MEMORANDUM 

TO: Docket ID No. EPA-HQ-OAR-2014-0831 

FROM: Alexis McKittrick and Mark de Figueiredo, EPA/CCD

DATE: September 23, 2015 

SUBJECT: Data Category Assignments and Confidentiality Determinations for All Data 

Elements (excluding inputs to emission equations) in the Final “2015 Revisions 

and Confidentiality Determinations for Petroleum and Natural Gas Systems” 

In the rulemaking titled “2015 Revisions and Confidentiality Determinations for 

Petroleum and Natural Gas Systems” (referred hereafter as the Subpart W 2015 Amendments), 

the EPA is finalizing revisions to the current subpart W reporting requirements. These revisions 

include the addition of reporting requirements for two new industry segments (onshore 

petroleum and natural gas gathering and boosting and onshore natural gas transmission pipeline), 

and the addition of reporting requirements for emissions from hydraulically fractured oil wells 

and for well identification numbers in the onshore petroleum and natural gas production industry 

segment. The additions to the reporting requirements would involve revisions to existing 

reporting requirements and the addition of new data elements. In conjunction with the revisions, 

the EPA is finalizing confidentiality determinations for the new data elements. In this 

memorandum, we provide a list of all the new data elements (excluding those assigned to the 

“Inputs to Emission Equations” data category), the confidentiality determinations, and where 

appropriate, the data category assignments. 

Table 1 shows the category assignments for all new data elements assigned to data 

categories for which a categorical confidentiality determination was previously finalized in 

2011.1 The categorical confidentiality determinations established in 2011 apply to the data 

elements listed in this table. 

Table 2 shows the finalized categorical assignments and confidentiality determinations 

for all new data elements assigned to the data categories “Unit/Process Operating Characteristics 

That Are Not Inputs to Emission Equations” and “Unit/Process ‘Static’ Characteristics that Are 

Not Inputs to Emission Equations.” For the data elements listed in this table, the EPA is 

 

1

 See “Proposed Confidentiality Determinations for Data Required Under the Mandatory Greenhouse Gas Reporting 

Rule and Proposed Amendment to Special Rules Governing Certain Information Obtained Under the Clean Air Act” 

published on July 7, 2010 (75 FR 39094); and “Confidentiality Determinations for Data Required under the 

Mandatory Greenhouse Gas Reporting Rule and Amendment to Special Rules Governing Certain Information 

Obtained under the Clean Air Act” published on May 26, 2011 (76 FR 30782). 
2 

finalizing confidentiality determinations based on a case-by-case review for each listed data 

element. 

Table 3 shows the final confidentiality determinations for six new data elements for 

which no categorical assignment was proposed. 

The Subpart W 2015 Amendments also include new subpart W reporting requirements 

assigned to the “Inputs to Emission Equations” data category. For a list of the inputs to emission 

equations, see the memorandum titled “Review for Potential Disclosure Concerns for Inputs to 

Emission Equations Affected by the ‘2015 Revisions and Confidentiality Determinations for 

Petroleum and Natural Gas Systems.’” We determined that three data elements are inputs only in 

certain situations (§98.236(g)(5)(i), §98.236(i)(1)(i) and §98.236(j)(3)(ii)). Specifically, these 

data elements are inputs when the applicable data are available for only one well, one blowdown, 

or one gas-liquid separator. For situations when these data elements are not inputs (i.e., when 

data are available for multiple wells, blowdowns, or gas-liquid separators), the confidentiality 

determinations noted in this memorandum apply. 

A copy of the Subpart W 2015 Amendments can be found on EPA’s website at 

http://www.epa.gov/ghgreporting/reporters/rules/index.html. Copies of the proposed and final 

CBI rules identified in this memorandum are available on EPA’s website: 

http://www.epa.gov/ghgreporting/reporters/cbi/index.html, at the following links: 

http://www.gpo.gov/fdsys/pkg/FR-2010-07-07/pdf/2010-16317.pdf and 

http://www.gpo.gov/fdsys/pkg/FR-2011-05-26/pdf/2011-12930.pdf. 
3 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

Natural Gas Pneumatic Devices §98.236(b)(1)(ii)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if the total number of devices of each type is an estimated value determined according to §98.233(a)(2), whether the calendar year is the first calendar year of reporting or the second calendar year of reporting. 

