PINEDALE ANTICLINE SPATIAL AIR QUALITY ASSESSMENT PASQUA SPATIAL DISTRIBUTION SURVEYS. 11/01/2010 to 04/30/2011. Data Summaries and Plots

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1 PINEDALE ANTICLINE SPATIAL AIR QUALITY ASSESSMENT PASQUA SPATIAL DISTRIBUTION SURVEYS 11/01/2010 to 04/30/2011 Data Summaries and Plots Prepared for WYOMING DEPARTMENT OF ENVIRONMENTAL QUALITY 122 West 25 th Street Cheyenne, Wyoming Prepared by Jeffrey Soltis and Robert Field University of Wyoming Atmospheric Science Department 1000 East University Avenue Laramie, WY With support from Derek Montague Brittni Emery Abram Pearce 1

2 TABLE OF CONTENTS 1.0 INTRODUCTION BACKGROUND... 6 Figure 2-1. Map showing overview of the study area Figure 2-2. Map showing June 2011 well locations METHODOLOGY Spatial Monitoring Specifications Monitoring site selection Monitoring site locations VOC canisters... 9 Table 3-1. Spatial canister survey monitoring sites and survey numbers Figure 3-1. Map showing locations of VOC canister survey sites Figure 3-2. Map showing locations of VOC canister survey sites by survey Monitoring site locations BTEX/NO X samplers Table 3-2. Spatial BTEX, NO and NO2 Survey Monitoring Sites Figure 3-3. Map showing locations of BTEX and NO X survey sites Spatial monitoring equipment Spatial monitoring equipment canisters Spatial monitoring equipment passive samplers Spatial monitoring sampling Table 3-3. Ambient air survey dates Sampling protocols Sampling protocols Canisters Sampling protocols BTEX Sampling protocols NO X Validation Field Validation blanks Field Validation passive sampler co-location Table 3-4. BTEX/NO X co-located sites Sample Analysis Sample Analysis canisters Sample Analysis NO X passive samplers Sample Analysis BTEX passive samplers Results Spatial Surveys

3 4.0.1 Survey One Spatial Canister Survey Table 4-1. Measured compounds in ppb for survey one (16 November November 2010) Survey Two Spatial Canister Survey Table 4-2. Measured compounds in ppb for survey two (14 December December 2010) Survey Three Spatial Canister Survey Table 4-3. Measured compounds in ppb for survey three (01 February February 2011) Survey Four Spatial Canister Survey Table 4-4. Measured compounds in ppb for survey four (16 February February 2011) Survey Five Spatial Canister, BTEX and NOx Survey Table 4-5. Measured compounds in ppb for survey five (22 February March 2011).. 23 Table 4-7. NO X Measured compounds in ppb for survey five (22 February March 2011) Figure 4-1. Map showing locations of benzene Figure 4-2. Map showing locations of toluene Figure 4-3. Map showing locations of ethylbenzene Figure 4-4. Map showing locations of m+p-xylene Figure 4-5. Map showing locations of o-xylene Figure 4-6. Map showing locations of NO X Figure 4-7. Map showing locations of NO X, including DEQ-AQD monitoring locations Survey Six Spatial Canister Survey Table 4-8. Measured compounds in ppb for survey six (10 March March 2011) All Surveys Spatial Canister Survey Table 4-9. Measured compounds in ppb for six surveys Figure 4-8. Measurement means for alkanes, alkenes (and alkynes), and aromatics for six surveys Validation Comparative canister analysis Table 4-9. Comparative Canister analysis by UW and Air Toxics inc Co-location Table Simultaneous sampling and analysis of BTEX compounds using canister and passive sampling methodologies

