The URL can be used to link to this page

Browse Search

Home My WebLink About20201829.tiffOFFICE OF BOARD OF COMMISSIONERS PHONE: 970-336-7204 FAX: 970-336-7233 1 150 O STREET P.O. BOX 758 GREELEY, COLORADO 80632 June 23, 2020 Via Email and U.S. Mail The Honorable Jared Polis, Governor 136 State Capitol Denver, CO 80203-1792 Re: Citizen Petition to Shutdown Well Pad Near Bella Romero Academy in Greeley Dear Governor Polls: We are writing in opposition to the petition submitted by certain citizens asking you to shut down an oil and gas production facility located near Bella Romero Academy in Greeley. Weld County believes the petitioners' use of the Barrett Engineering Report as the basis for the petition unnecessarily and irresponsibly politicizes the delivery of health information of understandable concern to the families, students and the faculty/staff of Bella Romero Academy (Bella Romero community). Weld County opposes the petition based upon the prior work of the Colorado Department of Public Health and Environment (CDPHE) in evaluating the monitoring data it collected at Bella Romero Academy [cite to CDPHE report], and also on a more recent independent analysis of those CDPHE data by our consultants with Ramboll. A copy of Ramboll's data analysis report, entitled "Independent Analysis of CDPHE Monitoring Data at the Bella Romero 4-8 Academy" is also enclosed, for your reference (hereafter "Ramboll Independent Analysis"). The petitioners rely on an unqualitified report by Barrett Engineering that suffers from a number of flaws in approach and methodology rendering it's conclusions inappropriate and misleading. Weld County's consultants with Ramboll also reviewed the report, entitled "Monitoring Results Show Exceedances of Safe Levels _ Bella Romero Academy" (hereafter "Barrett Engineering Report"), which was released on March 11, 2020 to members of the Colorado Department of Public Health & Environment (CDPHE), the press, and others. Though prepared prior to completion of the enclosed Ramboll Independent Analysis, Ramboll's initial review of the Barrett Engineering Report found that it reflected: A misunderstanding and inappropriate use of relevant standards and guidelines; Errors and omissions in the reduction and interpretation of sampling data; • Unsubstantiated attribution to sources; and Selective and incomplete presentation of benzene measurement data. The initial conclusions of Ramboll concerning the Barrett Engineering Report are strengthened by the recent completion of the Ramboll Independent Analysis of all available CDPHE data, including data not considered by Barrett Engineering, for Weld County. aor irn ; ea.+� o ng oCs3/ a9 / '.o apa©-I%*o`�`� Indeed, the prior mischaracterization of benzene monitoring data by 350Colorado, which commissioned the Barrett Engineering Report, prompted Weld County to provide additional objective health information in the form of a Benzene Fact Sheet for the benefit of the Bella Romero community and the public at large (copy also enclosed). Under these circumstances, we urge you to rely on the prior work of CDPHE in its recent Public Health Assessment, as supported by the Ramboll Independent Analysis, and to reject the citizen petition for its undue reliance on the flawed and misleading Barrett Engineering Report. Weld County would be pleased to confer further with you, your staff, and CDPHE staff regarding the Ramboll Independent Analysis, if that would be helpful. We thank you in advance for your attention to this important health -related correspondence. Sincerely, BOARD OF COUNTY COMMISSIONERS Mike Freeman, Chair Steve Moreno, Pro Tern Enclosures C: Jill Hunsaker Ryan — CDPHE John Putnam — CDPHE Garr)/ Kaufman — CDPHE Dan Gibbs - DNR Jeff Robbins — COGCC Julie Murphy — COGCC Bruce Barker — Weld County Attorney Scott K. James Kevin D. Ross RAMB LL FACT SHEET March 5, 2020 Review of Monitored Benzene Levels in Greeley, Colorado The Weld County Board of County Commissioners and the Department of Environmental Health engaged Ramboll US Corporation, to review the data collected by the Colorado Department of Public Health and Environment (CDPHE) near the Bella Romero Academy 4-8 campus in Greeley and its characterization in public statements by CDPHE to put the data in a broader scientific and public health context for the benefit of Weld County's residents. This Fact Sheet was prepared for that purpose. CDPHE reported a benzene concentration of 10.24 parts per billion (ppb) occurring on November 5th, 2019 over a single 45 -minute period at the Bella Romero Academy's 4-8 campus in Greeley. This measurement occurred once amongst over 1,500 measurements (CDPHE 2020). Following this observation, the State of Colorado issued a series of responses under the premise that the event exceeded federal short-term health -based guidelines for the hazardous air pollutant. The fact is that federal health -based exposure guidelines for benzene vary widely, ranging from an Acute Exposure Guideline Level (AEGL) of 52,000 ppb for an infrequent 1 -hour exposure, to an acute Minimal Risk Level (MRL) of 9 ppb as a daily average for exposure over 1 to 14 days. These numbers vary so much because they are based on different tests, report on different time periods, and agencies take different approaches in establishing guideline values. The measured concentrations of benzene at Bella Romero Academy's 4-8 campus in Greeley are comparable to typical concentrations in urban outdoor air and are well below both one -hour and daily exposure guidelines. Classified by the United States Environmental Protection Agency (US EPA) as a hazardous air pollutant (HAP), benzene originates from many common sources including car exhaust, gasoline fueling stations, industrial sources, and cigarette smoke. Following exposures to high concentrations (for example, a 1 -hour exposure to more than 52,000 ppb), benzene can cause health effects such as headaches or eye irritation. Exposure to sufficient concentrations of benzene over long periods of time have also been associated with increased cancer risk, although CDPHE notes that "breathing the levels of benzene measured near Bella Romero would not increase the risk of cancer above what the US EPA considers acceptable" (CDPHE 2019). Typical benzene concentrations in urban outdoor air are between 1 - 10 ppb (US EPA 2009; HEI 2007), which is comparable to the maximum and full range of concentrations measured at Bella Romero. The Centers for Disease Control sets the MRL guidelines which are the levels below which health effects are unlikely to occur. The acute MRL for benzene is 9 ppb (ATSDR 2007). Importantly, the Agency for Toxic Substances and Disease Registry defines the MRL as "an estimate of the amount of a chemical a person can eat, drink, or breathe each day without a detectable risk to RAMB LL health" (emphasis added) and acute MRLs are derived for an exposure duration of between 1 to 14 days (ATSDR 2018). The elevated benzene measurement at the Bella Romero Academy was from a sample collected over a 45 -minute period, not a full day. CDPHE compares the 45 - minute concentrations to the daily MRL as a screening assessment. Importantly, based on the summary of measured concentrations from CDPHE, it appears that all 1 -hour measurements since sampling began are well below the one -hour guidance level of 52,000 ppb. Furthermore, all the daily average benzene concentrations are well below the MRL of 9 ppb, including the daily average concentration on November 5th, 2019. Sampling at Bella Romero Academy does not indicate a pattern of elevated exposures. Furthermore, benzene concentrations greater than 9 ppb are common for short periods of time, especially near everyday sources such as in cars in heavy traffic, busy roadways, and at gasoline filling stations. Federal and global health agencies intentionally set health -based guideline concentrations much lower than concentrations that are expected to lead to health effects. This conservative practice safeguards public safety and well-being. MRL values, such as 9 ppb for benzene, are intended to help identify areas for additional assessment rather than to indicate potential health impacts. While continued monitoring at Bella Romero can be helpful, daily -average benzene concentrations of 9 ppb or less are not a cause for concern. For further information regarding health effects from benzene and other hazardous air pollutants, please visit the EPA website at https:/Jwww.ena.gov, or the Agency for Toxic Substances and Disease Registry (ATSDR) website at https:/Lwww.aasdr.cdc.gav_t. References Agency for Toxic Substances and Disease Registry (ATSDR). 2007. Toxicological Profile for Benzene. US Department of Health and Human Services, Atlanta, GA. Download from: https.....//www.atsdr..ccic.clovjtoxp.rofi1esl_t.E?.. I`7.p.?.!d.._4Q.&Ctc...--�...14. Agency for Toxic Substances and Disease Registry (ATSDR). 2018. Minimal Risk Levels (MRLs). US Department of Health and Human Services, Atlanta, GA. Accessed from: https://www.atsdr.cdc.govirninimairisklevelsiindex.html Colorado Department of Public Health and the Environment. 2020. Air Monitoring at Bella Romero Academy Near Vetting Oil and Gas Site: May - November, 2019. Accessed from: https://drive.google.cc>rn/file/cl/ 1 ZnbWbMSo71. fit.a3nSrhj.AEJEN.VOci95B/view Colorado Department of Public Health and the Environment. 2019b. Benzene Investigations at Bella Romero School. Accessed from: https_ f[clrive.gcogle :corn/file/d./.1.f3f3Kfg2RNAdiI5UCScxuwWZ8jpA2_0fsoz/_view Health Effects Institute Air Toxics Review Panel (HEI). 2007. Mobile -Source Air Toxics: A Critical Review of the Literature on Exposure and Health Effects. HEI Special Report 16. Health Effects Institute, Boston, MA RAMB LL US Environmental Protection Agency (US EPA). 2009. Benzene: Interim Acute Exposure Guideline Levels 9 (AEGLs). NAS/COT Subcommittee for AEGLS. Accessed December 13, 2019 from: https://www.epa_,.govjsites/produ_c..:tionlfiles/.2014- 081documentsjbenzene_,interirn dec 20C)8 vl.pdf Intended for Weld County Document type Report Date June 19, 2020 INDEPENDENT ANALYSIS OF CDPHE MONITORING DATA AT THE BELLA ROMERO 4-8 ACADEMY Bright ideas. Sustainable change. Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 CONTENTS 1. EXECUTIVE SUMMARY 2. INTRODUCTION 3. DESCRIPTION OF THE DATA 3.1 Data Collection 3.2 Quality Assurance on Measurements 4. HEALTH BASED BENCHMARKS 4.1 Definitions of benchmark values for shorter -duration exposures relevant to the Bella Romero campus 4.2 Derivation of benchmark values: va-ying approaches 5. ANALYSIS OF MONITORING DATA 5.1 Baseline measurements 5.2 Hydraulic fracturing (fracking) period 5.3 Drilling Activities 5.4 Hybrid Flowback/Production Period 5.5 Phase -Dependent Patterns of Benzene 6. CONCLUSIONS 7. REFERENCES APPENDICES Appendix 1 CDPHE Benzene Monitoring Data TABLES Table 1: Relevant Federal and State Health -Based Risk Assessment Benchmark Values for Short -Term Exposures Table 2: Relevant Federal and State Health -Based Risk Assessment Benchmark Values for Longer Exposures (>24 -hour) Table 3: Number of samples collected at tie Bella Romero Academy, by Well Development Phase 1 3 4 4 5 6 7 8 16 17 19 21 22 24 26 29 11 14 26 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 FIGURES Figure 1: Location of Bella Romero Academy 4-8 Campus (near top of map), the CAMML unit (blue pin on map) and the Vetting wellsite operation (pink pin, near bottom of map). 4 Figure 2: Health -Based Benchmark Risk Assessment Values 16 Figure 3: 45 -Minute Samples During Baseline Period. 17 Figure 4: School -Day Averages During Baseline Period. 18 Figure 5: 45 -Minute Samples During Hydraulic Fracturing Period. 19 Figure 6: School -Day Averages During Hydraulic Fracturing Period. 20 Figure 7: 45 -Minute Samples During Period When Mill -out and Coil Tube Activities Might Occur. 21 Figure 8: School -Day Averages During Period When Mill -out and Coil Tube Activities Might Occur. 22 Figure 9: 45 -Minute Samples During Flowback/Production Periods. 23 Figure 10: School -Day Averages During Flowback/Production. 24 Figure 11: 45 -Minute Samples During All Sampling Periods. 25 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 ACRONYMS AND ABBREVIATIONS AEGL ATSDR BMD CAMML CDC CDPHE EPA ESL GC HRV LOAEL MDH MRL NOAEL OEHHA ppb ppm REL ReV TCEQ VOC acute exposure guideline level Agency for Toxic Substances and Disease Registry benchmark dose Colorado Air Monitoring Mobile Lab Center for Disease Control and Prevention Colorado Department of Public Health and Environment Environmental Protection Agency effect screening level gas chromatography health risk value lowest observed adverse effects level Minnesota Department of Health minimal risk level no observed adverse effects level Office of the Environmental Health Hazard Assessment parts per billion parts per million reference exposure level reference value Texas Commission on Environmental Quality volatile organic chemical Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 1. EXECUTIVE SUMMARY The Colorado Department of Public Health and Environment (CDPHE) collected a total of 1,930 individual 45 -minute air samples at the Bella Romero 4-8 Academy over 96 intermittent days from May 6, 2019 through December 20, 2019. This time period reflects different phases of development of the nearby Vetting wellsite operated by Extraction Oil and Gas. This report focuses on one chemical of potential concern - benzene. Of the 1,930 individual samples, 1,796 had detectable benzene in the range where instruments can accurately measure concentrations. Ramboll undertook a risk assessment process to assess potential health impacts of exposures to benzene at the observed concentrations. Risk assessment is a conservative process wherein chemical exposure concentrations are compared to health -based benchmark values set by various regulatory bodies. These benchmark values are exceedingly conservative, often hundreds of, or even a thousand of times below concentrations associated with even minor health effects. Rather than predicting actual risk, these values are estimates of exposure concentrations, which accommodate large margins for uncertainty, where humans are likely to be without an appreciable risk of adverse health effects over a specified duration of exposure, even in sensitive populations such as children, pregnant women, the elderly, or people with underlying medical conditions. Importantly, this does not mean that any exposures above these health -based benchmark value concentrations will result in adverse health effects, but rather, this means that the risk of having certain health effects may be elevated in individuals, particularly sensitive individuals. Benzene concentrations in all but one of the 1,796 valid 45 -minute sample fell below all health - based benchmark risk assessment concentrations (as developed by multiple State and Federal agencies). This single sample exceeded one State and one Federal benchmark value, but not other State and Federal benchmark values. Of the 24 samples collected on that day, the other 23 were more than 10 -fold lower. This is indicative of an isolated, exceptional event. Valid benzene samples were collected over 96 individual days. Recognizing that students and teachers are at school for a large number of days each year and for extended periods of time each day, we calculated school day averages and compared these values to health -based benchmark risk assessment values relevant for 8 -hour periods' or 24 -hour exposure periods. The latter is a conservative comparison, as the period of exposure assumed in the benchmark is longer than the 8- to 12 -hour period of exposure experienced by students and staff during the school day. Looking across the school day, average benzene concentrations typically fell below all risk assessment benchmarks. Of the 96 days with valid benzene sampling data, only 4 days exceeded a single risk assessment benchmark value2 for health effects from 8 -hr average exposures. Further, one of the 4 days which resulted in a school day average above the California 8 -hour benchmark was the same day as the exceedance of a 1 -hour benchmark, which dominated the average. Without this one high value, the typical exposure across the day was considerably lower than the health -based benchmark risk assessment values. No other risk assessment screening values were exceeded. ' California OEHHA, 8 -hr REL z California OEHHA, 8 -hr REL 1/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Although these screening values were exceeded, the observed exposures are well below the lowest levels where adverse health effects were observed The California health -based benchmark risk assessment value for evaluating repeated 8 -hour exposures was developed based on a study in a worker population where individuals were exposed to very high concentrations of benzene — much higher than the values near the Bella Romero Academy — for many years The California 8 -hour risk assessment value is therefore exceedingly conservative, as school children and teachers at the Bella Romero Academy are not only exposed to much lower concentrations than the worker population, but also do not have the same constant exposures as the worker population All the exceedances, either in 1 -hour sample or a school day average, occurred during the flowback/production phase This is the phase of oil and gas development that has the greatest potential for benzene exposures Note that these operations are temporary, and typically occur only during the flowback and initial production of the well Cancer risk was not analyzed in this report since neither students nor teachers are at the school continuously for their lifetimes, and their lifetime exposure to benzene will more likely reflect exposures elsewhere Overall, these data reflect that the benzene concentrations measured at the Bella Romero Academy do not reflect a health risk to students or teachers An extensive dataset of benzene samples was collected and analyzed, and only a few that exceeded any health -based risk assessment benchmarks were found 2/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 2. INTRODUCTION Beginning in May 2019, the Colorado Department of Public Health and Environment (CDPHE) collected air samples near the Bella Romero Academy 4-8 campus ("Bella Romero") in Greeley, Colorado. The school campus is located about 1,400 feet north of a wellsite location with active oil and gas development activities, the Extraction Oil and Gas Inc.'s Vetting/15-H wellsite ("the Vetting wellsite"). This proximity to an oil and gas development site prompted questions from the Greeley Evans 6 School District and surrounding community members about potential exposures at the school. The CDPHE initially deployed their Colorado Air Monitoring Mobile Lab (CAMML) to measure volatile organic chemicals (VOCs) in the air near the Bella Romero campus. The CAMML was stationed at the campus three times between May and November 2019, for about one month at each time. A total of 1,796 valid 45 -minute (a surrogate for hourly) samples of ambient air on the campus were collected over 96 intermittent days between May 6, 2019 and December 20, 2019. Each sampling event included 45 minutes of sampling and 15 minutes between sampling events for analysis and preparation. For the sake of comparison, these 45 -minute samples can be used as a surrogate of a 1 -hour measurement. Although numerous other air contaminants were measure, this analysis focuses on benzene due to the occurrence of a single 45 -minute sample on November 5, 2019 with a concentration of 14.72 parts per billion (ppb) that raised concerns. This sample exceeded the Agency for Toxic Substances and Disease Registry (ATSDR) acute -duration inhalation minimal risk level (MRL) guideline of 9 ppb. The acute MRL is an estimate of the daily human exposure to a hazardous substance above which there may be risk of non -cancer health effects over a duration of exposure lasting 1-14 days. If an exposure is elevated above the MRL, there is a possibility of short-term health impacts due to benzene exposure, which could include headaches or eye irritation. Benzene and other VOCs measured spiked for only 10 minutes during this 1 -hour sample though benzene was the only VOC that exceeded its health guideline value of 9 ppb3. Due to this single occurrence of a higher benzene concentration, CDPHE conducted follow up with a fourth monitoring campaign, from December 4 to December 20, 2019, where the CAMML collected additional air samples at the Bella Romero campus. All air samples collected during this follow-up period yielded VOCs at levels below health guideline values for non -cancer health effects. There was no evidence for a similar large spike in VOC levels as that observed on November 5, 2019. As stated in a CDPHE Fact Sheet about the benzene investigations at Bella Romero school, dated January 22, 2020, CDPHE has had VOC sensors at the school and no more short-term elevated levels like that observed November 5, 2019 have been detected. 3 Data for other VOCs not shown in this report https://drive.google.com/open?id=187eNJemCfK5PD5UCuN4-xt14axkdgOEV 3/31 Ramboll - Independent Analysis of CDPHE Monitoring Data 3. DESCRIPTION OF THE DATA June 19, 2020 The CAMML measured air quality during discreet phases of oil and gas operations at the Vetting wellsite (CDPHE, 2020). This site is the closest wellsite to the school, located about 1,400 feet south of the Bella Romero Academy campus (Figure 1). I- 20th St E 20thISI Figure 1: Location of Bella Romero Academy 4-8 Campus (near top of map), the CAMML unit (blue pin on map) and the Vetting wellsite operation (pink pin, near bottom of map). 3.1 Data Collection Sampling of benzene, other VOCs, and other pollutants occurred during the various phases of oil and gas development including drilling, tracking, and flowback/production from May 6, 2019 through December 20, of 2019. Wells were drilled in the summer of 2018, but little activity had occurred early in 2019. Initially, according to CDPHE (2020), the CAMML collected air samples: • May 6 to May 26, 2019: Sampling from May 6 to May 26 provided baseline samples before oil and gas activities restarted after drilling in the summer of 2018. 4/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 • May 265 to June 3, 2019: Hydraulic fracturing occurred starting on May 26, 2019. The CAMML left the site on June 3, 2019, and hydraulic fracturing continued. • July 29 to August 27, 2019: Well millout and coil tube unit activities were scheduled during this period of time, although the exact timing of the activities is not known. Millout activities include operations to remove plugs from the wellbore. This period of time included the start of the school year (August 156). • October 16 to November 12, 2019: This period of time overlaps with the hybrid flowback/production phase (started on October 16'). • December 4 to December 20, 2019. After finding the November 5, 2019 elevated benzene sample, additional sampling was initiated. The December time period was also considered a hybrid flowback/production phase. Note, schools were closed for Thanksgiving Break November 23 -December 1, 2019. Air samples were drawn in through at inlet located 16-18 feet from the ground. The instrument (a Markes UNITY 2 Air Server) used a Tenax-based sorbent thermal desorption system to collect samples, which were subsequently analyzed using a Gas Chromatography (GC) system (Thermo Scientific ISQ Series) coupled with flame ionization detection to determine ambient concentrations of selected contaminants of concern (CDPHE 2020). Air samples were collected for 45 minutes every hour. Prior to each sample collection, 15 minutes are needed for injection, cooling, equilibration and other processes necessary to complete a measurement. These 45 - minute averages were used by CDPHE to approximate 1 -hour averages. The CDPHE mobile laboratory also collected meteorological data to aid in analysis of the air samples. The combination of meteorological data and spikes in ethane and other species associated with well operations allowed CDPHE to identify probable oil and gas operation plumes with higher levels of benzene likely associated with the Vetting operation 1,400 feet away. 3.2 Quality Assurance on Measurements As part of their quality assurance procedures for benzene and other VOC measurements, CDPHE followed data quality assurance protocols outlined by the Environmental Protection Agency (EPA) (https://www.epa.gov/amtic/pams-technical-assistanct document -tad). Ramboll obtained data files for the CAMML measurements of benzene and other VOC from CDPHE and examined the underlying values. Values were flagged if samples resulted in undetectable benzene concentrations, were less than the method detection limits, or had detectable benzene but failed calibration quality control (134 samples, had either no detectable benzene or were below the method detection limit; none were flagged for quality assurance issues8). These flagged data were not used in Ramboll's analysis. 