Calculation Methodology and Methodological Tier 

§98.236(b)(3) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, for the natural gas pneumatic devices combined, calculated using Equation W-1 and §98.233(a)(4), and reported in paragraph (b)(1)(i) of this section. 

Emissions 

§98.236(b)(4) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, for the natural gas pneumatic devices combined, calculated using Equation W-1 and §98.233(a)(4), and reported in paragraph (b)(1)(i) of this section. 

Emissions 

Natural Gas Driven Pneumatic Pumps §98.236(c)(3) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, for all natural gas driven pneumatic pumps combined, calculated according to §98.233(c)(1) and (2). 

Emissions 

2 The categorical confidentiality determinations for the data categories listed in this table were finalized on May 26, 2011 (see 76 FR 30782). 
4 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(c)(4) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, for all natural gas driven pneumatic pumps combined, calculated according to §98.233(c)(1) and (2). 

Emissions 

Acid Gas Removal Units §98.236(d)(1)(i) Unique name or ID number for acid gas removal units. Facility and Unit 

Identifier Information 

§98.236(d)(1)(iii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, the calculation method used to calculate CO2emissions from the acid gas removal unit, as specified in §98.233(d). 

Calculation Methodology and Methodological Tier 

§98.236(d)(1)(iv) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if any CO2 emissions from the acid gas removal unit were recovered and transferred outside the facility, the annual quantity of CO2, in metric tons CO2, that was recovered and transferred outside the facility. 

Emissions 

§98.236(d)(1)(v) For the onshore petroleum and natural gas gathering and boosting 

industry segment, the annual CO2 emissions, in metric tons CO2, from the acid gas removal unit, calculated using any one of the calculation methods specified in §98.233(d) and as specified in §98.233(d)(10) and (11). 

Emissions 

§98.236(d)(1)(vi) For the onshore petroleum and natural gas gathering and boosting 

industry segment, name of the county that best represents the equipment supplying gas to the unit. 

Facility and Unit Identifier Information 
5 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(d)(2)(ii)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each unit for which Calculation Method 3 in §98.233(d) is used, which equation was used (Equation W-4A or W4B). 

Calculation Methodology and Methodological Tier 

§98.236(d)(2)(iii)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each unit for which Calculation Method 4 in §98.233(d) is used, the name of the simulation software package used. 

Calculation Methodology and Methodological Tier 

Dehydrators §98.236(e)(1)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, a unique name or ID number for the dehydrator. 

Facility and Unit Identifier Information 

§98.236(e)(1)(xvi)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, if any emissions are vented to a flare or regenerator firebox/fire tubes, annual CO2 emissions, in metric tons CO2, for the dehydrator. 

Emissions 
6 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(e)(1)(xvi)(B) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, if any emissions are vented to a flare or regenerator firebox/fire tubes, annual CH4 emissions, in metric tons CH4, for the dehydrator. 

Emissions 

§98.236(e)(1)(xvi)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, if any emissions are vented to a flare or regenerator firebox/fire tubes, annual N2O emissions, in metric tons N2O, for the glycol dehydrator. 

Emissions 

§98.236(e)(1)(xvii)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, if any emissions are not routed to a flare or regenerator firebox/fire tubes, annual CO2 emissions, in metric tons CO2, for the dehydrator when not venting to a flare orregenerator firebox/fire tubes. 

Emissions 
7 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(e)(1)(xvii)(B) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, if any emissions are not routed to a flare or regenerator firebox/fire tubes, annual CH4 emissions, in metric tons CH4, for the dehydrator when not venting to a flare orregenerator firebox/fire tubes. 

Emissions 

§98.236(e)(1)(xviii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, name of the county that best represents the equipment supplying gas to the dehydrator. 

Facility and Unit Identifier Information 

§98.236(e)(2)(iv)(B) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, for the glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd vented to a flare or regenerator firebox/fire tubes. 

Emissions 

§98.236(e)(2)(iv)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, for the glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd vented to a flare or regenerator firebox/fire tubes. 

Emissions 
8 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(e)(2)(iv)(D) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual N2O emissions, in metric tons N2O, for the glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd vented to a flare or regenerator firebox/fire tubes. 

