Current through Register 2024 Notice Reg. No. 38, September 20, 2024
In lieu of the requirements for estimating missing data
in Subparts C and D of 40 CFR Part 98 , the operator of a facility who is
reporting emissions under section
95115 or
95112 of this article, and who is
not eligible for abbreviated reporting under section
95103(a), must
follow the applicable procedures of this section for estimating missing or
invalid data. The operator must include the substituted data in the GHG
emissions data report and maintain all records, calculations, and data used to
estimate substituted data according to the requirements of section
95105 and
40 CFR Part 98 . Alternatively,
under the limited circumstances specified in this section for equipment
breakdown, the operator may request approval of an interim data collection
procedure as specified in section
95129(h)-(i). For
units combusting pure biomass-derived fuels or for de minimis
sources, the operator who is reporting emissions must follow either the
requirements below or the requirements of
40 CFR §
98.35. In the event that section
95129 becomes applicable to a
source, compliance with the requirements of section
95129 does not relieve the
operator from complying with other sections of this article.
(a)
Missing Data Substitution
Procedures for Units Reporting Under 40 CFR Part 75 . The operator of
a unit that is reporting CO2 using 40 CFR Part 75 must
follow the applicable missing data substitution procedures in Part 75 for
CO2 concentration, stack gas flow rate, fuel flow rate,
high heat value, and fuel carbon content, except as otherwise provided in this
section. Paragraphs (b) through (g) of this section do not apply to these units
for CO2 emissions. The operator may use applicable Part
75 missing data procedures or the procedures in paragraphs (b) through (g) of
this section for CH4 and N2O
emissions that are not de minimis if data required for
calculating CH4 and N2O emissions
are missing or invalid.
(b)
Missing Data Substitution Procedures for Other Units Equipped with
CEMS. The operator of a stationary combustion unit who monitors and
reports emissions and heat input data for that unit under section
95115 of this article using Tier 4
of Subpart C (40 CFR §
98.33(a)(4)) must follow the
applicable missing data substitution procedures in
40 CFR §
75.31 to
75.37 (revised as of July 1,
2009). For the purpose of missing data substitution, for CEMS certified under
40 CFR Part 60 , quality-assured data is defined according to the quality
assurance/quality control procedures in 40 CFR Part 60. Paragraphs (c) through
(h) of this section do not apply to units using Tier 4 for
CO2 emissions, but do apply for
CH4 and N2O emissions that are
not de minimis if data required for calculating
CH4 and N2O emissions are missing
or invalid.
(c)
Missing
Data Substitution Procedures for Fuel Characteristic Data. When the
applicable emissions estimation methods of this article require periodic
collection of fuel characteristic data (including carbon content, high heat
value, and molecular weight) the operator must demonstrate every reasonable
effort to obtain a fuel characteristic data capture rate of 100 percent for
each data year. When fuel characteristic data of a required fuel sample are
missing or invalid, the operator must first attempt to either reanalyze the
original sample or perform the fuel analysis on a backup sample, or replacement
sample from the same collection period as specified in
40 CFR §
98.34(a)(2)-(3), to obtain
valid fuel characteristic data. If the sample collection period has elapsed and
no valid fuel characteristic data can be obtained from a backup or replacement
sample, the operator must substitute for the missing data the values obtained
according to the procedures in section
95129(c)(1)-(3).
The data capture rate for the data year must be calculated as follows for each
type of fuel and each fuel characteristic parameter:
Data capture rate = S / T x 100%
Where:
S = Number of fuel samples for which valid fuel
characteristic data were obtained according to the applicable sampling
requirements (including sampling schedule)
T = Total number of fuel samples required by the
applicable sampling requirements
(1)
If the fuel characteristic data capture rate is at least 90.0 percent for the
data year, the operator must substitute the arithmetic average of the values of
that parameter immediately preceding and immediately following the missing data
incident that are representative of the fuel type. If the "after" value has not
been obtained by the time that the GHG emissions data report is due, the
operator must use the "before" value for missing data substitution.
(2) If the fuel characteristic data capture
rate is at least 80.0 percent but not more than 90.0 percent for the data year,
the operator must substitute for each missed value with the highest valid value
recorded for that type of fuel during the data year as well as the two previous
data years.