4 6.0 Conclusions ACKNOWLEDGEMENTS

5 1.0 INTRODUCTION The University of Wyoming s (UW) Atmospheric Science Department (ATSC) Pinedale Anticline Spatial Air Quality Survey (PASQUA) study commenced in November UW designed and implemented six VOC canister surveys, one BTEX, and one NO X spatial distribution survey. These spatial distribution surveys were conducted through a contract with the Pinedale Anticline Project Office (PAPO) with oversight by Wyoming Department of Environmental Quality, Air Quality Division (DEQ-AQD), and with the support of the UW School of Energy Resources. This report describes work performed for each of the surveys conducted during the period from November 2010 through April Any comments or questions regarding this report should be addressed to: Dr. Robert Field, Principal Investigator RField1@uwyo.edu (307) University of Wyoming Atmospheric Science Department 1000 East University Avenue Laramie, WY Or Dr. Derek Montague, Principal Investigator DCM@uwyo.edu (307) University of Wyoming Atmospheric Science Department 1000 East University Avenue Laramie, WY Or Ken Rairigh, Project Manager Wyoming Department of Environmental Quality Air Quality Division 122 West 25 th Street Cheyenne, Wyoming

6 2.0 BACKGROUND A spatial survey using passive sampling enables an assessment of pollutant distribution over relatively large geographic areas. This approach has utility for a number of purposes most often to determine where elevated pollutant levels reside within an area. When monitoring data from spatial surveys are displayed as contour maps, pollutant behavior can be visualized. Contour maps are useful for determination of which areas contain either higher and lower pollutant levels. Contour maps may also be used to evaluate options for placement of monitoring stations. This study conducted spatial sampling in Sublette County in the vicinity of the Pinedale Anticline Development Area (PAPA) and Jonah Field (Jonah) oil and gas developments. Figure 2-1 provides an overview of the study area with population centers indicated. The map in Figure 2-2 indicates the location of the PAPA and Jonah developments. Sampling was conducted during the winter of The first survey took place in November 2010 and the final survey was conducted in mid-march Three techniques were used during monitoring for PASQUA canister sampling of speciated VOCs, diffusive sampling of BTEX, and passive sampling of NO X (NO and NO 2 ). Six VOC surveys were conducted using 6L Entech Silonite canister samplers. During five of the VOC surveys, samplers were placed in the field for 24 hours, a sixth VOC survey was conducted for a period of one week. The BTEX surveys were conducted using Radiello diffusive samplers. The NO X survey was conducted using ambient air passive samplers by Ogawa. BTEX and NO X surveys were conducted simultaneously for a period of one week. For the purpose of spatial monitoring during PASQUA, sixty ambient monitoring sites were selected to represent different positions relative to the PAPA and Jonah developments. Maps are provided in Figures 3-1 and 3-2 that indicate the location of each of these monitoring sites. 6

7 Figure 2-1. Map showing overview of the study area. 7

8 Figure 2-2. Map showing June 2011 well locations. 8

9 3.0 METHODOLOGY 3.1 Spatial Monitoring Specifications Monitoring site selection Sixty unique sampling locations were chosen for the spatial survey study conducted as part of the UW ATSC PASQUA project. Twenty-four sites were used during six canister sampling surveys; fifty-five sites were used during the BTEX and NO X surveys. Eleven canisters were co-located with BTEX and NO X samplers during survey five. Sites were selected through the use of a simple ten by ten grid projected over the study area. Based on this grid, approximately 108 sites were located. Final site locations were determined through consultation with DEQ-AQD, based upon criteria including modeling needs, representativeness, accessibility, and safety Monitoring site locations VOC canisters Six VOC canister surveys were conducted during PASQUA. Surveys one and two are considered wide area surveys. The goal of canister placement for surveys one and two was to assess pollutant distribution in the entire development region, including potential upwind and downwind source locations. Canister placement for surveys three and five was shifted towards the east and provided a more focused picture of PAPA development area. The goal for sampler placement for survey five was to measure values along a generally northwest to southeast line transecting PAPA. Table 3-1 provides a listing of the twenty-four canister survey site names and positions, including which survey they were used for. Figure 3-1 provides a map that displays the locations of the canister sites. Figure 3-2 provides four maps, which show canister survey locations for each of the six surveys. The different distributions were a result of the study design. The map for surveys 1 and 2 show the widest distribution that aimed to give a broad assessment of ambient concentrations. Surveys 3 and 5 were the same, though two sampler valves malfunctioned during survey 5. These surveys gave a greater focus upon PAPA. The results of survey 3 informed the selection of sites for surveys 4 and 6. These surveys were designed as a transect through the most concentrated oil and gas development. 9