Emissions 

§98.236(e)(2)(v)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions in metric tons CO2, for emissions from all dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd that were not vented to a flare or regenerator firebox/fire tubes, where emissions are added together for all such dehydrators. 

Emissions 

§98.236(e)(2)(v)(B) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions in metric tons CH4, for emissions from all dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd that were not vented to a flare or regenerator firebox/fire tubes, where emissions are added together for all such dehydrators. 

Emissions 

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, for emissions from all desiccant dehydrators venting to a flare or regenerator firebox/fire tubes. 

Emissions 

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, for emissions from all desiccant dehydrators venting to a flare or regenerator firebox/fire tubes. 

Emissions 
9 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual N2O emissions, in metric tons N2O, for emissions from all desiccant dehydrators venting to a flare or regenerator firebox/fire tubes. 

Emissions 

§98.236(e)(3)(ii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, for emissions from all desiccant dehydrators that are not venting to a flare or regenerator firebox/fire tubes, summing for all such dehydrators. 

Emissions 

§98.236(e)(3)(iii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, for emissions from all desiccant dehydrators that are not venting to a flare or regenerator firebox/fire tubes, summing for all such dehydrators. 

Emissions 

Liquids Unloading §98.236(f)(1)(ii) A list of the well ID numbers associated with each sub-basin and well 

tubing diameter and pressure group ID for which Calculation Method 1 was used to calculate natural gas emissions from well venting for liquids unloading. 

Facility and Unit Identifier Information 

§98.236(f)(2)(i) A list of the well ID numbers associated with each sub-basin for 

which Calculation Method 2 or 3 was used to calculate natural gas emissions from well venting for liquids unloading. 

Facility and Unit Identifier Information 

Completions and Workovers with Hydraulic Fracturing§98.236(g)(1) For oil wells, for each completion or workover and well type 

combination, the sub-basin ID. 

Facility and Unit Identifier Information 
10 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(g)(1) A list of the well ID numbers associated with each sub-basin that had 

completions or workovers with hydraulic fracturing during the calendar year. 

Facility and Unit Identifier Information 

§98.236(g)(2) For each sub-basin and well type combination, the well type 

combination (horizontal or vertical, gas well or oil well). 

Facility and Unit Identifier Information 

§98.236(g)(4) For each sub-basin and well type combination, the calculation method 

used. 

Calculation Methodology and Methodological Tier 

§98.236(g)(5)(ii) The well ID numbers of the wells for which flowback rate is 

measured. 

Facility and Unit Identifier Information 

§98.236(g)(6)(iii) If using Equation W-10B to calculate annual volumetric total gas 

emissions, the well ID number for which vented natural gas volume was measured. 

Facility and Unit Identifier Information 

§98.236(g)(7) For each sub-basin and well type combination, annual gas emissions, 

in standard cubic feet (“Es,n” in Equation W-10A or W-10B). 

Emissions 

§98.236(g)(8) For each sub-basin and well type combination, annual CO2 emissions, 

in metric tons CO2. 

Emissions 

§98.236(g)(9) For each sub-basin and well type combination, annual CH4 emissions, 

in metric tons CH4. 

Emissions 

§98.236(g)(10) For each sub-basin and well type combination, if the well emissions 

were vented to a flare, the total N2O emissions, in metric tons N2O. 

Emissions 
11 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

Completions and Workovers without Hydraulic Fracturing §98.236(h)(1)(i) A list of the well ID numbers associated with each sub-basin for gas 

well completions without hydraulic fracturing and without flaring. 

Facility and Unit Identifier Information 

§98.236(h)(2)(i) A list of the well ID numbers associated with each sub-basin for gas 

well completions without hydraulic fracturing and with flaring. 

Facility and Unit Identifier Information 

§98.236(h)(3)(i) A list of the well ID numbers associated with each sub-basin for gas 

well workovers without hydraulic fracturing and without flaring. 

Facility and Unit Identifier Information 

§98.236(h)(4)(i) A list of the well ID numbers associated with each sub-basin for gas 

well workovers without hydraulic fracturing and with flaring. 

Facility and Unit Identifier Information 

Blowdown Vent Stacks §98.236(i)(1)(ii) For the onshore petroleum and natural gas gathering and boosting and 

onshore natural gas transmission pipeline industry segments, if calculating emissions from blowdown vent stacks by equipment type, annual CO2 emissions for the equipment or event type, in metric tons CO2. 

