in this
appendix to: (1) Install, calibrate, operate, and maintain all
monitoring equipment necessary for continuously monitoring the
pollutants specified in this appendix for the applicable source
category; and (2) complete the installation and performance tests
of such equipment and begin monitoring and recording within 18
months of plan approval or promulgation. The source categories and
the respective monitoring requirements are listed below.
1.1.1 Fossil fuel-fired steam generators, as specified in
paragraph 2.1 of this appendix, shall be monitored for opacity,
nitrogen oxides emissions, sulfur dioxide emissions, and oxygen or
carbon dioxide.
1.1.2 Fluid bed catalytic cracking unit catalyst regenerators,
as specified in paragraph 2.4 of this appendix, shall be monitored
for opacity.
1.1.3 Sulfuric acid plants, as specified in paragraph 2.3 of
this appendix, shall be monitored for sulfur dioxide emissions.
1.1.4 Nitric acid plants, as specified in paragraph 2.2 of this
appendix, shall be monitored for nitrogen oxides emissions.
1.2 Exemptions. The States may include provisions within
their regulations to grant exemptions from the monitoring
requirements of paragraph 1.1 of this appendix for any source which
is:
1.2.1 Subject to a new source performance standard promulgated
in 40 CFR part 60 pursuant to section 111 of the Clean Air Act;
or
1.2.2 not subject to an applicable emission standard of an
approved plan; or
1.2.3 scheduled for retirement within 5 years after inclusion of
monitoring requirements for the source in appendix P, provided that
adequate evidence and guarantees are provided that clearly show
that the source will cease operations prior to such date.
1.3 Extensions. States may allow reasonable extensions of
the time provided for installation of monitors for facilities
unable to meet the prescribed timeframe (i.e., 18 months
from plan approval or promulgation) provided the owner or operator
of such facility demonstrates that good faith efforts have been
made to obtain and install such devices within such prescribed
timeframe.
1.4 Monitoring System Malfunction. The State plan may
provide a temporary exemption from the monitoring and reporting
requirements of this appendix during any period of monitoring
system malfunction, provided that the source owner or operator
shows, to the satisfaction of the State, that the malfunction was
unavoidable and is being repaired as expeditiously as
practicable.
2.0 Minimum Monitoring Requirement. States must, as a
minimum, require the sources listed in paragraph 1.1 of this
appendix to meet the following basic requirements.
2.1 Fossil fuel-fired steam generators. Each fossil
fuel-fired steam generator, except as provided in the following
subparagraphs, with an annual average capacity factor of greater
than 30 percent, as reported to the Federal Power Commission for
calendar year 1974, or as otherwise demonstrated to the State by
the owner or operator, shall conform with the following monitoring
requirements when such facility is subject to an emission standard
of an applicable plan for the pollutant in question.
2.1.1 A continuous monitoring system for the measurement of
opacity which meets the performance specifications of paragraph
3.1.1 of this appendix shall be installed, calibrated, maintained,
and operated in accordance with the procedures of this appendix by
the owner or operator of any such steam generator of greater than
250 million BTU per hour heat input except where:
2.1.1.1 gaseous fuel is the only fuel burned, or
2.1.1.2 oil or a mixture of gas and oil are the only fuels
burned and the source is able to comply with the applicable
particulate matter and opacity regulations without utilization of
particulate matter collection equipment, and where the source has
never been found, through any administrative or judicial
proceedings, to be in violation of any visible emission standard of
the applicable plan.
2.1.2 A continuous monitoring system for the measurement of
sulfur dioxide which meets the performance specifications of
paragraph 3.1.3 of this appendix shall be installed, calibrated,
maintained, and operated on any fossil fuel-fired steam generator
of greater than 250 million BTU per hour heat input which has
installed sulfur dioxide pollutant control equipment.