10 Table 3-1. Spatial canister survey monitoring sites and survey numbers. Survey No. No. Site Name Position * 6 1 CALPET ROAD , X X 2 DRY PINEY , X X 3 BIG PINEY HIGH SCHOOL , X X 4 OLSON RANCH , X X X 5 DEQ DANIEL , X X 6 DEQ PINEDALE , X X 7 DEQ BOULDER , X X X X X X 8 DEQ JUEL SPRINGS , X X X 9 SPEEDWAY CD TRAIL/IRISH CANYON , X X X X 10 BUCKHORN , X X X X 11 LUMAN ROAD , X X X X 12 QEP 1. MESA NORTH , X X X X 13 QEP 4. MESA SOUTH , X X X X 14 WARBONNET DEQ B , X X X X 15 YELLOWPOINT STUDHORSE , X X 16 BOULDER SOUTH ROAD , BOULDER LAKE BLAK , X X 18 MESA TOP A , X X 19 PARADISE ROAD A , X X 20 MESA MIDDLE QEP , X X 21 BOULDER CREST UW B , X X 22 BOULDER 351 UW , X X 23 MIDDLE CREST DEQ , X X 24 MIDDLE FORK DEQ A , X X * Survey five was conducted for a period of seven days. These sites were co-located with BTEX/NOx samplers during this period. 10

11 Figure 3-1. Map showing locations of VOC canister survey sites. 11

12 Figure 3-2. Map showing locations of VOC canister survey sites by survey. Surveys 1 & 2. Survey 3. Surveys 4 & 6. Survey Monitoring site locations BTEX/NO X samplers BTEX and NO X sampling sites were chosen using the same criteria that were employed in choosing the canister sampling sites. Nineteen of the BTEX/NO X sites coincide with canister sites, and nine of these sites were co-located with canister sites during survey five. Table 3-2 lists the fifty-five sites used during the BTEX/NO X survey. By using fifty-five sites, sampler density was much higher than in the VOC surveys, as shown in Figure 3-3. Additionally, samplers were placed both west and east of the PAPA and Jonah developments. These sites were along Green River Road and County Highway 353, respectively. 12

13 Table 3-2. Spatial BTEX, NO and NO2 Survey Monitoring Sites No. Site Name Route Position 1 BLM BLM , BLM 2. AA28NEW BLM , BLM 3. NEW Hennick Draw BLM , BLM A BLM , BLM B BLM , BLM A BLM , BLM BLM , BLM BLM , BP 1. LUMAN BP , CURED CURED , CURED CURED , CURED CURED , CURED CURED , DEQ 1. BUCKHORN DEQ , DEQ 2. YELLOWPOINT/STUDHORSE DEQ , DEQ DEQ , DEQ DEQ , DEQ A MIDDLE FORK DEQ , DEQ B WARBONNET DEQ , DEQ MIDDLE CREST DEQ , QEP 1. MESA NORTH QEP , QEP MESA MIDDLE QEP , QEP QEP , QEP 4. MESA SOUTH QEP , SCCD 1. JUEL SPRING SCCD , SCCD A SCCD , SCCD B SCCD , SCCD B SCCD , SCCD SCCD , SCCD SCCD , SHELL 1. DEQ BOULDER SHELL , SHELL SHELL , SHELL A PARADISE ROAD SHELL , TOP A MESA TOP TOP , TOP TOP , TOP TOP , TOP TOP , USFS 1. BOULDER LAKE BLAK2 USFS , USFS A USFS , USFS USFS , USFS 4. SPEEDWAY-CD IRISH CANYON USFS , USFS B USFS , USFS 6. NEWFS6 USFS , USFS B USFS , UW1 1. OLSON RANCH UW , UW1 2. NEW 6-05A UW , UW B UW , UW B BOULDER CREST UW , UW UW , UW1 6. UW LAB BSR UW , UW BOULDER 351 UW , UW UW , UW UW , UW C UW , UW XA UW ,