Emissions 

§98.236(i)(1)(iii) For the onshore petroleum and natural gas gathering and boosting and 

onshore natural gas transmission pipeline industry segments, if calculating emissions from blowdown vent stacks by equipment type, annual CH4 emissions for the equipment or event type, in metric tons CH4. 

Emissions 
12 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(i)(2)(i) For the onshore petroleum and natural gas gathering and boosting and 

onshore natural gas transmission pipeline industry segments, if you elect to calculate emissions from blowdown vent stacks by using a flow meter according to §98.233(i)(3), annual CO2 emissions from all blowdown vent stacks at the facility for which emissions were calculated using flow meters, in metric tons CO2 (the sum of all CO2mass emission values calculated according to §98.233(i)(3), for all flow meters). 

Emissions 

§98.236(i)(2)(ii) For the onshore petroleum and natural gas gathering and boosting and 

onshore natural gas transmission pipeline industry segments, if you elect to calculate emissions from blowdown vent stacks by using a flow meter according to §98.233(i)(3), annual CH4 emissions from all blowdown vent stacks at the facility for which emissions were calculated using flow meters, in metric tons CH4, (the sum of all CH4mass emission values calculated according to §98.233(i)(3), for all flow meters). 

Emissions 

§98.236(i)(3)(i) For the onshore natural gas transmission pipeline segment, for each 

state, the annual CO2 emissions in metric tons CO2. 

Emissions 

§98.236(i)(3)(ii) For the onshore natural gas transmission pipeline segment, for each 

state, the annual CH4 emissions in metric tons CH4. 

Emissions 

Onshore Production and Onshore Petroleum and Natural Gas Gathering and Boosting Storage Tanks §98.236(j) For the onshore petroleum and natural gas gathering and boosting 

industry segment, whether your facility sends produced oil to atmospheric tanks. 

Facility and Unit Identifier Information 
13 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(j)(1)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, the county name. 

Facility and Unit Identifier Information 

§98.236(j)(1)(ii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, calculation method used, and name of the software package used if using Calculation Method 1. 

Calculation Methodology and Methodological Tier 

§98.236(j)(1)(vii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, minimum and maximum concentration (mole fraction) of CO2 in flash gas from storage tanks. 

Emissions 

§98.236(j)(1)(viii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, minimum and maximum concentration (mole fraction) of CH4 in flash gas from storage tanks. 

Emissions 

§98.236(j)(1)(xii)(D) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if any emissions from the atmospheric tanks at your facility were controlled with vapor recovery systems, annual CO2 emissions, in metric tons CO2, from atmospheric tanks equipped with vapor recovery systems. 

Emissions 

§98.236(j)(1)(xii)(E) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if any emissions from the atmospheric tanks at your facility were controlled with vapor recovery systems, annual CH4 emissions, in metric tons CH4, from atmospheric tanks equipped with vapor recovery systems. 

Emissions 
14 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(j)(1)(xiii)(B) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if any atmospheric tanks at your facility vented gas directly to the atmosphere without using a vapor recovery system or without flaring, annual CO2 emissions, in metric tons CO2, that resulted from venting gas directly to the atmosphere. 

Emissions 

§98.236(j)(1)(xiii)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if any atmospheric tanks at your facility vented gas directly to the atmosphere without using a vapor recovery system or without flaring, annual CH4 emissions, in metric tons CH4, that resulted from venting gas directly to the atmosphere. 

Emissions 

§98.236(j)(1)(xiv)(B) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if you controlled emissions from any atmospheric tanks at your facility with one or more flares, annual CO2 emissions, in metric tons CO2, from atmospheric tanks that controlled emissions with one or more flares. 

Emissions 

§98.236(j)(1)(xiv)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if you controlled emissions from any atmospheric tanks at your facility with one or more flares, annual CH4 emissions, in metric tons CH4, from atmospheric tanks that controlled emissions with one or more flares. 

Emissions 
15 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(j)(1)(xiv)(D) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 1 or 2, if you controlled emissions from any atmospheric tanks at your facility with one or more flares, annual N2O emissions, in metric tons N2O, from atmospheric tanks that controlled emissions with one or more flares. 

