* A vo l ®! PRO"^ U.S. EPA Ambient Air Monitoring Protocol Gas Verification Program Annual Report CY 2020 ------- ------- EPA-454/R-21-006 July 2021 U.S. EPA Ambient Air Monitoring Protocol Gas Verification Program Annual Report CY 2020 U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Air Quality Assessment Division Research Triangle Park, NC ------- Table of Contents Acknowledgements 5 Acronyms and Abbreviations 6 1.0 Introduction 7 2.0 Implementation Summary 9 3.0 Survey and Verification Results 12 4.0 Summary and Conclusions 16 Appendix A QA Reports from Measurement Data Worksheets for 2020 19 Tables Table 1. RAVL Verification Dates 10 Table 2. Gas Standards Sent to RAVLs 13 Table 3. MQOs for the AA-PGVP 14 Table 4. AA-PGVP CO and S02 Verifications 15 Table 5. AA-PGVP NO and NOx Verifications 15 Figures Figure 1. AA-PGVP Flow Chart Figure 2 Annual Survey 11 12 ------- Acknowledge m e nts The following individuals and organizations are acknowledged for their contributions to this project: US EPA, Office of Air Quality Planning and Standards Douglas Jager US EPA, Office of Research and Development Bob Wright US EPA Region 7 Michael Davis Thien Bui James Regehr M o n i t o r i n g 0 rga n i z a t i o n s EPA acknowledges the monitoring organizations that supported the AA-PGVP Annual Survey. They include: Alaska Department of Environmental Conservation Canton City Health Department Air Pollution Control Cherokee Nation, Oklahoma Clark County, NV DAQEM FDEP Ambient Monitoring Section Forsyth County Environmental Affairs Department Idaho Department of Health & Welfare-Env. Div. Indiana Depart of Environ Management Kentucky Division for Air Quality Louisville, KY Metro Air Pollution Control District Maricopa County Air Quality Maryland Department of the Environment Michigan Dept of Environment, Air Quality Division Minnesota Pollution Control Agency, Div. of Air Quality Missouri Laboratory Services Program MT Dept of Environmental Quality, Air Quality Div. New Jersey State Department of Environmental Protection North Carolina Dept of Environmental Quality Ohio EPA, Central District Office Ohio EPA, Northeast District Office Ohio EPA, Southeast District Office Oklahoma Dept. of Environmental Quality, Air Qual. Div. Oregon Department of Environmental Quality South Carolina Department Health & Env. Control South Coast Air Quality Management District Washington State Department of Ecology Wisconsin Dept of Natural Resources ------- Acronyms and Abbreviations AA-PGVP Ambient Air Protocol Gas Verification Program AMTIC Ambient Monitoring Technology Information Center AQS Air Quality System CFR Code of Federal Regulations CO Carbon Monoxide coc Chain of Custody CONC Concentration COVID-19 Coronavirus Disease 2019 EPA Environmental Protection Agency GMIS Gas Manufacturer's Internal Standard ID Identification MFC Mass Flow Controller MQO Measurement Quality Objective NIST National Institute of Standards and Technology N02 Nitrogen Dioxide NOx Nitrogen Oxides NTRM NIST Traceable Reference Material NVLAP National Voluntary Laboratory Accreditation Program OAQPS Office of Air Quality Planning and Standards OAR Office of Air and Radiation OIG Office of the Inspector General ORD Office of Research and Development PQAO Primary Quality Assurance Organization PSI Pounds per Square Inch PSIG Pounds per Square Inch Gauge QA Quality Assurance QAPP Quality Assurance Project Plan QC Quality Control QTR Quarter RAVL Regional Analytical Verification Laboratory RD Relative Difference RPD Relative Percent Difference S02 Sulfur Dioxide SOP Standard Operating Procedure SRM Standard Reference Material URL Upper Range Limit ------- 1.0 Introduction Backgrc nd Program Goals The basic principles of the U.S. Environmental Protection Agency's (EPA) Traceability Protocol for the Assay and Certification of Gaseous Calibration Standards (EPA, 2012)1 were developed jointly by EPA, the National Bureau of Standards (now National Institute of Standards and Technology [N 1ST]), and specialty gas producers over 40 years ago. At the time, commercially prepared calibration gases were perceived as being too inaccurate and too unstable for use in calibrations and audits of continuous source emission monitors and ambient air quality monitors2. The protocol was developed to improve the quality of the gases by establishing their traceability to NIST Standard Reference Materials (SRMs) and to provide reasonably priced products. This protocol established the gas metrological procedures for measurement and certification of these calibration gases for EPA's Acid Rain Program under 40 Code of Federal Regulations (CFR) Part 75, for the Ambient Air Quality Monitoring Program under 40 CFR Part 58, and for the Source Testing Program under 40 CFR Parts 60, 61, and 68. EPA required monitoring organizations implementing these programs ("the regulated community") to use EPA Protocol Gases as their calibration gases. EPA revised the protocol to establish detailed statistical procedures for estimating the total uncertainty of these gases. EPA's Acid Rain Program developed acceptance criteria for the uncertainty estimate3. Specialty gas producers prepare and analyze EPA Protocol Gases without direct governmental oversight. In the 1980s and 1990s, EPA conducted a series of EPA-funded accuracy assessments of EPA Protocol Gases sold by producers. The intent of these audits was to: • increase the acceptance and use of EPA Protocol Gases as calibration gases; • provide a quality assurance (QA) check for the producers of these gases; and • help users identify producers who can consistently provide accurately certified gases. Either directly or through third parties, EPA procured EPA Protocol Gases from the producers, assessed the accuracy of the gases' certified concentrations through independent analyses, and inspected the 1 EPA-600/R-12/531 2 Decker, C.E. et al., 1981. "Analysis of Commercial Cylinder Gases of Nitric Oxide, Sulfur Dioxide, and Carbon Monoxide at Source Concentrations," Proceedings of theAPCA Specialty Conference on Continuous Emission Monitoring-Design, Operation, and Experience, APCA Publication No. SP-43. 