(3) If the operator is
unable to obtain fuel characteristic data such that less than 80.0 percent of a
fuel characteristic data element are directly accounted for, the operator must
then substitute for each missed data point as follows:
(A) If historical fuel characteristics data
are available and kept according to the requirements of section
95105, substitute with the greater
of the following:
1. The highest valid value
recorded for that type of fuel for all records kept under the requirements of
section 95105, or
2. The default value in Table 3-1 of this
section (for carbon content) or Table C-1 of 40 CFR Part 98 (for high heat
value). If a substitute value is not available in Table 3-1 of this section or
Table C-1 of 40 CFR Part 98, the operator must substitute the highest value
recorded for that type of fuel for all records kept pursuant to the
requirements of section
95105.
(B) For carbon content data, if historical
fuel characteristics data are not available and a default value is not listed
in Table 3-1 of this section, use 90 percent for other liquid and gaseous fuels
and 100 percent for other solid fuels in substituting for missed carbon content
data.
Table 3-1. Default Carbon
Content
|
Parameter |
Missing Data
Value |
| Anthracite Coal | 90% |
|
| Bituminous | 85% |
|
| Subbituminous/Lignite | 75% |
|
| Oil | 90% |
|
| Natural Gas | 75% |
(d)
Missing Data Substitution
Procedures for Fuel Consumption Data. The operator subject to the
requirements of this article must demonstrate every reasonable effort to obtain
a total facility fuel consumption data capture rate of 100 percent for each
year for each type of fuel. The total facility fuel consumption for the data
year can be determined using any combination of meters and/or other fuel
measurement devices or methods that individually meet the accuracy requirements
of this article, provided that the total amount of fuel consumed at the
facility level is completely accounted for during each time period that the
facility is in operation. For each fuel type, when the total facility fuel
consumption data that meet the accuracy requirements of this article are
available during each time period that the facility is in operation, but such
data are missing or invalid at the unit level, the operator must either
estimate missing unit-level fuel consumption data using other available data
parameters that are routinely measured at the facility (e.g., electrical load,
steam production, operating hours, production output, or fuel consumption data
at other measurement points), or use an applicable missing data substitution
procedure from section
95129(d)(1)-(3).
If during any time periods that the facility is in operation, a portion of the
total facility fuel consumption is missing or cannot be determined at the
accuracy required by this article, the operator must use the applicable missing
data substitution procedure from section
95129(d)(1)-(3)
below, so that the total facility fuel consumption quantity for the missing
data periods is reconstructed. If a source is eligible for more than one
procedure in section
95129(d)(1)-(3),
the operator has the option to choose one of the applicable procedures in
section 95129(d)(1)-(3).
The requirements in section
95129(d)(1)-(3)
are optional for sources that are not required to meet the accuracy standard
specified in section
95103(k) and for
sources that do not utilize fuel consumption data for emission calculation.
(1)
Continuous Fuel Flow Rate Data
Using Load Ranges. The sources that meet the following criteria are
eligible for using the procedures in paragraph (d)(1): the sources combust
gaseous or liquid fuels, produce electrical or thermal output, use a fuel
flowmeter system to continuously measure fuel flow rate; and are equipped with
a data acquisition and handling system (DAHS) that continuously records fuel
flow rates and measured electrical or thermal output on an hourly basis, which
enables segregation of the fuel flow rate data into bins. The operator of such
sources that applies the requirements in this paragraph must substitute missing
fuel flow rate data according to this paragraph.
Whenever quality-assured fuel flow rate data are
missing and there is no backup system available to record the fuel flow rate,
the operator must use the following procedures to account for the flow rate of
fuel combusted at the source for each hour during the missing data period.
Before using these procedures, operators must establish load ranges for the
affected sources using the procedures in paragraph (f) of this section.
When load ranges are used for estimating missing fuel
flow rate data, the operator must create and maintain separate fuel-specific
databases for the source. The database for each type of fuel combusted must
include the hours in which the fuel is combusted alone at the source and the
hours in which it is co-fired with any other fuel types. The database must
record fuel flow rate and corresponding electrical output or thermal output,
and assign these values into the established load bins. To be eligible to use
the missing data procedures in this paragraph, measured electrical output or
thermal output must be available for the hour(s) in which fuel flow rate data
are missing. If output data are missing, the operator must follow the
requirements of paragraph (d)(3).