Emissions 

§98.236(j)(2)(ii)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each county with atmospheric tanks whose emissions were calculated using Calculation Method 3 and that did not control emissions with flares, county name. 

Facility and Unit Identifier Information 

§98.236(j)(2)(ii)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 3, annual CO2emissions, in metric tons CO2, from atmospheric tanks in the county that did not control emissions with flares, calculated using Equation W-15 and adjusted for vapor recovery, if applicable. 

Emissions 

§98.236(j)(2)(ii)(D) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 3, annual CH4emissions, in metric tons CH4, from atmospheric tanks in the county that vented gas directly to the atmosphere, calculated using Equation W-15 and adjusted for vapor recovery, if applicable. 

Emissions 

§98.236(j)(2)(iii)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for each county with atmospheric tanks whose emissions were calculated using Calculation Method 3 and that controlled emissions with flares, county name. 

Facility and Unit Identifier Information 
16 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(j)(2)(iii)(C) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 3, annual CO2emissions, in metric tons CO2, from atmospheric tanks in the county that controlled emissions with flares, calculated using Equation W-15. 

Emissions 

§98.236(j)(2)(iii)(D) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 3, annual CH4emissions, in metric tons CH4, from atmospheric tanks in the county that controlled emissions with flares, calculated using Equation W-15. 

Emissions 

§98.236(j)(2)(iii)(E) For the onshore petroleum and natural gas gathering and boosting 

industry segment, if using Calculation Method 3, annual N2O emissions, in metric tons N2O, from atmospheric tanks in the county that controlled emissions with flares. 

Emissions 

§98.236(j)(3)(iii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, that resulted from dump valves on gas-liquid separators in the county not closing properly during the calendar year, calculated using Equation W-16. 

Emissions 

§98.236(j)(3)(iv) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, that resulted from the dump valves on gas-liquid separators in the county not closing properly during the calendar year, calculated using Equation W-16. 

Emissions 
17 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

Well Testing §98.236(l)(1)(ii) If using Equation W-17A to calculate annual volumetric natural gas 

emissions at actual conditions from oil wells and the emissions were not vented to a flare, well ID numbers for the wells tested in the calendar year. 

Facility and Unit Identifier Information 

§98.236(l)(2)(ii) If using Equation W-17A to calculate annual volumetric natural gas 

emissions at actual conditions from oil wells and the emissions were vented to a flare, well ID numbers for the wells tested in the calendar year. 

Facility and Unit Identifier Information 

§98.236(l)(3)(ii) If using Equation W-17B to calculate annual volumetric natural gas 

emissions at actual conditions from oil wells and the emissions were not vented to a flare, well ID numbers for the wells tested in the calendar year. 

Facility and Unit Identifier Information 

§98.236(l)(4)(ii) If using Equation W-17B to calculate annual volumetric natural gas 

emissions at actual conditions from oil wells and the emissions were vented to a flare, well ID numbers for the wells tested in the calendar year. 

Facility and Unit Identifier Information 

Associated Natural Gas §98.236(m)(1) For each sub-basin, a list of well ID numbers for wells for which 

associated gas was vented or flared. 

Facility and Unit Identifier Information 

§98.236(m)(7)(i) A list of well ID numbers for wells in each sub-basin for which 

associated gas was vented directly to the atmosphere without flaring. 

Facility and Unit Identifier Information 
18 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(m)(8)(i) A list of well ID numbers for wells in each sub-basin for which 

associated gas was flared. 

Facility and Unit Identifier Information 

Flare Stacks §98.236(n)(1) For the onshore petroleum and natural gas gathering and boosting 

industry segment, unique name or ID for the flare stack. 

Facility and Unit Identifier Information 

§98.236(n)(2) For the onshore petroleum and natural gas gathering and boosting 

industry segment, indicate whether the flare stack has a continuous flow measurement device. 

Test and Calibration Methods 

§98.236(n)(3) For the onshore petroleum and natural gas gathering and boosting 

industry segment, indicate whether the flare stack has a continuous gas composition analyzer on feed gas to the flare. 

Test and Calibration Methods 

§98.236(n)(9) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions for each flare stack, in metric tons CO2 (refer to Equation W-20). 

Emissions 

§98.236(n)(10) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions for each flare stack, in metric tons CH4 (refer to Equation W-19), unless a CEMS was used to measure emissions. 