3 "Continuous Emission Monitoring," Code of Federal Regulations, Title 40, Part 75 Page 7 of 24 ------- accompanying certificates of analysis for completeness and accuracy. The producers were not aware that EPA had procured the gases for these audits. The accuracy of the EPA Protocol Gases' certified concentrations was assessed using SRMs as the analytical reference standards. If the difference between the audit's measured concentration and the producer's certified concentration was more than ±2.0 percent or if the documentation was incomplete or inaccurate, EPA notified the producer to resolve and correct the problem. The results of the accuracy assessments were published in peer-reviewed journals and were posted on EPA's Technology Transfer Network website. The accuracy assessments were discontinued in 1998. In 2009, the Office of the Inspector General (OIG) published the report EPA Needs an Oversight Program for Protocol Gases4. One of the report's findings suggested that EPA "does not have reasonable assurance that the gases that are used to calibrate emissions monitors for the Acid Rain Program and continuous ambient monitors for the nation's air monitoring network are accurate". OIG recommended that the Office of Air and Radiation (OAR) implement oversight programs to assure the quality of the EPA Protocol Gases that are used to calibrate these monitors. It also recommended that EPA's Office of Research and Development (ORD) update and maintain the document Traceability Protocol for Assay and Certification of Gaseous Calibration Standards to ensure that the monitoring programs' objectives are met. In order to address the OIG findings for ambient air monitoring, the Office of Air Quality Planning and Standards (OAQPS), in cooperation with two EPA Regional Offices, developed an Ambient Air Protocol Gas Verification Program (AA-PGVP). The program established two gas metrology laboratories to verify the certified concentrations of EPA Protocol Gases used to calibrate ambient air quality monitors. The program is expected to ensure that producers selling EPA Protocol Gases participate in the AA-PGVP and provides end users with information about participating producers and verification results. The EPA Ambient Air Quality Monitoring Program's QA requirements, as described in Section 2.6.1 of 40 CFR Part 58, Appendix A, include: Gaseous pollutant concentration standards (permeation devices or cylinders of compressed gas) used to obtain test concentrations for CO, S02, NO, and N02 must be traceable to either a National Institute of Standards and Technology (NIST) Traceable Reference Material (NTRM) or a NIST- certified Gas Manufacturer's Internal Standard (GMIS), certified in accordance with one of the procedures given in reference 4 of this appendix. Vendors advertising certification with the procedures provided in reference 4 of this appendix and distributing gases as "EPA Protocol Gas" for ambient air monitoring purposes must participate in the EPA Ambient Air Protocol Gas Verification Program or not use "EPA" in any form of advertising. Monitoring organizations must provide information to the EPA on the gas producers they use on an annual basis and those POAOs purchasing standards will be obligated, at the request of the EPA, to participate in the program at least once every 5 years by sending a new unused standard to a designated verification laboratory. 4 https://www.epa.gov/office-inspector-general/report-epa-needs-oversight-program-protocol-gases-09-P-0235.pdf Page 8 of 24 ------- This program is considered a verification program because its current level of evaluation does not allow for a large enough sample of EPA Protocol Gases from any one specialty gas producer to yield a statistically rigorous assessment of the accuracy of the producer's gases. It will not provide end users with a scientifically defensible estimate of whether gases of acceptable quality can be purchased from a specific producer. Rather, the results provide information to end users that the specialty gas producer is participating in the program and with information that may be helpful when selecting a producer. Purpose lis Document The purpose of this document is to report the activities that occurred in 2020 and provide the results of the verifications performed. This document will not explain the implementation of the AA-PGVP, the quality system or the verification procedure. That information has been documented in the Implementation Plan, Quality Assurance Project Plan (QAPP) and standard operating procedures (SOPs) that can be found on the AA-PGVP Web Page on the Ambient Monitoring Technology Information Center (AMTIC)5. 