(A)
Single Fuel Type. For missing data periods that occur when
only one type of fuel is being combusted, the operator must provide substitute
data for each hour of the missing data period as follows: Substitute the
arithmetic average of the hourly quality-assured fuel flow rate(s) measured and
recorded by a fuel flowmeter system at the corresponding operating source load
range during the previous 720 operating hours in which the source combusted
only that same fuel. If 720 hours of fuel flow rate data are not available at
the corresponding load range, the operator may combine available data with data
from higher load ranges if available until 720 hours are reached. If 720 hours
of quality-assured fuel flow rate data are not available when combined with
higher load ranges, the operator must substitute the maximum potential fuel
flow rate for each hour of the missing data period.
(B)
Multiple Fuel Types. For
missing data periods that occur when two or more different types of fuel are
being co-fired, the operator must provide substitute fuel flow rate data for
each hour of the missing data period as follows:
1. Substitute the maximum hourly
quality-assured fuel flow rate(s) measured and recorded by a fuel flowmeter
system at the corresponding operating source load range during the previous 720
operating hours when the fuel for which the flow rate data are missing was
co-fired with any other type of fuel. If 720 hours of fuel flow rate data are
not available at the corresponding load range, data from higher load ranges if
available may be combined until 720 hours are reached. If 720 hours of
quality-assured fuel flow rate data are not available when combined with higher
load ranges, the operator must substitute the maximum potential fuel flow rate
for each hour of the missing data period.
2. If, during an hour in which different
types of fuel are co-fired, quality-assured fuel flow rate data are missing for
two or more of the fuels being combusted, apply the procedures in subparagraph
(d)(1)(B)1. separately for each type of fuel.
3. If the missing data substitution required
in subparagraphs (d)(1)(B)1.-2. causes the reported hourly heat input rate
based on the combined fuel usage to exceed the maximum rated hourly heat input
of the unit, adjust the substitute fuel flow rate value(s) so that the reported
heat input rate equals the unit's maximum rated hourly heat
input.
(C)
Lookback Period. In any case where the missing data provisions
of this section require substitution of data measured and recorded more than
three years (26,280 clock hours) prior to the date and time of the missing data
period, the operator must substitute the maximum potential fuel flow rate for
each hour of the missing data period. In addition, for sources in operation
less than three years (26,280 clock hours), until 720 hours of quality-assured
fuel flowmeter data are available for the lookback periods described in
subparagraphs (d)(1)(A) and (d)(1)(B), the methodology in section (d)(3) must
be used to determine the appropriate substitute data
values.
(2)
Fuel
Consumption Data Without Load Ranges. The sources that meet the
following criteria are eligible to use the procedures in this paragraph: the
facility operator has established and implemented a fuel monitoring plan as a
part of the GHG Monitoring Plan specified in section
95105(c)(5), has
monitored fuel measurement equipment and maintained records of its proper
operation by recording fuel consumption quantities at least weekly, and has
compiled records of fuel consumption that are sufficient for the application of
the procedures in this paragraph. For operators that apply the requirements in
this paragraph, whenever quality-assured fuel consumption data are missing and
there is no backup system available to record the fuel consumption, the
operator must use the procedures in this paragraph to account for the
consumption of fuel combusted at the unit during the missing data period. For
fuels that are combusted less than 180 days in a calendar year, the operator
must record fuel consumption at least daily on each day the fuel is combusted.
For all other sources or fuels, the operator must record fuel consumption at
least weekly.
The data capture rate for the data year must be
calculated as follows for each unit with missing fuel consumption data:
Data capture rate = S / T x 100%
Where:
S = Number of fuel monitoring periods (e.g., days or
weeks) in the data year for which valid measured fuel consumption data are
available. Do not include fuel monitoring periods when the fuel was not
combusted at the unit.
T = Total number of fuel monitoring periods (e.g., days
or weeks) in the data year that the fuel is combusted at the unit.
