1. 1 Task 2 – High Tier Source Categories  Overall goal of Task 2 is to identify high-tier source categories and present detailed methodologies to estimate GHG emissions from these high-tier source categories  What are high-tier source categories? Sources with significant GHG emissions contributions to a region or field Sources with highly accurate estimation methodologies that utilize measured data or well-vetted input data or emissions factors

2. 2 Task 2 – High Tier Source Categories  Task 2 organizational structure is proposed to be broken down into the following major topics: 1.Definition and identification of high-tier source categories by geographic region and type of production 2.Ranking of high-tier source categories by geographic region 3.Definition and identification of minor source categories 4.Detailed GHG estimation methodologies, including input data/emissions factors, for the high-tier source categories 5.Simplified methodologies for minor source categories 6.Discussion of emissions estimation input data gaps for particular source categories, and discussion of potential measurement methods or alternative methodologies to address these gaps

3. 3 Task 2 – High Tier Source Categories 1.Definition and identification of high-tier source categories by geographic region  Regional variability in these definitions  What regions should be considered to determine whether source categories are high-tier? Fields Formations Basins Counties States/Provinces  What data to use to determine a high-tier source category Requires some inventory data for various regions What type of threshold or cut-off to use in categorizing high-tier vs. minor sources? How does accuracy of measurement affect this?

4. 4 Task 2 – High Tier Source Categories 2.Ranking of high-tier source categories by geographic region  Again what regions should be considered to determine the rankings of high-tier source categories?  How to rank these categories for regions where inventories are unavailable or insufficiently detailed?

5. 5 Task 2 – High Tier Source Categories 3.Definition and identification of minor source categories  These would be sources that either do not contribute significantly to regional GHG emissions or categories that do not have accurate estimation methodologies

6. 6 Task 2 – High Tier Source Categories 4.Detailed GHG estimation methodologies, including input data/emissions factors, for the high-tier source categories  Intent is to utilize those methodologies which were highly- ranked in Section 4 of the Background and Scoping paper  Will include recommended emissions factors and other input data for high-tier source categories GHG emissions estimations and a discussion of their accuracy  May include more than one recommended methodology for a source category based on availability of input data for the methodology

7. 7 Task 2 – High Tier Source Categories 5.Simplified methodologies for minor source categories  Identify simplified methodologies for estimating GHG emissions from those source categories identified as minor across all regions  Identify recommended input data and emissions factors for these simplified methodologies  Discuss instances where lack of availability of input data, or difficulty obtaining input data may make the use of these methodologies challenging

8. 8 Task 2 – High Tier Source Categories 6.Discussion of emissions estimation input data gaps for particular source categories, and discussion of potential measurement methods or alternative methodologies to address these gaps  Identify data gaps in estimating GHG emissions for some source categories due to unavailability of input data or difficulty in obtaining input data  Discuss possible alternative methodologies to address these data gaps, or specific measurements or new technologies that could address these data gaps This will require input from the broad stakeholder group to identify these technologies and alternative methodologies

9. 9 Task 2 – High Tier Source Categories  End result of Task 2 is a draft report detailing specific methodologies for high-tier source categories, specific quantitative input data to these methodologies by region and potential alternative methodologies or data sources where input data is unavailable  Task 2 will also present simplified methodologies for estimating GHG emissions from minor source categories including recommended input data

10. 10 Task 2 – High Tier Source Categories  Key issues that need to be resolved in moving forward on Task 2 1.Broad regional variations in production and how this affects what source categories are applicable and which ones are significant emissions contributors  Discussion of field-level aggregation seems to address this but we also will need guidance from industry and regulators on which source categories are applicable in various regions and the relative magnitudes of their emissions 2.Facility boundary definitions, and therefore how to aggregate emissions  Group consensus seems to be moving towards using the field/operational control model

11. 11 Task 2 – High Tier Source Categories  Key issues that need to be resolved in moving forward on Task 2 3.Definition of high-tier vs. minor source  Perhaps a three-tier categorization of source categories is suggested from the comments presented today: 1.Sources with well-defined methodologies, readily available metering/measurement data and/or contribute significantly to the GHG inventory for a field or region 2.Sources which are smaller in individual unit emissions, numerous, and can contribute significantly to the GHG inventory for a field or region but whose GHG emissions estimation methodologies are inaccurate or require data which may not be highly accurate 3.Those sources which both may not have a significant contribution to emissions and for which accurate data and estimation methodologies are not readily available

12. 12 Task 2 – High Tier Source Categories  Key issues that need to be resolved in moving forward on Task 2 3.Definition of high-tier vs. minor source (cont’d.)  Those sources described as having accurate methodologies and potentially significant inventory contributions would be high-tier  Those sources described as requiring less accurate estimation methodologies but which may have potentially significant inventory contributions would be small or minor sources  Other small sources that will be very difficult to quantify will be discussed and recommendations made for further measurements or analytical methods to address them if available – will benefit from guidance from agencies like CARB, EPA that have been researching these areas