EPA Oil and Gas VOC Speciation Improvement Efforts Madeleine Strum, EPA, OAQPS (strum.madeleine@epa.gov)

VOC SPECIATION Transforms inventory species (VOC) into Air Quality model species to support the chemistry of the model VOC speciation feeds into the ozone and secondary organic aerosol chemistry SPECIATE is EPA’s repository of speciation profiles SPECIATE4.5 update slated for Sept 2016 Speciation could also be used to estimate HAPs from VOCs Apply Profile to compute emissions of chemical compounds Map chemical compounds to Air Quality model species Assign Speciation Profile based on Process (SCC) VOC

Oil and Gas Profiles Added to SPECIATE4 Oil and Gas Profiles Added to SPECIATE4.5 All location-specific, All Uncontrolled WRAP Profiles – Modeling contractor D-J, Piceance, Powder River, Permian Basin, South San Juan, SW Wyoming, Uinta, Wind River Unita Basin Tribal Minor Source Registration (TMSR) –From Region 8 D-J Condensate Tanks – From ORD/Region 8, published paper, measurement study San Joaquin – From SPECIATE contractor – 2 studies (measurements) East Texas – From SPECIATE contractor – measurements CA- Bakersfield – From SPECIATE contractor - measurements/adjustments About 200 unique profiles being added

WRAP Profiles D-J, Piceance, Powder River, Permian Basin, South San Juan, SW Wyoming, Uinta, Wind River Processes Flashing – condensate tanks, oil tanks (Uinta) Produced Gas – non-CBM, CBM (some basins) Already widely used in modeling Vintage ~2006, based on measurements of gas composition and models (tanks), composited across operators (ranging from 1-28 samples) http://www.wrapair2.org/pdf/WRAP_P3_OG_speciation_rev27Aug2015.pdf

Uinta TMSR Profiles Uinta basin Processes Condensate Tanks and Oil Tanks Untreated natural gas (leaks, pneumatic devices) Glycol dehydrator Operator Specific (~40) and production-weighted composites Vintage ~2013, based on measurements of gas composition and models (TANKS, GLYCALC)

D-J Condensate Tank Profiles Measurements- Samples were acquired from condensate tank thief hatch leaks or other emission point prior to the control device 27 sample specific and one composite based on mean Halley L. Brantley, Eben D. Thoma & Adam P. Eisele (2015): Assessment of VOC and HAP Emissions from Oil and Natural Gas Well Pads Using Mobile Remote and Onsite Direct Measurements, Journal of the Air & Waste Management Association, DOI: 10.1080/10962247.

San Juaquin Censullo – added 3 composites of SPECIATE4.4 profiles Tests from 1989 Oil field wells, Oil field tanks, Oil field Vapor recovery A. Censullo, California Polytechnic State University, San Luis Obispo, "Development of Species Profiles for Selected Organic Emission Sources; Volume I: Oil Field Fugitive Emissions", ARB Contract A832-059, April 30, 1991. USGS – added sample specific and composites Tests from ~ 2003 77 sample specific. Sites described as “Oil well” “gas and condensate well” ; some are more detailed “gas well separator” 6 composites: gas wells, oil wells, oil and gas separators, oil well tanks, oil well casings, gas and oil condensate wells Overlap with Censullo data; Less compounds than Censullo (10 vs 59) U.S. Geological Survey, Professional Paper 1713, Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California, 2007, http://pubs.usgs.gov/pp/pp1713/

Bakersfield, CA Petroleum operations - extraction, processing, transmission Reflects ambient data (not source) Combined of observed data w/regressions Emissions of organic carbon and methane from petroleum and dairy operations in California’s San Joaquin Valley, Atmos. Chem. Phys., 14, 4955–4978, 2014

Next Steps Assign these new profiles to inventory sources (GSREF) for use in SMOKE Update flare profile (next version of SPECIATE)

Opportunities for Improvements More data for more sources/basins Standard terminology/naming system Consistency in estimation of HAPs in NEI vs speciation where possible How do SCCs reflect sources of data in SPECIATE? – e.g., Liquid vs gas service How to handle speciation of controlled streams