(A)
Single Fuel. For missing
data periods that occur when only one type of fuel is being combusted, the
operator must provide substitute data for each missing data period as follows:
1. If the fuel consumption data capture rate
is equal to or greater than 95.0 percent during the data year, the operator
must develop an estimate based on available process data that are routinely
measured and recorded at the unit (e.g., electrical load, steam production,
operating hours) or fuel consumption data recorded at other upstream or
downstream measurement points.
2.
If the fuel consumption data capture rate is equal to or greater than 90.0
percent but less than 95.0 percent during the data year, the operator must
calculate substitute data as the 90th percentile value of the fuel consumption
data recorded for the data year as well as the two previous data
years.
3. If the fuel consumption
data capture rate is at least 80.0 percent but less than 90.0 percent during
the data year, the operator must calculate substitute data as the 95th
percentile value of the fuel consumption data recorded for the data year as
well as the two previous data years.
4. If the fuel consumption data capture rate
is less than 80.0 percent during the data year, the operator must apply as
substitute data the maximum potential fuel consumption
rate.
(B)
Multiple Fuels. For missing data periods that occur when two
or more different types of fuel are being co-fired, the operator must provide
substitute fuel flow rate data for each missing data period as follows:
1. If the fuel consumption data for a single
fuel are missing, provide substitute fuel consumption data for the missing data
period using the procedures in section
95129(d)(2)(A).
2. If fuel consumption data are missing for
two or more of the fuels being combusted, apply the procedures in section
95129(d)(2)(A)
(as applicable) separately for each type of fuel.
3. If the missing data substitution required
in section
95129(d)(2)(A)
causes the reported heat input rate based on the combined fuel usage to exceed
the maximum rated heat input of the source, adjust the substitute fuel
consumption value(s) so that the reported heat input rate equals the source's
maximum rated heat input.
(C)
Prorating Substitute
Value. When applying the procedures in subparagraphs (d)(2)(A)-(B), if
an individual missing data period is shorter than the fuel consumption data
monitoring period, the operator must prorate the specified value for the fuel
consumption data monitoring period by the missing data period. For example, for
a unit with a missing data period length of one day but weekly fuel consumption
monitoring schedule, the operator may divide the substitute value, estimated on
a weekly basis, by the number of days the unit operates in a week to obtain the
substitute value for the missing data day.
(3)
Alternate Missing Data Procedure
for Fuel Consumption Data. This paragraph applies to fuel combusting
units that cannot use the missing data procedures in paragraphs (d)(1) and
(d)(2). If fuel consumption data are missing or invalid for a fuel combusting
unit, and the total facility fuel consumption data cannot be determined at the
accuracy required by this article for the particular missing data period, the
operator must substitute for each hour of missing data using the maximum
potential fuel consumption rate for the unit. If fuel consumption data at the
facility level or at a higher aggregated-units level are available and meet the
accuracy requirements of this article, the operator may estimate the missing
unit-level fuel consumption data using available process data that are
routinely measured at the facility (e.g., electrical load, steam production,
operating hours) or fuel consumption data recorded at other upstream or
downstream measurement points that meet the accuracy requirements of this
article.
(e)
Missing Data Substitution Procedures for Steam Production. The
operator of a steam-producing unit who calculates and reports emissions using
Equation C-2c in 40 CFR
§
98.33(a)(2) must
apply the procedures in this paragraph to substitute for missing steam
production data, unless a backup system to record steam production is
available. For sources for which steam production data are not used to
calculate emissions, the operator may develop an estimate using available
process data that are routinely measured and recorded at the unit (e.g.,
electrical load, steam production, product output, operating hours) to estimate
missing steam production.
If hourly steam production data are not available at
the facility, the operator must record steam production data at least weekly
and use the weekly records for substituting the missing steam production data.
The operator must prorate the steam data using the same procedure in paragraph
(d)(2)(C).
The data capture rate for the data year must be
calculated as follows for each unit with a missing data period:
Data capture rate = S / T x 100%
Where:
S = Number of monitoring intervals (e.g. hourly, daily,
or weekly) with valid measured steam production data.
T = Total number of monitoring intervals that the unit
is operated in the data year.
(1) If
the steam production data capture rate is at least 90.0 percent during the data
year, the operator must develop an estimate using available process data that
are routinely measured and recorded at the unit (e.g., electrical load, steam
production, product output, and operating hours).