2.0 Implementation Summary Since the program implementation started in 2010, when most of the initial preparation work took place, no major "new" implementation activities took place. However, EPA regional realignments and aging infrastructure reduced the capabilities of this program. Due to these constraints, the EPA Region 2 Regional Analytical Verification Laboratory (RAVL) ceased its active participation in the AA-PGVP in calendar year 2019. During 2020 the AA-PGVP began transitioning Region 2 operations to the Region 4 laboratory. However, during 2020 the AA-PGVP continued to operate with only the Region 7 RAVL. Operations with only a single RAVL resulted in the AA-PGVP unable to swap internal quality control samples and cylinders needing confirmatory assay between two independent RAVLs. During 2020 EPA began reengineering the AA-PGVP and as part of that process EPA began assisting the EPA Region 4 laboratory to serve as a replacement RAVL. The following provides a brief explanation of the 2020 implementation process. Producer Information Data Collection - In 2010 EPA sent out an Excel spreadsheet to each monitoring organization to obtain information on the gas standard producers being used by the monitoring organization and to determine their interest in participating in the program. In 2011, EPA began work with Research Triangle Institute to develop a web-based survey that one point of contact for each monitoring organization 5 www.epa.gov/amtic/ambient-air-protocol-eas-verification-program Page 9 of 24 ------- could access. The intent was to make recording and evaluation of the survey information easier for the monitoring organizations and EPA. This contracted survey work has since migrated to Battelle. Based on the information obtained from monitoring organization surveys, EPA would develop a list of the specialty gas producers being used by the monitoring organizations. From this list, EPA would attempt to perform representative sampling of the standards from protocol gas production facilities by identifying regulatory monitoring agencies that use standards from each of these producers. However, only 27 agencies participated in the survey for 2020. With only limited survey results, a systematic selection of producers could not be performed. The AA-PGVP performed assays on all cylinders submitted by regulatory monitoring agencies. Representative sampling was not attempted for CY-2020. OAQPS is in the process of developing an Air Quality System (AQS) database solution to upgrade and replace the specialty gas usage information that is currently acquired through the contractor based annual questionnaire. AA-PGVP Verification Dates - OAQPS worked with the Region 7 Regional Analytical Verification Laboratory (RAVL) to establish verification dates as indicated in Table 1. However, due to the COVID-19 pandemic the EPA Region 7 laboratory was shutdown during quarters 1 and 2 of calendar year 2020. Table 1. RAVL Verification Dates Quarter Region 7 Cylinder Receipt Analysis Is No later than Mar 20 Mar 30-April 10 2s No later than June 17 June 22 - July 3 3 No later than Sept 4 Sept 14-Sept 25 4 No later than Nov 27 Dec 7 - Dec 18 Open House December 16, 2020 Table 1. RAVL Verification Dates Note: * No assays were performed in Quarters 1 & 2 due to the COVID-19 pandemic. Table 1 RAVL Open House - During Open House the RAVL allows specialty gas producers to visit and ask questions regarding the laboratory processes and operations. During 2020 no specialty gas producers visited the Region 7 RAVL. Page 10 of 24 ------- Flow of the AA-PGVP Figure 1 provides a flow diagram of the implementation activities of the AA-PGVP. The major activities in these steps are explained below. More details of these steps are found in the AA-PGVP Implementation Plan, QAPP and SOPs. Monitoring Organizations *• Planning — • ~ Data Standards Ambic it Cylinders, COCs,; t Mfr. Certs. Regional Verification Lab Spec Gas Prod NIST possible reanalysis Technical Technical Assistance Assistance Audit Data Audit Data EPA Web Site End User Audit Data& Protocol Audit Data EPA Figure 1. AA-PGVP Flow Chart 1. EPA sends e-rnails to the monitoring organization's points of contact to complete the AA-PGVP Survey. EPA compiles information on specialty gas producers and the monitoring organizations that plan to participate. EPA tries to schedule the monitoring organization in an appropriate verification quarter based on delivery of standards from the specialty gas producer. 2. The monitoring organizations order gas standards from specialty gas producers during the normal course of business. If EPA cannot get a cylinder from the monitoring organization, and that producer is being used, EPA will invite the producer to send a cylinder directly to an RAVL. 3. The monitoring organizations send a new/unused standard, specialty gas certification and chain of custody form to the RAVLs. 4. The RAVLS analyze the cylinders and provide the validated results to OAQPS and the monitoring organizations. 5. OAQPS reviews the data and sends verification results to the specialty gas vendors. 6. At the end of the year, OAQPS compiles final results into a report, sends the report out to the specialty gas vendors and posts it on the AA-PGVP AMTIC web page. Page 11 of 24 ------- 3.0 Survey and Verification Results Monitoring Organization Survey Based upon the maximum capability of 40 gas cylinders per RAVL per year, the AA-PGVP selection goal, in the following order, is: 1) At least one gas standard from every specialty gas producer being used by the monitoring community. 2) If all specialty gas producers have been assessed at least once, then attempt to verify three standards per specialty gas producer. 