5 Note, there was some overlap between baseline and hydraulic fracturing phase sampling on May 26, 2019 6 https://www.greeleyschools.org/cms/lib/CO01001723/Centricity/Domain/4/2019-2020%20Student°/020Calendar.pdf https://drive.google.com/file/d/17kZ2fSI_9FBd5JXD98MCp9CgEP_ge9Kd/view s There are statistical methods that allow inclusion of data below detection limits or below method detection limits, but to be conservative we did not include these. 5/31 RamboII - Independent Analysis of CDPHE Monitoring Data June 19, 2020 4. HEALTH BASED BENCHMARKS Risk assessment is a conservative process wherein chemical exposure concentrations are compared to health -based benchmark values set by various regulatory bodies such as the US EPA, the ATSDR, or some state regulatory agencies (e.g. California Environmental Protection Agency, Texas Center for Environmental Quality, Minnesota Department of Health) taking into account study -specific factors, exposure duration, and potentially exposed population. These benchmark values are exceedingly conservative, often hundreds or a thousand of times below concentrations that have been shown to be associated with even minor health effects. Rather than predicting actual risk, these values are estimates (with uncertainties) of exposure concentrations where humans are likely to be without an appreciable risk of adverse health effects over a specified duration of exposure. These health -based benchmark values are developed so they are protective of all people, including potentially sensitive populations such as children, pregnant women, the elderly, or people with underlying medical conditions. The values are also developed for specific durations: short-term exposures (averaged over 1, 8, or 24 hours), or continuous exposures (averaged over months, years, or a lifetime). These standards or guidelines are conservative estimates for concentrations below which adverse health effects are not anticipated. Importantly, this does not mean that any exposures above these health -based benchmark value concentrations will result in adverse health effects, but rather, this means that the risk of having certain health effects may be elevated in individuals, particularly sensitive individuals. These standards and guidelines are based on scientific studies in people and experimental animals; they e rr on the side of caution when the information from the studies carries uncertainties in order to be most protective. Because of this caution, benchmark values are often hundreds- or thousands -fold below the concentrations where health effects were observed in animal e xperiments or human populations. Risk assessment values are generally based on the most sensitive substance -induced health e ndpoint relevant to humans. For example, ATSDR specifies that "exposure to a level above the MRL does not mean that adverse health effects will occur."9 Instead, MRLs and other similar health benchmark values are developed to serve as a tool to help public health professionals identify scenarios that may require further investigation. As with other risk assessment values, MRLs are very conservative in nature in order to protect sensitive human subpopulations and account for variability and inherent uncertainties due to extrapolation and modeling of values based on animal or small human studies. The health benchmark values used in risk assessment are situation- and population -dependent. Both the intensity (concentration and frequency) and the duration (how long, how often) of exposures are important. At the Bella Romero Academy campus, one spike of VOCs was observed in a single 45 -minute sample on November 5, 2019; this value prompted further investigation of exposures and the potential adverse health effects from breathing air while on campus. In addition, while children are a potentially susceptible population, students and teachers are not on https://www.atsdr.cdc.gov/mrls/index.html 6/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 campus all the time It is therefore important to consider the intent of the various health -based benchmark values when evaluating exposure measures for risk Tables 1 and 2 present benchmark risk assessment values for different durations of exposure — short-term (ranging from hours to days) (Table 1), longer -term (ranging from days to weeks), and long-term (ranging from months to a lifetime) (Table 2) In addition to federal government values, these tables include benchmark values from three state government agencies Each regulatory body may define durations differently Both tables only list risk assessment values for non -cancer health effects as most risk assessment values for cancer assume continuous lifetime exposures and are thus not relevant for a school where individuals are only present for daytime hours Monday through Friday for a limited number of years 4.1 Definitions of benchmark values for shorter -duration exposures relevant to the Bella Romero campus ATSDR is a Federal public health agency of the US Department of Health and Human Services, part of the Center for Disease Control and Prevention (CDC) ATSDR defines its acute MRL as an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse non -cancer health effects over a specified duration of exposure The MRL is intended to serve as a screening level to identify potential areas of concern The acute MRL is specific for estimating the risk of exposures lasting 1 to 14 days Thus, the unit of duration for the acute MRL is at least "daily average " Texas Commission on Environmental Quality (TCEQ) is the environmental agency for the state of Texas TCEQ defines Reference Values (ReVs) as safe concentrations of chemicals in the air based on health effects The ReVs are concentrations that humans, including children, the elderly, pregnant women, and people with pre-existing health conditions, can inhale for 1 -hour periods discontinuously without significant risk of adverse effects The acute ReV is used to evaluate short-term air monitoring data like the monitoring at the Bella Romero campus conducted between May and December 2019 TCEQ also has values specific to screening for air permitting, which are welfare -based in addition to health These Effect Screening Levels (ESLs) are one-third of the ReVs and are not relevant to the Bella Romero ambient air monitoring values California EPA's Office of the Environmental Health Hazard Assessment (OEHHA) is the department charged with protecting and enhancing the health of Californians and the California environment OEHHA derives Reference Exposure Levels (RELs), which are used as an indicator of potential non -cancer health impacts OEHHA derives acute and 8 -hour RELs — the concentration at which no adverse non -cancer health effects are anticipated An acute REL is set to protect against the maximum 1 -hour ground -level concentration inhaled by an individual An 8 -hour REL is developed to protect people who work daily shifts of 8-9 hours OEHHA specifies that the 8 -hour RELs are air concentrations at or below which health impacts would not be expected even for sensitive subpopulations in the general population with repeated daily 8 -hour exposures over a significant fraction of a lifetime This benchmark could be used to evaluate the health risk of children and teachers repeatedly exposed to a chemical at school 10 10 8 hour RELs can be used to evaluate the potential for health impacts (including effects of repeated exposures) in offsite workers, and to children and teachers exposed during school hours (https //oehha ca gov/media/downloads/crnr/2015guidancemanual pdf) 1 7/31 RamboII - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Minnesota Department of Health (MDH) is the state agency that Is charged with protecting, maintaining and improving the health of Minnesotans MDH has designated an acute Health Risk Value (HRV) defined as the concentration of a chemical or defined mixture of chemicals in ambient air, at or below which the chemical is unlikely to cause an adverse health effect to the general public over a given exposure period Acute HRVs are compared to 1 -hour averaged concentrations of a chemical US Environmental Protection Agency (US EPA) has developed Acute Exposure Guideline Levels (AEGLs) based on human exposure studies These values represent threshold exposure limits for the general public and are applicable to emergency exposure periods on the magnitude of minutes to hours AEGL-1 is defined by EPA as the airborne concentrations of a substance above which it is predicted that the general population, including susceptible individuals, could experience notable discomfort, irritation, or certain asymptomatic, non -sensory effects The effects are not disabling and are transient and reversible upon cessation of exposure Table 1 includes AEGL-1 exposure levels for 10 -minute, 30 -minute, and 1 -hour averages 4.2 Derivation of benchmark values: varying approaches In deriving risk assessment values, risk assessors usually start with all available studies related to toxicity of the chemical they are developing risk assessment values for Both human studies (either clinical studies or epidemiology studies) and experimental animal studies are considered Risk assessment values are then based off the most sensitive health outcome for that chemical For benzene, that health outcome appears to be related to blood cells, either measured in a specific blood cell's population of function (for example, reductions in B -lymphocyte cell counts in exposure workers) Some values are based on the highest exposures where no effects are observed (the No Observed Adverse Effects Level, or NOAEL), while others are based on the lowest exposures where effects are observed (the Lowest Observed Adverse Effects Level, or LOAEL) Some values are based on conservative models showing where 10% of a population might show an effect (benchmark dose, or BMD) Risk assessors then further refine that number to account for the many uncertainties in the process Using the highest level at which no adverse effect was observed (the NOAEL) in an experiment and extrapolating that to apply to all humans, including sensitive subpopulations, exposed during a specific duration of exposure (I e acute, chronic, lifetime) requires many adjustment factors and assumptions For example, these adjustment factors (some of which are called "uncertainty factors") can account for variability between humans' sensitivity to the chemical, uncertainties in extrapolating results from an animal model to the human population, and uncertainty in using a LOAEL for deriving the benchmark value rather than a NOAEL In deriving benchmark values for human health risk assessment, conservatism is employed every step of the way, as scientists account for their uncertainties in extrapolating the data to be used to assess health of any and all people who may be exposed and the resulting benchmark value is often hundreds -fold lower than the exposure level that produced an effect in an experimental study Benchmark risk assessment values intended to assess the health risk for the same exposure duration for the same general population differ from one another though they are often based on 8/31 RamboII - Independent Analysis of CDPHE Monitoring Data June 19, 2020 the same key studies The derivation of benchmark risk assessment values is grounded in science, and each agency took its own route in assumptions and adjustments from the experimental results Even the highest benchmark risk assessment values for a certain exposure level (e g TCEQ REL vs ATSDR MRL) are inherently conservative, as adjustments and assumptions are still applied when the benchmark is developed These points are illustrated below Each agency develops its own criteria and decision -making process to account for the unknowns when extrapolating an experimental or modeled value to a health risk value, leading to different values derived from the exact same data For example, both ATSDR and TCEQ used the same animal exposure study (Rozen et al 1984 as cited in ATSDR 2007 and TCEQ 2015) as the key study in developing their benchmark risk assessment values for shorter -duration exposures for the general population Rozen et al (1984) conducted a study wherein mice were exposed by inhalation to benzene concentrations up to 301 parts per million (ppm) for 6 hours per day, 6 days a week The critical system evaluated was the immune system (reduced lymphocyte proliferation), and the resulting LOAEL was 10 2 ppm (10,200 ppb) Using the LOAEL of 10 2 ppm, ATSDR and TCEQ made assumptions and adjustments to best estimate a health benchmark ATSDR's acute MRL of 9 ppb for benzene is intended for contextualizing risk of acute exposures lasting 1 to 14 days In developing the MRL from the LOAEL, the LOAEL was adjusted for intermittent exposure and extrapolated for 24 -hour exposure, resulting in a LOAEL of 2 55 ppm The LOAEL was converted to a human equivalent concentration and then divided by uncertainty factors to account for human variability (10) and uncertainties due to extrapolation from animals to humans using dosimetric conversion (3) and use of a LOAEL instead of a NOAEL (10) (ATSDR Tox Profile, 2007) TCEQ's acute ReV of 180 ppb of benzene is intended to be used to evaluate risk of adverse effects during 1 -hour discontinuous exposures Using the LOAEL from the Rozen et al (1984) study, TCEQ adjusted for exposure duration and dosimetric differences between animal and human exposures, resulting in an estimated human exposure concentration of 18 5 ppm (18,500 ppb) Uncertainty factors were applied to account for human variability (10), database uncertainty (1), and uncertainties due to extrapolation from a LOAEL to a NOAEL (3), and extrapolation from animals to humans (3) (TCEQ, 2015) These variations in health risk values are also seen in those derived from human studies for example, ATSDR and California OEHHA both use the same study of shoe manufacturing workers (Lan et al 2004) to derive their benchmark values for chronic exposure to inhaled benzene In the study, 250 shoe manufacturing workers in China having been employed for an average of 6 years were found to have been exposed to up to over 10 ppm (10,000 ppb) benzene via inhalation, and the study authors determined a LOAEL of 570 ppb The Rothman et al (1996) study was in the same worker population ATSDR defines the chronic MRL as an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse non -cancer health effects over 365 days of exposure or longer Using the Lan et al (2004) study, ATSDR's MRL for chronic exposures is 3 ppb, based on a benchmark dose (BMD) analysis of the critical health endpoint of decreased B -lymphocyte cell counts instead of relying on the study's reported LOAEL In determining the chronic exposure MRL, various adjustments 9/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 and assumptions were made in interpreting the study results, including adjusting from an 8 -hour time -weighted average to a continuous (24 hour) exposure concentration, and adjusting for human variability California EPA OEHHA defines the chronic REL as the concentration level at or below which no adverse health effects are anticipated for a continuous, chronic exposure duration Like ATSDR, California OEHHA also employed benchmark dose modeling of the critical health endpoint of decreased peripheral blood cells observed in the study of shoe manufacturing workers (Lan et al 2004) However, California used different adjustments and assumptions than ATSDR, resulting in an REL of 1 ppb as compared to ATSDR's 3 ppb value 10/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Table 1: Relevant Federal and State Health -Based Risk Assessment Benchmark Values for Short -Term Exposures e • era or tate a gency = enc mar xposure xposure A • justment Value Name (Reference) Period Level Most Sensitive Health Effect Factors Agency for Toxic Substances and Diseases Acute -duration 9 ppb Immune system: reduced lymphocyte proliferation 300 Registry (ATSDR) 1-14 days Based on LOAEL' of 10.2 ppm (10,200 ppb) for Minimal Risk Level (MRL)" immunological effects in exposed for 6 mice hours/day for 6 consecutive days (Rozen et al. An estimate of the daily human exposure to a 1984) hazardous substance that is likely to be without appreciable risk of adverse non -cancer health effects over a specified duration of exposure (ATSDR 2007). California Office of Environmental Health Hazard Acute: 27 pg/m3 Reproductive/ development, immune system, 600 Assessment (OEHHA) infrequent 1- (8.3 ppb) hematologic system hour exposures Reference Exposure Level (RELY' Based on a LOAEL of 5 ppm (5,000 ppb) with developmental hematotoxicity endpoints (decreased The concentration level at or below which no early nucleated red blood cell counts) in fetal and adverse health effects are anticipated for a neonatal mice (Keller and Snyder, 1988) specified exposure duration. (OEHHA 2014). Repeated 8- 3 pg/m3 Decreased peripheral blood cell counts 200 hour (0.9 ppb) 8 -hour RELs are air concentrations at or below Based on decreased peripheral blood cells in shoe which health impacts would not be expected manufacturing workers (Lan et al. 2004). For health even for sensitive subpopulations in the general protective purposes, the same study and principles population with repeated daily 8 -hour exposures upon which the chronic value is based are used for over a significant fraction of a lifetime. (OEHHA the basis of the 8 -hour REL. It is unknown if the 2015)13 adverse effects of repeated benzene exposure are reversed overnight or after brief periods of non- https://www.atsdr.cdc.gov/toxprofilesApipcif 12 httpsi/oehha,ca.gov/mediaidownloadsicrnr/appendixdlfinal.pdf https://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary https://oehha.ca.gov/media/downloads/crnr/201 Sguidancemanual .pdf 11/31 RamboII - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Federal Value or Name State (Reference) Agency / Benchmark Exposur Period xposure Level Most Sensitive Health Effect djustment tors . _ exposure. Furthermore, continue to worsen adverse repeated effects exposure. are likely to with Texas Reference ReVs in facilities (TCEQ Center Value are used outdoor air that 2015). for Environmental Quality (ReV)" to evaluate chemical levels samples collected by TCEQ release chemicals into (TCEQ) found around the air Acute, discontinuous exposure 1 -hour 180 ppb lymphocytes Depressed mitogen-induced Based reported for supported Snyder for 6 1 -hour on hours in 1996). a peripheral by concentration. LOAEL a study per day Dempster Adjusted blastogenesis of of for lymphocytes 10.2 ppm exposure 18.5 of (10,200 ppm femoral and depressed et ppb) 0-301 al. B - ppm 1984, Corti and ppb) 100 days to to 1991, (18,500 (Rozen Snyder Acute, 24 -hour exposure 100 ppb mice 6 and Minnesota Health The mixture which chemicals effect occurs implementation compared of chemicals air (MDH concentration the to Risk over of the 2002). Department Values chemicals chemical is unlikely general a to prescribed one or (HRV)'`' of purposes, -hour defined or of Health a chemical in ambient defined to cause public when time. acute averaged mixtures mixture an (MDH) or defined air, at adverse exposure For HR Vs concentrations of chemicals or below of health are in Acute or less) (24 hours 1,000 pg/m3 ppb) (307 Reproductive/developmental HRVs California's development, NOAEL HRV was differs rounded are as based 40 OEHHA the ppm from to on one OEHHA OEHHA variables REL (40,000 significant database. REL REL ppb; presented in database that figure 130 At the the mg/m3). (MDH, in listed time 2001)16 the The HRV HRV 100, OEHHA' database based � REL on final 14 https://www.tceq.texas.gov/assets/public/implementation/tox/dsd/final/benzene,pdf 15 https://www.health.state.mn.us/communities/environment/risk/rules/air.html 16 https://www.health.state.mn.us/communities/environment/risk/docs/rules/hrvsonar.pdf " rittps://www.health.state.mn.us/communities/environmentlrisk/docs/ru es/hrvsonar.pdf page 47 Cal EPA (1999). The Determination of Acute Reference Exposure Levels for Airborne Toxicants, Office of Environmental Health Hazard Assessment. Berkeley, CA. 12/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 ederal Value or State Name (Reference) Agency / Benchmark Exposure Period Exposure Level Most Sensitive Health Effect • - Adjustment actors EPA Acute Exposure Guideline Threshold exposure applicable to emergency airborne concentration which it is predicted including the elderly, susceptible individuals, discomfort, irritation, nonsensory effects. are transient and reversible limits that children Effects Levels for the exposure of a substance the general and could experience or certain are (US (AEGL-1)18 general public; periods. The above population, other notable asymptomatic not disabling and EPA 2009). 10 -minute average 130 (130,000 ppb) 72 (72,000 ppb) 52 (52,000 ppb) ppm ppm ppm Mild Based observed 1950, Based hours central on Yin on for in concentrations et NOAEL mild nervous several al. central 1987, of human 110 system; where Kraut ppm nervous eye studies et (110,000 system effects al. or airway (Srbova 1988). were ppb) effects. irritation et al. for 2 3 30 -minute average 1 -hour average 'The preferred study or and adjustment basis of a health human clinical or epidemiologic factors are applied. -based risk assessment benchmark value is the highest concentration where no adverse effect is observed (the No Observable Adverse Effects Level, or NOAEL) in an animal study. Where a NOAEL is not available, the lowest concentration where an adverse effect is observed (the Lowest Observable Adverse Effects Level, or LOAEL) is used 19 https://www.epa.gov/sites/production/files/2014-08/documents/benzene__interim dec 2008. vi.pdf 13/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Table 2: Relevant Federal and State Health -Based Risk Assessment Benchmark Values for Longer Exposures (>24 -hour) Federal Value Name(Reference) or State Agency / Benchmark Exposure Period Exposure Level Most Sensitive .. Health Effect Adjustment Factors Agency for Toxic Substances and Diseases Acute -duration 9 ppb system: reduced lymphocyte proliferation 300 Immune Registry (ATSDR) 1-14 days Risk Level (MRL)19 immunological Based on LOAEL' for effects 6 consecutive of 10.2 ppm in mice (10,200 exposed (Rozen ppb) for et for 6 al. days Minimal hours/day An estimate of the daily human exposure to a 1984) hazardous substance that is likely to be without Intermediate 6 ppb system: Delayed splenic 300 Immune lymphocyte appreciable risk of adverse non -cancer health duration reaction effects over a specified duration of exposure >14 - 365 (ATSDR 2007). days lymphocyte Based significantly foreign mice days/week on antigens to benzene LOAEL delayed reaction for of evaluated vapors 20 exposure 10 splenic following ppm for (10,000 lymphocyte in 6 days vitro the hours/day, (Rosenthal ppb) mixed exposure for reaction 5 of and to male Snyder 1987) Agency for Toxic Substances and Diseases Chronic 3 ppb Immune system: decreased lymphocyte count 10" Registry (ATSDR) duration (365 days or Based on the results of benchmark dose modeling Minimal Risk Level (MRL)70 longer) (BMD) of B -lymphocyte manufacturing workers cell (Lan counts et al. in shoe 2004). The An estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse non -cancer health effects over a specified duration of exposure NOAEL was 0.57 ppm (570 ppb). (ATSDR 2007) . :5 https://www.atsdr.cdc.gov/toxprofiles/tp3.pdf https://www.atsdr.cdc.gov/toxprofiles/tp3.pdf 14/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 ..' Value deral Name or State (Reference) Agency / Benchmark Exposure Period Exposure Level Most Sensitive Health Effect Adjustment Factors Environmental Reference Concentration Protection Agency (EPA) (RfC)" Chronic exposure 9 ppb Immune system: decreased lymphocyte count 9022 (lifetime) Based on benchmark dose (BMD) modeling of An inhalation exposure concentration at or below hematological effects in a study of workers exposed which adverse health effects are not likely to to benzene for an average of 6.3 years (Rothman et occur. At lifetime exposures increasingly greater al. 1996). Note, the LOAEL was 7.6 ppm (7,600 than the reference exposure level, the potential for adverse health effects increases (US EPA ppb). 2003) . California Assessment Office of (OEHHA) Environmental Health Hazard Continuous, chronic 3 (0.9 pg/m3 Decreased peripheral blood cell counts 200 ppb) exposure"' Based on benchmark dose (BMD) of modeling Reference Exposure Level (REL) decreased peripheral blood cells in shoe workers (Lan et al. 2004). Workers manufacturing The concentration level at or below which no were exposed to benzene for an average of 6.1 adverse health effects are anticipated specified exposure duration (OEHHA for a 2014). years. The LOAEL was 0.57 ppm (570 ppb). Texas Center for Environmental Quality (TCEQ) Chronic 86 ppb Decreased lymphocyte count 30 Reference Value (ReV) Based on a study of benzene -exposed workers (Rothman et al. 1996, supported by Lan et al. 2004) ReVs are used to evaluate chemical levels found outdoor air samples collected by TCEQ around facilities that release chemicals into the air (TCEQ in 2015). 