Emissions 

§98.236(n)(11) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual N2O emissions for each flare stack, in metric tons N2O (refer to Equation W-40), unless a CEMS was used to measure emissions. 

Emissions 
19 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(n)(12) For the onshore petroleum and natural gas gathering and boosting 

industry segment, whether a CEMS was used to measure emissions from the flare. 

Calculation Methodology and Methodological Tier 

Centrifugal Compressors §98.236(o)(5)(ii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, from centrifugal compressors with wet seal oil degassing vents. 

Emissions 

§98.236(o)(5)(iii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, from centrifugal compressors with wet seal oil degassing vents. 

Emissions 

Reciprocating Compressors §98.236(p)(5)(ii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, from reciprocating compressors. 

Emissions 

§98.236(p)(5)(iii) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, from reciprocating compressors. 

Emissions 

Equipment Leaks by Population Count §98.236(r)(1)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, emission source type, component type, service type, and geographic location. 

Facility and Unit Identifier Information 
20 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(r)(1)(iv) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CO2 emissions, in metric tons CO2, for the emission source by component type, service type, and geographic location. 

Emissions 

§98.236(r)(1)(v) For the onshore petroleum and natural gas gathering and boosting 

industry segment, annual CH4 emissions, in metric tons CH4, for the emission source by component type, service type, and geographic location. 

Emissions 

§98.236(r)(3)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, calculation method used for equipment leaks. 

Calculation Methodology and Methodological Tier 

§98.236(r)(3)(ii)(A) For the onshore petroleum and natural gas gathering and boosting 

industry segment, an indication of whether the facility contains the major equipment type. 

Facility and Unit Identifier Information 

Combustion Equipment at Onshore Petroleum and Natural Gas Production Facilities, Onshore Petroleum and Nand Boosting Facilities, and Natural Gas Distribution Facilities §98.236(z)(1)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for external fuel combustion units with a rated heat capacity less than or equal to 5 million Btu per hour or internal fuel combustion units that are not compressor-drivers, with a rated heat capacity less than or equal to 1 million Btu per hour (or the equivalent of 130 horsepower), the type of combustion unit. 

Facility and Unit Identifier Information 
21 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(z)(2)(i) For the onshore petroleum and natural gas gathering and boosting 

industry segment, for external fuel combustion units with a rated heat capacity greater than 5 mmBtu/hr; internal fuel combustion units that are not compressor-drivers, with a rated heat capacity greater than 1 million Btu per hour (or the equivalent of 130 horsepower); or internal fuel combustion units of any heat capacity that are compressordrivers, the type of combustion unit. 

Facility and Unit Identifier Information 

§98.236(z)(2)(iv) For each combustion unit type listed in §98.236(z)(2), annual CO2

emissions, in metric tons CO2, calculated according to §98.233(z)(1) and (2). 

Emissions 

§98.236(z)(2)(v) For each combustion unit type listed in §98.236(z)(2), annual CH4

emissions, in metric tons CH4, calculated according to §98.233(z)(1) and (2). 

Emissions 

§98.236(z)(2)(vi) For each combustion unit type listed in §98.236(z)(2), annual N2O 

emissions, in metric tons N2O, calculated according to §98.233(z)(1) and (2). 

Emissions 

Onshore Petroleum and Natural Gas Production §98.236(aa)(1)(ii)(D) For the onshore petroleum and natural gas production industry 

segment only, a list of the well ID numbers for producing wells at the end of the calendar year (exclude only those wells permanently taken out of production, i.e., plugged and abandoned). 

Facility and Unit Identifier Information 

§98.236(aa)(1)(ii)(E) For the onshore petroleum and natural gas production industry 

segment only, a list of the well ID numbers for wells acquired during the calendar year. 

Facility and Unit Identifier Information 
22 

Table 1. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to Cat

Determinations2

Rule Citation Final Data Element 

Final Category 

Assignment 

§98.236(aa)(1)(ii)(F) For the onshore petroleum and natural gas production industry 

segment only, a list of the well ID numbers for wells divested during the calendar year. 

Facility and Unit Identifier Information 

§98.236(aa)(1)(ii)(G) For the onshore petroleum and natural gas production industry 

segment only, a list of the well ID numbers for wells completed during the calendar year. 