2.1.3 A continuous monitoring system for the measurement of
nitrogen oxides which meets the performance specification of
paragraph 3.1.2 of this appendix shall be installed, calibrated,
maintained, and operated on fossil fuel-fired steam generators of
greater than 1000 million BTU per hour heat input when such
facility is located in an Air Quality Control Region where the
Administrator has specifically determined that a control strategy
for nitrogen dioxide is necessary to attain the national standards,
unless the source owner or operator demonstrates during source
compliance tests as required by the State that such a source emits
nitrogen oxides at levels 30 percent or more below the emission
standard within the applicable plan.
2.1.4 A continuous monitoring system for the measurement of the
percent oxygen or carbon dioxide which meets the performance
specifications of paragraphs 3.1.4 or 3.1.5 of this appendix shall
be installed, calibrated, operated, and maintained on fossil
fuel-fired steam generators where measurements of oxygen or carbon
dioxide in the flue gas are required to convert either sulfur
dioxide or nitrogen oxides continuous emission monitoring data, or
both, to units of the emission standard within the applicable
plan.
2.2 Nitric acid plants. Each nitric acid plant of greater
than 300 tons per day production capacity, the production capacity
being expressed as 100 percent acid, located in an Air Quality
Control Region where the Administrator has specifically determined
that a control strategy for nitrogen dioxide is necessary to attain
the national standard shall install, calibrate, maintain, and
operate a continuous monitoring system for the measurement of
nitrogen oxides which meets the performance specifications of
paragraph 3.1.2 for each nitric acid producing facility within such
plant.
2.3 Sulfuric acid plants. Each Sulfuric acid plant of
greater than 300 tons per day production capacity, the production
being expressed as 100 percent acid, shall install, calibrate,
maintain and operate a continuous monitoring system for the
measurement of sulfur dioxide which meets the performance
specifications of paragraph 3.1.3 for each sulfuric acid producing
facility within such plant.
2.4 Fluid bed catalytic cracking unit catalyst regenerators
at petroleum refineries. Each catalyst regenerator for fluid
bed catalytic cracking units of greater than 20,000 barrels per day
fresh feed capacity shall install, calibrate, maintain, and operate
a continuous monitoring system for the measurement of opacity which
meets the performance specifications of paragraph 3.1.1.
3.0 Minimum specifications. All State plans shall require
owners or operators of monitoring equipment installed to comply
with this appendix, except as provided in paragraph 3.2, to
demonstrate compliance with the following performance
specifications.
3.1 Performance specifications. The performance
specifications set forth in appendix B of part 60 are incorporated
herein by reference, and shall be used by States to determine
acceptability of monitoring equipment installed pursuant to this
appendix except that (1) where reference is made to the
“Administrator” in appendix B, part 60, the term State
should be inserted for the purpose of this appendix (e.g., in
Performance Specification 1, 1.2, “ * * * monitoring systems
subject to approval by the Administrator,” should be
interpreted as, “* * * monitoring systems subject to approval by
the State”), and (2) where reference is made to the
“Reference Method” in appendix B, part 60, the State may allow the
use of either the State approved reference method or the Federally
approved reference method as published in part 60 of this chapter.
The Performance Specifications to be used with each type of
monitoring system are listed below.
3.1.1 Continuous monitoring systems for measuring opacity shall
comply with Performance Specification 1.
3.1.2 Continuous monitoring systems for measuring nitrogen
oxides shall comply with Performance Specification 2.
3.1.3 Continuous monitoring systems for measuring sulfur dioxide
shall comply with Performance Specification 2.
3.1.4 Continuous monitoring systems for measuring oxygen shall
comply with Performance Specification 3.
3.1.5 Continuous monitoring systems for measuring carbon dioxide
shall comply with Performance Specification 3.
3.2 Exemptions. Any source which has purchased an
emission monitoring system(s) prior to September 11, 1974, may be
exempt from meeting such test procedures prescribed in appendix B
of part 60 for a period not to exceed five years from plan approval
or promulgation.