'The preferred basis of a health -based risk assessment benchmark value is the highest concentration where no adverse effect is observed (the No Observable Adverse Effects Level, or NOAEL) in an animal study or human clinical or epidemiologic study. Where a NOAEL is not available, the lowest concentration where an adverse effect is observed (the Lowest Observable Adverse Effects Level, or LOAEL) is used and adjustment factors are applied. "In addition to the adjustment factors, the BMD modeling also includes conservative adjustments. "'Long-term exposure to the annual average air concentration, spread over 24 hours/day, 7 days/week. 21 https://cfpub.epa.gov/ncea/iris2/chemicalLanding.cfm2substance nmbr=276 2-1 https://cfpub•epa•gov/ncea/irisliris documents/documents/Subst/0276 summary.pdf 15/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 5. ANALYSIS OF MONITORING DATA This section includes graphical presentation of the exposure samples obtained in the CAMML located at the Bella Romero Academy. All individual samples reflect a 45 -minute period but are u sed as a surrogate for 1 -hour air concentrations. There are multiple possible health -based risk assessment values to use for comparison, as discussed in Section 4. Figure 1 presents the range o f health -based risk values for short-term exposures, as would be relevant for the Bella Romero Academy scenario. As we are not endorsing any of these values at this time, we considered all values presented in Table 1 to compare exposures to appropriate health -based benchmark risk assessment values. Each health -based benchmark value has its own strengths and weaknesses, but for the sake of being as conservative as possible, we present the lowest (most conservative) values in the figures. It is important to understand that exposures above that comparison value are likely still safe. • Health -based values for comparison to 1 -hour measurements ATSDR acute -duration MRL (9 ppb). Although this value is meant for averaged measurements over the course of 1-14 days, it is the shortest time period for comparison, so we apply it for screening. o California acute -duration REL (8 ppb). o TCEQ acute -duration ReV (180 ppb). o MDH acute acute -duration HRV (307 ppb). Although this value is meant for averaged measurements over the course of 24 hours or less, it is the shortest time period for comparison, so we apply it for screening. o US EPA 1 -hour AEGL-1 (52,000 ppb). • Health -based values for comparison to core and extended school -day measurements ATSDR acute -duration (9 ppb). Although this value is meant for averaged measurements over the course of 1-14 days, it is the shortest time period for comparison, so we apply it for screening. California 8 -hour REL (0.9 ppb). Although this value is meant for averaged measurements over the course of 24 hours or less, it is the shortest time period for comparison, so we apply it for screening. TCEQ 24 -hour ReV (100 ppb). Although this value is meant for averaged measurements over the course of 24 hours, it is the shortest time period for comparison, so we apply it for screening Figure 2: Health -Based Benchmark Risk Assessment Values 16/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 5.1 Baseline measurements Sampling from May 6 through May 26, 2019 provided baseline measurements before oil and gas activities restarted after previous drilling at the Vetting wellsite in the summer of 2018. A total of 405 individual 45 -minute samples were collected during this period. Figure 3 shows all samples obtained during the sampling period, regardless of time of day. All samples reflect benzene concentrations less than 0.8 ppb, which are below all relevant health -based risk assessment benchmark values. For the sake of comparisons, we include both the California OEHHA 1 -hour REL of 8 ppb and the ATSDR acute MRL of 9 ppb on this graph. The TCEQ ReV of 180 ppb; the MDH HRV of 307 ppb; and the US EPA 1 -hour AEGL-1 of 52,000 ppb are all beyond the upper - bound scale of this graph. Baseline 45 -Minute Samples 15 14 13 12 11 7 10 9 a) 2 c 6 m 5 4 3 2 1 0 5/6/2019 O 5/11/2019 0 Baseline 5/16/2019 5/21/2019 5/26/2019 CalEPA OEHHA Acute REL ATSDR Acute MRL Figure 3: 45 -Minute Samples During Baseline Period. Each open gray dot represents one 45 -minute sample, regardless to time of day. Solid lines represent California 1 -hour REL (8 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ 1 -hour ReV (180 ppb), MDH HRV (307 ppb), and US EPA 1 -hour AEGL-1 (52,000 ppb) are not shown. To represent potential exposures during a school day, we calculate "core" school -day average concentrations during the 8 -hour period where students and teachers are likely to be present (8 AM to 4 PM). Since the sampling occurred at various times throughout the day (not starting or stopping on the hour), we include all samples overlap with times within this range. To account for the extended period where teachers or students might be present for pre- or after -school activities, we also calculate "extended" school day averages over the longer 12 -hour period (overlapping with 6 AM to 6 PM). Figure 4 shows core and extended school -day average benzene concentrations for the period May 6 through May 26, 2019. Standard procedures are to only calculate averages when 75% of the data is valid. For 8 -hour averages, this would mean 6 or more valid samples need to be available in the averaging period; for 12 -hour averages, 9 or 17/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 more valid samples need to be available. However, to be inclusive, we also calculated averages when 5 or fewer samples were present and noted the values as hatched bars in the graphs below. All core and extended school day averages reflect benzene concentrations less than 0.3 ppb, which are below all relevant health -based risk assessment benchmark values. For the sake of comparisons, we include both the California OEHHA 8 -hour REL of 8 ppb and the ATSDR acute MRL of 9 ppb on this graph. Baseline: School Day Benzene Averages Benzene (ppb) 8 7 5 4 3 2 1 O 'warm ti� ti� lie) ti� ti� ors, ti� ti� ti°� ti°� ti�111111, ,tiO �O .LO .�O ,tiO .tiO \\\\\\ \ Full School Day (6am - 6 pm) Normal School Day (8 am - 4 pm) ATSDR Acute MRL CalEPA OEHHA Repeated 8 -hour REL Figure 4: School -Day Averages During Baseline Period. Green bars represent the 8 -hour core school -day period (8 AM - 4 PM); blue bars represent a 12 -hour extended school -day period (6 AM - 6 PM). All days, Monday through Sunday, are included. Green hatched bars reflect days when less than 6 samples were available for averaging for core averages; blue hatch bars reflect days when less than 9 samples were available. Solid lines represent California 8 -hour REL (0.9 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ 24 -hour ReV (100 ppb) is not shown. 18/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 5.2 Hydraulic fracturing (fracking) period Hydraulic fracturing occurred at the Vetting wellsite starting on May 26th, 2019. The CAMML continued sampling May 26 through June 3, 2019, when it left the Bella Romero Academy site. A total of 132 individual 45 -minute samples were collected during this period. Note that hydraulic fracturing continued beyond the June 3, 2019 sampling date. Figure 5 shows all samples, regardless of time of day. All measurements reflect benzene concentrations less than 0.3 ppb, which are below all relevant health -based risk assessment benchmark values. Hydraulic Fracturing 45 -Minute Samples 15 14 13 12 11 15- 10 Q 9 a 8 v c 6 m 5 4 3 2 1 0 5/28/2019 5/29/2019 5/30/2019 5/31/2019 6/1/2019 6/2/2019 6/3/2019 ii GP 0 Hydraulic Fracturing --CalEPA OEHHA Acute REL ATSDR Acute MRL Figure 5: 45 -Minute Samples During Hydraulic Fracturing Period. Each open gray represents one 45 -minute sample, regardless to time of day. Solid lines represent California 1 -hour REL (8 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ ReV (180 ppb), MDH HRV (307 ppb), and US EPA 1 -hour AEGL-1 (52,000 ppb) are not shown. 19/31 Ramboll - Independent Analysis of CDPHE Monitor ng Data June 19, 2020 Figure 6 shows core and extended school -day average benzene concentrations for the period May 26 through June 3, 2019, when hydraulic fracturing was occurring. All samples reflect average benzene concentrations less than 0.4 ppb, which are below all relevant health -based risk assessment benchmark values. Hydraulic Fracturing: School Day Benzene Averages Benzene (ppb) 6 5 4 3 2 1 0 5/27/2019 5/28/2019 5/29/2019 5/30/2019 Full School Day (6 am - 6 pm) ATSDR Acute MRL 5/31/2019 6/1/2019 6/2/2019 Normal School Day (8 am - 4 pm) CaJEPA OEHHA Repeated 8 -hour REL • Dr :1 Figure 6: School -Day Averages During Hydraulic Fracturing Period. Green bars represent the 8 -hour core school -day period (8 AM - 4 PM); blue bars represent a 12 -hour extended school -day period (6 AM - 6 PM). All days, Monday through Sunday, are included. Green hatched bars reflect days when less than 6 samples were available for averaging for core averages; blue hatch bars reflect days when less than 9 samples were available. Solid lines represent California 8 -hour REL (0.9 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ 24 -hour ReV (100 ppb) is not shown. 20/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 5.3 Drilling Activities Air samples were collected July 29 to August 27, 2019, during the drilling activities phase of well development. During this period, well mill -out and coil tube unit activities were scheduled. Mill - out activities include operations to remove plugs from the wellbore. However, we do not know the exact timing of these activities. Note that this period overlaps with the start of the school year, which began on August 15, 2019. A total of 467 samples were collected during this period, with 27 resulting in values below method limits of detection of below the level of detection. The latter were excluded, yielding 440 samples. Figure 7 shows benzene concentration in 45 -minute samples obtained during the drilling activity period of July 27, 2019 through August 27, 2019, regardless of time of day. All samples reflect benzene concentrations less than 0.9 ppb, which are below all relevant health - based risk assessment benchmark values. Mill Out 45 -Minute Samples 15 14 Benzene (ppb) 13 12 11 10 9 8 7 6 5 4 3 2 1 0 7/29/2019 8/3/2019 8/8/2019 8/13/2019 8/18/2019 8/23/2019 8/28/2019 0 0 0 0 8 0 o Mill Out CalEPA OEHHA Acute REL ATSDR Acute MRL Figure 7: 45 -Minute Samples During Period When Mill -out and Coil Tube Activities Might Occur. Each gray open dot represents one 45 -minute sample, regardless to time of day. Solid lines represent California 1 -hour REL (8 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ ReV (180 ppb), MDH HRV (307 ppb), and US EPA 1 -hour AEGL-1 (52,000 ppb) are not shown. 21/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Figure 8 shows core and extended school -day average benzene concentrations for the period July 27 through August 27, 2019, when drilling activities were occurring. All samples reflect average benzene concentrations less than 0.3 ppb, which are below all relevant health -based risk assessment benchmark values. Mill Out: School Day Benzene Averages Benzene (ppb) 9 8 7 6 S 4 3 2 1 01 Q1 Q1 Q1 Q1 C1 Ol O1 Gn C1 cn C1 G1 Q1 G1 O1 O1 O1 G1 C1 Ql Q1 Q1 O1 O1 O1 O1 O1 Q1 Q1 r-1 el r-1 eel el eel e1 el - - - e -1 e-4 t-1 el el el el el el v-1 e -I el el e1 el el r-1 el el O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N \ \p \ \ \ \ \ \ \ \ \ Ql v-4 '••• M 1rl t0 N- CO O1 O e -1 N M Tr in O N 00 c7)O c-i N rig cr in to r% rn ' \ \ \ \ \ \ el \ e-�l e-�I e- l e-i ele l v -I el e- I N N N N N N N N N N 00 00 CO 00 CO CO CO 00 CO 0000 0\0 00 00 CO CO 00 00 CO 00 00 00 CO 00 00 00 00 00 Full School Day (6 am - 6 pm) Normal School Day (8 am - 4 pm) ATSDR Acute MRL — CalEPA OEHHA Repeated 8 -hour REL Figure 8: School -Day Averages During Period When Mill -out and Coil Tube Activities Might Occur. Green bars represent the 8 -hour core school -day period (8 AM - 4 PM); blue bars represent a 12 -hour extended school -day period (6 AM - 6 PM). All days, Morday through Sunday, are included. Green hatched bars reflect days when less than 6 samples were available for averaging for core averages; blue hatch bars reflect days when less than 9 samples were available. Solid lines represent California 8 -hour REL (0.9 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ 24 -hour ReV (100 ppb) is not shown. 5.4 Hybrid Flowback/Production Period Air samples were collected during the hybrid flowback/production phase that started on October 16, 2019. The initial sampling campaign occurred October 16 through November 12, 2019. A total of 562 samples were collected during this period, with 107 resulting in values below method limits of detection of below the level of detection. The latter were excluded, yielding 455 samples. Following observance of a single peak benzene exposure measurement of 14.72 ppb23 on November 5, 2019, the CAMML returned for additional measurements. The second measurement period started on December 4, 2019 and continued through the start of Winter break on December 20, 2019. A total of 364 samples were collected during this period. All were included in the analysis. 23 This value was originally calculated by CDPHE as 10.27 ppb; an errata was later released. 22/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Figures 9 shows benzene concentrations in 45 -minute samples obtained during the period when flowback/production activities were occurring. To emphasize which measurements were relevant to potential student exposures, samples collected during the extended school day are depicted in solid blue dots (samples collected outside of the extended school days remain as open gray dots). There was one measurement that exceeded the California Acute REL of 8 ppb and the ATSDR Acute MRL of 9 ppb. The exceedance (14.72 ppb) occurred on November 5, 2019 between 3:30 and 4:30 PM, when students and teachers were likely on campus. None of the measurements exceeded the TCEQ ReV of 180 ppb; the MDH HRV of 307 ppb; or the US EPA 1 - hour AEGL-1 of 52,000 ppb. All Phases: 45 -Minute Samples, May - Dec 2019 Benzene (ppb) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 • V 0 • 0 e • • 0 0 0 •- 10/14/2019 10/24/2019 11/3/2019 11/13/2019 11/23/2019 12/3/2019 12/13/2019 12/23/2019 • Benzene during school hours (6 am - 6 pm) ATSDR Acute MRL o Benzene (outside school hours) CaVEPA OEHHA Acute REL Figure 9: 45 -Minute Samples During Flowback/Production Periods. Each dot represents one 45 -minute sample regardless of time of day. Blue dots reflect measurements taken during extended school hours; open gray dots represent hours outside the extended school day. Solid lines represent California 1 -hour REL (8 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ ReV (180 ppb), MDH HRV (307 ppb), and US EPA 1 -hour AEGL-1 (52,000 ppb) are not shown. Figure 10 shows core and extended school -day average benzene concentrations for the period October 16 through December 20, 2019, during the flowback/production period. Standard procedures are to only calculate 8 -hour averages when there are 5 or more valid samples available in the averaging period. However, to be inclusive, we also calculated average concentrations when less than 6 samples were present (or less than 9 valid samples for extended school day) and noted the values as hatched bars in the graphs below. For example, the October 26, 2019 bar reflects only 1 value during the core school hours of 8 AM to 4 PM, and 3 values during the extended school day of 6 AM to 6 PM. Similarly, the December 20, 2019 average 23/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 reflects only 1 value during the core school hours and 3 values during the extended school day. However, the benzene concentrations in the time periods surrounding the time period of interest (before 6 AM or after 6 PM) on these days were similar to the limited measurements between 6 AM and 6 PM, lending some confidence to the averages even if fewer samples were present during the time period of interest. Comparing these school -day averages with the Californian OEHHA 8 -hour REL of 1 ppb shows that four out of the total 96 days with sampling had average school day (core days) benzene concentration averages that exceeded the California OEHHA 8 -hour REL. Note, the November 5, 2019 school day average value (2.21 ppb for the core school day; 1.68 ppb for extended school day) was driven by the single 14.72 ppb value. Excluding this single value would result in averages of 0.50 ppb for the extended school day and 0.42 ppb for the core school day. In contrast, the December 5, 2019 and December 19, 2019 individual 45 -minute benzene concentrations were consistently above 1 ppb, indicating that even though they had fewer samples than optimal, they likely reflected averages above 1 ppb. Flowback: School Day Benzene Averages 1u Benzene (ppb) 9 8 7 6 5 4 3 2 1 0 b__. c, ci a) a, cn o o0000 N IN OD O N ▪ 0000 O O O O O O el el H el el el kir h• b 1 si L C71 cn O1 O, O1 m ci CI G, c, c, O1 O, c, c, O, C7, O1 H H H r-i el el el el el e1 el el e-1 H H el el el el el H H el el H O O O O O O O O O O O O O O O O O O O O O O O O O N N N N N N N N N N N N N N N N N N NN N N N N N H c 1 t, N ci H m fl N ci H M Ui N O�1 H M tw cri H f 1 ►1 N cn e-i e-i el e-i H N N N N N 1 el el H H H el el .-+ e-i e-1 e- `-1 e`-i e1 H H e—i H H H e`i eH-1 H H H H N N N N N el H el H el el H el el el H el el H e-4 Full School Day (6 am - 6 pm) Normal School Day (8 am - 4 pm) -- ATSDR Acute MRL CalEPA OEHHA Repeated 8 -hour REL Figure 10: School -Day Averages During Flowback/Production Green bars represent the 8 -hour core school -day period (8 AM - 4 PM); blue bars represent a 12 -hour extended school -day period (6 AM - 6 PM). All days, Monday through Sunday, are included. Green hatched bars reflect days when less than 6 samples were available for averaging for core averages; blue hatch bars reflect days when less than 9 samples were available. Solid lines represent California 8 -hour REL (9.9 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ 24 -hour ReV (100 ppb) is not shown. 5.5 Phase -Dependent Patterns of Benzene Looking across all development phases may give insight into where the highest benzene concentrations may occur. This is important both to understand the phase -specific exposure patterns, as well as in projecting future exposures. Figure 11 shows a composite of all 45 -minute samples, starting with the baseline activity period in May 6, 2019 and ending with the last sampling for which data was available, December 20, 2019. 24/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 45 -minute samples: Baseline, Hydraulic Fracturing, Mill Out, and Flowback Phases • 9 Benzene (ppb) 8 7 6 S 4 3 • • • • t • • • • • • • • • • • • • ' • i` • • 2 • • •• •• • ' •' •• • ' • • • •. • • t t r • • • it A• • .tip `. • �_AIL III a 5/2/2019 5/22/2019 6/11/2019 7/1/2019 7/21/2019 8/10/2019 8/30/2019 9/19/2019 10/9/2019 10/29/2019 11/18/2019 12/8/2019 1.2/28/2019 • Baseline • Hydraulic Fracturing • Mill Out • Flowback CaPEPA OEHHA Acute REL Figure 11: 45 -Minute Samples During All Sampling Periods. ATSDR Acute MRL Each dot represents one 45 -minute sample, regardless of time of day. Blue dots represent measurements during the baseline period; Green dots represent measurements during the fracking period; Pink solid dots represent samples during the mill -out period; purple dots represent measurements during the flowback/production period. Solid lines represent California 1 -hour REL (8 ppb) and ATSDR acute (1-14 days) MRL (9 ppb). TCEQ ReV (180 ppb), MDH HRV (307 ppb), and US EPA 1 -hour AEGL-1 (52,000 ppb) are not shown. Although the average benzene concentration during individual phases may range from 0.19 ppb to 0.78 ppb. Looking just at the values available to date, the average benzene concentration across the entire dataset period is 0.47 ppb. Even excluding the baseline period, the average benzene concentrations across the development phases is 0.55 ppb. These values are all below the long-term health -based benchmark risk assessment values presented in Table 2. As the flowback component of the hybrid flowback/production phase finishes and the well is in production, benzene concentrations are expected to decrease. With time, as the well becomes less productive, concentrations should decrease further. Thus, over the lifetime of the well, the average benzene exposure concentrations are anticipated to be lower than the averages obtained during this 7 -month period when the most activity was occurring. 25/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 6. CONCLUSIONS Using a CAMML mobile laboratory equipped with sensitive equipment, total of 1,930 individual 45 -minute air samples were collected by CDPHE during the period May 6, 2019 through December 20, 2019 and analyzed for benzene concentration. This time period spans reflect different phases of development of the nearby Vetting wellsite. After removing those samples below the method limit of detection, 1,795 individual samples remained (Table 3). Table 3: Number of samples collected at the Bella Rcmero Academy, by Well Development Phase Phase Removed due to QC Valid samples Total samples Baseline 405 0 405 Hydraulic fracturing 132 0 132 Drilling/Millout 467 27 440 Flowback/production 926 107 819 Total 1,930 134 1,796 To assess potential health impacts of exposures to benzene at these concentrations, a risk assessment process was undertaken. Risk assessment is a conservative process wherein chemical exposure concentrations are compared to health -based benchmark values set by various regulatory bodies. These benchmark values are exceedingly conservative, often hundreds o r a thousand of times below concentrations that have been shown to be associated with even minor health effects. Rather than predicting actual risk, these values are estimates (with u ncertainties) of exposure concentrations where humans are likely to be without an appreciable risk of adverse health effects over a specified duration of exposure, even in sensitive populations such as children, pregnant women, the elderly, or people with underlying medical conditions. Importantly, this does not mean that any exposures above these health -based benchmark value concentrations will result in adverse health effects, but rather, this means that the risk of having certain health effects may be elevated in individuals, particularly sensitive individuals. Benzene concentrations in all but 1 of the 1,796 valid 45 -minute sample fell below all health - based benchmark risk assessment concentrations (as developed by ATSDR, California OEHHA, TCEQ, MDH, and US EPA). This one sample, collected on November 5, 2019 between 3:48 PM and 4:33 PM, exceeded the ATSDR and California OEHHA benchmarks, but not the TCEQ, MDH, o r US EPA benchmarks. This one sample was surrounded by 23 other samples collected on November 5, 2019 - all below 1.2 ppb. This suggests that while something may have occurred on November 5, 2019, it was a brief event that did not reoccur. Benzene sampling occurred during 101 individual days. Recognizing that students and teachers are at school for a large number of days each year, for extended periods of time, we calculated school day averages and compared these values to health -based benchmark risk assessment values relevant for 8 -hour periods or 24 -hour periods. The latter is a conservative comparison, as the average over a 24 -hour period is likely lower than the shorter -term average. To be conservative, we calculated school day averages both during the 8 -hour time when children and teachers were most likely to be in school (8 AM to 4 PM), as well as during a 12 -hour extended period that might reflect before- and after -school activities (6 AM to 6 PM). 