14 Figure 3-3. Map showing locations of BTEX and NO X survey sites. 14

15 3.2 Spatial monitoring equipment Spatial monitoring equipment canisters A 6L Entech Silonite canister equipped with a Nupro valve was deployed at each sampling site. These canisters meet or exceed EPA method TO-14A and TO-15 specifications. Each 6L canister can collect either instantaneous, or up to, seven day integrated samples when outfitted with the properly sized time-integrated sampling valve orifice Spatial monitoring equipment passive samplers Each BTEX spatial site was equipped with a Radiello diffusive tube sampler. Tube samplers house a diffusive body and adsorbent cartridge treated to accumulate selected ambient air species. In this case, cartridges accumulated benzene, toluene, ethylbenzene, and m+p-xylene and o-xylene. Each NO X spatial site was equipped with an Ogawa passive sampler which house an NO 2 and NO X reagent pad treated to absorb these ambient air species. 3.3 Spatial monitoring sampling Spatial monitoring volunteers were solicited prior to the monitoring period. Volunteers were chosen from a pool of local residents, organizations, industry, and government individuals who had assisted the UW group in the past. Placement of samplers was facilitated with the cooperation of ten teams of individuals. Teams were representative of Local, State, and Federal Governments, University, Industry, and local citizenry. A full list of all participants is contained in the acknowledgement section at the end of this report. Team members participated in a training session before they took part in the sampler placement exercise. During this training session, they were instructed as to the use and placement of passive samplers, as well as instruction as to the location of assigned sampling sites. Canister-based ambient air surveys were conducted throughout the Sublette County ozone season, which is generally considered wintertime. The first survey took place on November 16-17, 2010, and the last survey on March 10-11, The BTEX/NO X survey was conducted February 22-March 01, This survey was concurrent with canister survey five. Table 3-1 provides a list of survey dates and duration. 15

16 Table 3-3. Ambient air survey dates. Survey Start Date End Date Duration Canister Survey #1 16 NOV NOV hours Canister Survey #2 14 DEC DEC hours Canister Survey #3 01 FEB FEB hours Canister Survey #4 16 FEB FEB hours Canister Survey #5 22 FEB MAR days Canister Survey #6 10 MAR MAR hours BTEX/NOx Survey* 22 FEB MAR days *Conducted simultaneously with canister survey # Sampling protocols Sampling protocols Canisters Canisters were cleaned and evacuated prior to deployment using the Entech 3100A Canister Cleaning System. The system uses an oven, humidification chamber, and nitrogen gas to displace contaminants from interior canister surface. Canisters are evacuated to a vacuum level of 100 Millitorr (mtorr) immediately following cleaning. Canisters are fitted with an appropriate sampling valve and calibrated according to manufacturer's specifications prior to field deployment. For PASQUA, two valves were employed a 24-hour valve and a 7-day valve. Canisters were distributed to the sampler placement team the day before the ambient air survey. During sampler placement, teams completed a log that specified placement time and any problems encountered. Samplers were placed at specified locations starting at 09:00 the day of the survey, and retrieved 24 hours later. After retrieval, samplers were delivered to the UW team for analysis Sampling protocols BTEX Samplers were stored in a controlled environment in original packaging until the day before the planned survey. Immediately before placement, sampling tubes and cartridges are assembled by volunteers according to handling protocols suggested by Radiello and given in the quality assurance project plan. Samplers were distributed to teams and individuals the evening before the sampler placement exercise. Participants stored samplers overnight in a cool dry place in a container provided to them and placed samplers the day of the sampling operation starting at 9 am. Each team retrieved samplers approximately seven days later. During sampler placement, teams completed a log that specified placement time and any problems encountered. Samplers were collected and prepared for analysis immediately upon receipt from sampler placement teams or human exposure subjects. Samplers were stored within an insulated cooler overnight. Samplers were shipped in an insulated container next day, via air-mail to the analysis laboratory. 16

