MEMORANDUM 

TO: Docket ID No. EPA-HQ-OAR-2015-0764 

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

DATE: January 21, 2016 

SUBJECT: Data Category Assignments and Confidentiality Determinations for All Data 

Elements in the Proposed “Leak Detection Methodology Revisions and 

Confidentiality Determinations for Petroleum and Natural Gas Systems” 

In the proposed rulemaking titled “Leak Detection Methodology Revisions and 

Confidentiality Determinations for Petroleum and Natural Gas Systems” (referred to hereafter as 

the Subpart W Leak Detection Proposed Amendments), the EPA is proposing revisions to the 

current subpart W reporting requirements. These revisions include the proposed addition of leak 

detection methodologies and leaker emission factors. The proposed additions to the reporting 

requirements would involve revisions to existing reporting requirements and the addition of new 

data elements. In conjunction with the proposed revisions, the EPA is proposing confidentiality 

determinations for proposed new and substantially revised data elements. In this memorandum, 

we provide a list of all the proposed new and substantially revised data elements, the proposed 

confidentiality determinations, and where appropriate, the data category assignments. 

Table 1 shows the proposed category assignments for all new and substantially revised 

assigned to data categories for which a categorical confidentiality determination was previously 

finalized in 2011. As explained in the preamble to the Subpart W Leak Detection Proposed 

Amendments, for data elements listed in Table 1, the EPA is proposing to apply the categorical 

determinations established in 2011.1

 For discussion of the proposed new and substantially 

revised data elements where we are proposing to use previously finalized categorical 

determinations, their proposed category assignments, and the proposed application of the 

categorical confidentiality determinations, see Section III.B of the preamble to the Subpart W 

Leak Detection Proposed Amendments. 

Table 2 shows the proposed categorical assignments and confidentiality determinations 

for all new and substantially revised data elements assigned to the data category “Unit/Process 

Operating Characteristics That Are Not Inputs to Emission Equations.” As explained in the 

 

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 

preamble to Subpart W Leak Detection Proposed Amendments, the EPA did not establish 

categorical confidentiality determinations for this data category in 2011, and confidentiality 

determinations for data elements assigned to this data category are made on a case-by-case basis 

for these data elements. See Section III.C of the preamble to the Subpart W Leak Detection 

Proposed Amendments for more information on the proposed new and substantially revised data 

elements assigned to these two data categories, their proposed confidentiality determinations, 

and the rationales for the proposed determinations. 

As shown in Tables 1 and 2, the EPA is proposing that none of the new or substantially 

revised data elements in the Subpart W Leak Detection Proposed Amendments are eligible for 

confidential treatment. A copy of the Subpart W Leak Detection Proposed Amendments can be 

found on EPA’s website at http://www2.epa.gov/ghgreporting/rulemaking-notices-ghg-reporting. 

Copies of the proposed and final CBI rules identified in this memorandum are available on 

EPA’s website: http://www2.epa.gov/ghgreporting/confidential-business-information-ghgreporting, and 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. 

Proposed Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to C

Determinations2

Rule Citation 

New/Substantially Revised by 

Industry Segment3 Proposed Data Element 

Proposed 

Assign

§98.236(q)(1)(i) New: OPNGP, OPNGGB The number of complete equipment leak 

surveys performed during the calendar year. 

Test and CaMethods 

§98.236(q)(1)(iii) New: OPNGP, OPNGGB, ONGP, 

ONGTC, UNGS, LNGS, LNGIEE, NGD 

Whether any equipment leak component types were subject to 40 CFR part 60, subpart OOOOa. 

Facility and Identifier Information 

§98.236(q)(1)(iv) New: OPNGP, OPNGGB, ONGP, 

ONGTC, UNGS, LNGS, LNGIEE, NGD 

Whether you elected to comply with §98.233(q)(1)(iii). 

Facility and Identifier Information 

§98.236(q)(1)(v) New: OPNGP, OPNGGB, ONGP, 

ONGTC, UNGS, LNGS, LNGIEE, NGD 

Each type of method described in §98.234(a) that was used to conduct leak surveys. 

Test and CaMethods 

§98.236(q)(2)(i) New: OPNGP, OPNGGB 

Substantially Revised: ONGP, ONGTC, UNGS, LNGS, LNGIEE 

For each component type that is located at your facility, component type. 

Facility and Identifier Information 

§98.236(q)(2)(iv) New: OPNGP, OPNGGB 

Substantially Revised: ONGP, ONGTC, UNGS, LNGS, LNGIEE 

For each component type that is located at your facility, annual CO2 emissions, in metric tons CO2. 

Emissions 

§98.236(q)(2)(v) New: OPNGP, OPNGGB 

Substantially Revised: ONGP, ONGTC, UNGS, LNGS, LNGIEE 

For each component type that is located at your facility, annual CH4 emissions, in metric tons CH4. 

Emissions 

2 The categorical confidentiality determinations for the data categories listed in this table were finalized on May 26, 2011 (see 76 FR 30782). 3 OPNGP = Onshore Petroleum and Natural Gas Production; OPNGGB = Onshore Petroleum and Natural Gas Gathering and Boosting; ONGP = 

ONGTC = Onshore Natural Gas Transmission Compression; UNGS = Underground Natural Gas Storage; LNGS = Liquefied Natural Gas (LNG

and Export Equipment; NGD = Natural Gas Distribution. 
4 

Table 2. 

Proposed Data Category Assignments and Confidentiality Determinations for New Data Elements Assigned to t

Characteristics Data Category

Rule Citation 

New/Substantially 

Revised by Industry 

Segment4 Proposed Data Element 

Proposed Ca

Assignme

§98.236(q)(2)(ii) New: OPNGP, OPNGGB 

Substantially Revised: ONGP, ONGTC, UNGS, LNGS, LNGIEE 

For each component type that is located at your facility, total number of the surveyed component type that were identified as leaking in the calendar year (“xp” in Equation W-30). 

Unit/Process OpCharacteristics tNot Inputs to EmEquations 

§98.236(q)(2)(iii) New: OPNGP, OPNGGB 

Substantially Revised: ONGP, ONGTC, UNGS, LNGS, LNGIEE 

For each component type that is located at your facility, average time the surveyed components are assumed to be leaking and operational, in hours (average of “Tp,z” from Equation W-30). 

Unit/Process OpCharacteristics tNot Inputs to EmEquations 

4 OPNGP = Onshore Petroleum and Natural Gas Production; OPNGGB = Onshore Petroleum and Natural Gas Gathering and Boosting; ONGP = 

ONGTC = Onshore Natural Gas Transmission Compression; UNGS = Underground Natural Gas Storage; LNGS = Liquefied Natural Gas (LNG

and Export Equipment; NGD = Natural Gas Distribution.