26/31 RamboII - Independent Analysis of CDPHE Momtonng Data June 19, 2020 Looking across the school day, the average benzene concentrations ranged from 0 03 to 2 0 ppb These school day averages were compared to various 8 -hour and 24 -hour health -based benchmark risk assessment concentrations (as developed by ATSDR, California OEEHA, and TCEQ) Of the 96 days with sampling data, 12 days had extended (6 AM to 6 PM) school day values that exceeded one or more of these benchmarks For the core school day (8 AM to 4 PM), only 4 days exceeded the California OEHHA 8 -hr REL of 0 9 ppb (but not any other risk assessment values) One of these exceedances occurred on November 5, 2019, where the single 45 -minute value of 14 72 ppb dominated the average Without this one high value, the average benzene concentration for the day would have been less than half the average value including it, indicating that the typical exposure across the day was considerably lower than the health -based benchmark risk assessment values One of the core school day exceedances was for a day when standard data analysis would exclude the average because it contained less than 75% of the samples in the range The other two exceedances were 0 98 and 1 2 ppb, very close to the California OEHHA benchmark value of 0 9 ppb Although taking averages during an extended school day (6 AM to 6 PM) resulted in 12 days with exceedances, all of these 12 -hour averages only exceeded the California OEHHA 8 -hr REL of 0 9 ppb and not any other risk assessment values Furthermore, these averages were all below 1 9 ppb, and do not reflect very high values The California OEHHA 8 -hour REL was developed based on a study in a worker population where individuals were exposed to very high concentrations of benzene For health -protective purposes, the same study that was used for long-term exposures (Lan et al , 2004) was used to derive an 8 -hour health -based risk assessment value In the study, workers were employed for an average of 6 years, with benzene concentrations in the air sometimes exceeding 10 ppm (10,000 ppb) The lowest benzene concentration where any health impacts were observed (reflected in blood cell counts), occurred with exposures of 570 ppb The California OEHHA 8 -hour REL of 1 ppb is therefore exceedingly conservative, as school children and teachers at the Bella Romero Academy are not only exposed to much lower concentrations than the worker population, but also do not have the same constant exposures as the worker population Because students and teachers are not present at the school 24 hours a day, 7 days a week, 52 weeks a year, their average annual exposures from being present at the school will be lower than simply calculating averages For the sake of conservatism, we compared average exposures at the school as if they occurred constantly and year-round The average benzene concentration over the entire sampling period is 0 47 ppb Even excluding the baseline period, the average benzene concentrations across the development phases is 0 55 ppb These values are all below the long-term health -based benchmark risk assessment values presented in Table 2 Cancer risk was not analyzed in this report since neither students nor teachers are at the school continuously for their lifetimes, and their lifetime exposure to benzene will more likely reflect exposures elsewhere 27/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 Overall, these data reflect that the benzene concentrations measured at the Bella Romero Academy do not reflect a health risk to students or teachers An extensive dataset of benzene samples was collected and analyzed, and only a few exceeded any health -based risk assessment benchmarks For acute exposures (45 minutes, a surrogate for 1 -hour exposures) Only 1 of almost 1,800 measurements exceeded a risk assessment value For exposures across the school day, a handful of days slightly exceeded one of the multiple risk assessment values The observation that all the exceedances, 1 -hour or school day, occurred during the flowback/production phase indicates that this is the phase of oil and gas development that has the greatest potential for benzene exposures 28/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 7. REFERENCES ATSDR (2007) Agency for Toxic Substances and Disease Registry (ATSDR) (2007). Toxicological Profile for Benzene. US Department of Health and Human Services, Atlanta, GA. Downloaded from: https://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=40&tid-- . See also https://www.atsdr.cdc.gov/toxprofiles/tp3.pdf Colorado Department of Public Health and Environment (CDPHE) (2020a). Air monitoring at Bella Romero Academy Near Vetting Oil and Gas Site: May - November 2019. Downloaded from: https://drive.google.com/file/d/17kZ2fSI 9FBd5JXD98MCp9CgEP ge9Kd/view CDPHE (2020b). Follow-up Investigation at Bella Romero Academy Near Vetting Oil and Gas Site: January 2020. Downloaded from: https://drive.google.com/file/d/17v5lM8d155swRGlud82iyAvZIvwOiGiV/view CDPHE (2020c) "Benzene investigations at Bella Romero school." Accessed on June 12, 2020 at https://drive._gpogle.com/open?id=187eNJemCfK5PD5UCuN4-xt14axkdcQEV Corti M, Snyder CA (1996) as cited in TCEQ (2015) Influences of gender, development, pregnancy and ethanol consumption on the hematotoxicity of inhaled 10 ppm benzene. Arch Toxicol 70:209-217 Dempster, A. M., & Snyder, C. A. (1991) as cited in TCEQ (2015). Kinetics of granulocytic and e rythroid progenitor cells are affected differently by short-term, low-level benzene e xposure. Archives of toxicology, 65(7), 556-561. Keller KA, Snyder CA (1988) as cited in OEHHA (2014). Mice exposed in utero to 20 ppm benzene exhibit altered numbers of recognizable hematopoietic cells up to seven weeks after exposure. Toxicological Sciences. 10(2) :224-32. Kraut A, Lilis R, Marcus M, Valciukas JA, Wolff MS, Landrigan PJ (1988) as cited in US EPA (2009). Neurotoxic effects of solvent exposure on sewage treatment workers. Archives of Environmental Health: An International Journal. 43(4) :263-8. Lan Q, Zhang L, Li G, Vermeulen R, Weinberg RS, Dosemeci M, Rappaport SM, Shen M, Alter BP, Wu Y, Kopp W. (2004) as cited in OEHHA (2014), ATSDR (2007), TCEQ (2015). Hematotoxicity in workers exposed to low levels of benzene. Science. 306(5702):1774-6. Minnesota Department of Health (MDH) (2002). Health Risk Values Rules for Ambient Air. Minnesota Department of Health. Accessed June 12, 2020 from: https://www.health.state.mn. us/communities/environment/risk/rules/air.html MDH (2001) Statement of Need and Reasonableness: Proposed Permanent Rules Relating to Health Risk Values - Minnesota Rules, Parts 4717.8000 to 4717.8600. Downloaded from: https://www.health.state.mn.us/communities/environment/risk/docs/rules/hrvsonar.pdf OEHHA (2008) Technical Support Document for the Derivation of Noncancer Reference Exposure Levels. Air Toxicology and Epidemiology Branch, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, CA. Downloaded from: https://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference- e xposure-level-rel-summary 29/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 OEHHA (2014) Appendix D. Individual Acute, 8 -Hour, and Chronic Reference Exposure Level Summaries. Technical Support Document for Noncancer RELs, December 2008, Updated July 2014. Downloaded from: https://oehha.ca.gov/media/dowrloads/crnr/appendixdlfinal.pdf OEHHA (2019) OEHHA Acute, 8 -hour and Chronic Reference Exposure Level (REL) Summary. Accessed on June 12, 2020 at: https://oehha.ca.gov/air/general-info/oehha-acute-8- hour-and-chronic-reference-exposure-level-rel-summary OEHHA (2015) Air Toxics Hot Spots Program Risk Assessment Guidelines: Guidance Manual for Preparation of Health Risk Assessments. Air, Community, and Environmental Research Branch, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency. Downloaded from: https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf Rosenthal GJ, Snyder CA (1987) as cited in ATSDR (2007), TCEQ (2015). Inhaled benzene reduces aspects of cell -mediated tumor surveillance in mice. Toxicology and applied pharmacology. 88(1):35-43. Rothman N, Li GL, Dosemeci M, Bechtold WE, Marti GE, Wang YZ, Linet M, Xi LQ, Lu W, Smith MT, Titenko-Holland N (1996) as cited in US EPA (2003), TCEQ (2015). Hematotoxicity among Chinese workers heavily exposed to benzene. American journal of industrial medicine. 1996 Mar; 29(3) :236-46. Rozen MG, Snyder CA, and Albert RE (1984) as cited in ATSDR (2007), TCEQ (2015). Depressions in B -and T -lymphocyte mitogen-induced blastogenesis in mice exposed to low concentrations of benzene. Toxicology letters, 20(3) : 343-349. Srbova J, Teisinger J, Skramovsky S (1950) as cited in US EPA (2009). Absorption and elimination of inhaled benzene in man. Arch. Indust. Hyg. & Occupational Med. 2(1):1-8. TCEQ (2015) Benzene Development Support Document, October 2007, Revised September 2015. Texas Commission on Environmental Quality. Downloaded from: https://www.tceq,texas.gov/assets/public/implementation/tox/dsd/final/benzene.pdf US Environmental Protection Agency (US EPA). 2009. Benzene: Interim Acute Exposure Guideline Levels 9 (AEGLs). NAS/COT Subcommittee for AEGLS. Downloaded from: https://www.epa.gov/sites/production/files/2014- 08/documents/benzene interim dec 2008 vl.pdf US Environmental Protection Agency (US EPA). 2003. Benzene. Integrative Risk Information System (IRIS). Accessed June 12, 2020 from: https://cfpub.epa.govJncea/iris2/chemicalLanding.cfm?substance nmbr=276 Yin SN, Hayes RB, Linet MS, Li GL, Dosemeci M, Travis LB, Zhang ZN, Li DG, Chow WH, Wacholder S, Blot WJ (1987) as cited in US EPA (2009). An expanded cohort study of cancer among benzene -exposed workers in China. Environmental health perspectives. 104(suppl 6) :1339-41. 30/31 Ramboll - Independent Analysis of CDPHE Monitoring Data June 19, 2020 APPENDIX 1 CDPHE BENZENE MONITORING DATA 31/31 Appendix 1 CDPHE Benzene Monitoring Data , Downloaded from https //www colorado gov/aurquality/tech_doc_repository aspx#camml_data on June 8, 2020 Phase StartTime_[LST] EndTime_[LST] benzene_[ppbV] benzene_Flags Baseline 05/06/2019 10 49 00 05/06/2019 11 34 00 0 117041 Baseline 05/06/2019 11 52 00 05/06/2019 12 37 00 0 0808261 Baseline 05/06/2019 15 03 00 05/06/2019 15 48 00 0 0746626 Baseline 05/06/2019 16 07 00 05/06/2019 16 52 00 0 0728721 Baseline 05/06/2019 17 10 00 05/06/2019 17 55 00 0 0756335 Baseline 05/06/201918 14 00 05/06/2019 18 59 00 0 222107 Baseline 05/06/2019 19 18 00 05/06/2019 20 03 00 0 0845188 Baseline 05/06/2019 20 21 00 05/06/2019 21 06 00 0 0691176 Baseline 05/06/2019 21 25 00 05/06/2019 22 10 00 0 0591002 Baseline 05/06/2019 22 29 00 05/06/2019 23 14 00 0 0739438 Baseline 05/06/2019 23 32 00 05/07/2019 00 17 00 0 0619528 Baseline 05/07/2019 00 36 00 05/07/2019 01 21 00 0 103382 Baseline 05/07/2019 0140 00 05/07/2019 02 25 00 0 10233 Baseline 05/07/2019 02 43 00 05/07/2019 03 28 00 0 107279 Baseline 05/07/2019 03 47 00 05/07/2019 04 32 00 0 131582 Baseline 05/07/2019 04 50 00 05/07/2019 05 35 00 0 164307 Baseline 05/07/2019 05 54 00 05/07/2019 06 39 00 , 0 129188 Baseline 05/07/2019 06 57 00 05/07/2019 07 42 00 0 111963 Baseline 05/07/2019 09 1100 05/07/2019 09 56 00 0 122457 Baseline 05/07/2019 10 15 00 05/07/2019 11 00 00 0 160559 Baseline 05/07/2019 11 19 00 05/07/2019 12 04 00 0 0854281 Baseline 05/07/2019 12 22 00 05/07/2019 13 07 00 0 158274 Baseline 05/07/2019 13 26 00 05/07/2019 14 11 00 0 157779 Baseline 05/07/2019 14 29 00 05/07/2019 15 15 00 0 0906809 Baseline 05/07/2019 15 33 00 05/07/2019 16 18 00 0 133854 Baseline 05/07/2019 16 37 00 05/07/2019 17 22 00 0 129161 Baseline 05/07/2019 17 40 00 05/07/2019 18 25 00 0 225304 Baseline 05/07/2019 18 44 00 05/07/2019 19 29 00 0 165192 Baseline 05/07/2019 19 47 00 05/07/2019 20 32 00 0 119938 Baseline 05/07/2019 20 51 00 05/07/2019 21 36 00 0 276651 Baseline 05/07/2019 21 54 00 05/07/2019 22 40 00 0 0851234 Baseline 05/07/2019 22 58 00 05/07/2019 23 43 00 0 0681535 Baseline 05/08/2019 00 02 00 05/08/2019 00 47 00 0 0777207 Baseline 05/08/2019 01 05 00 05/08/2019 01 51 00 0 0905301 Baseline 05/08/2019 02 09 00 05/08/2019 02 54 00 0 0764071 Baseline 05/08/2019 03 13 00 05/08/2019 03 58 00 0 0802396 Baseline 05/08/2019 04 16 00 05/08/2019 05 01 00 0 0938137 Baseline 05/08/2019 05 20 00 05/08/2019 06 05 00 0 102591 Baseline 05/08/2019 06 24 00 05/08/2019 07 09 00 0 08384 Baseline 05/08/2019 07 27 00 05/08/2019 08 12 00 0 095751 Baseline 05/08/2019 08 31 00 05/08/2019 09 16 00 0 105984 Baseline 05/08/2019 09 34 00 05/08/2019 10 19 00 0 105718 Baseline 05/08/2019 11 41 00 05/08/2019 12 26 00 0 0963855 Baseline 05/08/2019 12 45 00 05/08/2019 13 30 00 0 0835386 Baseline 05/08/2019 13 49 00 05/08/2019 14 34 00 0 0840324 Baseline 05/08/2019 14 52 00 05/08/2019 15 37 00 0 394678 1 of 42 Appendix 1 CDPHE Benzene Monitoring Data 2 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/08/2019 15 56 00 05/08/2019 16 41 00 0 0904735 Baseline 05/08/2019 17 00 00 05/08/2019 17 45 00 0 0856188 Baseline 05/08/2019 18 03 00 05/08/2019 18 48 00 0 0730253 Baseline 05/08/2019 19 07 00 05/08/2019 19 52 00 0 076658 Baseline 05/08/2019 20 10 00 05/08/2019 20 55 00 0 0750341 Baseline 05/08/2019 21 14 00 05/08/2019 21 59 00 0 0715391 Baseline 05/08/2019 22 17 00 05/08/2019 23 02 00 0 0720681 Baseline 05/08/2019 23 20 00 05/09/2019 00 06 00 0 0790637 Baseline 05/09/2019 00 24 00 05/09/2019 01 09 00 0 0795329 Baseline 05/09/2019 01 27 00 05/09/2019 02 12 00 0 0838766 Baseline 05/09/2019 02 30 00 05/09/2019 03 16 00 0 171412 Baseline 05/09/2019 03 34 00 05/09/2019 04 19 00 0 216897 Baseline 05/09/2019 04,37 00 05/09/2019 05 22 00 0 159848 Baseline 05/09/2019 05 40 00 05/09/2019 06 25 00 0 247475 Baseline 05/09/2019 06 44 00 05/09/2019 07 29 00 0 367961 Baseline 05/09/2019 07 47 00 05/09/2019 08 32 00 0 0998314 Baseline 05/09/2019 08 50 00 05/09/2019 09 35 00 0 139967 Baseline 05/09/2019 09 53 00 05/09/2019 10 38 00 0 0873598 Baseline 05/09/2019 12 47 00 05/09/2019 13 32 00 0 150313 Baseline 05/09/2019 13 50 00 05/09/2019 14 35 00 0 155627 Baseline 05/09/2019 14 54 00 05/09/2019 15 39 00 0 0626464 Baseline 05/09/2019 15 57 00 05/09/201916 42 00 0 0566275 Baseline 05/09/2019 17 01 00 05/09/2019 17 46 00 0 0597512 Baseline 05/09/2019 18 04 00 05/09/2019 18 49 00 0 0534012 Baseline 05/09/2019 19 08 00 05/09/2019 19 53 00 0 0843147 Baseline 05/09/2019 20 11 00 05/09/2019 20 56 00 2 2816 Baseline 05/09/2019 21 15 00 05/09/2019 22 00 00 0 170357 Baseline 05/09/2019 22 18 00 05/09/2019 23 04 00 0 334393 Baseline 05/09/2019 23 22 00 05/10/2019 00 07 00 0 209662 Baseline 05/10/2019 00 26 00 05/10/2019 01 11 00 0 138831 Baseline 05/10/2019 01 29 00 05/10/2019 02 14 00 0 412794 Baseline 05/10/2019 02 33 00 05/10/2019 03 18 00 0 126991 Baseline 05/10/2019 03 36 00 05/10/2019 04 21 00 0 185347 Baseline 05/10/2019 04 40 00 05/10/2019 05 25 00 0 279896 Baseline 05/10/2019 05 44 00 05/10/2019 06 29 00 0 247964 Baseline 05/10/2019 10 38 00 05/10/2019 11 23 00 0 0817954 Baseline 05/10/2019 1141 00 05/10/2019 12 26 00 0 102729 Baseline 05/10/2019 12 45 00 05/10/2019 13 3Q 00 0 110072 Baseline 05/10/2019 13 48 00 05/10/2019 14 33 00 0 126289 Baseline 05/10/2019 14 52 00 05/10/2019 15 37 00 0 135835 Baseline 05/10/2019 15 55 00 05/10/2019 16 40 00 0 14793 Baseline 05/10/2019 16 59 00 05/10/2019 17 43 00 0 146282 Baseline 05/10/2019 18 02 00 05/10/2019 18 47 00 0 12793 Baseline 05/10/2019 19 06 00 05/10/2019 19 51 00 0 287062 Baseline 05/10/2019 20 09 00 05/10/2019 20 54 00 0 264291 Baseline 05/10/2019 21 12 00 05/10/2019 21 57 00 0 698464 Baseline 05/10/2019 22 16 00 05/10/2019 23 01 00 0 637208 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/10/2019 23 20 00 05/11/2019 00 04 00 0 523197 Baseline 05/11/2019 00 23 00 05/11/2019 01 08 00 0 701628 Baseline 05/11/2019 01 27 00 05/11/2019 02 11 00 0 620006 Baseline 05/11/2019 02 30 00 05/11/2019 03 15.00 0 488348 Baseline 05/11/2019 03 33 00 05/11/2019 04 18.00 0 624193 Baseline 05/11/2019 04 37 00 05/11/2019 05 22:00 0 504341 Baseline 05/11/2019 05 40 00 05/11/2019 06 25 00 0 735011 Baseline 05/11/2019 06 44 00 05/11/2019 07 29 00 0 32969 Baseline 05/11/2019 07 47 00 05/11/2019 08 32 00 0 208878 Baseline 05/11/2019 08 51 00 05/11/2019 09 36.00 0 105785 Baseline 05/11/2019 09 54 00 05/11/2019 10 39.00 0 0714023 Baseline 05/11/2019 12 01 00 05/11/2019 12 46.00 0 059696 Baseline 05/11/2019 13 04 00 05/11/2019 13 49 00 0 0608131 Baseline 05/11/2019 14 08 00 05/11/2019 14 53 00 0 0677133 Baseline 05/11/2019 15 11 00 05/11/2019 15 56 00 0 0731607 Baseline 05/11/2019 16 15 00 05/11/2019 17 00 00 0 0583957 Baseline 05/11/2019 17 18 00 05/11/2019 18 03 00 0 0538098 Baseline 05/11/2019 18 22 00 05/11/2019 19 07 00 0 143978 Baseline 05/11/2019 19 26 00 05/11/2019 20 11 00 0 141904 Baseline 05/11/2019 20 29 00 05/11/2019 21 14 00 0 367025 Baseline 05/11/2019 2133 00 05/11/2019 22 18 00 0 124314 Baseline 05/11/2019 22 36 00 05/11/2019 23 21 00 0 145976 Baseline 05/11/2019 23 40 00 05/12/2019 00 25 00 0 154125 Baseline 05/12/2019 00 43 00 05/12/2019 01 28 00 0 224145 Baseline 05/12/2019 0147 00 05/12/2019 02 32 00 0 257389 Baseline 05/12/2019 02 50 00 05/12/2019 03 35 00 0 259875 Baseline 05/12/2019 03 54 00 05/12/2019 04 39 00 0 492486 Baseline 05/12/2019 04 57 00 05/12/2019 05 42 00 0 322816 Baseline 05/12/2019 06 01 00 05/12/2019 06 46 00 0 564073 Baseline 05/12/2019 07 04 00 05/12/2019 07 49 00 0 351738 Baseline 05/12/2019 08 08 00 05/12/2019 08 53 00 0 156912 Baseline 05/12/2019 09 11 00 05/12/2019 09 56 00 0 148515 Baseline 05/12/2019 10 15 00 05/12/2019 11 00 00 0 105576 Baseline 05/12/2019 11 18 00 05/12/2019 12 03 00 0 055829 Baseline 05/12/2019 12 22 00 05/12/2019 13 07 00 0 0666549 Baseline 05/12/2019 14 28 00 05/12/2019 15 13 00 0 0784827 Baseline 05/12/2019 15 32 00 05/12/2019 16 17 00 0 0947333 Baseline 05/12/2019 16 35 00 05/12/2019 17 20 00 0 0767039 Baseline 05/12/2019 17 39 00 05/12/2019 18 24 00 0 0695361 Baseline 05/12/2019 18 42 00 05/12/2019 19 27 00 0 415139 Baseline 05/12/2019 19 46 00 05/12/2019 20 30 00 0 448713 Baseline 05/12/2019 20 49 00 05/12/2019 21 34 00 0 150813 Baseline 05/12/2019 21 52 00 05/12/2019 22 37 00 0 453754 Baseline 05/12/2019 22 56 00 05/12/2019 23 41 00 0 130322 Baseline 05/12/2019 23 59 00 05/13/2019 00 44 00 0 152824 Baseline 05/13/2019 01 03 00 05/13/2019 0148 00 0 0989692 Baseline 05/13/2019 02 06 00 05/13/2019 02 51 00 0 0835724 3 of 42 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/13/2019 03 10 00 05/13/2019 03 55 00 0 277749 Baseline 05/13/2019 04 13 00 05/13/2019 04 58 00 0 519278 Baseline 05/13/2019 05 17 00 05/13/2019 06 02 00 0 502688 Baseline 05/13/2019 06 20 00 05/13/2019 07 05 00 0 406603 Baseline 05/13/2019 07 24 00 05/13/2019 08 09 00 0 260715 Baseline 05/13/2019 08 27 00 05/13/2019 09 12 00 0 233191 Baseline 05/13/2019 09 31 00 05/13/201910 16 00 0 181239 Baseline 05/13/2019 10 34 00 05/13/2019 11 19 00 0 072334 Baseline 05/13/2019 11 38 00 05/13/2019 12 23 00 0 0718116 Baseline 05/13/2019 12 41 00 05/13/2019 13 26 00 0 0617364 Baseline 05/13/2019 13 45 00 05/13/2019 14 30 00 0 0623076 Baseline 05/13/2019 14 48 00 05/13/2019 15 33 00 0 0636586 Baseline 05/13/2019 16 55 00 05/13/2019 17 40 00 0 0719743 Baseline 05/13/2019 17 59 00 05/13/2019 18 43 00 0 0785368 Baseline 05/13/2019 19 02 00 05/13/2019 19 47 00 0 190428 Baseline 05/13/2019 20 05 00 05/13/2019 20 50 00 0 221177 Baseline 05/13/2019 21 09 00 05/13/2019 21 54 00 0 574592 Baseline 05/13/2019 22 12 00 05/13/2019 22 57 00 0 290192 Baseline 05/13/2019 23 16 00 05/14/2019 00 01 00 0 437053 Baseline 05/14/2019 00 19 00 05/14/2019 01 04 00 0 425108 Baseline 05/14/2019 01 23 00 05/14/2019 02 08 00 0 420363 Baseline 05/14/2019 02 26 00 05/14/2019 03 11 00 0 49605 Baseline 05/14/2019 03 30 00 05/14/2019 04 15 00 0 907516 Baseline 05/14/2019 04 34 00 05/14/2019 05 19 00 0 806696 Baseline 05/14/2019 05 37 00 05/14/2019 06 22 00 0 577376 Baseline 05/14/2019 06 41 00 05/14/2019 07 26 00 0 44372 Baseline 05/14/2019 07 44 00 05/14/2019 08 29 00 0 486087 Baseline 05/14/2019 08 48 00 05/14/2019 09 33 00 0 330879 Baseline 05/14/2019 09 51 00 05/14/2019 10 36 00 0 104471 Baseline 05/14/2019 10 55 00 05/14/2019 1140 00 0 0474515 Baseline 05/14/2019 11 58 00 05/14/2019 12 43 00 0 0577373 Baseline 05/14/2019 13 02 00 05/14/2019 13 47 00 0 0607667 Baseline 05/14/2019 14 05 00 05/14/2019 14 50 00 0 0617761 Baseline 05/14/2019 15 08 00 05/14/2019 15 53 00 0 0600793 Baseline 05/14/2019 16 12 00 05/14/2019 16 57 00 0 0742846 Baseline 05/14/2019 17 15 00 05/14/2019 18 00 00 0 0810851 Baseline 05/14/2019 19 22 00 05/14/2019 20 07 00 0 0650606 Baseline 05/14/2019 20 26 00 05/14/2019 21 11 00 0 127107 Baseline 05/14/2019 21 29 00 05/14/2019 22 14 00 0 284314 Baseline 05/14/2019 22 33 00 05/14/2019 23 18 00 0 388036 Baseline 05/14/2019 23 36 00 05/15/2019 00 21 00 0 238468 Baseline 05/15/2019 00 40 00 05/15/2019 01 25 00 0 268274 Baseline 05/15/2019 0143 00 05/15/2019 02 28 00 0 335357 Baseline 05/15/2019 02 47 00 05/15/2019 03 32 00 0 465018 Baseline 05/15/2019 03 50 00 05/15/2019 04 35 00 0 303877 Baseline 05/15/2019 04 54 00 05/15/2019 05 39 00 0 195458 Baseline 05/15/2019 05 57 00 05/15/2019 06 42 00 0 461736 4 of 42 1 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/15/2019 07 0100 05/15/2019 07 46 00 0 743294 Baseline 05/15/2019 08 04 00 05/15/2019 08 49 00 0 304488 Baseline 05/15/2019 09 08 00 05/15/2019 09 53 00 0 171287 Baseline 05/15/2019 10 12 00 05/15/2019 10 56 00 0 137212 Baseline 05/15/2019 11 15 00 05/15/2019 12 00 00 0 124883 Baseline 05/15/2019 12 18 00 05/15/2019 13 03 00 0 0585133 Baseline 05/15/2019 22 53 00 05/15/2019 23 38 00 0 113255 Baseline 05/15/2019 23 56 00 05/16/2019 00 41.00 2 01788 Baseline 05/16/2019 01 00 00 05/16/2019 01 45:00 0 467264 Baseline 05/16/2019 02 04 00 05/16/2019 02 49.00 0 355185 Baseline 05/16/2019 03 07 00 05/16/2019 03 52 00 ' 0 487481 Baseline 05/16/2019 04 1'1 00 05/16/2019 04 56 00 0 355778 Baseline 05/16/2019 05 1'4 00 05/16/2019 05 59 00 0 504862 Baseline 05/16/2019 06 18 00 05/16/2019 07 03 00 0 423304 Baseline 05/16/2019 07 21 00 05/16/2019 08 06 00 0 428665 Baseline 05/16/2019 08 25 00 05/16/2019 09 10 00 0 397594 Baseline 05/16/2019 13 28 00 05/16/2019 14 13 00 0 0670007 Baseline 05/16/2019 14 32 00 05/16/2019 15 17 00 0 0567912 Baseline 05/16/2019 15 35 00 05/16/201916 20 00 0 0621648 Baseline 05/16/2019 16 39 00 05/16/2019 17 24 00 0 119264 Baseline 05/16/2019 17 42 00 05/16/2019 18 27 00 0 0561201 Baseline 05/16/201920 17 00 05/16/2019 21 02 00 0 421359 Baseline 05/16/2019 21 20 00 05/16/2019 22 05 00 0 380714 Baseline 05/16/2019 22 24 00 05/16/2019 23 09 00 0 35159 Baseline 05/16/2019 23 27 00 05/17/2019 00 12 00 0 298224 Baseline 05/17/2019 00 31 00 05/17/2019 01 16 00 0 314764 Baseline 05/17/2019 01 35 00 05/17/2019 02 19 00 0 122943 Baseline 05/17/2019 02 38 00 05/17/2019 03 23 00 0 113561 Baseline 05/17/2019 03 42 00 05/17/2019 04 27 00 0 0987057 Baseline 05/17/2019 04 45 00 05/17/2019 05 30 00 0 147536 Baseline 05/17/2019 05 49 00 05/17/2019 06 34 00 0 116954 Baseline 05/17/2019 06 52 00 05/17/2019 07 37 00 0 0899789 Baseline 05/17/2019 07 56 00 05/17/2019 08 41 00 0 0801812 Baseline 05/17/2019 08 59 00 05/17/2019 09 44 00 0 0626805 Baseline 05/17/2019 10 03 00 05/17/2019 10 48 00 0 053693 Baseline 05/17/2019 11 06 00 05/17/2019 11 51 00 0 060192 Baseline 05/17/2019 13 13 00 05/17/2019 13 58 00 0 0695797 Baseline 05/17/2019 14 17 00 05/17/2019 15 02 00 0 124043 Baseline 05/17/2019 15 20 00 05/17/2019 16 05 00 0 0814713 Baseline 05/17/2019 16 24 00 05/17/2019 17 09 00 0 0823059 Baseline 05/17/2019 17 28 00 05/17/2019 18 13 00 0 0637289 Baseline 05/17/2019 18 31 00 05/17/2019 19 17 00 0 0805234 Baseline 05/17/2019 19 35 00 05/17/2019 20 20 00 0 0730381 Baseline 05/17/2019 20 39 00 05/17/2019 21 24 00 0 16484 Baseline 05/17/2019 2142 00 05/17/2019 22 27 00 0 174277 Baseline ,05/17/2019 22 46 00 05/17/2019 23 31 00 0 194801 Baseline 05/17/2019 23 49 00 05/18/2019 00 34 00 0 23708 5 of 42 Appendix 1 CDPHE Benzene Monitoring Data 6 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/18/2019 00 53 00 05/18/2019 01 38 00 0 275214 Baseline 05/18/2019 01 56 00 05/18/2019 02 41 00 0 248182 Baseline 05/18/2019 03 00 00 05/18/2019 03 45 00 0 431579 Baseline 05/18/2019 04 04 00 05/18/2019 04 49 00 0 401137 Baseline 05/18/2019 05 07 00 05/18/2019 05 52 00 - 0 488301 Baseline 05/18/2019 06 11 00 05/18/2019 06 56 00 0 462437 Baseline 05/18/2019 07 14 00 05/18/2019 07 59 00 0 332495 Baseline 05/18/2019 08 18 00 05/18/2019 09 03 00 0 378288 Baseline 05/18/2019 09 21 00 05/18/2019 10 06 00 0 0875953 Baseline 05/18/2019 10 25 00 05/18/2019 11 10 00 0 0555012 Baseline 05/18/2019 11 28 00 05/18/201912 13 00 0 0721463 Baseline 05/18/2019 12 32 00 05/18/2019 13 17 00 0 0531196 Baseline 05/18/2019 13 35 00 05/18/2019 14 20 00 0 126938 Baseline 05/18/2019 15 43 00 05/18/2019 16 28 00 0 0653612 Baseline 05/18/2019 16 46 00 05/18/201917 3100 0 054269 Baseline 05/18/2019 17 50 00 05/18/2019 18 35 00 0 0588467 Baseline 05/18/2019 18 53 00 05/18/2019 19 38 00 0 09171 Baseline 05/18/2019 19 57 00 05/18/2019 20 42 00 0 068782 Baseline 05/18/2019 21 00 00 05/18/2019 2145 00 0 0640519 Baseline 05/18/2019 22 04 00 05/18/2019 22 49 00 0 0656796 Baseline 05/18/2019 23 08 00 05/18/2019 23 53 00 0 0608001 Baseline 05/19/2019 00 11 00 05/19/2019 00 56 00 0 0606056 Baseline 05/19/2019 01 15 00 05/19/2019 02 00 00 0 0533731 Baseline 05/19/2019 02 18 00 05/19/2019 03 03 00 0 0508894 Baseline 05/19/2019 03 22 00 05/19/2019 04 07 00 0 0444852 Baseline 05/19/2019 04 25 00 05/19/2019 05 10 00 0 051187 Baseline 05/19/2019 05 29 00 05/19/2019 06 14 00 0 0515098 Baseline 05/19/2019 06 33 00 05/19/2019 