17 3.5.3 Sampling protocols NO X Samplers were stored in a controlled environment in original packaging until the day before the planned survey. Several hours before distribution, sampler bodies and pre-coated NO2 and NO X collection pads were assembled and prepared for use, according to protocols supplied by Ogawa and given in the quality assurance project plan. Samplers were distributed to teams and individuals the evening before the sampler placement exercise. Participants stored samplers overnight in a cool dry place in a container provided to them and placed samplers the day of the sampling operation starting at 09:00. Each team retrieved samplers approximately seven days later. During sampler placement, teams completed a log that specified placement time, and whether or not they encountered any problems. Samplers were collected and prepared for analysis immediately upon receipt from sampler placement teams or human exposure subjects. Samplers were stored within an insulated cooler overnight. Samplers were shipped in an insulated container next day, via air-mail to the analysis laboratory. 3.6 Validation Field Validation blanks Field blanks are used for validation to discern whether or not species reported during analysis are measured, or sampler contamination. One canister blank was used for each spatial canister survey. For the BTEX/NO X survey, five of each type of sampler was reserved for blank validation. Blank analyses showed that all species of interest were below the data detection limit, except for i-octane. This species was therefore not reported for the canister samples Field Validation passive sampler co-location Co-location of passive and diffusive samplers was employed to test the accuracy of these samplers relative to another sampler. Since passive sampling is a scoping methodology, samplers were co-located with two other types of samplers in the study area. BTEX samplers were colocated with nine canister samplers and the UW MAQML Boulder South Road site as indicated in Table 3-4. NO X samplers were co-located with DEQ Boulder and the UW MAQML. The DEQ Boulder and UW MAQML locations may be considered Regulatory Equivalent Method (REM) sites. 17

18 Table 3-4. BTEX/NO X co-located sites. University of Wyoming BTEX and NO X Co-located Sites Co-located Site BTEX NO X DEQ Boulder CD Irish Canyon Buckhorn Draw Luman Road Mesa North Mesa South Warbonnet Yellowpoint Boulder South Road UW Boulder Lake 3.7 Sample Analysis Sample Analysis canisters Canister samples are processed immediately they have been delivered by volunteer teams. Samples are passed through the sampling trap and gas chromatograph. A chromatogram of speciated VOC is created for each sample using Perkin-Elmer TotalChrom processing software Sample Analysis NO X passive samplers Samplers were analyzed by RTI International, using standard protocols supplied by Ogawa, USA. RTI International supplied a spreadsheet with a mass loading for each sampler. UW then converted the mass loading for each sample to a final ambient NO X concentration using a derived uptake rate with blank correction. Travel blanks were used for approximately ten percent of the total number of samplers for the surveys Sample Analysis BTEX passive samplers Samplers were analyzed by Air Toxics, Inc., using standard protocols supplied by Supelco, USA. Air Toxics, Inc. supplied a spreadsheet with a mass loading for each sampler. UW then converted the mass loading for each sample to final ambient concentrations using a standard uptake rate with blank correction. Travel blanks were used for approximately ten percent of the total number of samplers for the surveys. 18

19 4.0 Results Spatial Surveys Survey One Spatial Canister Survey Spatial canister survey one was conducted from November 16-17, 2010 over a period of twenty-four hours. This was a wide coverage survey at eleven locations encircling both PAPA and Jonah developments. Sites were also located to the west and east of the area of interest, notably at Calpet Road in the Big Piney/LaBarge oil and gas development area. Table 4-1. Measured compounds in ppb for survey one (16 November November 2010). Dry Piney Big Piney HS DEQ Juel Spring Speedway Calpet Road DEQ Daniel ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5-trimethylbenzene % 1,2,4-trimethylbenzene % decane % 1,2,3-trimethylbenzene % Totals % DEQ Pinedale Luman road Buckhorn DEQ Boulder Olson Ranch Mean SD Sum % 19

