FEATURE
Air monitoring equivalency regs Step-by-step procedures to be taken by an applicant and the EPA make for better air quality data
Thomas R. Hauser S. David Shearer EPA/NERC Research Triangle Park, N.C. 277 1 1 The quality of ambient air monitoring data is of paramount concern to policy makers faced with difficult air resource management decisions. Often, these decisions must be made by using air quality data to demonstrate: achievement or compliance with a statutory standard the existence of a health or welfare problem caused by high pollution levels the need for interim control strategies or other management decisions. The correctness of these decisions are only as valid as the aerometric data used to make them. To make valid air resource management decisions, valid air quality and emission data are a necessity: to collect valid aerometric data, it is necessary to conduct the air monitoring program under an adequate quality assurance program. A basic and integral part of EPA's overall quality assurance program is the new equivalency program. A total quality assurance program for the measurement of air pollutants, both in sources and ambient air, is being developed by the EPA through its Quality Assurance and Environmental Monitoring Laboratory (QAEML) at the National Environmental Research Center (NERC) in Research Triangle Park, N.C In the promulgation of the National Ambient Air Quality Standards (NAAQS) on April 30, 197 1 (40 CFR Part 50), EPA presented a "reference method" for measuring each of the six criteria pollutants. This promulgation also contained the provision that measurements could also be made by an "equivalent method," which was defined as "any method of sampling and analyzing for an air pollutant which can be demonstrated to the Administrator's satisfaction to have a consistent relationship to the reference method." Specific details covering the requirements for demonstrating equivalency were not covered in these regulations. Section 110 of the Clean Air Act required all states to prepare a State Implementation Plan (SIP) within nine months after the promulgation of the NAAQS. On August 14, 1971,
EPA published the "Requirements for Preparation, Adoption, and Submittal of Implementation Plans" (40 CFR Part 51). In this publication certain types of automated methods were designated to be "equivalent methods" provided the methods met certain performance specifications listed in the promulgation (40 FR Part 51.17). On October 12, 1973, EPA published proposed equivalency regulations entitled, "Ambient Air Monitoring, Equivalent and Reference Methods" (40 CFR Part 53). This promulgation contained a description of the requirements necessary to designate a reference or equivalent method including a description of the performance specification and consistent relationship requirements. In addition, the proposal also contained necessary amendments to 40 CFR Part 50 (Air Quality Standards) and 40 CFR Part 5 1 (Requirements for State Implementation Plans). Interested persons were invited to submit written comments on the proposed regulations to EPA for consideration prior to final promulgation of the regulations. Comments were received from 32 individuals or organizations representing all facets of the air pollution monitoring field. Final equivalency regulations and amendments to 40 CFR Parts 50 and 51 were published in the Federal Register on February 18, 1975 (Vol. 40, No. 33, Part 2, p. 7042-7078, 1975).
Approach Under the new regulations in 40 CFR Part 53 and revisions to 40 CFR Parts 50 and 51 requirements are provided for both reference and equivalent method determinations. Two kinds of reference methods-manual and automated-are possible. Specifications for measuring concentrations of an ambient air pollutant, using a manual reference method in which sample collection, analysis, or measurement, or some combination thereof is performed manually are found in Part 50, and the requirements of the new regulations in Part 53 are not applicable. Specifications for automated reference methods in which sample collection, analysis, and measurement are performed automatically are given in Part 50. Any automated analyzer may be designated as a reference method if it is based on the measurement principle and calibrition procedure specified in the appropriate appendix of Part 50, and meets the performance requirements specified in Subpart B of the new regulations (Part 53). The measurement principle for the reference method for photochemical oxidants is the gas phase chemiluminescent reaction between ozone and ethylene and the calibrstion procedure is the neutral buffered potassium iodide procedure. Consequently, an automated analyzer employing the gas phase chemiluminescence principle and the neutral potassium iodide calibration procedure will be considered a candidate for a reference method and not an equivalent method. Two kinds of equivalent methods are possible-manual and automated. Candidate manual methods need only demonstrate a consistent relationship to the reference method as described in Subpart C of 40 CFR Part 53 to be designated an equivalent method. Candidate automated methods will be designated as equivalent methods if they meet certain perforVolume 9, Number 6, June 1975
539
FIGURE 1
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If applicant (instrument manufacturer) wants to