07 17 00 0 0611202 Baseline 05/19/2019 07 36 00 05/19/2019 08 21 00 0 0522941 Baseline 05/19/2019 08 40 00 05/19/2019 09 25 00 0 0573916 Baseline 05/19/2019 09 43 00 05/19/2019 10 28 00 0 0459971 Baseline 05/19/2019 10 47 00 05/19/2019 11 32 00 0 0613592 Baseline 05/19/2019 11 50 00 05/19/2019 12 35 00 0 0747199 Baseline 05/19/2019 12 54 00 05/19/2019 13 39 00 0 0785876 Baseline 05/19/2019 13 57 00 05/19/2019 14142 00 0 0693553 Baseline 05/19/2019 15 01 00 05/19/2019 15 45 00 0 18341 Baseline 05/19/2019 16 04 00 05/19/2019 16 49 00 0 0654204 Baseline 05/19/2019 18 11 00 05/19/2019 18 56 00 0 0498543 Baseline 05/19/2019 19 14 00 05/19/2019 19 59 00 0 0483938 Baseline 05/19/2019 20 18 00 05/19/2019 21 03 00 0 0397311 Baseline 05/19/2019 21 21 00 05/19/2019 22 06 00 0 0548921 Baseline 05/19/2019 22 25 00 05/19/2019 23 10 00 0 061656 Baseline 05/19/2019 23 29 00 05/20/2019 00 14 00 0 04272 Baseline 05/20/2019 00 32 00 05/20/2019 01 17 00 0 0367946 Baseline 05/20/2019 01 36 00 05/20/2019 02 21 00 0 0498636 Baseline 05/20/2019 02 39 00 05/20/2019 03 24 00 0 115955 Baseline 05/20/2019 03 43 00 05/20/2019 04 28 00 0 0507637 Appendix 1 CDPHE Benzene Monitoring Data 7'of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/20/2019 04 46 00 05/20/2019 05 31 00 0123376 Baseline 05/20/2019 05 50 00 05/20/2019 06 34 00 0 070142 Baseline 05/20/2019 06 53 00 05/20/2019 07 38 00 0 0620241 Baseline 05/20/2019 07 56 00 05/20/2019 08 41 00 0 0487006 Baseline 05/21/2019 08 52 00 05/21/2019 09 37 00 0 0819195 Baseline 05/21/2019 09 56 00 05/21/2019 10 41 00 0 0723247 Baseline 05/21/2019 10 59 00 05/21/2019 1144 00 0 0647976 Baseline 05/21/2019 13 40 00 05/21/2019 14 25 00 0 0683717 Baseline 05/21/2019 14 42 00 05/21/2019 15 27 00 0 111298 Baseline 05/21/2019 15 44 00 05/21/2019 16 29 00 0 0694897 Baseline 05/21/2019 16 46 00 05/21/2019 17 31 00 0 0562775 Baseline 05/21/2019 17 49 00 05/21/2019 18 34 00 0 0475537 Baseline 05/21/2019 18 51 00 05/21/2019 19 36 00 0 0642841 Baseline 05/21/2019 19 52 00 05/21/2019 20 37 00 0 129195 Baseline 05/21/2019 20 54 00 05/21/2019 21 39 00 0 071646 Baseline 05/21/2019 21 56 00 05/21/2019 22 41 00 0 0668218 Baseline 05/21/2019 22 58 00 05/21/2019 23 43 00 0 0628234 Baseline 05/22/2019 00 00 00 05/22/2019 00 45 00 0 0490678 Baseline 05/22/2019 01 02 00 05/22/2019 01 47 00 0 0677363 Baseline 05/22/2019 02 04 00 05/22/2019 02 49 00 0 13397 Baseline 05/22/2019 03 06 00 05/22/2019 03 51 00 0 205861 Baseline 05/22/2019 04 08 00 05/22/2019 04 53 00 0 583926 Baseline 05/22/2019 05 10 00 05/22/2019 05 55 00 0 356901 Baseline 05/22/2019 06 12 00 05/22/2019 06 57 00 0 192016 Baseline 05/22/2019 07 14 00 05/22/2019 07 59 00 0 155498 Baseline 05/22/2019 08 16 00 05/22/2019 09 01 00 0 0712815 Baseline 05/22/2019 10 32 00 05/22/2019 11 17 00 0 079667 Baseline 05/22/2019 11 34 00 05/22/2019 12 19 00 0 0593946 Baseline 05/22/2019 12 36 00 05/22/2019 13 21 00 0 0542721 Baseline 05/22/2019 13 38 00 05/22/2019 14 23 00 0 057625 Baseline 05/22/2019 14 40 00 05/22/2019 15 25 00 0 116819 Baseline 05/22/2019 15 42 00 05/22/2019 16 27 00 0 0824665 Baseline,- 05/22/201916 44 00 05/22/201917 29 00 0 0762051 Baseline 05/22/201917 46 00 05/22/201918 3100 0 0575103 Baseline 05/22/2019 18 48 00 05/22/2019 19 33 00 0 0687789 Baseline 05/22/2019 19 51 00 05/22/2019 20 36 00 0 0812803 Baseline 05/22/2019 20 53 00 05/22/2019 21 38 00 0 0688035 Baseline 05/22/2019 21 55 00 05/22/2019 22 40 00 0 0528004 Baseline 05/22/2019 22 57 00 05/22/2019 23 42 00 0 145077 Baseline 05/22/2019 23 59 00 05/23/2019 00 44 00 0 0687918 Baseline 05/23/2019 01 01 00 05/23/2019 0146 00 0 13721 Baseline 05/23/2019 02 03 00 05/23/2019 02 48 00 0 0622168 Baseline 05/23/2019 03 05 00 05/23/2019 03 50 00 0 0632086 Baseline 05/23/2019 04 07 00 05/23/2019 04 52 00 0 109222 Baseline 05/23/2019 05 09 00 05/23/2019 05 54 00 0 112793 Baseline 05/23/2019 06 11 00 05/23/2019 06 56 00 0 0930915 Baseline 05/23/2019 07 13 00 05/23/2019 07 58 00 0 218617 Appendix 1 CDPHE Benzene Monitoring Data 8 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/23/2019 08 15 00 05/23/2019 09 00 00 0 104076 Baseline 05/23/2019 09 17 00 05/23/2019 10 02 00 0 197199 Baseline 05/23/2019 11 21 00 05/23/2019 12 06 00 0 109353 Baseline 05/23/2019 12 23 00 05/23/2019 13 08 00 0 13896 Baseline 05/23/2019 13 25 00 05/23/2019 14 10 00 0 139755 Baseline 05/23/2019 14 27 00 05/23/2019 15 12 00 0 252183 Baseline 05/23/2019 15 29 00 05/23/2019 16 14 00 0 0554783 Baseline 05/23/2019 16 31 00 05/23/2019 17 16 00 0 105132 Baseline 05/23/2019 17 33 00 05/23/2019 18 18 00 0 18522 Baseline 05/23/2019 18 35 00 05/23/2019 19 20 00 0 154753 Baseline 05/23/2019 19 37 00 05/23/2019 20 22 00 0 136795 Baseline 05/23/2019 20 39 00 05/23/2019 21 24 00 0 145141 Baseline 05/23/2019 2141 00 05/23/2019 22 26 00 0 230084 Baseline 05/23/2019 22 43 00 05/23/2019 23 28 00 0 528231 Baseline 05/23/2019 23 45 00 05/24/2019 00 30 00 0 54958 Baseline 05/24/2019 00 47 00 05/24/2019 01 32 00 0 452693 Baseline 05/24/2019 0149 00 05/24/2019 02 34 00 0 53137 Baseline 05/24/2019 02 51 00 05/24/2019 03 36 00 0 556736 Baseline 05/24/2019 03 53 00 05/24/2019 04 38 00 0 393047 Baseline 05/24/2019 04 55 00 05/24/2019 05 40 00 0 31487 Baseline 05/24/2019 05 57 00 05/24/2019 06 42 00 0 431535 Baseline 05/24/2019 06 59 00 05/24/2019 07 44 00 0 373378 Baseline 05/24/2019 08 01 00 05/24/2019 08 46 00 0 14449 Baseline 05/24/2019 11 35 00 05/24/2019 12 20 00 0 0645203 Baseline 05/24/2019 12 38 00 05/24/2019 13 23 00 0 0530291 Baseline 05/24/2019 13 42 00 05/24/2019 14 27 00 0 0702467 Baseline 05/24/2019 14 45 00 05/24/2019 15 30 00 0 0688094 Baseline 05/24/2019 15 49 00 05/24/2019 16 34 00 0 0613207 Baseline 05/24/2019 16 52 00 05/24/2019 17 37 00 0 050441 Baseline 05/24/2019 17 56 00 05/24/2019 18 40 00 0 0776351 Baseline 05/24/2019 18 59 00 05/24/2019 19 44 00 0 144077 Baseline 05/24/2019 20 03 00 05/24/2019 20 48 00 0 230713 Baseline 05/24/2019 22 21 00 05/24/2019 23 06 00 0 127386 Baseline 05/24/2019 23 23 00 05/25/2019 00 08 00 0 166103 Baseline 05/25/2019 00 25 00 05/25/2019 01 10 00 0 44092 Baseline 05/25/2019 01 27 00 05/25/2019 02 12 00 0 448762 Baseline 05/25/2019 02 29 00 05/25/2019 03 14 00 0 376034 Baseline 05/25/2019 03 31 00 05/25/2019 04 16 00 0 450458 Baseline 05/25/2019 04 33 00 05/25/2019 05 18 00 0 609097 Baseline 05/25/2019 05 35 00 05/25/2019 06 20 00 0 319784 Baseline 05/25/2019 06 37 00 05/25/2019 07 22 00 0 206082 Baseline 05/25/2019 07 39 00 05/25/2019 08 24 00 0 293611 Baseline 05/25/2019 08 41 00 05/25/2019 09 26 00 0 118769 Baseline 05/25/2019 09 43 00 05/25/2019 10 28 00 0 125892 Baseline 05/25/2019 10 45 00 05/25/2019 11 30 00 0 0481622 Baseline 05/25/2019 1147 00 05/25/2019 12 32 00 0 0560216 Baseline 05/25/2019 12 49 00 05/25/2019 13 34 00 0 0446966 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Baseline 05/25/2019 13 5100 05/25/2019 14 36 00 0 053212 Baseline 05/25/2019 14 53 00 05/25/2019 15 38 00 0 0499562 Baseline 05/25/2019 15 55 00 05/25/2019 16 40 00 0 0527427 Baseline 05/25/2019 16 57 00 05/25/2019 17 42 00 0 0508805 Baseline 05/25/2019 17 59 00 05/25/2019 18 44 00 0 0673025 Baseline 05/25/2019 19 01 00 05/25/201919 46 00 0 109901 Baseline 05/25/2019 20 03 00 05/25/2019 20 48 00 0 0670783 Baseline 05/25/2019 21 05 00 05/25/2019 21 50 00 0 0602164 Baseline 05/25/2019 22 07 00 05/25/2019 22 52 00 0 177098 Baseline 05/25/2019 23 09 00 05/25/2019 23 54 00 0 227283 Baseline 05/26/2019 00 11 00 05/26/2019 00 56 00 0 31161 Baseline 05/26/2019 01 13 00 05/26/2019 01 58 00 0 178652 Baseline 05/26/2019 02 15 00 05/26/2019 03 00 00 0 152793 Baseline 05/26/2019 03 18 00 05/26/2019 04 03 00 0 122761 Baseline 05/26/2019 04 20 00 05/26/2019 05 05 00 0 128622 Baseline 05/26/2019 05 22 00 05/26/2019 06 07 00 0 104851 Baseline 05/26/2019 06 24 00 05/26/2019 07 09 00 0 0988275 Baseline 05/26/2019 07 26 00 05/26/2019 08 11 00 0 0722017 Baseline 05/26/2019 08 28 00 05/26/2019 09 13 00 0 079392 Baseline 05/26/2019 09 30 00 05/26/2019 10 15 00 0 0861764 Baseline 05/26/2019 10 32 00 05/26/2019 11 17 00 0 116692 Baseline 05/26/2019 12 36 00 05/26/2019 13 2100 0 0960121 Baseline 05/26/201913 38 00 05/26/201914 23 00 0 0678488 Baseline 05/26/201914 40 00 05/26/201915 25 00 0 0832266 Baseline 05/26/2019 15 42 00 05/26/2019 16 27 00 0 0829101 Baseline 05/26/2019 16 44 00 05/26/2019 17 29 00 0 0905066 Baseline 05/26/2019 17 46 00 05/26/2019 18 31 00 0 0749909 Baseline 05/26/2019 18 48 00 05/26/2019 19 33 00 0 065504 Baseline 05/26/2019 19 50 00 05/26/2019 20 35 00 0 0661613 Baseline' 05/26/2019 20 52 00 05/26/2019 2137 00 0 112645 Hydraulic 1 05/26/2019 21 54 00 05/26/2019 22 39 00 0 0918946 Hydraulic f 05/26/2019 22 56 00 05/26/2019 23 41 00 0 0846577 Hydraulic f 05/26/2019 23 58 00 05/27/2019 00 43 00 0 158036 Hydraulic 105/27/2019 01 00 00 05/27/2019 01 45 00 0 215685 Hydraulic E 05/27/2019 02 02 00 05/27/2019 02 47 00 0 464938 Hydraulic 105/27/2019 03 05 00 05/27/2019 03 49 00 0 330157 Hydraulic 105/27/2019 04 07 00 05/27/2019 04 52 00 0 415593 Hydraulic f 05/27/2019 05 09 00 05/27/2019 05 54 00 0 613125 Hydraulic E 05/27/2019 06 11 00 05/27/2019 06 56 00 0 171033 Hydraulic 105/27/2019 07 13 00 05/27/2019 07 58 00 0 194295 Hydraulic E 05/27/2019 08 15 00 05/27/2019 09 00 00 0 117072 Hydraulic 105/27/2019 17 37 00 05/27/2019 18 22 00 0 253876 Hydraulic 105/27/2019 18 39 00 05/27/2019 19 24 00 0 0509806 Hydraulic! 05/27/2019 19 41 00 05/27/2019 20 26 00 0 0886616 Hydraulic 105/27/2019 20 43 00 05/27/2019 21 28 00 0 106806 Hydraulic f 05/27/2019 2145 00 05/27/2019 22 30 00 0 0648877 Hydraulic E 05/27/2019 22 47 00 05/27/2019 23 32 00 0 0483447 ` 9 of 42 Appendix 1 CDPHE Benzene Monitoring Data 10 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Hydraulic 105/27/2019 23 49 00 05/28/2019 00 34 00 0 0612994 Hydraulic 105/28/2019 00 51 00 05/28/2019 01 36 00 0 0675131 Hydraulic 105/28/2019 01 54 00 05/28/2019 02 39 00 0 0633 Hydraulic 105/28/2019 02 56 00 05/28/2019 03 41 00 0 0572875 Hydraulic 105/28/2019 03 58 00 05/28/2019 04 43 00 0 0687439 Hydraulic 105/28/2019 05 00 00 05/28/2019 05 45 00 0 162646 Hydraulic 105/28/2019 06 02 00 05/28/2019 06 47 00 0 0757791 Hydraulic 105/28/2019 07 04 00 05/28/2019 07 49 00 0 138073 Hydraulic 105/28/2019 08 06 00 05/28/2019 08 51 00 0 0831698 Hydraulic f 05/28/2019 09 09 00 05/28/2019 09 54 00 0 103544 Hydraulic 105/28/2019 10 11 00 05/28/2019 10 56 00 0 0670011 Hydraulic 105/28/2019 11 12 00 05/28/2019 11 57 00 0 0656352 Hydraulic 05/28/2019 12 14 00 05/28/2019 12 59 00 0 0717745 Hydraulic 05/28/2019 13 16 00 05/28/2019 14 01 00 0 0959548 Hydraulic 05/28/2019 14 18 00 05/28/2019 15 03 00 0 128363 Hydraulic 105/28/2019 15 21 00 05/28/2019-16 06 00 0 0775085 Hydraulic 1 05/28/2019 16 23 00 05/28/2019 17 08 00 0 048356 Hydraulic f 05/28/2019 17 25 00 05/28/2019 18 10 00 0 112376 Hydraulic 105/28/2019 22 12 00 05/28/2019 22 57 00 0 0660991 Hydraulic 105/28/2019 23 15 00 05/29/2019 00 00 00 0 053324 Hydraulic 105/29/2019 00 17 00 05/29/2019 01 02 00 0 0682733 Hydraulic 105/29/2019 01 19 00 05/29/2019 02 04 00 0 0673298 Hydraulic f 05/29/2019 02 21 00 05/29/2019 03 06 00 0 0631894 Hydraulic f 05/29/2019 03 23 00 05/29/2019 04 08 00 0 0978806 Hydraulic 105/29/2019 04 25 00 05/29/2019 05 10 00 0 176384 Hydraulic 105/29/2019 05 27 00 05/29/2019 06 12 00 0 17497 Hydraulic 105/29/2019 06 29 00 05/29/2019 07 14 00 0 133937 Hydraulic 105/29/2019 07 31 00 05/29/2019 08 16 00 0 072436 Hydraulic 1 05/29/2019 08 33 00 05/29/2019 09 18 00 0 0544778 Hydraulic f 05/29/2019 09 35 00 05/29/2019 10 20 00 0 0634794 Hydraulic 105/29/2019 10 37 00 05/29/2019 11 22 00 0 077782 Hydraulic 105/29/2019 11 39 00 05/29/2019 12 24 00 0 0598499 Hydraulic 105/29/2019 12 41 00 05/29/2019 13 26 00 0 0630069 Hydraulic 105/29/2019 13 43 00 05/29/2019 14 28 00 0 0650927 Hydraulic f 05/29/201914 45 00 05/29/2019 15 30 00 0 0659553 Hydraulic f 05/29/2019 15 47 00 05/29/2019 16 32 00 0 0506512 Hydraulic f 05/29/2019 16 49 00 05/29/2019 17 34 00 0 0525207 Hydraulic 105/29/2019 17 51 00 05/29/2019 18 36 00 0 057759 Hydraulic 105/29/2019 18 53 00 05/29/2019 19 38 00 0 208466 Hydraulic 105/29/2019 19 55 00 05/29/2019 20 40 00 0 214018 Hydraulic 105/29/2019 20 57 00 05/29/2019 21 42 00 0 264834 Hydraulic 105/29/2019 21 59 00 05/29/2019 22 44 00 0 3273 Hydraulic 105/30/2019 00 03 00 05/30/2019 00 48 00 0 253626 Hydraulic 105/30/2019 01 06 00 05/30/2019 01 51 00 0 210841 Hydraulic 105/30/2019 02 08 00 05/30/2019 02 53 00 0 235549 Hydraulic 1 05/30/2019 03 10 00 05/30/2019 03 55 00 0 281755 Hydraulic 105/30/2019 04 12 00 05/30/2019 04 57 00 0 403928 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airqualrty/tech_doc_repository aspx#camml_data on June 8, 2020 Hydraulic 105/30/2019 05 14 00 05/30/2019 05 59 00 0 379237 Hydraulic 105/30/2019 06 16 00 05/30/2019 07 01 00 0 43427 Hydraulic 1 05/30/2019 07 18 00 05/30/2019 08 03 00 0 169538 Hydraulic 1 05/30/2019 08 20 00 05/30/2019 09 05 00 0 127552 Hydraulic 105/30/2019 09 22 00 05/30/2019 10 07 00 0 129215 Hydraulic 105/30/2019 10 24 00 05/30/2019 11 09 00 0 137731 Hydraulic! 05/30/2019 11 26 00 05/30/2019 12 11 00 0 0951092 Hydraulic 105/30/2019 12 28 00 05/30/2019 13 13 00 0 098665 Hydraulic 105/30/2019 13 30 00 05/30/2019 14 15 00 0 105841 Hydraulic I 05/30/2019 14 32 00` 05/30/2019 15 17 00 0 0980308 Hydraulic 1 05/30/2019 15 34 00 05/30/2019 16 19 00 0 101175 Hydraulic 105/30/2019 16 36 00 05/30/2019 17 21 00 0 120837 Hydraulic 105/30/2019 17 38 00 05/30/2019 18 23 00 0 0779267 Hydraulic 105/30/2019 18 40 00 05/30/2019 19 25 00 0 111717 Hydraulic 105/30/2019 19 42 00 05/30/2019 20 27 00 2 90713 Hydraulic 105/30/2019 20 44 00 05/30/2019 21 29 00 0 277028 Hydraulic 105/30/2019 2147 00 05/30/2019 22 32 00 0 427136 Hydraulic 105/30/2019 23 51 00 05/31/2019 00 36 00 0 67338 Hydraulic 105/31/2019 00 53 00 05/31/2019 01 38 00 0 631801 Hydraulic 1 05/31/2019 0155 00 05/31/2019 02 40 00 0 469224 Hydraulic 105/31/2019 02 57 00 05/31/2019 03 42 00 0 45208 Hydraulic 105/31/2019 03 59 00 05/31/2019 04 44 00 0 745516 Hydraulic 1 05/31/2019 05 02 00 05/31/2019 05 47 00 0 827473 Hydraulic 105/31/2019 06 04 00 05/31/2019 06 49 00 0 518307 Hydraulic 105/31/2019 07 06 00 05/31/2019 07 51 00 0 421854 Hydraulic 105/31/2019 08 08 00 05/31/2019 08 53 00 0 385543 Hydraulic 105/31/2019 09 10 00 05/31/2019 09 55 00 0 22672 Hydraulic 105/31/2019 10 12 00 05/31/2019 10 57 00 0 0836658 Hydraulic 105/31/2019 11 14 00 05/31/2019 11 59 00 0 107188 Hydraulic 105/31/2019 12 16 00 05/31/2019 13 01 00 0 126939 Hydraulic 105/31/2019 13 18 00 05/31/2019 14 03 00 0 128038 Hydraulic 105/31/2019 14 20 00 05/31/2019 15 05 00 0 105377 Hydraulic 105/31/2019 15 22 00 05/31/2019 16 07 00 0 0873392 Hydraulic 105/31/2019 16 24 00 05/31/2019 17 09 00 0 114223 Hydraulic 1 05/31/2019 17 26 00 05/31/2019 18 11 00 0 0844294 Hydraulic 1 05/31/2019 18 28 00 05/31/2019 19 13 00 0 467219 Hydraulic 106/01/2019 22 26 00 06/01/2019 23 11 00 0 782743 Hydraulic 106/01/2019 23 28 00 06/02/2019 00 13 00 0 91232 Hydraulic 106/02/2019 00 30 00 06/02/2019 01 15 00 0 56697 Hydraulic 1 06/02/2019 01 32 00 06/02/2019 02 17 00 0 298438 Hydraulic 106/02/2019 02 34 00 06/02/2019 03 19 00 0 43046 Hydraulic 4 06/02/2019 03 37 00 06/02/2019 04 22 00 0 448524 Hydraulic 106/02/2019 04 39 00 06/02/2019 05 24 00 0 89362 Hydraulic 106/02/2019 05 41 00 06/02/2019 06 26 00 1 02504 Hydraulic 106/02/2019 06 43 00 06/02/2019 07 28 00 0 368016 Hydraulic 1 06/02/2019 07 45 00 06/02/2019 08 30 00 0 498455 Hydraulic 106/02/2019 08 47 00 06/02/2019 09 32 00 0 190286 11 of 42 Appendix 1 CDPHE Benzene Monitoring Data 12 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Hydraulic f 06/02/2019 09 49 00 06/02/2019 10 34 00 0 1195 Hydraulic f 06/02/2019 10 51 00 06/02/2019 11 36 00 0 0892393 Hydraulic f 06/02/2019 11 53 00 06/02/2019 12 38 00 0 0930876 Hydraulic f 06/02/2019 12 55 00 06/02/2019 13 40 00 0 0805455 Hydraulic f 06/02/2019 13 58 00 06/02/2019 14 43 00 0 0958275 Hydraulic f 06/02/2019 15 00 00 06/02/2019 15 45 00 0 10334 Hydraulic f 06/02/2019 16 02 00 06/02/2019 16 47 00 0 0730725 Hydraulic f 06/02/2019 17 04 00 06/02/2019 17 49 00 0 0903737 Hydraulic f 06/02/2019 18 06 00 06/02/2019 18 51 00 0 177546 Hydraulic f 06/02/2019 19 08 00 06/02/2019 19 53 00 0 29602 Hydraulic f 06/02/2019 20 10 00 06/02/2019 20 55 00 0 0927996 Hydraulic f 06/02/2019 21 12 00 06/02/2019 21 57 00 0 118124 Hydraulic f 06/02/2019 22 14 00 06/02/2019 23 00 00 0 126444 Hydraulic f 06/03/2019 00 19 00 06/03/2019 01 04 00 0 288002 Hydraulic I 06/03/2019 01 21 00 06/03/2019 02 06 00 0 653674 Hydraulic f 06/03/2019 02 23 00 06/03/2019 03 08 00 0 329014 Hydraulic I 06/03/2019 03 25 00 06/03/2019 04 10 00 0 417648 Hydraulic I 06/03/2019 04 27 00 06/03/2019 05 13 00 0 486651 Hydraulic f 06/03/2019 05 30 00 06/03/2019 06 15 00 0 618984 Hydraulic f 06/03/2019 06 32 00 06/03/2019 07 17 00 0 405582 Hydraulic f 06/03/2019 07 34 00 06/03/2019 08 19 00 0 396374 - Mill Out 07/29/2019 14 57 00 07/29/2019 15 42 00 0 119759 Mill Out 07/29/2019 15 54 00 07/29/2019 16 39 00 0 0171427 4 Mill Out 07/29/2019 16 51 00 07/29/2019 17 36 00 -0 0060662 4 Mill Out 07/29/2019 17 49 00 07/29/2019 18 33 00 0 00299949 4 Mill Out 07/29/2019 18 46 00 07/29/2019 19 30 00 0 0992254 Mill Out 07/29/2019 19 43 00 07/29/2019 20 27 00 0 0316814 Mill Out 07/29/2019 20 40 00 07/29/2019 21 25 00 0 085067 Mill Out 07/29/2019 21 37 00 07/29/2019 22 22 00 0 477428 Mill Out 07/29/2019 22 35 00 07/29/2019 23 19 00 0 0656946 Mill Out 07/29/2019 23 32 00 07/30/2019 00 16 00 0 0731151 Mill Out 07/30/2019 00 29 00 07/30/2019 01 14 00 0 10844 Mill Out 07/30/2019 01 27 00 07/30/2019 02 11 00 0 177919 Mill Out 07/30/2019 02 24 00 07/30/2019 03 08 00 - -0 276778 Mill Out 07/30/2019 03 21 00 07/30/2019 04 05 00 0 247162 Mill Out 07/30/2019 04 18 00 07/30/2019 05 03 00 0 209858 Mill Out 07/30/2019 05 15 00 07/30/2019 06 00 00 0 166812 Mill Out 07/30/2019 06 13 00 07/30/2019 06 57 00 0 177722 Mill Out 07/30/2019 07 10 00 07/30/2019 07 54 00 0 166982 Mill Out 07/30/2019 08 07 00 07/30/2019 08 51 00 0 173638 Mill Out 07/30/2019 09 04 00 07/30/2019 09 49 00 0 178925 Mill Out 07/30/2019 10 11 00 07/30/2019 10 55 00 0 135784 Mill Out 07/30/2019 18 19 00 07/30/2019 19 03 00 0 18527 Mill Out 07/30/2019 19 16 00 07/30/2019 20 00 00 0 122126 Mill Out 07/30/2019 20 13 00 07/30/2019 20 58 00 0 2979 Mill Out 07/30/2019 21 10 00 07/30/2019 21 55 00 0 289953 Mill Out 07/30/2019 22 07 00 07/30/2019 22 52 00 0 138188 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airqualrty/tech_doc_repository aspx##camml_data on June 8, 2020 Mill Out 07/30/2019 23 05 00 07/30/2019 23 49 00 016088 Mill Out 07/31/2019 00 02 00 07/31/2019 00 46 00 0 278073 Mill Out 07/31/2019 00 59 00 07/31/2019 0144 00 0 306632 Mill Out 07/31/2019 01 56 00 07/31/2019 02 41 00 0 337348 Mill Out 07/31/2019 02 54 00 07/31/2019 03 38 00 0 62602 Mill Out 07/31/2019 03 51 00 07/31/2019 04 35 00 0 281332 Mill Out 07/31/2019 04 48 00 07/31/2019 05 33 00 0 44545 Mill Out 07/31/2019 05 45 00 07/31/2019 06 30 00 0 512628 Mill Out 07/31/2019 06 43 00 07/31/2019 07 27 00 0 63922 Mill Out 07/31/2019 07 40 00 07/31/2019 08 25 00 0 700304 Mill Out 07/31/2019 09 35 00 07/31/201910 20 00 0 0896243 Mill Out 07/31/2019 10 32 00 07/31/2019 11 17 00 0 0478177 Mill Out 07/31/2019 11 29 00 07/31/2019 12 14 00 0 090719 Mill Out 07/31/2019 12 26 00 07/31/2019 13 11 00 0 10263 Mill Out 07/31/2019 13 24 00 07/31/2019 14 08 00 0 107887 Mill Out 07/31/2019 14 21 00 07/31/2019 15 06 00 0 125265 Mill Out 07/31/2019 15 18 00 07/31/2019 16 03 00 0 0947043 Mill Out 07/31/2019 16 15 00 07/31/2019 17 00 00 0 0779718 Mill Out 07/31/2019 17 13 00 07/31/2019 17 57 00 0 040328 Mill Out 07/31/2019 18 10 00 07/31/2019 18 54 00 0 129465 Mill Out 07/31/2019 19 07 00 07/31/2019 19 52 00 0 0205203 4 Mill Out 07/31/2019 20 04 00 07/31/2019 20 49 00 0 0779805 Mill Out 07/31/2019 21 02 00 07/31/2019 21 46 00 0 179255 Mill Out 07/31/2019 21 59 00 07/31/2019 22 43 00 0 0293522 4 Mill Out 07/31/2019 22 56 00 07/31/2019 23 40 00 0 00695483 4 Mill Out 07/31/2019 23 53 00 08/01/2019 00 37 00 0 052831 Mill Out 08/01/2019 00 50 00 08/01/2019 01 35 00 1 8384 Mill Out 08/01/2019 0147 00 08/01/2019 02 32 00 1 70256 Mill Out 08/01/2019 02 44 00 08/01/2019 03 29 00 2 35714 Mill Out 08/01/2019 03 41 00 08/01/2019 04 26 00 0 555243 Mill Out 08/01/2019 04 39 00 08/01/2019 05 23 00 0 428552 Mill Out 08/01/2019 05 36 00 08/01/2019 06 20 00 0 594203 Mill Out 08/01/2019 06 33 00 08/01/2019 07 17 00 0 38951 Mill Out 08/01/2019 07 30 00 08/01/2019 08 14 00 0 261409 Mill Out 08/01/2019 09 24 00 08/01/2019 10 09 00 0 120819 Mill Out 08/01/2019 10 21 00 08/01/2019 11 06 00 0 109529 Mill Out 08/01/2019 11 18 00 08/01/2019 12 03 00 0 0637501 Mill Out 08/01/2019 12 15 00 08/01/2019 13 00 00 0 0926044 Mill Out 08/01/2019 13 12 00 08/01/2019 13 57 00 0 0474516 Mill Out 08/01/2019 14 09 00 08/01/2019 14 54 00 0 0555686 Mill Out 08/01/201915 06 00 08/01/2019 15 51 00 0 0624644, Mill Out 08/01/2019 16 04 00 08/01/2019 16 48 00 0 0781791 Mill Out 08/01/2019 17 01 00 08/01/2019 17 45 00 0 0408451 Mill Out 08/01/2019 17 58 00 08/01/2019 18 42 00 0 130166 Mill Out 08/01/2019 18 55 00 08/01/2019 19 39 00 0 0506409 Mill Out 08/01/2019 19 52 00 08/01/2019 20 37 00 0 0635092 Mill Out 08/01/2019 20 49 00 08/01/2019 21 34 00 0 0939628 13 of 42 Appendix 1 CDPHE Benzene Monitoring Data 14 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/01/2019 2146 00 08/01/2019 22 3100 0 115308 Mill Out 08/01/2019 22 44 00 08/01/2019 23 28 00 0 116057 Mill Out 08/01/2019 23 41 00 08/02/2019 00 25 00 0 161351 Mill Out 08/02/2019 00 38 00 08/02/2019 01 22 00 0 140675 Mill Out 08/02/2019 01 35 00 08/02/2019 02 19 00 -0 0260797 4 Mill Out 08/02/2019 02 32 00 08/02/2019 03 17 00 0 19232 Mill Out 08/02/2019 03 30 00 08/02/2019 04 14 00 0 397033 Mill Out 08/02/2019 04 27 00 08/02/2019 05 11 00 0 588276 Mill Out 08/02/2019 05 24 00 08/02/2019 06 09 00 0 191196 Mill Out 08/02/2019 06 21 00 08/02/2019 07 06 00 0 436545 Mill Out 08/02/2019 07 19 00 08/02/2019 08 03 00 0 484934 Mill Out 08/02/2019 09 13 00 08/02/2019 09 57 00 0 214077 Mill Out 08/02/2019 10 10 00 08/02/2019 10 54 00 0 190786 Mill Out 08/05/2019 09 19 00 08/05/2019 10 04 00 1 Mill Out 08/05/2019 11 14 00 08/05/2019 11 58 00 0 0678625 Mill Out 08/05/2019 12 11 00 08/05/2019 12 55 00 0 122151 Mill Out 08/05/2019 13 08 00 08/05/2019 13 52 00 0 0550784 Mill Out 08/05/2019 14 05 00 08/05/2019 14 49 00 0 155849 Mill Out 08/05/2019 15 02 00 08/05/2019 15 46 00 0 0153414 4 Mill Out 08/05/2019 15 59 00 08/05/2019 16 44 00 0 00617043 4 Mill Out 08/05/2019 16 56 00 08/05/2019 17 41 00 0 109012 Mill Out 08/05/2019 17 53 00 08/05/2019 18 38 00 0 123823 Mill Out 08/05/2019 18 51 00 08/05/2019 19 35 00 0 0543266 Mill Out 08/05/2019 19 48 00 08/05/2019 20 32 00 0 0538767 Mill Out 08/05/2019 20 45 00 08/05/2019 21 29 00 0 109685 Mill Out 08/05/2019 2142 00 08/05/2019 22 27 00 0 167808 Mill Out 08/05/2019 22 39 00 08/05/2019 23 24 00 0 213806 Mill Out 08/05/2019 23 36 00 08/06/2019 00 21 00 0 145179 Mill Out 08/06/2019 00 34 00 08/06/2019 01 18 00 0 214582 Mill Out 08/06/2019 01 31 00 08/06/2019 02 15 00 0 194819 Mill Out 08/06/2019 02 28 00 08/06/2019 03 12 00 0 109292 Mill Out 08/06/2019 03 25 00 08/06/2019 04 09 00 0 193431 Mill Out 08/06/2019 04 22 00 08/06/2019 05 07 00 0 230404 Mill Out 08/06/2019 05 19 00 08/06/2019 06 04 00 0 33996 Mill Out 08/06/2019 06 17 00 08/06/2019 07 01 00 0 561469 Mill Out 08/06/2019 07 14 00 08/06/2019 07 58 00 0 499875 Mill Out 08/06/2019 08 11 00 08/06/2019 08 55 00 0 432204 Mill Out 08/06/2019 09 08 00 08/06/2019 09 52 00 0 446542 Mill Out 08/06/2019 11 02 00 08/06/2019 11 47 00 0 360932 Mill Out 08/06/2019 11 59 00 08/06/2019 12 44 00 0 373287 Mill Out 08/06/2019 12 57 00 08/06/2019 13 41 00 0 266781 Mill Out 08/06/2019 13 54 00 08/06/2019 14 38 00 0 216 Mill Out 08/06/2019 14 51 00 08/06/2019 15 35 00 0 067581 Mill Out 08/06/2019 15 48 00 08/06/2019 16 32 00 0 0554944 Mill Out 08/06/2019 16 45 00 08/06/2019 17 30 00 0 144436 Mill Out 08/06/2019 17 42 00 08/06/2019 18 27 00 0 0579488 Mill Out 08/06/2019 18 39 00 08/06/2019 19 24 00 0 114851 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/06/201919 36 00 08/06/2019 20 21 00 0 130613 Mill Out 08/06/2019 20 34 00 08/06/2019 21 18 00 0 195372 Mill Out 08/06/2019 21 31 00 08/06/2019 22 15 00 0 367758 Mill Out 08/06/2019 22 28 00 08/06/2019 23 12 00 0 238835 Mill Out 08/06/2019 23 25 00 08/07/2019 00 10 00 0 390206 Mill Out 08/07/2019 00 22 00 08/07/2019 01 07 00 0 259427 Mill Out 08/07/2019 01 19 00 08/07/2019 02 04 00 0 362068 Mill Out 08/07/2019 02 16 00 08/07/2019 03 01 00 0 121569 Mill Out 08/07/2019 03 14 00 08/07/2019 03 58 00 0 303665 Mill Out 08/07/2019 04 11 00 08/07/2019 04 55 00 0 144007 Mill Out 08/07/2019 05 08 00 08/07/2019 05 52 00 0 0873361 Mill Out 08/07/2019 06 05 00 08/07/2019 06 50 00 0 161571 Mill Out 08/07/2019 07 02 00 08/07/2019 07 47 00 0 223535 Mill Out 08/07/2019 07 59 00 08/07/2019 08 44 00 0 0617692 Mill Out 08/07/2019 08 57 00 08/07/2019 09 41 00 0 0558547 Mill Out 08/07/2019 10 51 00 08/07/2019 11 35 00 0 207087 Mill Out 08/07/2019 1148 00 08/07/2019 12 32 