20 4.0.2 Survey Two Spatial Canister Survey Spatial canister survey two was conducted from December 14-15, 2010 over a period of twenty-four hours. This was a wide coverage survey at eleven locations encircling both PAPA and Jonah developments. Sites were also located to the west and east of the area of interest, notably at Calpet Road in the Big Piney/LaBarge oil and gas development area. Table 4-2. Measured compounds in ppb for survey two (14 December December 2010). DEQ Juel Spring Speedway Buckhorn Calpet Road Big Piney HS Luman Road ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5-trimethylbenzene % 1,2,4-trimethylbenzene % decane % 1,2,3-trimethylbenzene % Totals % Dry Piney Olson Ranch DEQ Boulder DEQ Daniel DEQ Pinedale Mean SD Sum % 20

21 4.0.3 Survey Three Spatial Canister Survey Spatial canister survey three was conducted from February 01-02, 2011 over a period of twenty-four hours. The survey area included eleven locations situated along Mesa Road and eastward, and as far south as the DEQ Juel monitoring site. Sites were also located within the Jonah Field, notably in the Yellowpoint and Warbonnet areas. Table 4-3. Measured compounds in ppb for survey three (01 February February 2011). Buckhorn Yellowpoint DEQ Juel Spring Speedway Olson Ranch Luman Road ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5-trimethylbenzene % 1,2,4-trimethylbenzene % decane % 1,2,3-trimethylbenzene % Totals % Boulder Lake Warbonnet Mesa South Mesa North DEQ Boulder Mean SD Sum % 21

22 4.0.4 Survey Four Spatial Canister Survey Spatial canister survey four was conducted from February 16-17, 2011 over a period of twenty-four hours. The geographic area for this survey was reduced to focus exclusively on the PAPA development. As shown in Figure 3-2, sampler placement was along a generally northwest to southwest line transecting PAPA. Table 4-4. Measured compounds in ppb for survey four (16 February February 2011). Boulder Crest Warbonnet Warbonnet Fork Middle Crest 351 Middle Crest Center Mesa North ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5-trimethylbenzene % 1,2,4-trimethylbenzene % decane % 1,2,3-trimethylbenzene % Totals % Mesa South Mesa Middle Paradise Road Mesa Top DEQ Boulder Mean SD Sum % 22

23 4.0.5 Survey Five Spatial Canister, BTEX and NOx Survey Spatial canister survey five was conducted from February 22 to March 01, 2010 over a period of seven days. The survey area included eleven locations situated along Mesa Road and eastward, and as far south as the DEQ Juel monitoring site. Sites were also located within the Jonah Field, notably in the Yellowpoint area. Nine canisters were returned with results for this survey and two canisters were determined to have malfunctioned. This survey was conducted in conjunction with the BTEX/NO X spatial surveys using passive samplers. The spatial BTEX/NO X survey included fifty-five sites placed within the canister survey area albeit at a much higher density. A comparison of the canister and passive samplers is given in section Table 4-5. Measured compounds in ppb for survey five (22 February March 2011). Speedway Yellowpoint Buckhorn Warbonnet Luman Road ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5-trimethylbenzene % 1,2,4-trimethylbenzene % decane % 1,2,3-trimethylbenzene % Totals % DEQ Boulder Mesa North Mesa South Boulder Lake Mean SD Sum % 23

