Western Air Quality Study (WAQS) Intermountain Data Warehouse (IWDW) 2011b-based future year Emissions and 2020 D-J Basin O&G Emission Inventory University of North Carolina (UNC-IE) Ramboll-Environ (Environ) January 12, 2016 IWDW-WAQS Technical Committee Meeting

2 Summary 2011b Future Emissions Sources and Results – IWDW 2011b-2025 Wiki WAQS Basin Inventory Projections Denver-Julesburg Basin 2020 Inventory – Methodology for the IWDW 2011b update – Oil and Gas Activity Growth Factors – Emission Results

3 Emissions Projection Conventions Base Year  Future Year Projections = growth + controls Do not decouple a base and future year inventory pair Natural emissions categories are held constant Anthropogenic emissions categories may be projected Typically no changes to spatial allocation, temporal patterns, or speciation

4 Projection Inventories for Base11b Platform Non-O&G – EPA 2011NEIv2 Platform – 2025 projection year Documentation and NODA available from EPA – Same categories as 2011 base (including O&G) O&G – 2020 projections off of 2011 Phase 2

2011 vs Emissions CO NOx VOC (no biogenics)

2011 vs Emissions PM2.5 NH3 SO2 CH4

2011 vs Emissions PM2.5 NH3 SO2 CH4 (no O&G)

2011 vs Emissions Methane 90% of the UT Area O&G CH4 is from pneumatic devices and dehydrators 97% of the CA Nonpoint CH4 is from landfills

2011 vs Emissions SO2 Big reductions from base to future in EGU Point SO2 in several states

2011 vs Emissions IWDW 2011b-2025 Wiki

11 Colorado – Permitted sources (including all midstream and some well-site sources) from CDPHE APENS database – Survey-based well-site sources forecast from WestJumpAQMS a,c – Note: 2020 D-J Basin emissions forecast was developed from the RAQC 2017 inventory Wyoming – Comprehensive O&G emission provided by WYDEQ Utah – Midstream sources from UTDEQ, EPA – Survey-based well-site sources forecast from WestJumpAQMS a,b,c New Mexico – Midstream sources from NMED, EPA – Survey-based well-site sources forecast from WestJumpAQMS a,c a fracing engine emissions added as described in 2011b memo b Uinta Basin tribal minor source data was used as described in the 2011b memo c No survey-based well-site emissions were available for Raton and Paradox Basins IWDW O&G Emission Inventory Primary Data Sources

12 RAQC 2017 emission inventory – Developed as part of 8-hour Ozone SIP based on input from the top six oil and gas producers – 9-county NAA only (includes all of Weld and Larimer Counties) IWDW D-J Basin Inventory includes 9-County NAA and counties outside of NAA – In 2014, 78% of wells, 92% of gas production, and 97% of condensate production is inside the 9-County NAA 2020 Emissions Forecast Basis – 9-County NAA forecast: RAQC 2017 emission inventory – Outside 9-County NAA area Area sources: Based on 9-County RAQC 2017 emission rates Point sources: No change in emissions from D-J Basin 2011a inventory D-J Basin 2020 Emission Inventory Update Methodology

13 D-J Basin 2020 Emission Inventory Update Activity Forecasts, 9-county NAA Surrogate 2020/2017 Scaling Factor Well Counts1.14 Gas Production1.60 Oil Production1.77 Water Production2.10 Spuds0.88

14 D-J Basin 2020 Emission Inventory Update Activity Forecasts, Outside 9-County NAA Surrogate Non-NAA/NAA Surrogate Ratio Well Counts0.22 Gas Production0.08 Oil Production0.03 Water Production1.37 Spuds0.05

15 D-J Basin 2020 Emission Inventory Update Results

16 D-J Basin 2020 (from 2011b) Emission Inventory Update Results Content slide

17 D-J Basin 2020 (from 2011b) Emission Inventory Update Results Content slide

18 D-J Basin 2020 (from 2011b) Emission Inventory Update Results Inventory Forecast Emissions (tpy) NOxVOCCOSOxPM 9-County NAA IWDW 2020 b 31,729100,52929, IWDW 2020 a 23,895356,41420, RAQC ,26855,73615,585na Outside 9-County NAA IWDW 2020 b 6,7148,8795, IWDW 2020 a 6,09227,5144, Basin-wide Totals IWDW 2020 b 38,443109,40835, IWDW 2020 a 29,987383,92824, a 2011a-based b 2011b-based