00 0 24116 Mill Out 08/07/2019 12 45 00 08/07/2019 13 29 00 0 113438 Mill Out 08/07/2019 13 42 00 08/07/2019 14 27 00 0 0305007 Mill Out 08/07/201914 39 00 08/07/2019 15 24 00 0 0413322 Mill Out 08/07/2019 15 36 00 08/07/2019 16 21 00 0 0257001 4 Mill Out 08/07/2019 16 33 00 08/07/2019 17 18 00 0 0863019 Mill Out 08/07/2019 17 31 00 08/07/2019 18 15 00 0 0705864 Mill Out 08/07/2019 18 28 00 08/07/2019 19 12 00 0 0756156 Mill Out 08/07/2019 19 25 00 08/07/2019 20 09 00 0 0936267 Mill Out 08/07/2019 20 22 00 08/07/2019 21 06 00 0 136901 Mill Out 08/07/2019 21 19 00 08/07/2019 22 04 00 0 155756 Mill Out 08/07/2019 22 16 00 08/07/2019 23 01 00 0 073475 Mill Out 08/07/2019 23 13 00 08/07/2019 23 58 00 0 0535116 Mill Out 08/08/2019 00 11 00 08/08/2019 00 55 00 0 0944179 Mill Out 08/08/2019'01 08 00 08/08/2019 01 52 00 0 0617418 Mill Out 08/08/2019 02 05 00 08/08/2019 02 49 00 0 153486 Mill Out 08/08/2019 03 02 00 08/08/2019 03 46 00 0 148844 Mill Out 08/08/2019 03 59 00 08/08/2019 04 44 00 0 171841 Mill Out 08/08/2019 04 56 00 08/08/2019 05 41 00 0 309378 Mill Out 08/08/2019 05 53 00 08/08/2019 06 38 00 0 241679 Mill Out 08/08/2019 06 51 00 08/08/2019 07 35 00 0 498959 Mill Out 08/08/2019 07 48 00 08/08/2019 08 32 00 0 800697 Mill Out 08/08/2019 08 45 00 08/08/2019 09 29 00 0 559825 Mill Out 08/08/2019 10 39 00 08/08/2019 11 24 00 0 212426 Mill Out 08/08/2019 11 36 00 08/08/2019 12 21 00 0 194657 Mill Out 08/08/2019 12 33 00 08/08/2019 13 18 00 0 292414 Mill Out 08/08/2019 13 30 00 08/08/2019 14 15 00 0 129358 Mill Out 08/08/2019 14 28 00 08/08/2019 15 12 00 0 122493 Mill Out 08/08/2019 15 25 00 08/08/2019 16 09 00 0 156594 Mill Out 08/08/2019 16 22 00 08/08/2019 17 06 00 0 104962 Mill Out 08/08/2019 17 19 00 08/08/2019 18 04 00 0 0452191 i 15 of 42 Appendix 1 CDPHE Benzene Monitoring Data 16 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/08/2019 18 16 00 08/08/2019 19 01 00 0 0596786 Mill Out 08/08/2019 19 13 00 08/08/2019 19 58 00 0 758005 Mill Out 08/08/2019 20 11 00 08/08/2019 20 55 00 0 171511 Mill Out 08/08/2019 21 08 00 08/08/2019 21 52 00 0 14933 Mill Out 08/08/2019 22 05 00 08/08/2019 22 49 00 0 434088 Mill Out 08/08/2019 23 02 00 08/08/2019 23 46 00 0 272788 Mill Out 08/08/2019 23 59 00 08/09/2019 00 44 00 0 157126 Mill Out 08/09/2019 00 56 00 08/09/2019 01 41 00 0 818245 Mill Out 08/09/2019 01 53 00 08/09/2019 02 38 00 -0 962369 Mill Out 08/09/2019 02 51 00 08/09/2019 03 35 00 1 51397 Mill Out 08/09/2019 03 48 00 08/09/2019 04 32 00 134165 Mill Out 08/09/2019 04 45 00 08/09/2019 05 29 00 0 751855 Mill Out 08/09/2019 05 42 00 08/09/2019 06 27 00 0 218073 Mill Out 08/09/2019 06 39 00 08/09/2019 07 24 00 0 277814 Mill Out 08/09/2019 07 36 00 08/09/2019 08 21 00 0 507876 Mill Out 08/09/2019 08 34 00 08/09/2019 09 18 00 0 724051 Mill Out 08/09/2019 11 16 00 08/09/2019 12 00 00 0 203058 Mill Out 08/09/2019 13 10 00 08/09/2019 13 55 00 0 0290316 4 Mill Out 08/09/2019 14 08 00 08/09/2019 14 52 00 0 0568301 Mill Out 08/09/2019 15 05 00 08/09/2019 15 49 00 0 0649394 Mill Out 08/09/2019 16 02 00 08/09/2019 16 47 00 0 0471745 Mill Out 08/09/2019 16 59 00 08/09/2019 17 44 00 0 0458988 Mill Out 08/09/2019 17 56 00 08/09/2019 18 41 00 0 125918 Mill Out 08/09/2019 18 54 00 08/09/2019 19 38 00 0 301188 Mill Out 08/09/2019 19 51 00 08/09/2019 20 35 00 0 139526 Mill Out 08/09/2019 20 48 00 08/09/2019 21 32 00 0 0330034 Mill Out 08/09/2019 2145 00 08/09/2019 22 30_00 0 0699127 Mill Out 08/09/2019 22 42 00 08/09/2019 23 27 00 0 121648 Mill Out 08/09/2019 23 39 00 08/10/2019 00 24 00 0 254121 Mill Out 08/10/2019 00 37 00 08/10/2019 01 21 00 0 190811 Mill Out 08/10/2019 01 34 00 08/10/2019 02 18 00 0 544972 Mill Out 08/10/2019 02 31 00 08/10/2019 03 15 00 0 450628 Mill Out 08/10/2019 03 28 00 08/10/2019 04 13 00 0 288903 Mill Out 08/10/2019 04 25 00 08/10/2019 05 10 00 0 332164 Mill Out 08/10/2019 05 23 00 08/10/2019 06 07 00 0 476531 Mill Out 08/10/2019 06 20 00 08/10/2019 07 04 00 2 57278 Mill Out 08/10/2019 07 17 00 08/10/2019 08 01 00 0 438446 Mill Out 08/10/2019 08 14 00 08/10/2019 08 58 00 0 611385 Mill Out 08/10/2019 09 11 00 08/10/2019 09 56 00 0 36946 Mill Out 08/10/2019 10 08 00 08/10/2019 10 53 00 0 131598 Mill Out 08/10/2019 11 06 00 08/10/2019 11 50 00 0 0642639 Mill Out 08/10/2019 13 00 00 08/10/2019 13 44 00 0 0152198 4 Mill Out 08/10/2019 13 57 00 08/10/2019 14 42 00 0 0630122 Mill Out 08/10/2019 14 54 00 08/10/2019 15 39 00 0 0122105 4 Mill Out 08/10/2019 15 52 00 08/10/2019 16 36 00 0 0145231 4 Mill Out 08/10/2019 16 49 00 08/10/2019 17 33 00 0 0114651 4 Mill Out 08/10/2019 17 46 00 08/10/2019 18 30 00 0 030071 1 Appendix 1 CDPHE Benzene Monitoring Data 17 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/10/2019 18 43 00 08/10/2019 19 28 00 0 142303 Mill Out 08/10/2019 19 40 00 08/10/2019 20 25 00 0 691985 Mill Out 08/10/2019 20 38 00 08/10/2019 21 22 00 0 699678 Mill Out 08/10/2019 21 35 00 08/10/2019 22 19 00 0 0542913 Mill Out 08/10/2019 22 32 00 08/10/2019 23 16 00 0 280975 Mill Out 08/10/2019 23 29 00 08/11/2019 00 14 00 0 226781 Mill Out 08/11/2019 00 26 00 08/11/2019 01 11 00 0 0879019 Mill Out 08/11/2019 01 24 00 08/11/2019 02 08 00 0 058468 Mill Out ' 08/11/2019 02 21 00 08/11/2019 03 05 00 0 103214 Mill Out 08/11/2019 03 18 00 08/11/2019 04 02 00 0 14355 Mill Out 08/11/2019 04 15 00 08/11/2019 04 59 00 0 101711 Mill Out 08/11/2019 05 12 00 08/11/2019 05 57 00 0 0890641 Mill Out 08/11/2019 06 09 00 08/11/2019 06 54 00 0 19686 Mill Out 08/11/2019 07 07 00 08/11/2019 07 51 00 0 0841318 Mill Out 08/11/2019 08 04 00 08/11/2019 08 48 00 0 0737755 Mill Out 08/11/2019 09 01 00 08/11/2019 09 45 00 0 0742626 Mill Out 08/11/2019 09 58 00 08/11/2019 10 42 00 0 147421 Mill Out 08/11/2019 10 55 00 08/11/2019 1140 00 0 107733 Mill Out 08/11/2019 12 50 00 08/11/2019 13 34 00 0 207766 Mill Out 08/11/2019 13 47 00 08/11/2019 14 31 00 0 12242 Mill Out 08/11/2019 14 44 00 08/11/2019 15 28 00 0 0400234 Mill Out 08/11/2019 15 41 00 08/11/2019 16 25 00 0 0157051 4 Mill Out 08/11/2019 16 38 00 08/11/2019 17 23 00 0 0262928 4 Mill Out 08/11/2019 17 35 00 08/11/2019 18 20 00 0 0252189 4 Mill Out 08/11/2019 18 32 00 08/11/2019 19 17 00 0 0473017 Mill Out 08/11/2019 19 30 00 08/11/2019 20 14 00 0 079516 Mill Out 08/11/2019 20 27 00 08/11/2019 21 11 00 0 0472937 Mill Out 08/11/2019 21 24 00 08/11/2019 22 09 00 0 0737692 Mill Out 08/11/2019 22 21 00 08/11/2019 23 06 00 0 139951 Mill Out 08/11/2019 23 19 00 08/12/2019 00 03 00 0 104523 Mill Out 08/12/2019 00 16 00 08/12/2019 01 00 00 0 167928 Mill Out 08/12/2019 01 13 00 08/12/2019 01 57 00 0 113483 Mill Out 08/12/2019 02 10 00 08/12/2019 02 55 00 0 119716 Mill Out 08/12/2019 03 07 00 08/12/2019 03 52 00 0 292844 Mill Out 08/12/2019 04 05 00 08/12/2019 04 49 00 0 343557 Mill Out 08/12/2019 05 02 00 08/12/2019 05 46 00 0 521071 Mill Out 08/12/2019 05 59 00 08/12/2019 06 43 00 0 447434 Mill Out 08/12/2019 06 56 00 08/12/2019 07 41 00 0 673727 Mill Out 08/12/2019 07 53 00 08/12/2019 08 38 00 0 260453 Mill Out 08/12/2019 08 50 00 08/12/2019 09 35 00 0 116542 Mill Out 08/12/2019 09 47 00 08/12/2019 10 32 00 0 0968214 Mill Out 08/12/2019 10 45 00 08/12/2019 11 29 00 0 111396 Mill Out 08/12/2019 12 39 00 08/12/2019 13 23 00 0 0377113 Mill Out 08/12/2019 13 36 00 08/12/2019 14 20 00 0 0430921 Mill Out 08/12/2019 14 33 00 08/12/2019 15 17 00 0 041578 Mill Out 08/12/2019 15 30 00 08/12/2019 16 15 00 0 0663766 Mill Out 08/12/2019 16 27 00 08/12/2019 17 12 00 0 100828 Appendix 1 CDPHE Benzene Monitoring Data 18 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/12/2019 17 24 00 08/12/2019 18 09 00 0 0698702 Mill Out 08/12/2019 18 21 00 08/12/2019 19 06 00 0 103664 Mill Out 08/12/2019 19 19 00 08/12/2019 20 03 00 0 0593876 Mill Out 08/12/2019 20 16 00 08/12/2019 21 00 00 0 114497 Mill Out 08/12/2019 21 13 00 08/12/2019 21 57 00 0 0419333 Mill Out 08/12/2019 22 10 00 08/12/2019 22 54 00 0 113496 Mill Out 08/12/2019 23 07 00 08/12/2019 23 52 00 0 0635064 Mill Out 08/13/2019 00 04 00 08/13/2019 00 49 00 0 0566655 Mill Out 08/13/2019 01 02 00 08/13/2019 0146 00 0 0381765 Mill Out 08/13/2019 01 59 00 08/13/2019 02 43 00 0 187725 Mill Out 08/13/2019 02 56 00 08/13/2019 03 40 00 0 263761 Mill Out 08/13/2019 03 53 00 08/13/2019 04 37 00 0 203332 Mill Out 08/13/2019 04 50 00 08/13/2019 05 35 00 0 169223 Mill Out 08/13/2019 05 47 00 08/13/2019 06 32 00 0 256636 Mill Out 08/13/2019 06 44 00 08/13/2019 07 29 00 0 14378 Mill Out 08/13/2019 07 42 00 08/13/2019 08 26 00 0 128752 Mill Out 08/13/2019 08 41 00 08/13/2019 09 25 00 0 109805 Mill Out 08/19/2019 11 41 00 08/19/2019 12 25 00 0-16069 Mill Out 08/19/2019 13 35 00 08/19/2019 14 20 00 0 185894 Mill Out 08/19/2019 14 33 00 08/19/2019 15 17 00 0 190247 Mill Out 08/19/2019 15 30 00 08/19/2019 16 14 00 0 0658281 Mill Out 08/19/2019 16 27 00 08/19/2019 17 12 00 0 039533 Mill Out 08/19/2019 17 24 00 08/19/2019 18 09 00 0 042654 Mill Out 08/19/2019 18 22 00 08/19/2019 19 06 00 0 0317068 Mill Out 08/19/2019 19 19 00 08/19/2019 20 03 00 0 438888 Mill Out 08/19/2019 20 16 00 08/19/2019 21 01 00 0 235065 Mill Out 08/19/2019 21 13 00 08/19/2019 21 58 00 0 105207 Mill Out 08/19/2019 22 11 00 08/19/2019 22 55 00 0 0798044 Mill Out 08/19/2019 23 08 00 08/19/2019 23 52 00 0 228013 Mill Out 08/20/2019 00 05 00 08/20/2019 00 50 00 0 403782 Mill Out 08/20/2019 01 03 00 08/20/2019 0147 00 0 307171 Mill Out 08/20/2019 02 00 00 08/20/2019 02 44 00 0 122799 Mill Out 08/20/2019 02 57 00 08/20/2019 03 42 00 0 165997 Mill Out 08/20/2019 03 55 00 08/20/2019 04 39 00 0 135129 Mill Out 08/20/2019 04 52 00 08/20/2019 05 36 00 0 16845 Mill Out 08/20/2019 05 49 00 08/20/2019 06 34 00 0 319369 Mill Out 08/20/2019 06 47 00 08/20/2019 07 31 00 0 614756 Mill Out 08/20/2019 08 31 00 08/20/2019 09 16 00 0 61992 Mill Out 08/20/2019 10 25 00 08/20/2019 11 10 00 0 330124 Mill Out 08/20/2019 11 23 00 08/20/2019 12 07 00 0 269001 Mill Out 08/20/2019 12 20 00 08/20/2019 13 05 00 0 396825 Mill Out 08/20/2019 13 17 00 08/20/2019 14 02 00 0 11928 Mill Out `08/20/2019 14 15 00 08/20/2019 14 59 00 0 0694686 Mill Out 08/20/2019 15 12 00 08/20/2019 15 56 00 0 0323495 Mill Out 08/20/2019 16 09 00 08/20/2019 16 54 00 0 0513311 Mill Out 08/20/2019 17 06 00 08/20/2019 17 51 00 0 0344545 Mill Out 08/20/2019 18 03 00 08/20/2019 18 48 00 0 0638958 Appendix 1 CDPHE Benzene Monitoring Data 19 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/20/2019 19 01 00 08/20/2019 19 45 00 0 0490882 Mill Out 08/20/2019 19 58 00 08/20/2019 20 42 00 0 0940798 Mill Out 08/20/2019 20 55 00 08/20/2019 2140 00 0 155684 Mill Out 08/20/2019 21 52 00 08/20/2019 22 37 00 0 179523 Mill Out 08/20/2019 22 50 00 08/20/2019 23 34 00 0 137054 Mill Out 08/20/2019 23 47 00 08/21/2019 00 31 00 0 135226 Mill Out 08/21/2019 00 44 00 08/21/2019 01 29 00 0 0412344 Mill Out 08/21/2019 01 41 00 08/21/2019 02 26 00 0 0491018 Mill Out 08/21/2019 02 39 00 08/21/2019 03 23 00 0 0371042 Mill Out 08/21/2019 03 36 00 08/21/2019 04 21:00 0 0488343 Mill Out 08/21/2019 04 34 00 08/21/2019 05 18:00 0 154082 Mill Out 08/21/2019 05 31 00 08/21/2019 06 16:00 0 193051 Mill Out 08/21/2019 06 29 00 08/21/2019 07 13:00 0 12155 Mill Out 08/21/2019 07 26 00 08/21/2019 08 10.00 0 154457 Mill Out 08/21/2019 08 23 00 08/21/2019 09 08.00 0 144614 Mill Out 08/21/2019 10 17 00 08/21/2019 11 02 00 0 229026 Mill Out 08/21/2019 11 15 00 08/21/2019 11 59 00 0 169831 Mill Out 08/21/2019 12 12 00 08/21/2019 12 56 00 0 193528 Mill Out 08/21/2019 13 09 00 08/21/2019 13 53 00 0 0678424 Mill Out 08/21/2019 14 06 00 08/21/2019 14 50 00 0 102502 Mill Out 08/21/2019 15 03 00 08/21/2019 15 48 00 0 207626 Mill Out 08/21/2019 16 00 00 08/21/2019 16 45 00 0 288128 Mill Out 08/21/2019 16 5,7 00 08/21/2019 17 42 00 0 0920595 Mill Out 08/21/2019 17 55 00 08/21/2019 18 39 00 0 148001 Mill Out 08/21/2019 18 52 00 08/21/2019 19 36 00 0 101077 Mill Out 08/21/2019 19 49 00 08/21/2019 20 34 00 0 113698 Mill Out 08/21/2019 20 47 00 08/21/2019 21 31 00 0 132161 Mill Out 08/21/2019 2144 00 08/21/2019 22 28 00 0 149089 Mill Out 08/21/2019 22 41 00 08/21/2019 23 25 00 0 151562 Mill Out 08/21/2019 23 38 00 08/22/2019 00 23 00 0 0868536 Mill Out 08/22/2019 00 35 00 08/22/2019 01 20 00 0 165834 Mill Out 08/22/2019 01 33 00 08/22/2019 02 17 00 0 0563932 Mill Out 08/22/2019 02 30 00 08/22/2019 03 15 00 0 0405593 Mill Out 08/22/2019 03 27 00 08/22/2019 04 12 00 0 0236728 4 Mill Out 08/22/2019 04 25 00 08/22/2019 05 09 00 0 21338 Mill Out 08/22/2019 05 22 00 08/22/2019 06 07 00 0 0853867 Mill Out 08/22/2019 06 20 00 08/22/2019 07 04 00 0 648722 Mill Out 08/22/2019 07 17 00 08/22/2019 08 01 00 0 062351 Mill Out 08/22/2019 08 14 00 08/22/2019 08 59 00 0 220711 Mill Out 08/22/2019 10 09 00 08/22/2019 10 53 00 0 211008 Mill Out 08/22/2019 11 06 00 08/22/2019 11 50 00 0 130074 Mill Out 08/22/2019 12 03 00 08/22/2019 12 48 00 0 073618 Mill Out 08/22/2019 13 00 00 08/22/2019 13 45 00 0 0462185 Mill Out 08/22/2019 13 58 00 08/22/2019 14 42 00 0 0363443 Mill Out 08/22/2019 14 55 00 08/22/2019 15 39 00 0 1001 Mill Out 08/22/2019 15 52 00 08/22/2019 16 37 00 0 180879 Mill Out 08/22/2019 16 49 00 08/22/2019 17 34 00 0 315928 \ Appendix 1 CDPHE Benzene Monitoring Data 20 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/22/2019 17 47 00 08/22/2019 1831 00 0 0810739 Mill Out 08/22/2019 18 44 00 08/22/2019 19 28 00 0 144858 Mill Out 08/22/2019 19 41 00 08/22/2019 20 25 00 0 0569087 Mill Out 08/22/2019 20 38 00 08/22/2019 21 23 00 0 0516604 Mill Out 08/22/2019 21 35 00 08/22/2019 22 20 00 0 138427 Mill Out 08/22/2019 22 33 00 08/22/2019 23 17 00 0 138344 Mill Out 08/22/2019 23 30 00 08/23/2019 00 14 00 0 220243 Mill Out 08/23/2019 00 27 00 08/23/2019 01 12 00 0 0629303 Mill Out 08/23/2019 01 25 00 08/23/2019 02 09 00 0 309732 Mill Out 08/23/2019 02 22 00 08/23/2019 03 06 00 0 490946 Mill Out 08/23/2019 03 19 00 08/23/2019 04 04 00 0 521357 Mill Out 08/23/2019 04 17 00 08/23/2019 05 01 00 0 296456 Mill Out 08/23/2019 05 14 00 08/23/2019 05 59 00 0 35336 Mill Out 08/23/2019 06 12 00 08/23/2019 06 56 00 0 553217 Mill Out 08/23/2019 07 09 00 08/23/2019 07 53 00 0 329677 Mill Out 08/23/2019 08 06 00 08/23/2019 08 51 00 0 230874 Mill Out 08/23/2019 10 01 00 08/23/2019 10 45 00 0 0680564 Mill Out 08/23/2019 10 58 00 08/23/2019 1143 00 0 0659812 Mill Out 08/23/2019 11 55 00 08/23/2019 12 40 00 0 0649821 Mill Out 08/23/2019 12 53 00 08/23/2019 13 37 00 0 045088 Mill Out 08/23/2019 13 50 00 08/23/2019 14 34 00 0 0347338 Mill Out 08/23/2019 14 47 00 08/23/2019 15 31 00 0 0400573 Mill Out 08/23/2019 15 44 00 08/23/2019 16 28 00 0 0422989 Mill Out 08/23/2019 16 41 00 08/23/2019 17 26 00 0 0396763 Mill Out 08/23/2019 17 38 00 08/23/2019 18 23 00 0 781801 Mill Out 08/23/2019 18 36 00 08/23/2019 19 20 00 0 0782156 Mill Out 08/23/2019 19 33 00 08/23/2019 20 17 00 0 134937 Mill Out 08/23/2019 20 30 00 08/23/2019 21 15 00 0 242936 Mill Out 08/23/2019 21 28 00 08/23/2019 22 12 00 0 971014 Mill Out 08/23/2019 22 25 00 08/23/2019 23 09 00 0 142971 Mill Out 08/23/2019 23 22 00 08/24/2019 00 07 00 0 128073 Mill Out 08/24/2019 00 20 00 08/24/2019 01 04 00 0 0757855 Mill Out 08/24/2019 01 17 00 08/24/2019 02 01 00 0 063311 Mill Out 08/24/2019 02 14 00 08/24/2019 02 59 00 0 100385 Mill Out 08/24/2019 03 12 00 08/24/2019 03 56 00 0 0921483 Mill Out 08/24/2019 04 09 00 08/24/2019 04 54 00 0 160854 Mill Out 08/24/2019 05 07 00 08/24/2019 05 51 00 0 0566167 Mill Out 08/24/2019 06 04 00 08/24/2019 06 49 00 0 10526 Mill Out 08/24/2019 07 02 00 08/24/2019 07 46 00 0 0584898 Mill Out 08/24/2019 07 59 00 08/24/2019 08 43 00 0 0892507 Mill Out 08/24/2019 09 53 00 08/24/2019 10 38 00 0 0596519 Mill Out 08/24/2019 10 51 00 08/24/2019 11 35 00 0 247524 Mill Out 08/24/2019 1148 00 08/24/2019 12 32 00 0 0856194 Mill Out 08/24/2019 12 45 00 08/24/2019 13 29 00 0 0986728 Mill Out 08/24/2019 13 42 00 08/24/2019 14 27 00 0 177033 Mill Out 08/24/2019 14 39 00 08/24/2019 15 24 00 0 0605425 Mill Out 08/24/201915 36 00 08/24/2019 16 2100 0 0488404 Appendix 1 CDPHE Benzene Monitoring Data 21 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/24/201916 34 00 08/24/2019 17 18 00 0 0489136 Mill Out 08/24/2019 17 31 00 08/24/2019 18 15 00 0 0416331 Mill Out 08/24/2019 18 28 00 08/24/2019 19 12 00 0 052559 Mill Out 08/24/2019 19 25 00 08/24/2019 20 10 00 0 337119 Mill Out 08/24/2019 20 22 00 08/24/2019 21 07 00 0 306082 Mill Out 08/24/2019 21 20 00 08/24/2019 22 04 00 0 400263 Mill Out 08/24/2019 22 17 00 08/24/2019 23 01 00 0 401574 Mill Out 08/24/2019 23 14 00 08/24/2019 23 59 00 0 256909 Mill Out 08/25/2019 00 12 00 08/25/2019 00 56 00 0 304881 Mill Out 08/25/2019 0109 00 08/25/2019 01 54 00 0 2276 Mill Out 08/25/2019 02 07 00 08/25/2019 02 51 00 0 124504 Mill Out 08/25/2019 03 04 00 08/25/2019 03 48 00 0 117772 Mill Out 08/25/2019 04 02 00 08/25/2019 04 46 00 0 573387 Mill Out 08/25/2019 04 59 00 08/25/2019 05 43 00 0 846131 Mill Out 08/25/2019 05 56 00 08/25/2019 06 41 00 0 683614 Mill Out 08/25/2019 06 54 00 08/25/2019 07 38 00 1 24698 Mill Out 08/25/2019 07 51 00 08/25/2019 08 35 00 0 616643 Mill Out 08/25/2019 09 45 00 08/25/2019 10 30 00 0 285181 Mill Out 08/25/2019 10 43 00 08/25/2019 11 27 00 0 0769193 Mill Out 08/25/2019 1140 00 08/25/2019 12 24 00 0 0533279 MITI Out 08/25/2019 12 37 00 08/25/2019 13 21 00 0 0356141 Mill Out 08/25/2019 13 34 00 08/25/2019 14 19 00 0 0489771 Mill Out 08/25/2019 14 31 00 08/25/2019 15 16 00 0 0511322 Mill Out 08/25/2019 15 29 00 08/25/2019 16 13 00 0 0274288 4 Mill Out 08/25/2019 16 26 00 08/25/2019 17 10 00 0 0181573 4 Mill Out 08/25/2019 17 23 00 08/25/2019 18 08 00 0 0464171 Mill Out 08/25/2019 18 20 00 08/25/2019 19 05 00 0 066568 Mill Out 08/25/201919 17 00 08/25/2019 20 02 00 0 14583 Mill Out 08/25/2019 20 15 00 08/25/2019 20 59 00 0 295839 Mill Out 08/25/2019 21 12 00 08/25/2019 21 56 00 0 192856 Mill Out 08/25/2019 22 09 00 08/25/2019 22 54 00 0 324097 Mill Out 08/25/2019 23 07 00 08/25/2019 23 51 00 0 102619 Mill Out 08/26/2019 00 04 00 08/26/2019 00 48 00 0 0417212 Mill Out 08/26/2019 01 01 00 08/26/2019 0146 00 0 0543774 Mill Out 08/26/2019 01 58 00 08/26/2019 02 43 00 0 145097 Mill Out 08/26/2019 02 56 00 08/26/2019 03 40 00 0 102534 Mill Out 08/26/2019 03 53 00 08/26/2019 04 38 00 0 109759 Mill Out 08/26/2019 04 51 00 08/26/2019 05 35 00 0 027576 4 Mill Out 08/26/2019 05 48 00 08/26/2019 06 33 00 0 0437089 Mill Out 08/26/2019 06 46 00 08/26/2019 07 30 00 0 0780367 Mill Out 08/26/2019 07 43 00 08/26/2019 08 27 00 0 0938071 Mill Out 08/26/2019 09 38 00 08/26/2019 10 22 00 0 0377006 Mill Out 08/26/2019 10 35 00 08/26/2019 11 19 00 0 0457533 Mill Out 08/26/2019 11 32 00 08/26/2019 12 17 00 0 0297552 4 Mill Out 08/26/2019 12 29 00 08/26/2019 13 14 00 0 0461857 MITI Out 08/26/2019 13 27 00 08/26/2019 14 11 00 0 0240555 4 Mill Out 08/26/2019 14 24 00 08/26/2019 15 08 00 0 0328183 Appendix 1 CDPHE Benzene Monitoring Data 22 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Mill Out 08/26/2019 15 21 00 08/26/2019 16 05 00 0 0341522 Mill Out 08/26/2019 16 18 00 08/26/2019 17 03 00 0 0385426 Mill Out 08/26/2019 17 16 00 08/26/2019 18 00 00 0 0253097 4 Mill Out 08/26/2019 18 13 00 08/26/2019 18 57 00 0 0325977 Mill Out 08/26/2019 19 10 00 08/26/2019 19 54 00 0 0294156 4 Mill Out 08/26/2019 20 07 00 08/26/2019 20 52 00 0 0411667 Mill Out 08/26/2019 21 05 00 08/26/2019 21 49 00 0 0381801 Mill Out 08/26/2019 22 02 00 08/26/2019 22 47 00 0 301301 Mill Out 08/26/2019 22 59 00 08/26/2019 23 44 00 0 221209 Mill Out 08/26/2019 23 57 00 08/27/2019 00 41 00 0 173914 Mill Out 08/27/2019 00 54 00 08/27/2019 01 39 00 0 234922 Mill Out 08/27/2019 01 52 00 08/27/2019 02 36 00 0 258791 Mill Out 08/27/2019 02 49 00 08/27/2019 03 34 00 0 127992 Mill Out 08/27/2019 03 47 00 08/27/2019 04 31 00 0 101277 Mill Out 08/27/2019 04 44 00 08/27/2019 05 28 00 0 110667 Mill Out 08/27/2019 05 41 00 08/27/2019 06 26 00 0 152204 Mill Out 08/27/2019 06 39 00 08/27/2019 07 23 00 0 0978972 Mill Out 08/27/2019 07 36 00 08/27/2019 08 21 00 0 131036 Flowback 10/16/2019 11 2148 10/16/2019 12 06 15 0 255589 Flowback 10/16/2019 12 19 09 10/16/2019 13 03 36 0 390249 Flowback 10/16/2019 13 16 33 10/16/2019 14 01 01 0 67887 Flowback 10/16/2019 14 13 53 10/16/2019 14 58 21 0 469075 Flowback 10/16/2019 15 11 16 10/16/2019 15 55 44 0 228015 Flowback 10/16/2019 16 08 42 10/16/2019 16 53 09 0 0929941 Flowback 10/16/2019 17 06 00 10/16/2019 17 50 27 6 9788 Flowback 10/16/2019 18 03 25 10/16/2019 18 47 53 2 08165 Flowback 10/16/2019 19 00 48 10/16/2019 19 45 16 0 801499 Flowback 10/16/2019 19 58 13 10/16/2019 20 42 40 1 23231 , Flowback 10/16/2019 20 55 32 10/16/2019 21 39 59 0 785778 Flowback 10/16/2019 21 53 00 10/16/2019 22 37 26 108975 Flowback 10/16/2019 22 50 19 10/16/2019 23 34 48 2 14597 Flowback 10/16/2019 23 47 43 10/17/2019 00 32 10 1 0338 Flowback 10/17/2019 00 45 07 10/17/2019 01 29 34 2 50347 Flowback 10/17/2019 0142 29 10/17/2019 02 26 57 170973 Flowback 10/17/2019 02 39 46 10/17/2019 03 24 13 5 90066 Flowback 10/17/2019 03 36 58 10/17/2019 04 21 25 1 62805 Flowback 10/17/2019 04 34 16 10/17/2019 05 18 43 2 22432 Flowback 10/17/2019 05 31 29 10/17/2019 06 15 56 1 24687 Flowback 10/17/2019 06 28 41 10/17/2019 07 13 09 1 91196 Flowback 10/17/2019 08 23 03 10/17/2019 09 07 31 0 923194 Flowback 10/17/2019 09 20 26 10/17/2019 10 04 54 0 377545 Flowback 10/17/2019 10 17 53 10/17/2019 11 02 22 0 396595 Flowback 10/17/2019 11 15 14 10/17/2019 11 59 42 0 307096 Flowback 10/17/2019 12 12 38 10/17/2019 12 57 04 0 436369 Flowback 10/17/2019 13 10 07 10/17/2019 13 54 34 0 673821 Flowback 10/17/2019 14 07 28 10/17/2019 14 51 54 0 361525 Flowback 10/17/2019 15 04 44 10/17/2019 15 49 11 0 42123 Appendix 1 CDPHE Benzene Monitoring Data 23 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 10/17/201916 02 07 10/17/201916 46 34 0 494958 Flowback 10/17/2019 16 59 30 10/17/2019 17 43 57 142267 Flowback 10/17/2019 17 56 59 10/17/2019 18 41 26 0 994628 Flowback 10/17/2019 18 54 17 10/17/2019 19 38 44 0 514547 Flowback 10/17/2019 19 51 35 10/17/2019 20 36 02 0 521179 Flowback 10/17/2019 20 49 00 10/17/2019 21 33 28 0 383081 Flowback 10/17/2019 2146 24' 10/17/2019 22 30 51 0 126616 Flowback 10/17/2019 22 43 43 10/17/2019 23 28 11 0 0794485 Flowback 10/17/2019 23 41 05 10/18/2019 00 25 31 0 260927 Flowback 10/18/2019 00 38 26 10/18/2019 01 22 54 0 718082 Flowback 10/18/2019 0135 51 10/18/2019 02 20 17 1 16612 Flowback 10/18/2019 02 33 12 10/18/2019 03 17 39 0 831944 Flowback 10/18/2019 03 30 30 10/18/2019 04 14 56 1 55875 Flowback 10/18/2019 04 27 49 10/18/2019 05 12 16 1 05939 Flowback 10/18/2019 05 25 11 10/18/2019 06 09 37 0 615737 Flowback 10/18/2019 06 22 23 10/18/2019 07 06 51 1 06567 Flowback 10/18/2019 10 26 42 10/18/2019 11 11 10 0 0464517 Flowback 10/18/2019 11 24 10 10/18/2019 12 08 37 0 0270161 4 Flowback 10/18/2019 12 21 32 10/18/2019 13 0601 0 0131993 4 Flowback 10/18/2019 13 19 06 10/18/2019 14 03 33 0 0266216 4 Flowback 10/18/2019 14 16 38 10/18/2019 15 01 05 0 032048 Flowback 10/18/2019 15 14 02 10/18/2019 15 58 30 0 0704308 Flowback 10/18/2019 16 11 22 10/18/2019 16 55 48 0 0173088 4 Flowback 10/18/2019 17 08 45 10/18/2019 17 53 12 0 0228669 4 Flowback 10/18/2019 18 06 20 10/18/2019 18 50 47 0 0449762 Flowback 10/18/2019 19 03 40 10/18/2019 19 48 07 1 18142 Flowback 10/18/2019 20 01 09 10/18/2019 20 45 37 0 00746499 4 Flowback 10/18/2019 20 58 41 10/18/2019 21 43 07 0 0165057 4 Flowback 10/18/2019 21 56 06 10/18/2019 22 40 31 0 050771 Flowback 10/18/2019 22 53 38 10/18/2019 23 38 07 0 012249 4 Flowback 10/18/2019 23 5104 10/19/2019 00 35 32 0 0865624 Flowback 10/19/2019 00 48 31 10/19/2019 01 32 58 0 49043 Flowback 10/19/2019 0145 56 10/19/2019 02 30 22 0 724835 Flowback 10/19/2019 02 43 20 10/19/2019 03 27 45 3 38818 Flowback 10/19/2019 03 40 39 10/19/2019 04 25 07 0 513182 Flowback 10/19/2019 04 37 54 10/19/2019 05 22 22 0 724224 Flowback 10/19/2019 05 35 07 10/19/2019 06 19 34 1 11178 Flowback 10/19/2019 06 32 19 10/19/2019 07 16 47 0 557737 Flowback 10/19/2019 07 29 31 10/19/2019 08 13 58 0 549155 Flowback 10/19/2019 08 26 46 10/19/2019 09 11 15 0 337442 Flowback 10/19/2019 10 21 41 10/19/2019 11 06 09 0 0645631 Flowback 10/19/2019 11 19 06 10/19/2019 12 03 33 0 0105956 4 Flowback 10/19/2019 12 16 30 10/19/2019 13 00 57 0 0241164 4 Flowback 10/19/2019 13 13 52 10/19/2019 13 58 20 -0 0138758 4 Flowback 10/19/2019 14 11 19 10/19/2019 14 55 47 0 0545701 Flowback 10/19/2019 15 08 44 10/19/2019 15 53 11 0 177685 Flowback 10/19/2019 16 06 09 10/19/2019 16 50 36 0 415866 Appendix 1 CDPHE Benzene Monitoring Data 24 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 10/19/2019 17 03 32 10/19/2019 17 47 59 0 792789 Flowback 10/19/2019 18 00 56 10/19/2019 18 45 23 0 119061 Flowback 10/19/2019 18 58 32 10/19/2019 19 43 00 0 275292 Flowback 10/19/2019 19 56 04 10/19/2019 20 40 31 0 866587 Flowback 10/19/2019 20 53 28 10/19/2019 21 37 55 0 59896 Flowback 10/19/2019 21 50 56 10/19/2019 22 35 23 0 436783 Flowback 10/19/2019 22 48 24 10/19/2019 23 32 51 1 32191 Flowback 10/19/2019 23 45 51 10/20/2019 00 30 18 0 643275 Flowback 10/20/2019 00 43 15 10/20/2019 01 27 42 0 238649 Flowback 10/20/2019 0140 40 10/20/2019 02 25 07 0 000275548 4 Flowback 10/20/2019 02 38 07 10/20/2019 03 