24 Table 4-6. BTEX Measured compounds in ppb for survey five (22 February March 2011). No. Site Name Position Benzene ppb Toluene ppb Ethbenz. ppb mpxylene ppb oxylene ppb SUM 1 BLM , BLM 2. AA28NEW , BLM 3. NEW Hennick Draw , BLM A , BLM B , BLM A , BLM , BLM , BP 1. LUMAN , CURED , CURED , CURED , CURED , DEQ 1. BUCKHORN , DEQ 2. YELLOWPOINT/STUDHORSE , DEQ , DEQ , DEQ A MIDDLE FORK , DEQ B WARBONNET , DEQ MIDDLE CREST , QEP 1. MESA NORTH , QEP MESA MIDDLE , QEP , QEP 4. MESA SOUTH , SCCD 1. JUEL SPRING , SCCD A , SCCD B , SCCD B , SCCD , SCCD , SHELL 1. DEQ BOULDER , SHELL , SHELL A PARADISE ROAD , TOP A MESA TOP , TOP , TOP , TOP , USFS 1. BOULDER LAKE BLAK , USFS A , USFS , USFS 4. SPEEDWAY CD IRISH CANYON , USFS B , USFS 6. NEWFS , USFS B , UW1 1. OLSON RANCH , UW1 2. NEW 6-05A , UW B , UW B BOULDER CREST , UW , UW1 6. UW LAB BSR , UW BOULDER , UW , UW , UW C , UW XA 42.57,

25 Only NO x values are reported, as the temperature during sampling was so low that the gel on the NO 2 filter did not collect the sample properly. The second filter, designed to give a value for NO with a calculation that includes subtraction of the NO 2 value therefore did provide meaningful sample collection. Since the manufacturer recommended approach could not be adopted, a surrogate value for NO 2 was estimated from UW and WDEQ-AQD monitoring sites. This value was used with a modified uptake rate that was selected to ensure comparability between simultaneous sampling of NO X using the continuous analyzers at the WDEQ-AQD and UW monitoring sites in Boulder and the spatial survey data. This data should be considered valid and is presented due to the importance of gaining a possible insight of the distribution of NO x concentrations in the region. Table 4-7. NO X Measured compounds in ppb for survey five (22 February March 2011). No. Site Name Position NO X 1 BLM , BLM 2. AA28NEW , BLM 3. NEW Hennick Draw , BLM A , BLM B , BLM A , BLM , BLM , BP 1. LUMAN , CURED , CURED , CURED , CURED , DEQ 1. BUCKHORN , DEQ 2. YELLOWPOINT/STUDHORSE , DEQ , DEQ , DEQ A MIDDLE FORK , DEQ B WARBONNET , DEQ MIDDLE CREST , QEP 1. MESA NORTH , QEP MESA MIDDLE , QEP , QEP 4. MESA SOUTH , SCCD 1. JUEL SPRING , SCCD A , SCCD B , SCCD B , SCCD , SCCD , SHELL 1. DEQ BOULDER , SHELL , SHELL A PARADISE ROAD , TOP A MESA TOP , TOP , TOP , TOP , USFS 1. BOULDER LAKE BLAK , USFS A , USFS , USFS 4. SPEEDWAY CD IRISH CANYON , USFS B , USFS 6. NEWFS , USFS B , UW1 1. OLSON RANCH , UW1 2. NEW 6-05A , UW B ,

26 48 UW B BOULDER CREST , UW , UW1 6. UW LAB BSR , UW BOULDER , UW , UW , UW C , UW XA 42.57, Figures 4-1 through 4-5 illustrate the distribution of each BTEX compound through isoconcentration contour mapping. The distribution for benzene is not homogenous with highest concentrations of between 4 ppb and 5 ppb evident along Mesa Road. This is a highly developed area of the PAPA development. A second area of elevated levels, of between 2 ppb and 3 ppb is evident along Middle Crest Road. Lower levels are evident elsewhere with most samplers recording concentrations less than 1 ppb. The passive samplers were exposed for a week and as such the map shows average levels for that period. At the Boulder South road site considerable variation was evident for the hourly data. Given the averaging period of the canister and passive sampler measurements it is likely that similar behavior would be evident at these sites. The maps for toluene, Figure 4-2, ethylbenzene, Figure 4-3, m+p-xylene, Figure 4-4 and o-xylene, Figure 4-5, show a similar distribution as that for benzene. This indicates the importance of common emission sources during the sampling period. 26