3) If all specialty gas producers have been assessed three times, weigh additional verifications by producer market share in the ambient air monitoring community. In order to assess which specialty gas producers are used by the monitoring organizations, EPA annually uses a web-based survey that each monitoring organization completes. Since 2016, EPA regulations found in 40 CFR Part 58 Appendix A 2.6.1 require monitoring organizations to annually provide this information. However, as can be seen from Figure 2, participation in the annual survey has not improved since the 2016 monitoring rule revisions. AA-PGVP Annual Survey Participation Trend 300 250 200 150 100 50 0 . r 81 r se 61 X /- 57 1 t L 51 67 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Year •All AQS Agencies ^^^Agencies (S02, CO, N02) ^^"Surveyed Figure 2 Annual Survey Page 12 of 24 ------- ! " «as Standards Sent to RAVLs in Calen i .i ¦« < '•1" Qtr Cylinder ID Pollutant Lab Producer Facility Agency 3 CC93605 CO 7 Air Gas Chicago, IL Missouri Laboratory Services Program 4 FF55927 so2 7 Air Gas Chicago, IL Kentucky Div. for Air Quality 4 CC178285 NO, NOx 7 Air Gas Chicago, IL Polk County Air Quality 4 FF36562 NO, NOx 7 Air Gas Chicago, IL Kentucky Div. for Air Quality 4 BAL4148 CO, NO, NOx 7 Air Gas Los Angeles, CA South Coast Air Quality Management District 3 SD15080 NO, NOx0 7 Matheson Waverly, TN Kansas Department of Health and Environment 3 DT0011078* NO, NOx0 7 PraxAir Los Angeles, CA (Sent by Producer) 3 DT0029223* NO, NOx0 7 PraxAir Toledo, OH (Sent by Producer) 3 LL127859 NO, NOx° 7 PraxAir Toledo, OH State Hygienic Lab (Univ of Iowa) 4 LL197504 S02 7 Tier 5 Indianapolis, IN Kentucky Div. for Air Quality 4 LL197501 NO, NOx0 7 Tier 5 Indianapolis, IN Kentucky Div. for Air Quality 3 CC460552" NO, NOx 7 WestAir Anaheim, CA San Diego Air Pollution Control District Table 2. Gas Standards Sent to RAVLs Notes: * Direct submission by producer, assay results not blind to producer ** Cylinder opened prior to submission to EPA CI NOx concentration provided by Producer as "informational only"; concentration not certified by Producer. Verification Results As indicated in 40 CFR Part 75 Appendix A, EPA Protocol Gases must have a certified uncertainty (95 percent confidence interval) that must not be greater than plus or minus 2 percent (±2.0%) of the certified concentration (tag value) of the gas mixture. This acceptance criterion is for the Acid Rain Program. The AA- PGVP adopted the criteria as its data quality objective and developed a quality system to allow the RAVLs to determine whether or not an individual protocol gas standard concentration was within ±2% of the certified value. The Ambient Air Program has never identified an acceptance criterion for the protocol gases. Since the AA-PGVP has not been established to provide a statistically rigorous assessment of any specialty gas producer, the RAVLs report all valid results as analyzed, but it is suggested that any difference greater than ±4% is cause for concern. Information related to the analytical reference standards, analytical instruments and methods used, the data reduction procedures and the data assessment procedures are all found in the AA-PGVP QAPP and SOP and are not repeated in this report. Table 3 provides the measurement quality objectives (MQOs) that are included in the AA-PGVP QAPP (Table 7-1 of the QAPP). The acceptance criteria in Table 3 were met for each day of verification. In addition, conformance to these requirements can be found in the measurement data worksheets that are generated for each comparison run and are available upon request. Appendix A provides a report of the quality control (QC) checks associated with each verification run. Table 4 provides the verification results for CO and S02, and Table 5 provides the NOx results. Page 13 of 24 ------- aOs for the AA-PGVP Requirement Frequency Acceptance Criteria Protocol Gas Doc. Reference Comments Completeness All standards analyzed 95% Based on an anticipated 40 cylinders per lab per year. Quarterly Flow Calibration Quarterly -no more than 1 mo. before verification Calibration flow accuracy within +1% 2.3.7 Using flow primary standard Calibrator Dilution Check Quarterly -within 2 weeks of assay + 1% RD 2.3.5.1 Second SRM. Three or more discrete measurements Analyzer Calibration Quarterly-within 2 weeks of assay + 1% RPD (each point) Slope 0.89-1.02 2.1.7.2 5 points between 50-90% of upper range limit of analyzer + zero point Zero & Span Verifications Each day of verification SE mean < 1% and accuracy + 5% RD 2.1.7.3, 2.3.5.4 Drift accountability. 3 discrete measurements of zero and span Precision Test1 Day of Verification + 1% RD standard error of the mean 2.3.5.4 SRM at conc. >80% of analyzer URL Routine Data Check Any Standard with Value >2% Tag Value NA Sample run three times to verify value. Lab Comparability 2/year + 2 % RPD NA Sample run three average value used. Standards Certification Primary flow standard Annually-Certified by NVLAP certified lab 1.0 % NA Compared to NIST Traceable NISTSRMs Expiration date SRM pressure > 150 psig Will follow NIST recertification requirements Table 3. MQOs for the AA-PGVP 1 The precision test does not need to be accomplished if analyzer calibrated on same day as analysis. Page 14 of 24 ------- Table 4. 2020 AA-PGVP CO and S02 Verifications* Qtr Lab Producer Facility Cylinder ID Pollutant Assay Cone Producer Cone % Bias 95% Uncertainty 4 7 Air Gas Los Angeles, CA BAL4148 CO 909.5 907.7 0.19 0.27 3 7 Air Gas Chicago, IL CC93605 CO 220.4 220.1 0.14 0.26 4 7 Air Gas Chicago, IL FF55927 so2 5.000 5.042 -0.82 0.42 4 7 Tier 5 Indianapolis, IN LL197504 so2 49.42 49.5 -0.15 0.21 Table 4. AA-PGVP CO and S02 Verifications Notes: t An Estimate for the national usage for specific protocol gas producers cannot be determined due to lack of participation in annual survey Table 5. 