22 35 -0 00607998 4 Flowback 10/20/2019 03 35 31 10/20/2019 04 19 57 -0 0105907 4 Flowback 10/20/2019 04 32 49 10/20/2019 05 17 17 -0 0128257 4 Flowback 10/20/2019 05 30 11 10/20/2019 06 14 38 -0 0160504 4 Flowback 10/20/2019 06 27 31 10/20/2019 07 11 58 0 000577208 4 Flowback 10/20/2019 07 24 53 10/20/2019 08 09 21 -0 00652227 4 Flowback 10/20/2019 08 22 16 10/20/2019 09 06 44 -0 00195749 4 Flowback 10/20/2019 10 17 14 10/20/2019 11 0142 -0 00591665 4 Flowback 10/20/2019 11 14 40 10/20/2019 11 59 07 -0 00245935 4 Flowback, 10/20/2019 12 12 04 10/20/2019 12 56 32 -0 0102442 4 Flowback 10/20/2019 13 09 36 10/20/2019 13 54 03 0 00393217 4 Flowback 10/20/2019 14 07 12 10/20/2019 14 51 38 -0 0567556 4 Flowback 10/20/2019 15 04 41 10/20/2019 15 49 08 0 00827889 4 Flowback 10/20/2019 16 02 10 10/20/2019 16 46 38 0 00829621 4 Flowback 10/20/2019 16 59 41 10/20/2019 17 44 08 0 00541154 4 Flowback 10/20/2019 17 57 07 10/20/2019 18 41 34 0 0275843 4 Flowback 10/20/2019 18 54 34 10/20/2019 19 39 03 -0 00058486 4 Flowback 10/20/2019 19 51 54 10/20/2019 20 36 20 -0 00305238 4 Flowback 10/20/2019 20 49 15 10/20/2019 21 33 42 0 0311775 Flowback 10/20/2019 2146 40 10/20/2019 22 31 09 0 00884395 4 Flowback 10/20/2019 22 43 58 10/20/2019 23 28 26 0 0319904 Flowback 10/20/2019 23 41 23 10/21/2019 00 25 51 0 00273371 4 Flowback 10/21/2019 00 38 40 10/21/2019 01 23 08 0 0226541 4 Flowback 10/21/2019 01 35 57 10/21/2019 02 20 23 0 0260614 4 Flowback 10/21/2019 02 33 08 10/21/2019 03 17 36 -0 00359248 4 Flowback 10/21/2019 03 30 21 10/21/2019 04 14 47 0 0168 4 Flowback 10/21/2019 04 27 32 10/21/2019 05 12 01 -0 00339875 4 Flowback 10/21/2019 05 24 44 10/21/2019 06 09 12 0 00305959 4 Flowback 10/21/2019 06 21 53 10/21/2019 07 06 20 0 0197267 4 Flowback 10/21/2019 07 19 02 10/21/2019 08 03 29 0 0109816 4 Flowback 10/21/2019 08 16 17 10/21/2019 09 00 44 0 011101 4 Flowback 10/21/2019 10 11 02 10/21/2019 10 55 30 0 00811423 4 Flowback 10/21/2019 1108 36 10/21/2019 11 53 03 -0 00433494 4 Flowback 10/21/2019 12 06 07 10/21/2019 12 50 34 -0 01056 4 Flowback 10/21/2019 13 03 36 10/21/2019 13 48 03 0 00908328 4 Flowback 10/21/2019 14 00 58 10/21/2019 14 45 24 0 00765018 4 Flowback 10/21/2019 14 58 31 10/21/2019 15 42 59 0 0321163 I 1 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 10/21/2019 15 5,6 03 10/21/2019 16 40 29 -0 0567556 4 Flowback 10/21/2019 16 53 33 10/21/2019 17 38 02 0 0164523 4 Flowback 10/21/2019 17 51 05 10/21/2019 18 35 32 0 0982561 Flowback 10/21/2019 18 48 38 10/21/2019 19 33 05 0 0421439 Flowback 10/21/2019 19 46 07 10/21/2019 20 30 34 0 0375547 Flowback 10/21/2019 20 43 32 10/21/2019 21 27 58 0 0615357 Flowback 10/21/2019 2140 52 10/21/2019 22 25 18 0 0308406 Flowback 10/21/2019 22 38 17 10/21/2019 23 22 44 0 129399 Flowback 10/21/2019 23 35 38 10/22/2019 00 20 05 0 0510459 Flowback 10/22/2019 00 32 56 10/22/2019 01 17 23 0 0536441 Flowback 10/22/2019 01 30 19 10/22/2019 02 14 45 0 121416 Flowback 10/22/2019 02 27 39 10/22/2019 03 12 07 0 437725 Flowback 10/22/2019 03 24 52 10/22/2019 04 09 19 0 58409 Flowback 10/22/2019 04 22 01 10/22/2019 05 06 28 0 375298 Flowback 10/22/2019 05 19 10 10/22/2019 06 03 39 0 451331 Flowback 10/22/2019 06 16 12 10/22/2019 07 00 40 0 791664 Flowback 10/22/2019 07 13 19 10/22/2019 07 57 47 1 04453 Flowback 10/22/2019 08 10 27 10/22/2019 08 54 54 0 850275 Flowback 10/22/2019 10 05 07 10/22/2019 10 49 35 0 468734 Flowback 10/22/2019 1102 37 10/22/2019 11 47 04 0 0996299 Flowback 10/22/2019 12 00 08 10/22/2019 12 44 35 0 0613401 Flowback 10/22/2019 12 57 39 10/22/2019 13 42 07 0 0309536 Flowback 10/22/2019 13 55 06 10/22/2019 14 39 33 0 0204575 4 Flowback 10/22/201914 52 27 10/22/2019 15 36 53 0 0230138 4 Flowback 10/22/2019 15 49 55 10/22/2019 16 34 22 0 00751251 4 Flowback , 10/22/2019 16 47 28 10/22/2019 17 31 54 0 33448 Flowback 10/22/2019 17 44 52 10/22/2019 18 29 19 0 0688095 Flowback 10/22/2019 18 42 18 10/22/2019 19 26 45 -0 0067864 4 Flowback 10/22/2019 19 39 42 10/22/2019 20 24 09 0 0890564 Flowback 10/22/2019 20 37 10 10/22/2019 21 21 37 1 61016 Flowback 10/22/2019 21 34 43 10/22/2019 22 19 10 0 519685 Flowback 10/22/2019 22 32 14 10/22/2019 23 16 41 0 284376 Flowback, 10/22/2019 23 29 39 10/23/2019 00 14 06 0 832446 Flowback 10/23/2019 00 27 10 10/23/2019 01 11 38 0 636956 Flowback 10/23/2019 01 24 38 10/23/2019 02 09 05 0 236041 Flowback 10/23/2019 02 22 01 10/23/2019 03 06 29 -0 0117834 4 Flowback 10/23/2019 03 19 32 10/23/2019 04 03 59 0 0156856 4 Flowback 10/23/2019 04 16 59 10/23/2019 05 01 27 0 00252818 4 Flowback 10/23/2019 05 14 21 10/23/2019 05 58 47 0 0300365 Flowback 10/23/2019 06 11 35 10/23/2019 06 56 03 0 0845962 Flowback 10/23/2019 07 08 53 10/23/2019 07 53 22 0 044738 Flowback 10/23/2019 08 06 10 10/23/2019 08 50 38 0 0283711 4 Flowback 10/23/2019 10 00 51 10/23/2019 10 45 19 -0 0567556 4 Flowback 10/23/2019 10 58 25 10/23/2019 1142 53 0 00407559 4 Flowback 10/23/2019 11 56 00 10/23/2019 12 40 27 0 0161607 4 Flowback 10/23/2019 12 53 32 10/23/2019 13 37 59 0 0228391 4 Flowback 10/23/2019 13 51 03 10/23/2019 14 35 31 0 00707885 4 25 of 42 i J Appendix 1 CDPHE Benzene Monitoring Data 26 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 10/23/2019 14 48 29 10/23/2019 15 32 56 0 0272463 4 Flowback 10/23/2019 15 46 00 10/23/2019 16 30 28 0 00887462 4 Flowback 10/23/2019 16 43 29 10/23/2019 17 27 57 0 0524935 Flowback 10/23/2019 17 40 51 10/23/2019 18 25 18 0 0468718 Flowback 10/23/2019 18 38 09 10/23/2019 19 22 35 0 01041 4 Flowback 10/23/2019 19 35 25 10/23/2019 20 19 53 0 0555134 Flowback 10/23/2019 20 32 35 10/23/2019 21 17 01 0 0119684 4 Flowback 10/23/2019 21 29 49 10/23/2019 22 14 15 -0 00142915 4 Flowback 10/23/2019 22 27 01 10/23/2019 23 11 30 0 0163456 4 Flowback 10/23/2019 23 24 16 10/24/2019 00 08 44 0 016335 4 Flowback 10/24/2019 00 21 27 10/24/2019 01 05 54 0 0441385 Flowback 10/24/2019 01 18 38 10/24/2019 02 03 06 0 0556392 Flowback 10/24/2019 02 15 40 10/24/2019 03 00 07 0 0497523 Flowback 10/24/2019 03 12 53 10/24/2019 03 57 21 0 029672 4 Flowback 10/24/2019 04 10 05 10/24/2019 04 54 33 0 0506211 Flowback 10/24/2019 05 07 14 10/24/2019 05 5141 0 12016 Flowback 10/24/2019 06 04 24 10/24/2019 06 48 50 0 21042 Flowback 10/24/2019 07 01 28 10/24/2019 07 45 54 0 170342 Flowback 10/24/2019 07 58 35 10/24/2019 08 43 01 0 13711 Flowback 10/24/2019 09 52 58 10/24/2019 10 37 25 0 0355437 Flowback 10/24/2019 10 50 24 10/24/2019 11 34 50 0 03894 Flowback 10/24/2019 1147 50 10/24/2019 12 32 17 0 0636222 Flowback 10/24/2019 12 45 14 10/24/2019 13 29 39 0 0593244 Flowback 10/24/2019 13 42 42 10/24/2019 14 27 09 0 0792946 Flowback 10/25/2019 09 19 26 10/25/2019 10 03 54 0 438334 Flowback 10/25/2019 10 16 44 10/25/2019 11 01 11 0 288307 Flowback 10/25/2019 11 14 12 10/25/2019 11 58 41 0 424935 Flowback 10/25/2019 12 11 41 10/25/2019 12 56 10 0 190654 Flowback 10/25/2019 13 09 02 10/25/2019 13 53 29 0 052804 Flowback 10/25/2019 14 06 23 10/25/2019 14 50 49 0 0382795 Flowback 10/25/2019 15 03 44 10/25/2019 15 48 11 0 0813868 Flowback 10/25/2019 16 01 05 10/25/2019 16 45 33 0 433644 Flowback 10/25/2019 16 58 25 10/25/2019 17 42 51 0 719135 Flowback 10/25/2019 17 55 50 10/25/2019 18 40 17 0 508057 Flowback 10/25/2019 18 53 14 10/25/2019 19 37 42 0 179256 Flowback 10/25/2019 19 50 32 10/25/2019 20 34 57 0 495363 Flowback 10/25/2019 20 47 56 10/25/2019 21 32 24 0 562511 Flowback 10/25/2019 2145 17 10/25/2019 22 29 44 1 85312 Flowback 10/25/2019 22 42 40 10/25/2019 23 27 07 104787 Flowback 10/25/2019 23 39 59 10/26/2019 00 24 27 0 71667 Flowback 10/26/2019 00 37 14 10/26/2019 01 2142 1 68251 Flowback 10/26/2019 01 34 27 10/26/2019 02 18 53 0 578119 Flowback 10/26/2019 02 31 35 10/26/2019 03 16 02 0 4051 Flowback 10/26/2019 03 28 42 10/26/2019 04 13 08 0 855996 Flowback 10/26/2019 04 25 41 10/26/2019 05 10 08 0 727792 Flowback 10/26/2019 05 22 43 10/26/2019 06 07 09 0 921279 Flowback 10/26/2019 06 19 38 10/26/2019 07 04 06 0 792962 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 10/26/2019 07 16 36 10/26/2019 08 01.03 0 837229 Flowback 10/28/2019 16 56 33 10/28/2019 17 41 00 0 230843 Flowback 10/28/2019 17 53 50 10/28/2019 18 38 18 0 0563158 Flowback 10/28/2019 18 51 17 10/28/2019 19 35 45 0 191516 Flowback 10/28/2019 19 48 41 10/28/2019 20 33 08 0 125323 Flowback 10/28/2019 20 46 01 10/28/2019 21 30 28 0 129271 Flowback 10/28/2019 2143 24 10/28/2019 22 27 51 0 105829 Flowback- 10/28/2019 22 40 43 10/28/2019 23 25 10 0 595962 Flowback 10/28/2019 23 38 05 10/29/2019 00 22 31 0 103244 Flowback 10/29/2019 00 35 30 10/29/2019 01 19 57 0 0925795 Flowback 10/29/2019 01 32 52 10/29/2019 02 17 20 0 136564 Flowback 10/29/2019 02 30 11 10/29/2019 03 14 38 0 32935 Flowback 10/29/2019 03 27 32 10/29/2019 04 11 58 0 0145899 4 Flowback 10/29/2019 04 24 47 10/29/2019 05 09 15 0 00175583 4 Flowback 10/29/2019 05 22 01 10/29/2019 06 06 28 0 00440295 4 Flowback 10/29/2019 06 19 10 10/29/2019 07 03 36 0 0555789 Flowback 10/29/2019 07 16 16 10/29/2019 08 00 43 0 0357759 Flowback 10/29/2019 08 13 24 10/29/2019 08 57 52 0 00730258 4 Flowback 10/29/2019 09 10 34 10/29/2019 09 55 02 0 0237696 4 Flowback 10/29/2019 10 07 41 10/29/2019 10 52 07 0 0159867 4 Flowback 10/29/2019 11 04 49 10/29/2019 1149 16 0 0318512 Flowback 10/29/2019 12 01 54 10/29/2019 12 46 21 0 00883894 4 Flowback 10/29/2019 12 59 04 10/29/2019 13 43 30 -0 00494633 4 Flowback 10/29/2019 13 56 14 10/29/2019 14 40 41 0 00327282 4 Flowback 10/29/2019 14 53 26 10/29/2019 15 37 54 0 0125646 4 Flowback 10/29/2019 16 47 35 10/29/2019 17 32 03 0 0241887 4 Flowback 10/29/2019 17 44 46 10/29/2019 18 29 12 0 00663874 4 Flowback 10/29/2019 18 41 48 10/29/2019 19 26 15 0 0179874 4 Flowback 10/29/2019 19 38 51 10/29/2019 20 23 20 0 00868588 4 Flowback 10/29/2019 20 35 56 10/29/2019 21 20 22 0 0284243 4 Flowback 10/29/2019 21 32 57 10/29/2019 22 17 25 0 0211218 4 Flowback 10/29/2019 22 30 02 10/29/2019 23 14 30 0 0137466 4 Flowback 10/29/2019 23 27 05 10/30/2019 00 11 31 0 0345308 Flowback 10/30/2019 00 24 05 10/30/2019 01 08 33 0 0309798 Flowback 10/30/2019 01 21 09 10/30/2019 02 05 39 0 0224388 4 Flowback 10/30/2019 02 18 20 10/30/2019 03 02 47 0 0298206 4 Flowback 10/30/2019 03 15 25 10/30/2019 03 59 54 0 0128963 4 Flowback 10/30/2019 04 12 27 10/30/2019 04 56 55 0 0370025 Flowback 10/30/2019 05 09 29 10/30/2019 05 53 56 0 0387317 Flowback 10/30/2019 06 06 30 '10/30/2019 06 50 58 0 413994 Flowback 10/30/2019 07 03 35 10/30/2019 07 48 02 0 190278 Flowback 10/30/2019 08 00 41 10/30/2019 08 45 08 0 110547 Flowback 10/30/2019 08 57 43 10/30/2019 09 42 11 0 0675768 Flowback 10/30/2019 09 54 51 10/30/2019 10 39 19 0 0902164 Flowback 10/30/2019 10 51 58 10/30/2019 11 36 26 0 199979 Flowback 10/30/2019 11 49 09 10/30/2019 12 33 35 0 814625 Flowback 10/30/2019 12 46 17 10/30/2019 13 30 42 0 221335 27 of 42 Appendix 1 CDPHE Benzene Monitoring Data 28 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 10/30/2019 13 43 25 10/30/2019 14 27 53 0 0483823 Flowback 10/30/2019 14 40 37 10/30/2019 15 25 03 0 0799935 Flowback 10/30/2019 16 34 59 10/30/2019 17 19 27 4 89291 Flowback 10/30/2019 17 32 14 10/30/2019 18 16 41 106162 Flowback 10/30/2019 18 29 29 10/30/2019 19 13 55 2 90487 Flowback 10/30/2019 19 26 36 10/30/2019 20 11 03 0 659456 Flowback 10/30/2019 20 23 48 10/30/2019 21 08 15 0 782875 Flowback 10/30/2019 21 20 56 10/30/2019 22 05 23 0 640761 Flowback 10/30/2019 22 18 02 10/30/2019 23 02 30 0 431139 Flowback 10/30/2019 23 15 08 10/30/2019 23 59 36 0 634696 Flowback 10/31/2019 00 12 14 10/31/2019 00 56 41 5 13121 Flowback 10/31/2019 01 09 18 10/31/2019 01 53 45 5 22416 Flowback 10/31/2019 02 06 16 10/31/2019'02 50 43 5 77798 Flowback 10/31/2019 03 03 13 10/31/2019 03 47 40 138187 Flowback 10/31/2019 04 00 13 10/31/2019 04 44 40 0 567914 Flowback 10/31/2019 04 57 10 10/31/2019 05 41 37 134219 Flowback 10/31/2019 05 54 09 10/31/2019 06 38 37 0 944212 Flowback 10/31/2019 06 51 05 10/31/2019 07 35 33 0 858303 Flowback 10/31/2019 07 48 06 10/31/2019 08 32 32 0 800834 Flowback 10/31/2019 08 45 09 10/31/2019 09 29 35 0 545851 Flowback 10/31/2019 09 42 20 10/31/2019 10 26 48 0 608143 Flowback 10/31/2019 10 39 36 10/31/2019 11 24 04 0 794514 Flowback 10/31/2019 11 36 47 10/31/2019 12 21 14 1 61904 Flowback 10/31/2019 12 34 08 10/31/2019 13 18 35 0 522022 Flowback 10/31/2019 13 31 28 10/31/2019 14 15 56 0 556001 Flowback 10/31/2019 14 28 55 10/31/2019 15 13 22 0 485515 Flowback 10/31/2019 16 23 41 10/31/2019 17 08 09 14492 Flowback 10/31/2019 17 21 04 10/31/2019 18 05 32 0 892103 Flowback 10/31/2019 18 18 27 10/31/2019 19 02 54 0 816788 Flowback 10/31/2019 19 15 47 10/31/2019 20 00 13 1 14076 Flowback 10/31/2019 20 13 07 10/31/2019 20 57 34 1 22574 Flowback 10/31/2019 21 10 27 10/31/2019 21 54 54 1 53984 Flowback 10/31/2019 22 07 46 10/31/2019 22 52 13 173542 Flowback 10/31/2019 23 05 07 10/31/2019 23 49 35 1 26015 Flowback 11/01/2019 00 02 26 11/01/2019 00 46 53 1 21521 Flowback 11/01/2019 00 59 50 11/01/2019 0144 17 0 875675 Flowback 11/01/2019 01 57 07 11/01/2019 02 41 35 0 635434 Flowback 11/01/2019 02 54 27 11/01/2019 03 38 53 0 745437 Flowback 11/01/2019 03 5147 11/01/2019 04 36 14 0 647084 Flowback 11/01/2019 04 49 04 11/01/2019 05 33 32 0 663471 Flowback 11/01/2019 05 46 22 11/01/2019 06 30 48 0 638905 Flowback 11/01/2019 06 43 45 11/01/2019 07 28 13 0 643886 Flowback 11/01/2019 07 41 01 11/01/2019 08 25 28 0 521001 Flowback 11/01/2019 08 38 20 11/01/2019 09 22 46 0 223339 Flowback 11/01/2019 09 35 40 11/01/2019 10 20 09 0 0389534 Flowback 11/01/2019 10 32 59 11/01/2019 11 17 26 0 0305372 Flowback 11/01/2019 11 30 13 11/01/2019 12 14 41 0 0250555 4 1 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 11/01/201912 27 35 11/01/201913 12 02 0 0147943 4 Flowback 11/01/2019 13 24 55 11/01/2019 14 09 22 0 0277417 4 Flowback 11/01/2019 14 22 07 11/01/2019 15 06 34 0 0851657 Flowback 11/01/2019 16 16 47 11/01/2019 17 01 14 0 128409 Flowback 11/01/2019 17 14 01 11/01/2019 17 58 29 0 154098 Flowback 11/01/2019 18 11 17 11/01/2019 18 55:43 0 117887 Flowback 11/01/2019 19 08 29 11/01/2019 19 52 56 0 170597 - Flowback 11/01/2019 20 05 43 11/01/2019 20 50 11 0 425171 Flowback 11/01/2019 21 03 06 11/01/2019 2147 33 0 564201 Flowback 11/01/2019 22 00 25 11/01/2019 22 44.52 1 04726 Flowback 11/01/2019 22 57 44 11/01/2019 23 42 11 0 300383 Flowback 11/01/2019 23 55 01 11/02/2019 00 39 29 0 606462 Flowback 11/02/2019 00 52 22 11/02/2019 01 36 50 0 498506 Flowback 11/02/2019 0149 41 11/02/2019 02 34 08 0 602871 Flowback 11/02/2019 02 47 00 11/02/2019 03 31 28 0 733989 Flowback 11/02/2019 03 44 23 11/02/2019 04 28 50 13053 Flowback 11/02/2019 04 41 43 11/02/2019 05 26 10 199748 Flowback 11/02/2019 05 39 00 11/02/2019 06 23 28 135784 Flowback 11/02/2019 06 36 22 11/02/2019 07 20 50 1 12353 Flowback 11/02/2019 07 33 43 11/02/2019 08 18 09 0 957149 Flowback 11/02/2019 08 30 52 11/02/2019 09 15 20 0 833019 Flowback 11/02/2019 09 28 05 11/02/2019 10 12 31 0 511714 Flowback 11/02/2019 10 25'20 11/02/2019 11 09 49 0 659463 Flowback 11/02/2019 11 22 36 11/02/2019 12 07 02 0 597508 Flowback 11/02/2019 12 19 53 11/02/2019 13 04 20 - 0 538246 Flowback 11/02/2019 13 17 09 11/02/2019 14 01 36 0 535446 Flowback 11/02/2019 14 14 31 11/02/2019 14 58 58 0 511237 Flowback 11/02/2019 16 09 07 11/02/2019 16 53 34 0 669253 Flowback 11/02/2019 17 06 25 11/02/2019 17 50 52 0 55696 Flowback 11/02/2019 18 03 43 11/02/2019 18 48 10 0 898176 Flowback 11/02/2019 19 01 00 11/02/2019 19 45 26 103918 Flowback 11/02/2019 19 58 12 11/02/2019 20 42 40 154346 Flowback 11/02/2019 20 55 31 11/02/2019 21 39 58 1 84553 Flowback 11/02/2019 21 52 49 11/02/2019 22 37 16 0 893613 Flowback 11/02/2019 22 50 08 11/02/2019 23 34 35 143391 Flowback 11/02/2019 23 47 27 11/03/2019 00 31 54 0 87919 Flowback 11/03/2019 00 44 44 11/03/2019 01 29 11 1 61127 Flowback 11/03/2019 0142 04 11/03/2019 02 26 31 171646 Flowback 11/03/2019 02 39 25 11/03/2019 03 23 51 1 21593 Flowback 11/03/2019 03 36 47 11/03/2019 04 21 15 1 00017 Flowback 11/03/2019 04 34 07 11/03/2019 05 18 33 1 20604 Flowback 11/03/2019 05 31 24 11/03/2019 06 15 50 145724 Flowback 11/03/2019 06 28 44 11/03/2019 07 13 12 1 56616 Flowback 11/03/2019 07 26 00 11/03/2019 08 10 27 1 05328 Flowback 11/03/2019 08 23 15 11/03/2019 09 07 42 0 753845 Flowback 11/03/2019 09 20 30 11/03/2019 10 04 58 0 439403 Flowback 11/03/2019 10 17 48 11/03/2019 11 02 14 0 566789 29 of 42 1 Appendix 1 CDPHE Benzene Monitoring Data 30 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 11/03/2019 11 15 11 11/03/2019 11 59 38 0 675964 Flowback 11/03/2019 12 12 34 11/03/2019 12 57 01 0 519101 Flowback 11/03/2019 13 09 50 11/03/2019 13 54 18 0 345116 Flowback 11/03/2019 14 07 08 11/03/2019 14 51 35 0 192812 Flowback 11/03/2019 16 01 50 11/03/2019 16 46 17 0 631739 Flowback 11/03/2019 16 59 07 11/03/2019 17 43 35 0 238322 Flowback 11/03/2019 17 56 32 11/03/2019 18 40 59 0 480996 Flowback 11/03/2019 18 53 55 11/03/2019 19 38 22 1 12743 Flowback 11/03/2019 19 51 16 11/03/2019 20 35 43 147801 Flowback 11/03/2019 20 48 33 11/03/2019 21 33 00 0 84279 Flowback 11/03/2019 2145 54 11/03/2019 22 30 21 0 407116 Flowback 11/03/2019 22 43 16 11/03/2019 23 27 43 0 326408 Flowback 11/03/2019 23 40 38 11/04/2019 00 25 07 0 30731 Flowback 11/04/2019 00 38 04 11/04/2019 01 22 30 0 2964 Flowback 11/04/2019 01 35 21 11/04/2019 02 19 48 0 829849 Flowback 11/04/2019 02 32 41 11/04/2019 03 17 08 0 112377 Flowback 11/04/2019 03 29 59 11/04/2019 04 14 26 0 0712175 Flowback 11/04/2019 04 27 15 11/04/2019 05 1142 0 0918396 Flowback 11/04/2019 05 24 33 11/04/2019 06 09 01 0 0777231 Flowback 11/04/2019 06 21 52 11/04/2019 07 06 20 0125651 Flowback 11/04/2019 07 19 05 11/04/2019 08 03 33 0 143871 Flowback 11/04/2019 08 16 25 11/04/2019 09 00 52 0 0118352 4 Flowback 11/04/2019 09 13 46 11/04/2019 09 58 14 0 0374398 Flowback 11/04/2019 10 11 05 11/04/2019 10 55 33 0 00849656 4 Flowback 11/04/2019 11 08 25 11/04/2019 11 52 52 0 0422211 Flowback 11/04/2019 12 05 46 11/04/2019 12 50 12 0 0629809 Flowback 11/04/2019 13 03 05 11/04/2019 13 47 33 0 122624 Flowback 11/04/2019 14 00 38 11/04/2019 14 45 05 0 119565 Flowback 11/04/2019 15 55 25 11/04/2019 16 39 53 0 0272846 4 Flowback 11/04/2019 16 52 53 11/04/2019 17 37 21 0 287952 Flowback 11/04/2019 17 50 17 11/04/2019 18 34 44 0 240048 Flowback 11/04/2019 18 47 34 11/04/2019 19 32 00 0 25497 Flowback 11/04/2019 19 44 51 11/04/2019 20 29 19 0 227703 Flowback 11/04/2019 20 42 13 11/04/2019 21 26 41 0 212399 Flowback 11/04/2019 21 39 33 11/04/2019 22 24 02 0 462498 Flowback 11/04/2019 22 36 55 11/04/2019 23 21 21 0 732208 Flowback 11/04/2019 23 34 17 11/05/2019 00 18 44 0 99556 Flowback 11/05/2019 00 31 37 11/05/2019 01 16 04 0 550801 Flowback 11/05/2019 01 28 59 11/05/2019 02 13 26 0 451915 Flowback 11/05/2019 02 26 22 11/05/2019 03 10 49 0 369676 Flowback 11/05/2019 03 23 38 11/05/2019 04 08 06 0 332141 Flowback 11/05/2019 04 20 56 11/05/2019 05 05 23 0 357992 Flowback 11/05/2019 05 18 09 11/05/2019 06 02 37 0 336872 Flowback 11/05/2019 06 15 29 11/05/2019 06 59 56 0 453337 Flowback 11/05/2019 07 12 48 11/05/2019 07 57 15 0 502643 Flowback 11/05/2019 08 10 09 11/05/2019 08 54 36 0 45448 Flowback 11/05/2019 09 07 24 11/05/2019 09 51 51 0 618044 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 11/05/2019 10 04 43 11/05/2019 10 49:11 0 456194 Flowback 11/05/2019 11 02 02 11/05/2019 11 46:29 0 498555 Flowback 11/05/2019 11 59 22 11/05/2019 12 43 50 0 223984 Flowback 11/05/201912 56 45 11/05/2019 13 41 11 0 266483 Flowback 11/05/2019 13 53 55 11/05/2019 14 38 22 0 445389 Flowback 11/05/2019 15 48 40 11/05/2019 16 33 08 14 7227 Flowback 11/05/2019 16 46 04 11/05/2019 17 30 31 0 756858 Flowback 11/05/2019 17 43 18 11/05/2019 18 27 45 0 775869 Flowback 11/05/2019 18 40 40 11/05/2019 19 25 06 1 24691 Flowback 11/05/2019 19 38 06 11/05/2019 20 22 34 0 810641 Flowback 11/05/2019 20 35 31 11/05/2019 21 19 58 0 673674 Flowback 11/05/2019 21 32 47 11/05/2019 22 17 14 0 807917 Flowback 11/05/2019 22 30 10 11/05/2019 23 14 37 0 676206 Flowback 11/05/2019 23 27 30 11/06/2019 00 11 57 0 763886 Flowback 11/06/2019 00 24 49 11/06/2019 01 09 16 106447 Flowback 11/06/2019 01 22 05 11/06/2019 02 06 31 147805 Flowback 11/06/2019 02 19 23 11/06/2019 03 03 51 1 20425 Flowback 11/06/2019 03 16 40 11/06/2019 04 01 08 1 10791 Flowback 11/06/2019 04 14 01 11/06/2019 04 58 27 0 680395 Flowback 11/06/2019 05 11 22 11/06/2019 05 55 49 0 557294 Flowback 11/06/2019 06 08 44 11/06/2019 06 53 12 0 821603 Flowback 11/06/2019 07 06 07 11/06/2019 07 50 34 0 994348 Flowback 11/06/2019 08 03 24 11/06/2019 08 47 52 0 659412 Flowback 11/06/2019 09 00 42 11/06/2019 09 45 09 0 326899 Flowback 11/06/2019 09 58 07 11/06/2019 10 42 34 0 00891164 4 Flowback 11/06/2019 13 20 25 11/06/2019 14 04 51 -0 00304755 4 Flowback 11/06/2019 14 17 40 11/06/2019 15 02 09 0 0273549 4 Flowback 11/06/2019 15 14 47 11/06/2019 15 59 15 0 0621797 Flowback 11/06/2019 16 11 56 11/06/2019 16 56 23 0 019845 4 Flowback 11/06/2019 17 08 56 11/06/2019 17 53 24 0 015348 4 Flowback 11/06/2019 18 06 01 11/06/2019 18 50 29 0 00550823 4 Flowback 11/06/2019 19 03 04 11/06/2019 19 47 31 -0 000674036 4 Flowback 11/06/2019 20 00 00 11/06/2019 20 44 28 0 0184252 4 Flowback 11/06/2019 20 56 55 11/06/2019 2141 22 0 0102724 4 Flowback 11/06/2019 21 53 52 11/06/2019 22 38 19 0 0255845 4 Flowback 11/06/2019 22 50 42 11/06/2019 23 35 08 0 0545661 Flowback 11/06/2019 23 47 38 11/07/2019 00 32 06 0 31484 Flowback 11/07/2019 00 44 35 11/07/2019 01 29 03 0 0814095 Flowback 11/07/2019 0141 30 11/07/2019 02 25 58 0 0704465 Flowback 11/07/2019 02 38 28 11/07/2019 03 22 55 0 0733848 Flowback 11/07/2019 03 35 26 11/07/2019 04 19 53 0 012843 4 Flowback 11/07/2019 04 32 23 11/07/2019 05 16 51 0 0133421 4 Flowback 11/07/2019 05 29 19 11/07/2019 06 13 46 1 03252 Flowback 11/07/2019 06 26 16 11/07/2019 07 10 42 1 05342 Flowback 11/07/2019 07 23 11 11/07/2019 08 07 38 0 0876217 Flowback 11/07/2019 08 20 10 11/07/2019 09 04 38 0 0612907 Flowback 11/07/2019 09 17 09 11/07/2019 10 01 36 0 0779363 31 of 42 Appendix 1 CDPHE Benzene Monitoring Data 32 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 11/07/2019 10 14 13 11/07/2019 10 58 40 0 0819445 Flowback 11/07/2019 11 11 19 11/07/2019 11 55 45 0 147848 Flowback 11/07/2019 13 05 47 11/07/2019 13 50 15 0 158099 Flowback 11/07/2019 14 03 13 11/07/2019 14 47 41 0 18216 Flowback 11/07/2019 15 00 30 11/07/2019 15 44 56 0 261004 Flowback 11/07/2019 15 57 57 11/07/2019 16 42 24 0 359762 Flowback 11/07/201916 55 27 11/07/201917 39 54 0 668444 Flowback 11/07/2019 17 52 51 11/07/2019 18 37 18 0 488328 Flowback 11/07/2019 18 50 12 11/07/2019 19 34 40 0 663919 Flowback 11/07/2019 19 47 32 11/07/2019 20 31 58 0 338111 Flowback 11/07/2019 20 44 45 11/07/2019 21 29 12 10813 Flowback 11/07/2019 2141 53 11/07/2019 22 26 19 0 710716 Flowback 11/07/2019 22 39 00 11/07/2019 23 23 27 0 815556 Flowback 11/07/2019 23 36 06 11/08/2019 00 20 33 0 567106 Flowback 11/08/2019 00 33 06 11/08/2019 01 17 33 1 31429 Flowback 11/08/2019 01 30 10 11/08/2019 02 14 36 0 490267 Flowback 11/08/2019 02 27 06 11/08/2019 03 11 34 0 322394 Flowback 11/08/2019 03 24 00 11/08/2019 04 08 26 0 526872 Flowback 11/08/2019 04 20 57 11/08/2019 05 05 24 0 432149 Flowback 11/08/2019 05 17 54 11/08/2019 06 02 21 0 990136 Flowback 11/08/2019 06 14 50 11/08/2019 06 59 18 0 965752 Flowback 11/08/2019 07 1145 11/08/2019 07 56 12 0 933707 Flowback 11/08/2019 08 08 44 11/08/2019 08 53 11 0 673128 Flowback 11/08/2019 09 05 43 11/08/2019 09 50 10 -0 372236 Flowback 11/08/2019 10 02 49 11/08/2019 10 47 16 0 383492 Flowback 11/08/2019 1100 07 11/08/2019 11 44 34 0 347339 Flowback 11/08/2019 12 54 43 11/08/2019 13 39 11 0 401541 Flowback 11/08/2019 13 51 57 11/08/2019 14 36 24 0 258461 Flowback 11/08/2019 14 49 13 11/08/2019 15 33 40 0 28086 Flowback 11/08/2019 15 46 34 11/08/2019 16 31 00 0 4602 Flowback 11/08/2019 16 43 55 11/08/2019 17 28 23 0 389528 Flowback 11/08/2019 17 41 14 11/08/2019 18 25 40 0 605058 Flowback 11/08/2019 18 38 38 11/08/2019 19 23 06 136394 Flowback 11/08/2019 19 35 58 11/08/2019 20 20 26 1 17408 Flowback 11/08/2019 20 33 22 11/08/2019 21 17 50 136733 Flowback 11/08/2019 21 30 43 11/08/2019 22 15 10 131504 Flowback 11/08/2019 22 28 02 11/08/2019 23 12 29 0 899457 Flowback 11/08/2019 23 25 20 11/09/2019 00 09 47 0 857191 Flowback 11/09/2019 00 22 28 11/09/2019 01 06 56 1 09743 Flowback 11/09/2019 01 19 44 11/09/2019 02 04 08 1 28042 Flowback 11/09/2019 02 16 50 11/09/2019 03 01 18 1 82687 Flowback 11/09/2019 03 14 04 _11/09/2019 03 58 31 1 76249 Flowback 11/09/2019 04 11 08 11/09/2019 04 55 35 3 03722 Flowback 11/09/2019 05 08 15 11/09/2019 05 52 43 1 09007 Flowback 11/09/2019 06 05 13 11/09/2019 06 49 40 0 964108 Flowback 11/09/2019 07 02 09 11/09/2019 07 46 36 1 56641 Flowback 11/09/2019 07 59 10 11/09/2019 08 43 38 1 9541 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 11/09/2019 08 56 21 11/09/2019 09 40 49 0 580083 Flowback 11/09/2019 09 53 33 11/09/2019 10 38 00 0 562817 Flowback 11/09/2019 10 50 50 11/09/2019 11 35 17 0 538903 Flowback 11/09/2019 12 45 40 11/09/2019 13 30 07 0 368919 Flowback 11/09/2019 13 42 51 11/09/2019 14 27 17 0 317971 Flowback 11/09/2019 