3.3 Calibration Gases. For nitrogen oxides monitoring
systems installed on fossil fuel-fired steam generators, the
pollutant gas used to prepare calibration gas mixtures (section
6.1, Performance Specification 2, appendix B, part 60 of this
chapter) shall be nitric oxide (NO). For nitrogen oxides monitoring
systems installed on nitric acid plants, the pollutant gas used to
prepare calibration gas mixtures (section 6.1, Performance
Specification 2, appendix B, part 60 of this chapter) shall be
nitrogen dioxide (NO2). These gases shall also be used for daily
checks under paragraph 3.7 of this appendix as applicable. For
sulfur dioxide monitoring systems installed on fossil fuel-fired
steam generators or sulfuric acid plants, the pollutant gas used to
prepare calibration gas mixtures (section 6.1, Performance
Specification 2, appendix B, part 60 of this chapter) shall be
sulfur dioxide (SO2). Span and zero gases should be traceable to
National Bureau of Standards reference gases whenever these
reference gases are available. Every 6 months from date of
manufacture, span and zero gases shall be reanalyzed by conducting
triplicate analyses using the reference methods in appendix A, part
60 of this chapter as follows: for SO2, use Reference Method 6; for
nitrogen oxides, use Reference Method 7; and for carbon dioxide or
oxygen, use Reference Method 3. The gases may be analyzed at less
frequent intervals if longer shelf lives are guaranteed by the
manufacturer.
3.4 Cycling times. Cycling times include the total time a
monitoring system requires to sample, analyze and record an
emission measurement.
3.4.1 Continuous monitoring systems for measuring opacity shall
complete a minimum of one cycle of operation (sampling, analyzing,
and data recording) for each successive 10-second period.
3.4.2 Continuous monitoring systems for measuring oxides of
nitrogen, carbon dioxide, oxygen, or sulfur dioxide shall complete
a minimum of one cycle of operation (sampling, analyzing, and data
recording) for each successive 15-minute period.
3.5 Monitor location. State plans shall require all
continuous monitoring systems or monitoring devices to be installed
such that representative measurements of emissions or process
parameters (i.e., oxygen, or carbon dioxide) from the
affected facility are obtained. Additional guidance for location of
continuous monitoring systems to obtain representative samples are
contained in the applicable Performance Specifications of appendix
B of part 60 of this chapter.
3.6 Combined effluents. When the effluents from two or
more affected facilities of similar design and operating
characteristics are combined before being released to the
atmosphere, the State plan may allow monitoring systems to be
installed on the combined effluent. When the affected facilities
are not of similar design and operating characteristics, or when
the effluent from one affected facility is released to the
atmosphere through more than one point, the State should establish
alternate procedures to implement the intent of these
requirements.
3.7 Zero and drift. State plans shall require owners or
operators of all continuous monitoring systems installed in
accordance with the requirements of this appendix to record the
zero and span drift in accordance with the method prescribed by the
manufacturer of such instruments; to subject the instruments to the
manufacturer's recommended zero and span check at least once daily
unless the manufacturer has recommended adjustments at shorter
intervals, in which case such recommendations shall be followed; to
adjust the zero and span whenever the 24-hour zero drift or 24-hour
calibration drift limits of the applicable performance
specifications in appendix B of part 60 are exceeded; and to adjust
continuous monitoring systems referenced by paragraph 3.2 of this
appendix whenever the 24-hour zero drift or 24-hour calibration
drift exceed 10 percent of the emission standard.
3.8 Span. Instrument span should be approximately 200 per
cent of the expected instrument data display output corresponding
to the emission standard for the source.
3.9 Alternative procedures and requirements. In cases
where States wish to utilize different, but equivalent, procedures
and requirements for continuous monitoring systems, the State plan
must provide a description of such alternative procedures for
approval by the Administrator. Some examples of situations that may
require alternatives follow:
3.9.1 Alternative monitoring requirements to accommodate
continuous monitoring systems that require corrections for stack
moisture conditions (e.g., an instrument measuring steam generator
SO2 emissions on a wet basis could be used with an instrument
measuring oxygen concentration on a dry basis if acceptable methods
of measuring stack moisture conditions are used to allow accurate
adjustments of the measured SO2 concentration to dry basis.)