2020 AA-PGVP NO and NOx Verifications* Qtr Lab Producer Facility Cylinder ID Pollutant Assay Cone Producer Cone % Bias 95% Uncertainty 3 7 PraxAir Toledo, OH DT0029223* NO 25.54 25.4 0.55 0.18 3 7 PraxAir Los Angeles, CA DT0011078* NO 49.69 49.7 -0.02 0.18 3 7 PraxAir Toledo, OH LL127859 NO 25.2 25.1 0.38 0.18 3 7 WestAir Anaheim, CA CC460552" NO 15 14.88 0.82 0.19 4 7 Air Gas Los Angeles, CA BAL4148 NO 44.88 45 -0.27 0.17 3 7 Matheson Waverly, TN SD15080 NO 19.55 19.96 -2.03" 0.19 4 Air Gas Chicago, IL CC178285 NO 10.024 9.886 1.4 D.5 4 I 7 | Air Gas | Chicago, IL | FF36562 NO | 9.644 | 9.439 | 2.17" | 0.52 4 7 Tier 5 Indianapolis, IN LL197501 NO 48.14 49.5 -2.75 0.16 3 7 PraxAir Toledo, OH DT0029223* NOx° 25.54 25.7 -0.62 0.21 3 7 PraxAir Los Angeles, CA DT0011078* NOx0 49.75 49.9 -0.3 0.21 3 7 PraxAir Toledo, OH LL127859 NOx0 25.19 25.4 -0.83 0.22 3 7 WestAir Anaheim, CA CC460552" NOx 15.06 14.97 0.63 0.22 4 7 Air Gas Los Angeles, CA BAL4148 NOx 45.21 45.11 0.23 0.17 3 7 Matheson Waverly, TN SD15080 NOx0 19.57 20.01 -2.22" 0.22 4 7 Air Gas Chicago, IL CC178285 NOx 10.063 9.886 1.79 0.41 4 7 Air Gas Chicago, IL FF36562 NOx 9.986 9.56 4.46 0.41 4 7 Tier 5 Indianapolis, IN LL197501 NOx0 48.25 50 -3.49 0.17 Table 5. AA-PGVP NO and NOx Verifications Notes: * Direct submission by producer, assay results not blind to producer ** Cylinder opened prior to submission to EPA t An Estimate for the national usage for specific protocol gas producers cannot be determined due to lack of participation in annual survey Li % Bias within the ±2% acid rain criteria acceptance criterion when RAVL 95% Uncertainty is considered CI NOx concentration provided by Producer as "informational only"; concentration not certified by Producer. Page 15 of 24 ------- Twelve cylinders were received by the AA-PGVP during calendar year 2020. Ten of these cylinders were received from regulatory monitoring agencies to support the AA-PGVP. Two of the cylinders were directly submitted from protocol gas producers. The assay results for all cylinders are included in Tables 4 and 5 but some are qualified with footnotes to denote that they do not fully meet the assessment requirements for the AA-PGVP. The NO cylinders directly submitted by Praxair were not blind to the producer. The NO cylinder provided by San Diego County Air Pollution Control District (SDAPCD) was opened by the agency prior to shipment to EPA. AA-PGVP requires that cylinders be unopened prior to receipt at the RAVL. While opened prior to receipt at the RAVL, the WestAir cylinder from SDAPCD is considered a valid sample based on the good agreement between EPA's independent assay and the assay results of the producer certified concentrations. All results for the CO and S02 standards were within the ±2% acid rain criteria acceptance criterion. Two of the nine protocol gas cylinder standards assayed for NOx (Cylinder IDs: FF36562 and LL197501) did not meet the ±2% acid rain criteria acceptance criterion. Cylinder ID FF36562 was also above the ±4% AA-PGVP action level criteria for NOx. Additionally, Cylinder ID FF36562 also approached the ±2% acid rain criteria acceptance criterion for NO, but based on the RAVL's 95% uncertainty value of 0.52% it was assessed in this annual report as meeting the ±2% acid rain criteria acceptance criterion for NO. Cylinder ID LL197501 exceeded the ±2% acid rain criteria acceptance criterion for NO in addition to NOx. The assay for Cylinder ID SD15080 was found to approach the ±2% acid rain criteria acceptance criterion for NOx and NO but was assessed in this annual report as meeting these criteria when the RAVL's 95% uncertainty was considered. The NOx concentration for five cylinders assayed were provided as "informational only" by the Producers and were not certified. While not certified, these NOx concentrations were assayed by the AA-PGVP to provide context to for the certified NO component in the protocol gas cylinder standard. In 2020 the AA-PGVP operated with a single RAVL. As such, the quality assurance designated for the laboratory intercomparison of the internal standards could not be performed. Protocol gas producers not meeting the ±2% acceptance criteria were offered, and accepted, an opportunity to perform their own confirmatory assay of the cylinders. The results of these producer independent assays were not provided to EPA to include in this report. 4.0 Summary and Conclusions General - The AA-PGVP is implementing a verification process that is blind to the specialty gas producers. One of goals of the ambient air monitoring rule (published March 28, 2016) was for the verifications performed by the RAVLs to be focused more on our ambient air monitoring organizations rather than as a resource to be utilized by specialty gas producers for their own quality assurance. The purpose of the program (blind verification of gas cylinders provided by monitoring organizations) cannot be accomplished if EPA relies on Page 16 of 24 ------- the specialty gas producers to submit cylinders for assessment. Of the 12 protocol gas cylinder standards submitted for analysis only two cylinders were directly submitted by gas producers. While the program is successfully implementing a blind verification process, only 12 cylinders were analyzed in 2020 or 15% of the AA-PGVP goal of 80 cylinders annually. EPA's single RAVL was only able to operate for the last half of 2020 due to the COVID-19 pandemic. Two of the 12 cylinders were sent direct from the producers and another cylinder was opened by the submitting agency before sent to EPA. These twelve- cylinder submissions resulted in only 22 verifications performed in 2020 (some cylinders are a blend of multiple gas standards). Results show that 3 of the 22 verifications (14%) failed the ±2% Acid Rain Program criteria. It is difficult to assess the extent to which this issue impacts our ambient air monitoring networks in 2020 due to the low utilization of the RAVLs by our monitoring programs and low participation rate in the annual protocol gas questionnaire. In 2020 there were 25 EPA protocol gas production facilities in operation nationally. It is uncertain how many of these facilities were used in the ambient air monitoring networks in 2020. Additionally, of the 25 protocol gas production facilities operating, only 7 were verified by our ambient air monitoring program in calendar year 2020. Survey Participation Improvement - Since its inception, the AA-PGVP