(2) If the steam production data capture rate
is at least 80.0 percent but less than 90.0 percent during the data year, the
operator must calculate substitute data as the 90th percentile value of the
steam production data recorded for the data year.
(3) If the steam production data capture rate
is less than 80.0 percent during the data year, the operator must substitute
the highest valid steam production value recorded in all records kept according
to section
95105(a).
(f)
Procedure for Establishing Load
Ranges. This paragraph is applicable to units that produce electrical
output or thermal output. For a single unit, the operator must establish ten
operating load ranges, each defined in terms of percent of the maximum hourly
average gross load of the unit, in gross megawatts (MW). (Do not use integrated
hourly gross load in MWh.) For a cogenerating unit or other unit at which some
portion of the heat input is not used to produce electricity, or for a unit for
which hourly average gross load in MW is not recorded separately, the operator
must use the hourly gross steam load of the unit, in pounds of steam per hour
at the measured temperature (°F) and pressure (psia), instead of gross MW.
Beginning with the first hour of unit operation after
installation and certification of the fuel flowmeter, for each hour of unit
operation the operator must record a number, 1 through 10, that identifies the
operating load range corresponding to the integrated hourly gross load of the
unit(s) recorded for each unit operating hour. The operator must calculate
maximum values and percentile values determined by this procedure using bias
adjusted values in the load ranges. When a bias adjustment is necessary for the
fuel flowmeter, the operator must apply the adjustment factor to all data
values placed in the load ranges. The operator must use the calculated maximum
values and percentile values to substitute for missing flow rate according to
the procedures in paragraph (d)(1) of this section.
(g)
Executive Officer Approved Load
Range. An operator may petition the Executive Officer for approval to
use an alternate load based methodology for substituting missing data to using
the procedures in section
95129(d)(1). The
operator must be able to prove to the satisfaction of the Executive Officer
that there is a direct correlation between fuel consumption and the proposed
load metric. At a minimum, the operator will have a system in place that
electronically measures and records fuel consumption and load at least hourly.
The alternate load metric must be a metric that can be accurately measured,
correlated to fuel consumption, and divided into ten operating load ranges. In
order to verify the feasibility of the methodology the Executive Officer will
require at least three years of fuel consumption and load data and may request
up to the maximum years of data required to be retained under section
95105(a).
(h)
Procedure for Approval of Interim
Fuel Analytical Data Collection Procedure During Equipment Breakdowns.
(1) In the event of an unforeseen breakdown
of the fuel characteristic data monitoring or fuel flow monitoring equipment
used to estimate emissions under this article, the Executive Officer may
authorize an operator to use an interim data collection procedure under the
circumstances specified below. The operator must satisfactorily demonstrate to
the Executive Officer that:
(A) The breakdown
may result in a loss of more than 10 percent of a fuel characteristic data
element or a fuel usage data element for the data year, and back-up sampling
for affected fuel characteristics is unavailable;
(B) The affected monitoring equipment cannot
be promptly repaired or replaced without shutting down a process unit
significantly affecting facility operations, or the monitoring equipment must
be replaced and replacement equipment is not immediately available;
and,
(C) The interim procedure will
not remain in effect longer than is reasonably necessary for repair or
replacement of the malfunctioning monitoring equipment.
(2) An operator seeking approval of an
interim data collection procedure must, within sixty days of the monitoring
equipment breakdown, submit a written request to the Executive Officer that
includes all of the following:
(A) The
proposed start date and end date of the interim procedure;
(B) A detailed description of what data are
affected by the breakdown;
(C) A
discussion of the accuracy of data collected during the interim procedure
compared with the data collected under the usual procedure used by the
operator;
(D) A demonstration that
the criteria in paragraph (h)(1) are satisfied, and operator certification that
no feasible alternative procedure exists that would provide more accurate
emissions data.
(3) The
Executive Officer may limit the duration of the interim data collection
procedure to ensure the criteria in paragraph (h)(1) are met.
(4) When reviewing an interim data collection
procedure, the Executive Officer shall determine whether the accuracy of data
collected under the procedure is reasonably equivalent to data collected from
properly functioning monitoring equipment, and if it is not, the relative
accuracy to assign for purposes of assessing possible material misstatement
under section
95131 of this article. Data
collected pursuant to an approved interim data collection procedure shall be
considered captured data for purposes of compliance with the capture rate
requirements in this section.