3.9.2 Alternative locations for installing continuous monitoring
systems or monitoring devices when the owner or operator can
demonstrate that installation at alternative locations will enable
accurate and representative measurements.
3.9.3 Alternative procedures for performing calibration checks
(e.g., some instruments may demonstrate superior drift
characteristics that require checking at less frequent
intervals).
3.9.4 Alternative monitoring requirements when the effluent from
one affected facility or the combined effluent from two or more
identical affected facilities is released to the atmosphere through
more than one point (e.g., an extractive, gaseous monitoring system
used at several points may be approved if the procedures
recommended are suitable for generating accurate emission
averages).
3.9.5 Alternative continuous monitoring systems that do not meet
the spectral response requirements in Performance Specification 1,
appendix B of part 60, but adequately demonstrate a definite and
consistent relationship between their measurements and the opacity
measurements of a system complying with the requirements in
Performance Specification 1. The State may require that such
demonstration be performed for each affected facility.
4.0 Minimum data requirements. The following paragraphs
set forth the minimum data reporting requirements necessary to
comply with § 51.214(d) and (e).
4.1 The State plan shall require owners or operators of
facilities required to install continuous monitoring systems to
submit a written report of excess emissions twice per year at
6-month intervals and the nature and cause of the excess emissions,
if known. The averaging period used for data reporting should be
established by the State to correspond to the averaging period
specified in the emission test method used to determine compliance
with an emission standard for the pollutant/source category in
question. The required report shall include, as a minimum, the data
stipulated in this appendix.
4.2 For opacity measurements, the summary shall consist of the
magnitude in actual percent opacity of all one-minute (or such
other time period deemed appropriate by the State) averages of
opacity greater than the opacity standard in the applicable plan
for each hour of operation of the facility. Average values may be
obtained by integration over the averaging period or by
arithmetically averaging a minimum of four equally spaced,
instantaneous opacity measurements per minute. Any time period
exempted shall be considered before determining the excess averages
of opacity (e.g., whenever a regulation allows two minutes of
opacity measurements in excess of the standard, the State shall
require the source to report all opacity averages, in any one hour,
in excess of the standard, minus the two-minute exemption). If more
than one opacity standard applies, excess emissions data must be
submitted in relation to all such standards.
4.3 For gaseous measurements the summary shall consist of
emission averages, in the units of the applicable standard, for
each averaging period during which the applicable standard was
exceeded.
4.4 The date and time identifying each period during which the
continuous monitoring system was inoperative, except for zero and
span checks, and the nature of system repairs or adjustments shall
be reported. The State may require proof of continuous monitoring
system performance whenever system repairs or adjustments have been
made.
4.5 When no excess emissions have occurred and the continuous
monitoring system(s) have not been inoperative, repaired, or
adjusted, such information shall be included in the report.
4.6 The State plan shall require owners or operators of affected
facilities to maintain a file of all information reported as
specified in paragraph 4.1 of this appendix, all other data
collected either by the continuous monitoring system or as
necessary to convert monitoring data to the units of the applicable
standard for a minimum of two years from the date of collection of
such data or submission of such summaries.
5.0 Data Reduction. The State plan shall require owners
or operators of affected facilities to use the following procedures
for converting monitoring data to units of the standard where
necessary.
5.1 For fossil fuel-fired steam generators the following
procedures shall be used to convert gaseous emission monitoring
data in parts per million to g/million cal (lb/million BTU) where
necessary:
5.1.1 When the owner or operator of a fossil fuel-fired steam
generator elects under paragraph 2.1.4 of this appendix to measure
oxygen in the flue gases, the measurements of the pollutant
concentration and oxygen concentration shall each be on a dry basis
and the following conversion procedure used:
E = CF [20.9/20.9 − %O2]
5.1.2 When the owner or operator elects under paragraph 2.1.4 of
this appendix to measure carbon dioxide in the flue gases, the
measurement of the pollutant concentration and the carbon dioxide
concentration shall each be on a consistent basis (wet or dry) and
the following conversion procedure used:
E = CFc (100 / %CO2)
5.1.3 The values used in the equations under paragraph 5.1 are
derived as follows:
E = pollutant emission, g/million cal (lb/million BTU),
C = pollutant concentration, g/dscm (lb/dscf), determined by
multiplying the average concentration (ppm) for each hourly period
by 4.16 × 10−5 M g/dscm per ppm (2.64 × 10−9 M lb/dscf per ppm)
where M = pollutant molecular weight, g/g-mole (lb/lb-mole). M = 64
for sulfur dioxide and 46 for oxides of nitrogen.