27 Figure 4-1. Map showing locations of benzene. 27

28 Figure 4-2. Map showing locations of toluene. 28

29 Figure 4-3. Map showing locations of ethylbenzene. 29

30 Figure 4-4. Map showing locations of m+p-xylene. 30

31 Figure 4-5. Map showing locations of o-xylene. Figure 4-6 shows the iso-concentration contour map for NOx. It shows a different spatial NO X distribution from that for BTEX compounds. Three regions of higher concentrations can be identified. The highest is along Middle Crest Road, another higher region is at the junction of Mesa and Paradise Roads. A third area is to the South around the Buckhorn Draw area, but this may result as an artifact of a single measurement at site 14. As WDEQ-AQD sites were measuring NOx at this time we have included these sites in the iso-concentration contour map given in Figure 4-7. This map shows the importance of sampler distribution but nevertheless reveals that highest concentrations are associated with roads inside the development. 31

32 Figure 4-6. Map showing locations of NO X. 32

33 Figure 4-7. Map showing locations of NO X, including DEQ-AQD monitoring locations. *DEQ monitoring locations included in the map: Site No. Site Name 56 DEQ Pinedale 57 DEQ Juel Springs 58 DEQ Daniel 59 DEQ Wyoming Range 60 DEQ Paradise Mobile Location 61 DEQ Boulder 33

34 4.0.6 Survey Six Spatial Canister Survey Spatial canister survey six was conducted from March 10-11, 2011 over a period of twenty-four hours. This survey was focused exclusively on the PAPA development. As previously mentioned, sampler placement was along a generally northwest to southeast line transecting PAPA. Table 4-8. Measured compounds in ppb for survey six (10 March March 2011). Middle Crest Boulder Crest Middle Crest 351 Warbonnet Fork Warbonnet Mesa South ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5- trimethylbenzene % 1,2,4- trimethylbenzene % decane % 1,2,3- trimethylbenzene % Totals % Mesa Middle Mesa North Mesa Top DEQ Boulder Paradise Road Mean SD Sum % 34

35 4.0.7 All Surveys Spatial Canister Survey Table 4-9 shows the average levels for each compound measured during the six surveys. Table 4-9. Measured compounds in ppb for six surveys. Mean SD Sum % ethane % ethene % propane % propene % i-butane % n-butane % ethyne % t-2-butene % 1-butene % c-2-butene % cyclopentane % i-pentane % n-pentane % 1,3-butadiene % propyne % 1-pentene % 2-methylpentane % 3-methylpentane % n-hexane % isoprene % benzene % cyclohexane % i-octane % n-heptane % toluene % n-octane % ethylbenzene % m+p-xylene % styrene % o-xylene % nonane % 1,3,5-trimethylbenzene % 1,2,4-trimethylbenzene % decane % 1,2,3-trimethylbenzene % Totals % Figure 4-8 shows the percentage distribution by compound class for each canister measurement from the first to the sixth survey. There is a similar distribution for the surveyed sites, with the notable exception of elevated alkenes for the two surveys at the WDEQ Pinedale site. This is likely to be due to the relatively higher proportion of traffic emission sources. Alkanes are by far the dominant hydrocarbon class (85%) followed by aromatics (10%). The highest levels of aromatics were measured at Mesa sites. This reinforces the findings of the BTEX survey. 35

36 Figure 4-8. Measurement means for alkanes, alkenes (and alkynes), and aromatics for six surveys. 4.1 Validation Comparative canister analysis A comparative canister analysis was performed to improve certainty of measurements during PASQUA. Three canisters used during survey six were only partially evacuated by UW during sample analysis. The remainder of the sample, which is normally unused and vented to the atmosphere, was sent to Air Toxics, Inc. for independent analysis. Table 4-9 shows the results of selected canister analysis by UW and then by Air Toxics inc. Only species present in all three canisters are shown. Many of the species were below reporting limits, or were outside the protocol range employed by Air Toxics, Inc. Values show excellent agreement considering all the factors associated with second run analysis using a different calibration and analysis approach. When considering expanded measurement uncertainty that is primarily related to 36