(5)
The Executive Officer shall provide written notification to the operator of
approval or disapproval of the interim data collection procedure within sixty
days of receipt of the request, or within thirty days of receipt of any
additional information requested by the Executive Officer, whichever is
later.
(i)
Procedure for Approval of Interim Data Collection Procedure During
Breakdown for Units Equipped with CEMS.
(1) In the event of an unforeseen breakdown
of CEMS equipment at a combustion unit where the operator uses the Tier 4
Calculation Methodology (40
CFR §
98.33(a)(4)) to
monitor and report emissions under this article, the operator may request
approval from the Executive Officer to temporarily use the Tier 1 Calculation
Methodology (40 CFR §
98.33(a)(1)) for pipeline
quality natural gas, or the Tier 2 Calculation Methodology (40 CFR §
98.33(a)(2)) for pipeline
quality natural gas, biomass, or municipal solid waste, or the Tier 3
Calculation Methodology (40
CFR §
98.33(a)(3)) for
other fuels, to calculate combustion emissions during the equipment breakdown
period. For cement kiln units where the operator uses the Tier 4 Methodology to
report both combustion and process emissions, the operator may request approval
from the Executive Officer to temporarily use the clinker-based process
emissions calculation methodology provided in
40 CFR §
98.83(d). The operator must
satisfactorily demonstrate to the Executive Officer that:
(A) The breakdown will result in a loss of
more than 10 percent of the concentration, flow rate, or other information used
to calculate and report annual emissions for the data year, and that back-up
monitoring is unavailable;
(B) The
affected monitoring equipment cannot be promptly repaired or replaced without
shutting down a process unit significantly affecting facility operations, or
the monitoring equipment must be replaced and replacement equipment is not
immediately available; and,
(C) The
interim procedure will not remain in effect longer than is reasonably necessary
for repair or replacement of the malfunctioning monitoring
equipment.
(2) The
operator must collect fuel samples and comply with all applicable requirements
of the Tier 2 or Tier 3 Calculation Methodology in
40 CFR §
98.33(a)(2) or (3), as
modified by section
95115 of this article, during the
equipment breakdown period. Fuel characteristics data provided by the fuel
suppliers can be used if available. The operator must, within sixty days of the
monitoring equipment breakdown, submit a written request to the Executive
Officer that includes all the following information:
(A) The proposed start date and end date of
the interim procedure, including a demonstration that the interim procedure
will not remain in effect longer than is reasonably necessary for repair or
replacement of the malfunctioning equipment;
(B) A detailed description of what data are
affected by the breakdown; and,
(C)
An interim monitoring plan that meets the requirements of the Tiers 2 and 3
Calculation Methodologies as applicable by fuel type in section
95115, and, if applicable, the
clinker-based process emissions calculation procedure (40 CFR §
98.83(d)) used to report
cement kiln process emissions.
(3) The Executive Officer may limit the
duration of the interim data collection procedure to ensure the criteria in
paragraph (i)(1) are met.
(4) The
Executive Officer shall provide written notification to the operator of
approval or disapproval of the interim data collection procedure within sixty
days of receipt of the request, or within thirty days of receipt of any
additional information requested by the Executive Officer, whichever is
later.
1. New
subarticle 3 (section
95129) and section filed
12-14-2011; operative 1-1-2012 pursuant to Government Code section
11343.4
(Register 2011, No. 50).
2. Amendment of subsections
(c)(3)-(c)(3)(B) filed 12-31-2013; operative 1-1-2014 pursuant to Government
Code section
11343.4(b)(3)
(Register 2014, No. 1).
3. Amendment of subsections (a),
(a)(3)(A)2., (a)(3)(B), including renumbering for former table 1 as table 3-1,
and amendment of subsections (i)(1) and (i)(2)(C) filed 9-1-2017; operative
1-1-2018 (Register 2017, No. 35).
Note: Authority cited: Sections
38510,
38530,
39600,
39601,
39607,
39607.4
and
41511,
Health and Safety Code. Reference: Sections
38530,
39600
and
41511,
Health and Safety Code.