has relied on an annual survey to determine which gas producers and facilities are used for generating CO, S02, and N02 test atmospheres from protocol gas cylinder standards. Participation in the annual survey was initially voluntary. To improve the participation rate and to more completely document which protocol gas producers are utilized by our ambient air monitoring organizations, in 2016 states using protocol gases were required to complete the survey every year. While it was thought at the time that this regulatory requirement would increase the participation and create a comprehensive list of the protocol gas producers used in the national network, the survey participation rate has not improved. In calendar year 2020 participation in the annual questionnaire was about 17% of the monitoring agencies that operate CO, S02, N02 ambient air analyzers. OAQPS is actively assessing EPA's AQS database as an alternative solution to gather this information. See Data Management Improvement section below for further details. RAVL Participation Improvement - Since the monitoring rule was revised in 2016, the AA-PGVP has made progress in achieving blind verifications of the protocol gas cylinders used in our ambient air monitoring networks. However, the program continues to not achieve its goal of having every Primary Quality Assurance Organization (PQAO) submit an unused cylinder at least once every five years for verification. The AA-PGVP's goal to perform 80 protocol gas verifications each year and to strategically select these protocol cylinders to represent the national ambient air monitoring networks was not achieved in calendar year 2020. Only twelve protocol gas cylinder standards were submitted by seven PQAOs in 2020 to support this national program. Region 7 assayed all the cylinders received in 2020. Four of the seven monitoring programs submitting protocol gas cylinders for the AA-PGVP were clustered in proximity to the Region 7 laboratory. A better national sampling of monitoring programs and protocol gas producers continues to be needed. Diminished assay capacity was due to only having a single RAVL in 2020 and operations being impacted by the COVID-19 pandemic. OAQPS is working to add assay capacity in 2021 and 2022 by using the Region 4 laboratory as an additional RAVL. Page 17 of 24 ------- Quality System Improvement - The Quality Assurance Project Plan (QAPP) has not been updated since the inception of the program in 2010. Since calendar year 2010, changes to the program have occurred, including regulatory changes in 2016. These documents need to be reconciled with current program practices and regulatory requirements. OAQPS began reviewing and revising the QAPP for this program in 2020 with a goal of having a draft revised QAPP by the end of 2021. In 2020, the AA-PGVP operated with a single RAVL. As such, the quality assurance designated for the laboratory intercomparison of the internal standards could not be performed. OAQPS is currently working with EPA Region 4 to begin using their laboratory as a second RAVL. The Region 4 RAVL is scheduled to become operational the end of calendar year 2021. Data Management Improvement - The AA-PGVP has relied solely on the annual survey for determining which protocol gas standard producers are used in the national ambient air monitoring networks. The annual survey was originally a voluntary program and later in 2016 it became a regulatory requirement. Neither implementation of this process has proven to be fully effective. The data management practices for conducting the annual survey and storing its results are not optimized to be readily reconciled with the data produced by the RAVLs. Additionally, data validation and data entry business rules are needed to ensure the accuracy of the data submitted for both portions of this program (protocol gas survey and RAVL analytical results). Once accomplished this will enable both datasets to be readily assessed with respect to monitoring organization, PQAO, and producer production facility. Data entry errors on the annual survey and chain of custody forms and the lack of key fields impede analysis of the information collected for this program. A revised spreadsheet based COC form with data validation will be used in calendar 2021 to help address so these issues. OAQPS is actively investigating an AQS database solution to replace some of the data management practices historically performed in the program. This includes assessing the feasibility of making modifications to the current AQS "QA-Transaction" file format for the single point quality control checks and annual performance audits. The proposed modifications being investigated would allow for documenting the protocol gas producer and facility of the protocol gas cylinder used for generating the test atmospheres for each of these checks. Utilizing this modified AQS data submission process would allow EPA to document 100% of the protocol gas production facilities used in the ambient air monitoring networks as opposed to the current process which has only been 44% effective between 2015-2020. Page 18 of 24 ------- Appendix A njorts from Measureme 11 11 'ta Worksheets for 2020 Ambient Air Protocol Gas Verification Program QA Reports from Measurement Data Worksheets for 2020 During the verification process, the Regional Air Verification Laboratories perform a number of quality control checks that are recorded on the Measurement Data Worksheets. This information is reported and saved along with the verification reports. The following sheets represent the quality control for all verifications that were implemented in 2020. Page 19 of 24 ------- QA Requirements Summary, Region 7 - 3rd Quarter of 2020 OA Requirement Result Status Primary SRM Cylinder