1. (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.
2. (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.

3. (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:

   1. (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. (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. (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:

      1. (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. 1. The highest valid value recorded for that type of fuel for all records kept under the requirements of section 95105, or
         2. 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.

      2. (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%

   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

4. (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. (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.

      1. (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.

      2. (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. 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. 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. 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.
      3. (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.

      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).

   2. (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.

      1. (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. 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. 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. 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. 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.

      2. (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. 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. 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. 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.
      3. (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.

      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.

   3. (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.

5. (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.

   1. (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. (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. (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).

   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.

6. (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.

7. (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).

8. (h) Procedure for Approval of Interim Fuel Analytical Data Collection Procedure During Equipment Breakdowns.

   1. (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:

      1. (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;
      2. (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,
      3. (C) The interim procedure will not remain in effect longer than is reasonably necessary for repair or replacement of the malfunctioning monitoring equipment.

   2. (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:

      1. (A) The proposed start date and end date of the interim procedure;
      2. (B) A detailed description of what data are affected by the breakdown;
      3. (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;
      4. (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. (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. (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. (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.

9. (i) Procedure for Approval of Interim Data Collection Procedure During Breakdown for Units Equipped with CEMS.

   1. (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:

      1. (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;
      2. (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,
      3. (C) The interim procedure will not remain in effect longer than is reasonably necessary for repair or replacement of the malfunctioning monitoring equipment.

   2. (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:

      1. (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;
      2. (B) A detailed description of what data are affected by the breakdown; and,
      3. (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. (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. (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.

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.

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.

History

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).