14 40 09 11/09/2019 15 24 36 0 490155 Flowback 11/09/201915 37 31 11/09/201916 2157 0 0621032 Flowback 11/09/2019 16 34 50 11/09/2019 17 19 16 3 17067 Flowback 11/09/2019 17 32 06 11/09/2019 18 16 34 145344 Flowback 11/09/2019 18 29 30 11/09/2019 19 13 58 1 24465 Flowback 11/09/2019 19 26 54 11/09/2019 20 11 20 0 627502 Flowback 11/09/2019 20 24 13 11/09/2019 21 08 41 0 643137 Flowback 11/09/2019 21 2140 11/09/2019 22 06 07 1 22401 Flowback 11/09/2019 22 19 02 11/09/2019 23 03 28 0 489875 Flowback 11/09/2019 23 16 18 11/10/2019 00 00:45 0 81072 Flowback 11/10/2019 00 13 39 11/10/2019 00 58:06 0 4554 Flowback 11/10/2019 01 10 54 11/10/2019 01 55:22 0 0751083 Flowback 11/10/2019 02 08 10 11/10/2019 02 52:37 0 0916634 Flowback 11/10/2019 03 05 19 11/10/2019 03 49 46 0 197901 Flowback 11/10/2019 04 02 25 11/10/2019 04 46 53 0 365791 Flowback 11/10/2019 04 59 28 11/10/2019 05 43 54 0 530981 Flowback 11/10/2019 05 56 36 11/10/2019 06 41 04 0 42088 Flowback 11/10/2019 06 53 35 11/10/2019 07 38 01 0 546621 Flowback 11/10/2019 07 50 41 11/10/2019 08 35 10 0 503597 Flowback 11/10/2019 08 47 57 11/10/2019 09 32 25 0 352704 Flowback 11/10/2019 09 45 17 11/10/2019 10 29 43 0 185329 Flowback 11/10/2019 10 42 32 11/10/2019 11 27 00 0 0955558 Flowback 11/10/2019 12 37 05 11/10/2019 13 21 33 0 125277 Flowback 11/10/2019 13 34 14 11/10/201914 18 41 0 0559313 Flowback 11/10/2019 14 31 25 11/10/2019 15 15 51 0 0902074 Flowback 11/10/2019 15 28 44 11/10/2019 16 13 11 0 190606 Flowback 11/11/2019 11 20 17 11/11/2019 12 04 44 0 0616846 Flowback 11/11/2019 12 17 10 11/11/2019 13 01 37 0 166211 Flowback 11/11/2019 13 14 02 11/11/2019 13 58 30 0 0623249 Flowback 11/11/2019 14 11 01 11/11/2019 14 55 29 0 104414 Flowback 11/11/2019 15 08 03 11/11/2019 15 52 30 0 195272 Flowback 11/11/2019 16 05 07 11/11/2019 16 49 34 0 113415 Flowback 11/11/2019 17 02 00 11/11/2019 17 46 27 0 15873 Flowback 11/11/2019 17 58 48 11/11/2019 18 43 15 1 82815 Flowback 11/11/2019 18 55 34 11/11/2019 19 40 01 0 189687 Flowback 11/11/2019 19 52 21 11/11/2019 20 36 48 0 0976489 Flowback 11/11/2019 20 49 07 11/11/2019 21 33 35 0 264877 Flowback 11/11/2019 2149 05 11/11/2019 22 33 32 0 270553 Flowback 11/11/2019 22 45 50 11/11/2019 23 30 17 0 41228 Flowback 11/11/2019 23 42 30 11/12/2019 00 26 58 0 238959 Flowback 11/12/2019 00 39 21 11/12/2019 01 23 49 0 237151 Flowback 11/12/2019 01 36 02 11/12/2019 02 20 29 0 343652 i 33 of 42 Appendix 1 CDPHE Benzene Monitoring Data 34 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 11/12/2019 02 32 44 11/12/2019 03 17 10 0 574053 Flowback 11/12/2019 03 29 22 11/12/2019 04 13 49 0 589697 Flowback 11/12/2019 04 26 05 11/12/2019 05 10 33 0 765591 Flowback 11/12/2019 05 22 43 11/12/2019 06 07 10 0 794089 Flowback 11/12/2019 06 19 18 11/12/2019 07 03 45 0 804933 Flowback 11/12/2019 08 12 36 11/12/2019 08 57 04 101892 Flowback 11/12/2019 09 09 18 11/12/2019 09 53 45 0 604486 Flowback 11/12/2019 10 06 05 11/12/2019 10 50 32 0 394787 Flowback 11/12/2019 1103 00 11/12/2019 1147 27 0 36263 Flowback 11/12/2019 12 00 09 11/12/2019 12 44 37 0 378799 Flowback 11/12/2019 14 00 41 11/12/2019 14 45 07 0 284814 Flowback 11/12/2019,14 57 56 11/12/2019 15 42 25 0 246158 Flowback 11/12/2019 15 55 19 11/12/2019 16 39 48 0 508479 Flowback 11/12/2019 16 52 40 11/12/2019 17 37 06 146782 Flowback 11/12/2019 17 49 57 11/12/2019 18 34 25 14043 Flowback 11/12/2019 18 47 21 11/12/2019 19 3148 1 99042 Flowback 12/04/2019 12 46 50 12/04/2019 13 31 17 1 65171 Flowback 12/04/2019 13 44 12 12/04/2019 14 28 41 2 1137 Flowback 12/04/2019 14 41 35 12/04/2019 15 26 02 2 10324 Flowback 12/04/2019 15 38 59 12/04/2019 16 23 27 1 95843 Flowback 12/04/2019 16 36 22 12/04/2019 17 20 50 1 52627 Flowback 12/04/2019 17 33 42 12/04/2019 18 18 09 1 9026 Flowback 12/04/2019 18 30 58 12/04/2019 19 15 25 1 96542 Flowback 12/04/2019 19 28 21 12/04/2019 20 12 48 1 94893 Flowback 12/04/2019 20 25 46 12/04/2019 21 10 13 2 77639 Flowback 12/04/2019 21 23 01 12/04/2019 22 07 29 2 682 Flowback 12/04/2019 22 20 20 12/04/2019 23 04 46 2 26 Flowback 12/04/2019 23 17 38 12/05/2019 00 02 06 2 68173 Flowback 12/05/2019 00 14 55 12/05/2019 00 59 21 2 93412 Flowback 12/05/2019 01 12 18 12/05/2019 01 56 45 2 03656 Flowback 12/05/2019 02 09 31 12/05/2019 02 53 58 2 18606 Flowback 12/05/2019 03 06 50 12/05/2019 03 51 17 1 10057 Flowback 12/05/2019 04 04 07 12/05/2019 04 48 34 0 940527 Flowback 12/05/2019 05 01 25 12/05/2019 05 45 53 0 480325 Flowback 12/05/2019 05 58 40 12/05/2019 06 43 06 0 260071 Flowback 12/05/2019 06 55 54 12/05/2019 07 40 20 0 193886 Flowback 12/05/2019 07 53 10 12/05/2019 08 37 36 0 345469 Flowback 12/05/2019 08 50 25 12/05/2019 09 34 52 0 20214 Flowback 12/05/2019 09 47 41 12/05/2019 10 32 07 0 286877 Flowback 12/05/2019 10 44 56 12/05/2019 11 29 25 0 462295 Flowback 12/05/2019 12 39 31 12/05/2019 13 23 58 0 127523 Flowback 12/05/2019 13 36 45 12/05/2019 14 21 13 0 110325 Flowback 12/05/2019 14 34 00 12/05/2019 15 18 27 1 80512 Flowback 12/05/2019 15 31 16 12/05/2019 16 15 44 0 355668 Flowback 12/05/2019 16 28 30 12/05/2019 17 12 57 0 284948 Flowback 12/05/2019 17 25 47 12/05/2019 18 10 14 0 489392 Flowback 12/05/2019 18 23 02 12/05/2019 19 07 31 0 383338 1 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 I Flowback 12/05/201919 20 18 12/05/2019 20 04 44 0 472308 Flowback 12/05/2019 20 17 33 12/05/2019 21 01 59 0 372106 Flowback 12/05/2019 21 14 49 12/05/2019 21 59 16 0 384241 Flowback 12/05/2019 22 12 02 12/05/2019 22 56 29 0 29188 Flowback 12/05/2019 23 09 19 12/05/2019 23 53 47 0 336188 Flowback 12/06/2019 00 06 39 12/06/2019 00 51 07 0 591299 Flowback 12/06/2019 01 03 55 12/06/2019 01 48 22 0 551051 Flowback 12/06/2019 02 01 17 12/06/2019 02 45 47 0 633157 Flowback 12/06/2019 02 58 38 12/06/2019 03 43 05 136275 Flowback 12/06/2019 03 55 52 12/06/2019 04 40 18 1 15158 Flowback 12/06/2019 04 53 06 12/06/2019 05 37 33 102432 ' Flowback 12/06/2019 05 50 20 12/06/2019 06 34 47 0 717918 Flowback 12/06/2019 06 47 33 12/06/2019 07 32 00 0 759002 Flowback 12/06/2019 07 44 52 12/06/2019 08 29 19 0 668941 Flowback 12/06/2019 08 42 08 12/06/2019 09 26 35 0 682857 Flowback 12/06/2019 09 39 29 12/06/2019 10 23 56 0 829469 Flowback 12/06/2019 10 36 44 12/06/2019 11 21 13 0 802689 Flowback 12/06/2019 12 31 17 12/06/2019 13 15 45 0 57855 Flowback 12/06/2019 13 28 34 12/06/2019 14 13 01 0 686969 Flowback 12/06/2019 14 25 46 12/06/2019 15 10 14 0 937232 Flowback 12/06/2019 15 23 01 12/06/2019 16 07 29 0 568128 Flowback 12/06/2019 16 20 17 12/06/2019 17 04 44 1 30234 Flowback 12/06/2019 17 17 32 12/06/2019 18 01 59 1 27315 Flowback 12/06/2019 18 14 50 12/06/2019 18 59:18 2 32038 Flowback 12/06/2019 19 12 08 12/06/2019 19 56:35 147166 Flowback 12/06/2019 20 09 24 12/06/2019 20 53.51 1 90296 Flowback 12/06/2019 21 06 42 12/06/2019 21 51 09 2 22105 Flowback 12/06/2019 22 04 04 12/06/2019 22 48 31 4 51719 Flowback 12/06/2019 23 01 26 12/06/2019 23 45.53 3 65946 Flowback 12/06/2019 23 58 42 12/07/2019 00 43 09 2 24753 Flowback 12/07/2019 00 55 57 12/07/2019 0140 24 2 45339 Flowback 12/07/2019 01 53 12 12/07/2019 02 37 41 2 58722 Flowback 12/07/2019 02 50 32 12/07/2019 03 35 00 2 19974 Flowback 12/07/2019 03 47 51 12/07/2019 04 32 17 1 57445 Flowback 12/07/2019 04 45 05 12/07/2019 05 29 33 159651 Flowback 12/07/2019 05 42 23 12/07/2019 06 26 51 1 12646 Flowback 12/07/2019 06 39 46 12/07/2019 07 24 14 0 974142 Flowback 12/07/2019 07 37 02 12/07/2019 08 21 29 0 91298 Flowback 12/07/2019 08 34 17 12/07/2019 09 18 45 0 883703 Flowback 12/07/2019 09 31 33 12/07/2019 10 16 00 1 13158 Flowback 12/07/2019 10 28 48 12/07/2019 11 13 16 0 820486 Flowback 12/07/2019 12 23 18 12/07/2019 13 07 45 0 848916 Flowback 12/07/2019 13 20 42 12/07/2019 14 05 09 0 66781 Flowback 12/07/2019 14 18 04 12/07/2019 15 02 32 0 606529 Flowback 12/07/2019 15 15 32 12/07/2019 15 59 59 0 545695 Flowback 12/07/2019 16 12 57 12/07/2019 16 57 24 0 845572 Flowback 12/07/2019 17 10 16 12/07/2019 17 54 43 1 12954 l 35 of 42 Appendix 1 CDPHE Benzene Monitoring Data 36 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 12/07/2019 18 07 35 12/07/2019 18 52 02 2 17086 Flowback 12/07/2019 19 04 53 12/07/2019 19 49 21 0 396512 Flowback 12/07/2019 20 02 13 12/07/2019 20 46 40 0 236365 Flowback 12/07/2019 20 59 30 12/07/2019 21 43 56 0 501328 Flowback 12/07/2019 21 56 52 12/07/2019 22 41 02 0 623484 Flowback 12/07/2019 22 53 55 12/07/2019 23 38 39 1 16703 Flowback 12/07/2019 23 51 29 12/08/2019 00 35 56 129082 Flowback 12/08/2019 00 48 51 12/08/2019 01 33 19 0 921943 Flowback 12/08/2019 0146 11 12/08/2019 02_30 39 1 17959 Flowback 12/08/2019 02 43 35 12/08/2019 03 28 03 1 20984 _ Flowback 12/08/2019 03 40 52 12/08/2019 04 25 20 100151 Flowback 12/08/2019 04 38 08 12/08/2019 05 22 35 0 794922 Flowback 12/08/2019 05 35 25 12/08/2019 06 19 51 0 472046 Flowback 12/08/2019 06 32 39 12/08/2019 07 17 06 0 578763 Flowback 12/08/2019 07 29 53 12/08/2019 08 14 20 0 784488 Flowback 12/08/2019 08 27 09 12/08/2019 09 11 35 0 738724 Flowback` 12/08/2019 09 24 23 12/08/201910 08 51 0 506935 Flowback 12/08/2019 10 21 38 12/08/2019 11 06 07 0 312947 Flowback 12/08/2019 12 16 12 12/08/2019 13 00 39 0 649602 Flowback 12/08/2019 13 13 34 12/08/2019 13 58 01 0 385468 Flowback 12/08/2019 14 11 03 12/08/2019 14 55 29 0 216567 Flowback 12/08/2019 15 08 28 12/08/2019 15 52 55 0 29371 Flowback 12/08/2019 16 05 53 12/08/2019 16 50 20 0 919278 Flowback 12/08/2019 17 03 20 12/08/2019 17 47 46 0 958543 Flowback 12/08/2019 18 00 37 12/08/2019 18 45 04 0 566562 Flowback 12/08/2019 18 57 58 12/08/2019 19 42 25 149128 Flowback 12/08/2019 19 55 19 12/08/2019 20 39 46 0 184624 Flowback 12/08/2019 20 52 35 12/08/2019 21 37 03 0 116987 Flowback 12/08/2019 2149 59 12/08/2019 22 34 26 0 0906608 Flowback 12/08/2019 22 47 20 12/08/2019 23 3146 0 102304 Flowback 12/08/2019 23 44 39 12/09/2019 00 29 07 0 0915383 Flowback 12/09/2019 00 42 00 12/09/2019 01 26 27 0 0931383 Flowback 12/09/2019 01 39 12 12/09/2019 02 23 40 0 102227 Flowback 12/09/2019 02 36 31 12/09/2019 03 20 57 0 109116 Flowback 12/09/2019 03 33 47 12/09/2019 04 18 16 0 105389 Flowback 12/09/2019 04 31 06 12/09/2019 05 15 33 0 0954697 Flowback 12/09/2019 05 28 25 12/09/2019 06 12 52 0 176224 Flowback 12/09/2019 06 25 42 12/09/2019 07 10 10 0 716438 Flowback 12/09/2019 07 22 59 12/09/2019 08 07 26 0 352908 Flowback 12/09/2019 08 20 13 12/09/2019 09 04 39 1 79085 Flowback 12/09/2019 09 17 25 12/09/2019 10 01 52 0 61512 Flowback 12/09/2019 10 14 37 12/09/2019 10 59 05 0 614436 Flowback 12/09/2019 12 08 54 12/09/2019 12 53 22 0 306295 Flowback 12/09/2019 13 06 09 12/09/2019 13 50 36 0 496715 - Flowback 12/09/2019 14 03 19 12/09/2019 14 47 46 0 264747 Flowback 12/09/2019 15 00 27 12/09/2019 15 44 55 0 389055 Flowback 12/09/2019 15 57 38 12/09/2019 16 42 04 0 657976 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 12/09/2019 16 54 52 12/09/2019 17 39 20 1 14452 Flowback 12/09/2019 17 52 04 12/09/2019 18 36 31 0 840729 Flowback 12/09/2019 18 49 20 12/09/2019 19 33 47 0 96762 Flowback 12/09/2019 19 46 32 12/09/2019 20 30 59 0 441324 Flowback 12/09/2019 20 43 46 12/09/2019 21 28 14 0 395687 Flowback 12/09/2019 2140 59 12/09/2019 22 25 26 0 688269 Flowback 12/09/2019 22 38 09 12/09/2019 23 22 36 0 603458 Flowback 12/09/2019 23 35 25 12/10/2019 00 19 51 0 550117 Flowback 12/10/2019 00 32 36 12/10/2019 01 17 04 0 645312 Flowback 12/10/2019 01 29 51 12/10/2019 02 14 20 0 552347 Flowback 12/10/2019 02 27 06 12/10/2019 03 11 33 0 480424 Flowback 12/10/2019 03 24 20 12/10/2019 04 08 48 0 545144 Flowback 12/10/2019 04 21 33 12/10/2019 05 06.01 0 746583 Flowback 12/10/2019 05 18 44 12/10/2019 06 03:13 0 734302 Flowback 12/10/2019 06 15 55 12/10/2019 07 00 21 0 889177 Flowback 12/10/2019 07 13 06 12/10/2019 07 57-33 1 14903 Flowback 12/10/2019 08 10 15 12/10/2019 08 54 43 0 908195 Flowback 12/10/2019 09 07 25 12/10/2019 09 51 52 0 350731 Flowback 12/10/2019 10 04 39 12/10/2019 10 49 07 0 221066 Flowback 12/10/2019 11 59 03 12/10/2019 12 43 30 0 231099 Flowback 12/10/201912 56 21 12/10/2019 13 40 48 0 254729 Flowback 12/10/201913 53 41 12/10/2019 14 38 10 0 186163 Flowback 12/10/2019 14 50 59 12/10/2019 15 35 25 0 220604 Flowback 12/10/2019 15 48 18 12/10/2019 16 32 45 0 317877 Flowback 12/10/2019 16 45 32 12/10/2019 17 29 59 0 440466 Flowback 12/10/2019 17 42 44 12/10/2019 18 27 11 0 684764 Flowback 12/10/2019 18 39 57 12/10/2019 19 24 25 0 681935 Flowback 12/10/2019 19 37 09 12/10/2019 20 21 35 0 996581 Flowback 12/10/2019 20 34 20 12/10/2019 21 18 48 1 89161 Flowback 12/10/2019 2131 34 12/10/2019 22 16 02 ' 2 19387 Flowback 12/10/2019 22 28 53 12/10/2019 23 13 19 135394 Flowback 12/10/2019 23 26 00 12/11/2019 00 10 27 1 14918 Flowback 12/11/2019 00 23 09 12/11/2019 0107 35 1 13531 Flowback 12/11/2019 01 20 26 12/11/2019 02 04 53 121149 Flowback 12/11/2019 02 17 42 12/11/2019 03 02 10 137434 Flowback 12/11/2019 03 14 54 12/11/2019 03 59 21 1 95148 Flowback 12/11/2019 04 12 09 12/11/2019 04 56 35 1 84114 Flowback 12/11/2019 05 09 19 12/11/2019 05 53 46 2 26532 Flowback 12/11/2019 06 06 28 12/11/2019 06 50 56 146588 Flowback 12/11/2019 07 03 38 12/11/2019 07 48 06 17094 Flowback 12/11/2019 08 00 49 12/11/2019 08 45 16 0 838961 Flowback 12/11/2019 08 57 55 12/11/2019 09 42 22 1 18522 Flowback 12/11/2019 09 55 05 12/11/2019 10 39 34 1 22447 Flowback 12/11/2019 1149 25 12/11/2019 12 33 53 0 435584 Flowback 12/11/2019 12 46 37 12/11/2019 13 31 02 0 560205 Flowback 12/11/2019 13 43 42 12/11/2019 14 28 10 0 489267 Flowback 12/11/2019 14 40 57 12/11/2019 15 25 26 0 651142 37 of 42 Appendix 1 CDPHE Benzene Monitoring Data 38 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 12/11/2019 15 38 13 12/11/2019 16 22 40 1 10538 Flowback 12/11/2019 16 35 27 12/11/2019 17 19 56 105494 Flowback 12/11/2019 17 32 40 12/11/2019 18 17 06 0 720616 Flowback 12/11/2019 18 29 53 12/11/2019 19 14 22 0 960459 Flowback 12/11/2019 19 27 10 12/11/2019 20 11 38 0 729434 Flowback 12/11/2019 20 24 26 12/11/2019 21 08 53 0 690711 Flowback 12/11/2019 21 2141 12/11/2019 22 06 09 0 765341 Flowback 12/11/2019 22 18 58 12/11/2019 23 03 26 170079 Flowback 12/11/2019 23 16 17 12/12/2019 00 00 45 0 634024 Flowback 12/12/2019 00 13 33 12/12/2019 00 58 01 142324 Flowback 12/12/2019 01 10 43 12/12/2019 01 55 10 1 62984 Flowback 12/12/2019 02 07 59 12/12/2019 02 52 27 1 60706 Flowback 12/12/2019 03 05 07 12/12/2019 03 49 35 14234 Flowback 12/12/2019 04 02 16 12/12/2019 04 46 44 129959 Flowback 12/12/2019 04 59 27 12/12/2019 05 43 54 140869 Flowback 12/12/2019 05 56 42 12/12/2019 06 41 10 1 8526 Flowback 12/12/2019 06 53 50 12/12/2019 07 38 18 0 995689 Flowback 12/12/2019 07 50 59 12/12/2019 08 35 26 0 914026 Flowback 12/12/2019 08 48 09 12/12/2019 09 32 36 1 36369 Flowback 12/12/2019 09 45 20 12/12/2019 10 29 48 0 772268 Flowback 12/12/2019 1139 44 12/12/2019 12 24 12 0 64672 Flowback 12/12/2019 12 36 59 12/12/2019 13 21 26 0 60257 Flowback 12/12/2019 13 34 16 12/12/2019 14 18 43 0 635846 Flowback 12/12/2019 14 3140 12/12/2019 15 16 08 0 665168 Flowback 12/12/2019 15 29 03 12/12/2019 16 13 31 100965 Flowback 12/12/2019 16 26 24 12/12/2019 17 10 53 10969 Flowback 12/12/2019 17 23 42 12/12/2019 18 08 10 15204 Flowback 12/12/2019 18 20 57 12/12/2019 19 05 24 156968 Flowback 12/12/2019 19 18 13 12/12/2019 20 02 40 1 69025 Flowback 12/12/2019 20 15 25 12/12/2019 20 59 51 143915, Flowback 12/12/2019 21 12 37 12/12/2019 21 57 06 145859 Flowback 12/12/2019 22 09 55 12/12/2019 22 54 22 0 523919 Flowback 12/12/2019 23 07 11 12/12/2019 23 51 38 0 445709 Flowback 12/13/2019 00 04 25 12/13/2019 00 48 53 0 835522 Flowback 12/13/2019 01 01 38 12/13/2019 0146 07 0 797934 Flowback 12/13/2019 01 58 49 12/13/2019 02 43 17 1 25472 Flowback 12/13/2019 02 56 04 12/13/2019 03 40 32 147914 Flowback 12/13/2019 03 53 16 12/13/2019 04 37 44 1 61443 Flowback 12/13/2019 04 50 29 12/13/2019 05 34 55 1 21709 Flowback 12/13/2019 05 47 39 12/13/2019 06 32 08 0 70539 Flowback 12/13/2019 06 44 55 12/13/2019 07 29 23 0 978107 Flowback 12/13/2019 07 42 12 12/13/2019 08 26 35 0 181155 Flowback 12/13/2019 08 39 21 12/13/2019 09 23 54 0 0923848 Flowback 12/13/2019 09 36 39 12/13/2019 10 21 06 0 0907472 Flowback 12/13/2019 12 17 47 12/13/2019 13 02 14 0 164053 Flowback 12/13/2019 13 15 09 12/13/2019 13 59 35 0 25719 Flowback 12/13/2019 14 12 38 12/13/2019 14 57 04 0 109798 Appendix 1 CDPHE Benzene Monitoring Data Downloaded from https //www colorado gov/airquality/tech_duc_repository aspx#camml_data on June 8, 2020 Flowback 12/13/201915 10 02 12/13/201915 54 30 0 152238 Flowback 12/13/2019 16 07 23 12/13/2019 16 5149 0 17704 Flowback 12/13/2019 17 04 39 12/13/2019 17 49 08 0 112939 Flowback 12/13/2019 18 01 54 12/13/2019 18 46 22 0 0829631 Flowback 12/13/2019 18 59 07 12/13/2019 19 43 36 0 107595 Flowback 12/13/2019 19 56 21 12/13/2019 20 40 47 0 241599 Flowback 12/13/2019 20 53 41 12/13/2019 21 38 09 0 231011 Flowback 12/13/2019 21 50 54 12/13/2019 22 35 20 0 906949 Flowback 12/13/2019 22 48 05 12/13/2019 23 32 31 0 489461 Flowback 12/13/2019 23 45 19 12/14/2019 00 29 47 0 448834 Flowback 12/14/2019 00 42 30 12/14/2019 01 26 57 0 635011 Flowback 12/14/2019 01 39 45 12/14/2019 02 24 13 0 613867 Flowback 12/14/2019 02 36 56 12/14/2019 03 21 24 0 320087 Flowback 12/14/2019 03 34 12 12/14/2019 04 18 36 0 304501 Flowback 12/14/2019 04 31 24 12/14/2019 05 15 53 0 324446 Flowback 12/14/2019 05 28 43 12/14/2019 06 13 10 0 284321 Flowback 12/14/2019 06 25 57 12/14/2019 07 10 24 0 208205 Flowback 12/14/2019 07 23 10 12/14/2019 08 07 38 0 112282 Flowback 12/14/2019 08 20 27 12/14/2019 09 04 55 0 148603 Flowback 12/14/2019 09 17 41 12/14/2019 10 02 09 0 119032 Flowback 12/14/201910 14 49 12/14/201910 59 16 0 240433 Flowback 12/14/201912 09 10 12/14/2019 12 53 38 0 137506 Flowback 12/14/2019 13 06 26 12/14/2019 13 50 53 0 113595 Flowback 12/14/2019 14 03 34 12/14/2019 14 48 01 0 130197 Flowback 12/14/2019 15 00 50 12/14/2019 15 45 16 0 112136 Flowback 12/14/2019 15 58 00 12/14/2019 16 42:29 0 231973 Flowback 12/14/2019 16 55 14 12/14/2019 17 39:41 0 580363 Flowback 12/14/2019 17 52 22 12/14/2019 18 36:50 0 452874 Flowback 12/14/2019 18 49 33 12/14/2019 19 33-59 0 337339 Flowback 12/14/2019 19 46 52 12/14/2019 20 31:20 0 44719 Flowback 12/14/2019 20 44 04 12/14/2019 21 28 31 0 509911 Flowback 12/14/2019 2141 12 12/14/2019 22 25 40 1 19021 Flowback 12/14/2019 22 38 27 12/14/2019 23 22 54 0 683303 Flowback 12/14/2019 23 35 37 12/15/2019 00 20 05 0 580164 Flowback 12/15/2019 00 32 52 12/15/2019 01 17 20 0 376604 Flowback 12/15/2019 01 30 07 12/15/2019 02 14 34 0 315301 Flowback 12/15/2019 02 27 21 12/15/2019 03 1147 0 232838 Flowback 12/15/2019 03 24 33 12/15/2019 04 09 01 0 101862 Flowback 12/15/2019 04 2148 12/15/2019 05 06 16 0 0981768 Flowback 12/15/2019 05 18 57 12/15/2019 06 03 24 0 127869 Flowback 12/15/2019 06 16 15 12/15/2019 07 00 42 0 164109 Flowback 12/15/2019 07 13 24 12/15/2019 07 57 51 0 163577 Flowback 12/15/2019 08 10 35 12/15/2019 08 55 04 0 26984 Flowback 12/15/2019 09 07 49 12/15/2019 09 52 16 0 21557 Flowback 12/15/2019 10 04 57 12/15/2019 10 49 24 0 151033 Flowback 12/15/2019 11 59 26 12/15/2019 12 43 53 0 126847 Flowback 12/15/2019 12 56 39 12/15/2019 13 41 07 0 179364 39 of 42 Appendix 1 CDPHE Benzene Monitoring Data 40 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 12/15/2019 13 53 54 12/15/2019 14 38 21 0 139147 Flowback 12/15/2019 14 51 05 12/15/2019 15 35 32 0 136261 Flowback 12/15/2019 15 48 17 12/15/2019 16 32 44 0 195407 Flowback 12/15/2019 16 45 32 12/15/2019 17 30 00 0 493293 Flowback 12/15/2019 17 42 45 12/15/2019 18 27 10 0 526142 Flowback 12/15/2019 18 39 58 12/15/2019 19 24 26 0 578095 Flowback 12/15/2019 19 37 12 12/15/2019 20 21 40 0 691047 Flowback 12/15/2019 20 34 28 12/15/2019 21 18 56 0 897368 Flowback 12/15/2019 2131 39 12/15/2019 22 16 07 0 498972 Flowback 12/15/2019 22 28 54 12/15/2019 23 13 22 0 395674 Flowback 12/15/2019 23 26 11 12/16/2019 00 10 37 0 311825 Flowback 12/16/2019 00 23 20 12/16/2019 0107 48 0 610532 Flowback 12/16/2019 01 20 33 12/16/2019 02 05 00 0 359658 Flowback 12/16/2019 02 17 52 12/16/2019 03 02 20 0 632217 Flowback 12/16/2019 03 15 07 12/16/2019 03 59 35 0 436412 Flowback 12/16/2019 04 12 26 12/16/2019 04 56 53 0 386313 Flowback 12/16/2019 05 09 40 12/16/2019 05 54 08 0 216534 Flowback 12/16/2019 06 06 55 12/16/2019 06 51 23 0 315912 Flowback 12/16/2019 07 04 10 12/16/2019 07 48 38 0 271534 Flowback 12/16/2019 08 01 24 12/16/2019 08 45 51 0 304903 Flowback 12/16/2019 08 58 36 12/16/2019 09 43 03 0 599604 Flowback 12/16/2019 09 55 50 12/16/2019 10 40 18 0 21498 Flowback 12/16/2019 11 50 14 12/16/2019 12 34 41 0 210389 Flowback 12/16/2019 12 47 26 12/16/2019 13 31 54 0 168478 Flowback 12/16/2019 13 44 37 12/16/2019 14 29 05 0 154458 Flowback 12/16/2019 14 41 53 12/16/2019 15 26 20 0 117855 Flowback 12/16/2019 15 39 06 12/16/2019 16 23 33 0 133592 Flowback 12/16/2019 16 36 15 12/16/2019 17 20 41 0 132788 Flowback 12/16/2019 23 16 48 12/17/2019 00 01 16 0 238642 Flowback 12/17/2019 00 13 51 12/17/2019 00 58 18 0 204317 Flowback 12/17/2019 01 10 53 12/17/2019 01 55 20 0 331259 Flowback 12/17/2019 02 07 55 12/17/2019 02 52 22 0 440544 Flowback 12/17/2019 03 04 55 12/17/2019 03 49 23 0 958118 Flowback 12/17/2019 04 01 55 12/17/2019 04 46 23 105052 Flowback 12/17/2019 04 59 00 12/17/2019 05 43 29 0 796565 Flowback 12/17/2019 05 56 01 12/17/2019 06 40 27 0 732408 Flowback 12/17/2019 06 53 00 12/17/2019 07 37 27 0 673444 Flowback 12/17/2019 07 49 56 12/17/2019 08 34 23 1 06995 Flowback 12/17/2019 08 46 55 12/17/2019 09 31 21 0 87052 Flowback 12/17/2019 09 44 01 12/17/2019 10 28 29 1 56649 Flowback 12/17/2019 10 41 10 12/17/2019 11 25 38 1 10438 Flowback 12/17/2019 11 38 19 12/17/2019 12 22 45 1 95362 Flowback 12/17/2019 12 35 30 12/17/2019 13 19 57 108574 Flowback 12/17/2019 13 32 42 12/17/2019 14 17 10 0 689274 Flowback 12/17/2019 14 30 01 12/17/2019 15 14 29 0 405891 Flowback 12/17/2019 15 27 18 12/17/2019 16 11 46 0 261882 Flowback 12/17/2019 16 24 36 12/17/2019 17 09 02 0 795763 Appendix 1 CDPHE Benzene Monitoring Data 41 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 12/17/201917 2146 12/17/2019 18 06 15 0 99049 Flowback 12/17/2019 18 19 03 12/17/2019 19 03 31 137278 Flowback 12/17/2019 19 16 15 12/17/2019 20 00 42 1 87517 Flowback 12/17/2019 20 13 32 12/17/2019 20 57 59 0 995636 Flowback 12/17/2019 21 10 45 12/17/2019 21 55 12 0 713906 Flowback 12/18/2019 11 33 25 12/18/2019 12 17 53 107527 Flowback 12/18/2019 12 30 41 12/18/2019 13 15 10 0 698962 Flowback 12/18/2019 13 28 05 12/18/2019 14 12 32 1 86197 Flowback 12/18/2019 14 25 26 12/18/2019 15 09 54 136764 Flowback 12/18/2019 15 22 53 12/18/2019 16 07 20 0 631328 Flowback 12/18/2019 16 20 14 12/18/2019 17 04 41 1 57219 Flowback 12/18/2019 17 17 28 12/18/2019 18 01 54 2 17503 Flowback 12/18/2019 18 14 45 12/18/2019 18 59 13 1 68876 Flowback 12/18/2019 19 12 00 12/18/2019 19 56 28 1 65629 Flowback 12/18/2019 20 09 16 12/18/2019 20 53 43 1 79952 Flowback 12/18/2019 21 06 28 12/18/2019 21 50 55 1 86685 Flowback 12/18/2019 22 03 40 12/18/2019 22 48 07 2 19287 Flowback 12/18/2019 23 00 58 12/18/2019 23 45 25 2 19917 Flowback 12/18/2019 23 58 09 12/19/2019 00 42 37 1 75644 Flowback 12/19/2019 00 55 22 12/19/2019 01 39 50 1 21841 Flowback 12/19/2019 01 52 36 12/19/2019 02 37 03 132795 Flowback 12/19/2019 02 49 49 12/19/2019 03 34 17 1 26824 Flowback 12/19/2019 03 47 00 12/19/2019 04 31 28 108765 Flowback 12/19/2019 04 44 14 12/19/2019 05 28 42 154269 Flowback 12/19/2019 05 41 30 12/19/2019 06 25 56 1 3798 Flowback 12/19/2019 06 38 42 12/19/2019 07 23 11 1 81881 Flowback 12/19/2019 07 35 58 12/19/2019 08 20 25 141602 Flowback 12/19/2019 09 30 23 12/19/2019 10 14 49 101242 Flowback 12/19/2019 10 27 35 12/19/2019 11 12 02 0 662363 Flowback 12/19/2019 11 24 52 12/19/2019 12 09 20 0 550302 Flowback 12/19/2019 12 22 06 12/19/2019 13 06 35 0 449354 Flowback 12/19/2019 13 19 27 12/19/2019 14 03 53 0 455716 Flowback 12/19/2019 14 16 43 12/19/2019 15 01 10 0 852134 Flowback 12/19/2019 15 13 59 12/19/2019 15 58:25 0 953233 Flowback 12/19/2019 16 11 19 12/19/2019 16 55:46 0 986244 Flowback 12/19/2019 17 08 38 12/19/2019 17 53 06 0 97274 Flowback 12/19/2019 18 05 57 12/19/2019 18 50 24 1 04429 Flowback 12/19/2019 19 03 14 12/19/2019 19 47 41 1 16259 Flowback 12/19/2019 20 00 26 12/19/2019 20 44 53 1 14594 Flowback 12/19/2019 20 57 42 12/19/2019 21 42 09 1 11389 Flowback 12/19/2019 21 54 54 12/19/2019 22 39 21 1 19071 Flowback 12/19/2019 22 52 07 12/19/2019 23 36 35 1 00436 Flowback 12/19/2019 23 49 24 12/20/2019 00 33 53 2 8087 Flowback 12/20/2019 00 46 42 12/20/2019 01 31 09 1 99368 Flowback 12/20/2019 0143 55 12/20/2019 02 28 22 192296 Flowback 12/20/2019 02 41 11 12/20/2019 03 25 38 1 54019 Flowback 12/20/2019 03 38 29 12/20/2019 04 22 57 1 53247 Appendix 1 CDPHE Benzene Monitoring Data 42 of 42 Downloaded from https //www colorado gov/airquality/tech_doc_repository aspx#camml_data on June 8, 2020 Flowback 12/20/2019 04 35 41 12/20/2019 05 20 09 1 52313 Flowback 12/20/2019 05 32 57 12/20/2019 06 17 25 1 69408 Flowback 12/20/2019 06 30 13 12/20/2019 07 14 40 177671 Flowback 12/20/2019 07 27 25 12/20/2019 08 11 53 1 83083 Hello