%O2, %CO2 = Oxygen or carbon dioxide volume (expressed as
percent) determined with equipment specified under paragraphs 3.1.4
and 3.1.5 of this appendix.
5.2 For sulfuric acid plants the owner or operator shall:
5.2.1 establish a conversion factor three times daily according
to the procedures to § 60.84(b) of this chapter;
5.2.2 multiply the conversion factor by the average sulfur
dioxide concentration in the flue gases to obtain average sulfur
dioxide emissions in Kg/metric ton (lb/short ton); and
5.2.3 report the average sulfur dioxide emission for each
averaging period in excess of the applicable emission standard in
the reports submitted as specified in paragraph 4.1 of this
appendix.
5.3 For nitric acid plants the owner or operator shall:
5.3.1 establish a conversion factor according to the procedures
of § 60.73(b) of this chapter;
5.3.2 multiply the conversion factor by the average nitrogen
oxides concentration in the flue gases to obtain the nitrogen
oxides emissions in the units of the applicable standard;
5.3.3 report the average nitrogen oxides emission for each
averaging period in excess of the applicable emission standard, in
the reports submitted as specified in paragraph 4.1 of this
appendix.
5.4 Any State may allow data reporting or reduction procedures
varying from those set forth in this appendix if the owner or
operator of a source shows to the satisfaction of the State that
his procedures are at least as accurate as those in this appendix.
Such procedures may include but are not limited to, the
following:
5.4.1 Alternative procedures for computing emission averages
that do not require integration of data (e.g., some facilities may
demonstrate that the variability of their emissions is sufficiently
small to allow accurate reduction of data based upon computing
averages from equally spaced data points over the averaging
period).
5.4.2 Alternative methods of converting pollutant concentration
measurements to the units of the emission standards.
6.0 Special Consideration. The State plan may provide for
approval, on a case-by-case basis, of alternative monitoring
requirements different from the provisions of parts 1 through 5 of
this appendix if the provisions of this appendix (i.e., the
installation of a continuous emission monitoring system) cannot be
implemented by a source due to physical plant limitations or
extreme economic reasons. To make use of this provision, States
must include in their plan specific criteria for determining those
physical limitations or extreme economic situations to be
considered by the State. In such cases, when the State exempts any
source subject to this appendix by use of this provision from
installing continuous emission monitoring systems, the State shall
set forth alternative emission monitoring and reporting
requirements (e.g., periodic manual stack tests) to satisfy the
intent of these regulations. Examples of such special cases
include, but are not limited to, the following:
6.1 Alternative monitoring requirements may be prescribed when
installation of a continuous monitoring system or monitoring device
specified by this appendix would not provide accurate
determinations of emissions (e.g., condensed, uncombined water
vapor may prevent an accurate determination of opacity using
commercially available continuous monitoring systems).
6.2 Alternative monitoring requirements may be prescribed when
the affected facility is infrequently operated (e.g., some affected
facilities may operate less than one month per year).
6.3 Alternative monitoring requirements may be prescribed when
the State determines that the requirements of this appendix would
impose an extreme economic burden on the source owner or
operator.
6.4 Alternative monitoring requirements may be prescribed when
the State determines that monitoring systems prescribed by this
appendix cannot be installed due to physical limitations at the
facility.
[40 FR 46247, Oct. 6, 1975, as amended at 51 FR 40675, Nov. 7,
1986; 81 FR 59808, Aug. 30, 2016; 85 FR 49600, Aug. 14, 2020]