Facility and Unit Identifier Information 

§98.236(aa)(1)(ii)(H) For the onshore petroleum and natural gas production industry 

segment only, a list of the well ID numbers for wells permanently taken out of production (i.e., plugged and abandoned) during the calendar year. 

Facility and Unit Identifier Information 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

Acid Gas Removal Units §98.236(d)(1)(iv) For the onshore petroleum and natural gas gathering and 

boosting industry segment, whether any CO2 emissions from the acid gas removal unit are recovered and transferred outside the facility. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio
23 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

Dehydrators §98.236(e)(1)(xv) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, whether any dehydrator emissions are vented to a vapor recovery device. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(1)(xvi) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, whether any dehydrator emissions are vented to a flare or regenerator firebox/fire tubes. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(1)(xvii) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 million standard cubic feet per day, whether any dehydrator emissions are vented to the atmosphere without being routed to a flare or regenerator firebox. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(2)(ii) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, the total number of dehydrators at the facility that vented to a vapor recovery device. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio
24 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

§98.236(e)(2)(iii) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, the number of dehydrators venting to a control device other than a vapor recovery device or a flare or regenerator firebox/fire tubes. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(2)(iv) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, whether any glycol dehydrator emissions are vented to a flare or regenerator firebox/fire tubes. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(2)(iv)(A) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, the total number of dehydrators venting to a flare or regenerator firebox/fire tubes. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for dehydrators that use desiccant, the total number of dehydrators at the facility. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for dehydrators that use desiccant, the total number of dehydrators venting to a vapor recovery device. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio
25 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for dehydrators that use desiccant, the number of dehydrators venting to a control device other than a vapor recovery device or a flare or regenerator firebox/fire tubes. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(e)(3)(i) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for dehydrators that use desiccant, the total number of dehydrators venting to a flare or regenerator firebox/fire tubes. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

Completions and Workovers with Hydraulic Fracturing§98.236(g) Whether the facility had any well completions or workovers 

with hydraulic fracturing during the calendar year.

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(g)(3) For each sub-basin and well type combination, the total number 

of completions or workovers. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(g)(5)(i)3 If using Equation W-10A to calculate annual volumetric total 

gas emissions for multiple wells in a sub-basin, the cumulative gas flowback time, in hours, from when gas is first detected until sufficient quantities are present to enable separation (sum of “Tp,i” values used in Equation W-10A). 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

3 Reporters may delay reporting of this data element for a period of two years in cases where wildcat wells and/or delineation wells are the only 

was collected. Note that the determination applies only in situations where data are available for multiple wells. The data element is an input wh

single well; see the Inputs memorandum for an evaluation of whether release of inputs data is likely to result in substantial competitive harm. 
26 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

§98.236(g)(5)(i)3 If using Equation W-10A to calculate annual volumetric total 

gas emissions for multiple wells in a sub-basin, the cumulative flowback time, in hours, after sufficient quantities of gas are present to enable separation (sum of “Tp,s” values used in Equation W-10A). 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

Blowdown Vent Stacks §98.236(i)(1)(i) If calculating emissions from blowdown vent stacks by 

equipment or event type, the total number of blowdowns in the calendar year for the equipment or event type (the sum of equation variable “N” from Equation W-14A or Equation W14B, for all unique physical volumes for the equipment or event type). 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(i)(3)(iii) For the onshore natural gas transmission pipeline segment, the 

annual number of blowdown events for each state. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

Onshore Production and Onshore Petroleum and Natural Gas Gathering and Boosting Storage Tanks §98.236(j) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if any of the atmospheric tanks are observed to have malfunctioning dump valves, indicate that dump valves were malfunctioning. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(1)(x) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 1 or 2, the number of atmospheric tanks. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio
27 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

§98.236(j)(1)(xii)(A) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 1 or 2, the number of atmospheric tanks that control emissions with vapor recovery systems. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(1)(xiii)(A) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 1 or 2, the number of atmospheric tanks that vented gas directly to the atmosphere without using a vapor recovery system or without flaring. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(1)(xiv)(A) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 1 or 2, the number of atmospheric tanks that controlled emissions with flares. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(2)(i)(D) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 3, the number of atmospheric tanks in the basin. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(2)(ii)(B) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 3, the number of atmospheric tanks in the county that did not control emissions with flares, including those that have vapor recovery. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(2)(iii)(B) For the onshore petroleum and natural gas gathering and 

boosting industry segment, if using Calculation Method 3, the number of atmospheric tanks in the county that controlled emissions with flares. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio
28 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