Expiration Date 13-Apr-24 Primary SRM Gas Standard OK SRM Gas Standards Primary SRM Cylinder Pressure >150 psi 2000 Primary SRM cylinder pressure is OK SRM Dilution Check Cylinder Expiration Date 20-Sep-21 Dilution Check SRM Gas Standard OK Dilution Check SRM Cylinder Pressure >150 psi 675 Dilution check SRM cylinder pressure is OK High Flow Standard Expiration Date 8-Jan-21 Standard OK Laboratory Flow Standard Low Flow Standard Expiration Date 8-Jan-21 Standard OK Ultra Low Flow Standard Expiration Date 21-Jan-21 Standard OK Calibrator Flow Calibration within 2 weeks of assay 13-Sep-20 Calibrator flow calibration within 2 weeks of assay Calibrator (mass flow controllers) Calibrated High Flow MFC Slope Range = 0.99 - 1.C 0.9999990 High MFC OK Calibrated Low Flow MFC Slope Range = 0.99 - 1.C 0.9999907 Low MFC OK Analyzer Calibration within 2 week of assay 13-Sep-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1 % at point #1 (>80% URL 0.25% Assay may be conducted at this concentration Estimate of Uncetainty < 1 % at point #2 0.26% Assay may be conducted at this concentration Carbon Monoxide Gas Analyzer Estimate of Uncetainty < 1 % at point #3 0.27% Assay may be conducted at this concentration Estimate of Uncetainty < 1 % at point #4 0.28% Assay may be conducted at this concentration Estimate of Uncetainty < 1 % at point #5 (~50% URL 0.31 % Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 1.0012 Analyzer Slope is acceptable Dilution Check Dilution Check Date within 2 weeks of assay 14-Sep-20 Dilution check within 2 weeks of assay Dilution Check Relative % Difference < 1% I O o sP 0s Dilution Check RSD is OK Day of Assay Zero/Span Check Day of Assay Zero Check - Std. Error < 1 % Std. Error is okay. Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas Std. Error is OK Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1 % Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Page 20 of 24 ------- QA Requirements Summary, Region 7 - 3rd Quarter of 2020 QA Requirement Result Status Primary SRM Cylinder Expiration Date 8-Aug-23 Primary SRM Gas Standard OK SRM Gas Standards Primary SRM Cylinder Pressure >150 psi 550 Primary SRM cylinder pressure is OK SRM Dilution Check Cylinder Expiration Date 1-Feb-24 Dilution Check SRM Gas Standard OK Dilution Check SRM Cylinder Pressure >150 psi 800 Dilution check SRM cylinder pressure is OK High Flow Standard Expiration Date 8-Jan-21 Standard OK Laboratory Flow Standard Low Flow Standard Expiration Date 8-Jan-21 Standard OK Ultra Low Flow Expiration Date 21-Jan-21 Standard OK Calibrator Flow Calibration within 2 weeks of assay 13-Sep-20 Calibrator flow calibration within 2 weeks of assay Calibrator (mass flow controllers) Calibrated High Flow MFC Slope Range = 0.99 - 1.C 0.9999990 High MFC OK Calibrated Low Flow MFC Slope Range = 0.99 - 1.C 0.9999915 Low MFC OK Analyzer Calibration within 2 weeks of assay 15-Sep-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1% at point #1 (>80% URL 0.27% Assay may be conducted at this concentration Oxides of Nitrogen Gas Analyzer NO Portion Estimate of Uncetainty < 1% at point #2 0.28% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #3 0.29% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #4 0.31% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #5 (~50% URL 0.34% Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 1.0005 Analyzer Slope is acceptable Analyzer Calibration within 2 week of assay 15-Sep-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1% at point #1 (>80% URL 0.32% Assay may be conducted at this concentration Oxides of Nitrogen Gas Analyzer NOx Portion Estimate of Uncetainty < 1% at point #2 0.33% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #3 0.34% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #4 0.36% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #5 (~50% URL 0.39% Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 0.9967 Analyzer Slope is acceptable Dilution Check Dilution Check Date within 2 weeks of assay 14-Sep-20 Dilution check within 2 weeks of assay Dilution Check Relative % Difference < 1% -0.407% Dilution Check RSD is OK Day of Assay Zero Check - Std. Error < 1% Std. Error is okay. Zero Gas Std. Error is OK Day of Assay Zero/Span Check NO Portion Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1% Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Day of Assay Zero Check - Std. Error < 1% Std. Error is okay. Zero Gas Std. Error is OK Day of Assay Zero/Span Check NOx Portion Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1% Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Page 21 of 24 ------- QA Requirements Summary, Region 7 - 4th Quarter of 2020 OA Requirement Result Status Primary SRM Cylinder Expiration Date 20-Sep-21 Primary SRM Gas Standard OK SRM Gas Standards Primary SRM Cylinder Pressure >150 psi 1900 Primary SRM cylinder pressure is OK SRM Dilution Check Cylinder Expiration Date 20-Sep-21 Dilution Check SRM Gas Standard OK Dilution Check SRM Cylinder Pressure >150 psi 675 Dilution check SRM cylinder pressure is OK High Flow Standard Expiration Date 8-Jan-21 Standard OK Laboratory Flow Standard Low Flow Standard Expiration Date 8-Jan-21 Standard OK Ultra Low Flow Standard Expiration Date 21-Jan-21 Standard OK Calibrator Flow Calibration within 2 weeks of assay 6-Dec-20 Calibrator flow calibration within 2 weeks of assay Calibrator (mass flow controllers] Calibrated High Flow MFC Slope Range = 0.99 - 1.C 0.9999993 High MFC OK Calibrated Low Flow MFC Slope Range = 0.99 - 1.C 0.9999844 Low MFC OK Analyzer Calibration within 2 week of assay 7-Dec-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1% at point #1 (>80% URL 0.38% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #2 0.39% Assay may be conducted at this concentration Carbon Monoxide Gas Analyzer Estimate of Uncetainty < 1% at point #3 0.41% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #4 0.44% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #5 (~50% URL 0.48% Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 1.0029 Analyzer Slope is acceptable Dilution Check Dilution Check Date within 2 weeks of assay 7-Dec-20 Dilution check within 2 weeks of assay Dilution Check Relative % Difference < 1% I O o sP 0s Dilution Check RSD is OK Day of Assay Zero/Span Check Day of Assay Zero Check - Std. Error < 1 % Std. Error is okay. Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas Std. Error is OK Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1 % Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Page 22 of 24 ------- QA Requirements Summary, Region 7 - 4th Quarter of 2020 QA Requirement Result Status Primary SRM Cylinder Expiration Date 8-Aug-23 Primary SRM Gas Standard OK SRM Gas Standards Primary SRM Cylinder Pressure >150 psi 475 Primary SRM cylinder pressure is OK SRM Dilution Check Cylinder Expiration Date 1-Feb-24 Dilution Check SRM Gas Standard OK Dilution Check SRM Cylinder Pressure >150 psi 800 Dilution check SRM cylinder pressure is OK High Flow Standard Expiration Date 8-Jan-21 Standard OK Laboratory Flow Standard Low Flow Standard Expiration Date 8-Jan-21 Standard OK Ultra Low Flow Expiration Date 21-Jan-21 Standard OK Calibrator Flow Calibration within 2 weeks of assay 6~Dec~20 Calibrator flow calibration within 2 weeks of assay Calibrator (mass flow controllers) Calibrated High Flow MFC Slope Range = 0.99 - 1.C 0.9999993 High MFC OK Calibrated Low Flow MFC Slope Range = 0.99 - 1.C 0.9999844 Low MFC OK Analyzer Calibration within 2 weeks of assay 10-Dec-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1% at point #1 (>80% URL 0.24% Assay may be conducted at this concentration Oxides of Nitrogen Gas Analyzer NO Portion Estimate of Uncetainty < 1% at point #2 0.25% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #3 0.26% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #4 0.27% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #5 (~50% URL 0.30% Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 1.0006 Analyzer Slope is acceptable Analyzer Calibration within 2 week of assay 10-Dec-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1% at point #1 (>80% URL 0.24% Assay may be conducted at this concentration Oxides of Nitrogen Gas Analyzer NOx Portion Estimate of Uncetainty < 1% at point #2 0.25% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #3 0.26% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #4 0.28% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #5 (~50% URL 0.31% Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 1.0002 Analyzer Slope is acceptable Dilution Check Dilution Check Date within 2 weeks of assay 7-Dec-20 Dilution check within 2 weeks of assay Dilution Check Relative % Difference < 1% 0.000% Dilution Check RSD is OK Day of Assay Zero Check - Std. Error < 1% Std. Error is okay. Zero Gas Std. Error is OK Day of Assay Zero/Span Check NO Portion Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1% Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Day of Assay Zero Check - Std. Error < 1% Std. Error is okay. Zero Gas Std. Error is OK Day of Assay Zero/Span Check NOx Portion Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1% Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Page 23 of 24 ------- QA Requirements Summary, Region 7 - 4th Quarter of 2020 OA Requirement Result Status Primary SRM Cylinder Expiration Date 27-Jun-23 Primary SRM Gas Standard OK SRM Gas Standards Primary SRM Cylinder Pressure >150 psi 1350 Primary SRM cylinder pressure is OK SRM Dilution Check Cylinder Expiration Date 5-Apr-22 Dilution Check SRM Gas Standard OK Dilution Check SRM Cylinder Pressure >150 psi 1625 Dilution check SRM cylinder pressure is OK High Flow Standard Expiration Date 8-Jan-21 Standard OK Laboratory Flow Standard Low Flow Standard Expiration Date 8-Jan-21 Standard OK Ultra Low Flow Standard Expiration Date 21-Jan-21 Standard OK Calibrator Flow Calibration within 2 weeks of assay 6-Dec-20 Calibrator flow calibration within 2 weeks of assay Calibrator (mass flow controllers] Calibrated High Flow MFC Slope Range = 0.99 - 1.C 0.9999993 High MFC OK Calibrated Low Flow MFC Slope Range = 0.99 - 1.C 0.9999929 Low MFC OK Analyzer Calibration within 2 weeks of assay 8-Dec-20 Analyzer calibration within 2 weeks of assay Estimate of Uncetainty < 1% at point #1 (>80% URL 0.31% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #2 0.32% Assay may be conducted at this concentration Sulfur Dioxide Gas Analyzer Estimate of Uncetainty < 1% at point #3 0.35% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #4 0.41% Assay may be conducted at this concentration Estimate of Uncetainty < 1% at point #5 (~50% URL 0.74% Assay may be conducted at this concentration Analyzer slope is within 0.98-1.02 1.0007 Analyzer Slope is acceptable Dilution Check Dilution Check Date within 2 weeks of assay 7-Dec-20 Dilution check within 2 weeks of assay Dilution Check Relative % Difference < 1% I O o sP 0s Dilution Check RSD is OK Day of Assay Zero/Span Check Day of Assay Zero Check - Std. Error < 1 % Std. Error is okay. Day of Assay Zero Check - Relative Difference < 5°/ RD is okay. Zero Gas Std. Error is OK Zero Gas RD is OK Day of Assay Span Check - Std. Error < 1 % Std. Error is okay. Span Gas Std. Error is OK Day of Assay Span Check - Relative Difference <5°/ RD is okay. Span Gas RD is OK Page 24 of 24 ------- United States Office of Air Quality Planning and Standards Publication No. EPA-454/R-21-006 Environmental Protection Air Quality Assessment Division July 2021 Agency Research Triangle Park, NC ------- |