§98.236(j)(3)(i) For the onshore petroleum and natural gas gathering and 

boosting industry segment, the total number of gas-liquid separators in the county whose liquid dump valves did not close properly during the calendar year. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(j)(3)(ii)4 For the onshore petroleum and natural gas gathering and 

boosting industry segment, if dump valves on multiple gasliquid separators in a county did not close properly, the total time the dump valves on gas-liquid separators did not close properly in the calendar year, in hours (sum of the “Tn” values used in Equation W-16). 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

Combustion Equipment at Onshore Petroleum and Natural Gas Production Facilities, Onshore Petroleum and Nand Boosting Facilities, and Natural Gas Distribution Facilities §98.236(z)(1)(ii) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for each combustion unit type listed in §98.236(z)(1), the total number of combustion units. 

Unit/Process “Static” Characteristics that are Not Inputs to Emission Equatio

§98.236(z)(2)(ii) For the onshore petroleum and natural gas gathering and 

boosting industry segment, for each combustion unit type listed in §98.236(z)(2), type of fuel combusted. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

4 Note that the determination applies only in situations where data are available for multiple separators. The data element is an input when data a

separator; see the Inputs memorandum for an evaluation of whether release of inputs data is likely to result in substantial competitive harm. 
29 

Table 2. 

Final Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to the 

Characteristics and the Unit/Process “Static” Characteristics Data Categories

Rule Citation Final Data Element Final Category Assignm

Onshore Natural Gas Transmission Pipeline Facilities §98.236(aa)(11)(i) The quantity of natural gas received at all custody transfer 

stations in the calendar year, in thousand standard cubic feet. This value may include meter corrections, but only for the calendar year covered by the annual report. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(aa)(11)(ii) The quantity of natural gas withdrawn from in-system storage in 

the calendar year, in thousand standard cubic feet.

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(aa)(11)(iii) The quantity of natural gas added to in-system storage in the 

calendar year, in thousand standard cubic feet. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(aa)(11)(iv) The quantity of natural gas transferred to third parties such as 

LDCs or other transmission pipelines, in thousand standard cubic feet. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(aa)(11)(v) The quantity of natural gas consumed by the transmission 

pipeline facility for operational purposes, in thousand standard cubic feet. 

Unit/Process Operating Characteristics that are Not Inputs to Emission Equatio

§98.236(aa)(11)(vi) The miles of transmission pipeline for each state in the facility. Unit/Process “Static” 

Characteristics that are Not Inputs to Emission Equatio
30 

Table 3. 

Final Confidentiality Determinations for New Data Elements Not Assigned to a Data Cate

Rule Citation Final Data Element 

Onshore Production and Onshore Petroleum and Natural Gas Gathering and Boosting Storage Tanks §98.236(j)(2)(i)(A)5 For the onshore natural gas gathering and boosting industry segment, if using Calculation Metho

the total annual oil/condensate throughput that is sent to all atmospheric tanks in the basin, in barrels. 

Onshore Petroleum and Natural Gas Gathering and Boosting Facilities §98.236(aa)(10)(i) The quantity of gas received by the gathering and boosting facility in the calendar year, in thousa

standard cubic feet. 

§98.236(aa)(10)(ii) The quantity of gas transported to a natural gas processing facility, a natural gas transmission 

pipeline, a natural gas distribution pipeline, or another gathering and boosting facility in the caleyear, in thousand standard cubic feet. 

§98.236(aa)(10)(iii) The quantity of all hydrocarbon liquids received by the gathering and boosting facility in the 

calendar year, in barrels. 

§98.236(aa)(10)(iv) The quantity of all hydrocarbon liquids transported to a natural gas processing facility, a natural 

transmission pipeline, a natural gas distribution pipeline, or another gathering and boosting faciliin the calendar year, in barrels. 

5 Reporters may delay reporting of this data element for a period of two years in cases where wildcat wells and delineation wells are the only we

oil/condensate production less than 10 barrels per day and that send oil/condensate to atmospheric tanks.