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A Applications are to be submitted in triplicate to the Director Quality Assurance and Environmental Monitoring Laboratory Department E National Environmental Research Center Research Triangle Park, North Carolina 2771 l B The application must be signed by an authorized representative and marked to identify trade secrets and confidential or privileged information (53 15) i f applicable C The application must contain the following information 1 A clear identification of the candidate method to distinguish it from all other methods 2 A detailed description of the method including but not limited to a measurement principle b manufacturer s name, model number, or other identification c listing of significant components d schematic diagrams e detailed description of apparatus and measurement principle 3 A copy of comprehensive operation or instruction manual See 53 4(b)(3) for specifics to be included in manual 4 A statement that candidate method has been tested in accordance with Subpart B Subpart C or both if applicable 5 Test data records calculation and test results as specified in Subpart B Subpart C, or both if applicable 6 Statement that the method or analyzer tested is representative of the candidate method described in the application
7 For candidate automated methods, the application must also contain a detailed description of quality control program to be used to ensure that all analyzers offered for sale will have the same performance characteristics as the analyzer tested, and a description of the durabtlity characteristics as required under 53 9(c)
acts (accepts, rejects or requests additional information or tests) on application; if rejected, applicant may appeal (40 CFR 53.5) . .
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Application is received by EPA and the Administrator publishes notice of application in the Federal Register B Within 75 days after receipt of application. the Administrator takes one or more of the following actions 1 Send notice to the applicant that the method has been determined to be an equivalent or reference method (notice must be submitted for publication in Federal Register within an additional 15 days) 2 Send notice and statement of reasons to the appgicanf that the method has been reiected The applicant may appeal in accordance with 53 10 3 Send notice to the applicant that additional information is needed before determination can be made The information needed must be specified A new 75-day period starts upon receipt of additional information A
4 Send notice to the appkcant that additmnal tests are required before determination can be made The Administrator must specify what tests are required A new 75-day period starts upon receipt of test data 5 Send notice to the applicant that the Administrator will conduct additional tests specify what tests will be conducted and give the approximate time period to conduct additional tests A new 75-day period starts when the additional tests are completed
C An applicant whose application has been rejected may appeal the decision as follows 1 Submit new or additional information to support the application 2 Request that the Administrator reconsider the information and data already submitted 3 Request that the Administrator repeat any test that was a material factor in the rejection
Numbers in parenlhesis c le specilic seclions or paragraphs ,n Ihe newly publrehed equ valency reguiations
mance specifications listed in Subpart B of Part 53 and demonstrate a consistent relationship to the reference method as required by Subpart C of Part 53. The "Equivalency Regulations" are comprised of three subparts. Subpart A contains the general requirements that must be met by an analytical method (manual or automated) to be considered for designation as a reference or equivalent method. The primary responsibility for conducting the tests required for determination of reference or equivalent methods is placed on the applicant, usually the manufacturer of the method (analyzer). Subpart A also specifies in detail all the pertinent information that must be submitted to EPA by an applicant desiring an equivalency or reference method determination. In addition, the procedures to be used by EPA in processing an application are also presented. Subpart B lists the procedures that must be followed for testing certain performance characteristics of automated analyzers. This subpart replaces all previous performance specifications and testing procedures listed in 40 CFR Parts 50 and 51. Subpart C gives the procedures that must be followed for determining a consistent relationship between candidate equivalent methods and reference methods. General provisions
As in all Federal regulations, the basic terms (reference method, equivalent method, candidate method, manual method, automated method) are defined. The general requirements for reference method and equivalent method determination are also presented. These requirements, concerning both EPA and the applicant, are summarized in Figures 1 through 4. Once the formal application is received by EPA, the Administrator is required to process the applications following a set procedure (Figure 2). Within 75 days after receipt of the application, EPA must either accept or reject the method, require the applicant to submit additional information, or require that 540
Environmental Science .8 Technology
additional tests be carried out by either EPA or the applicant. The applicant and EPA have the right to witness any additional required tests, which are to be conducted at a place and time mutually agreeable to both EPA and the applicant. In addition, EPA may independently initiate and conduct a reference or equivalent method determination, For example, an older analyzer may no longer be in production but may still be used by various monitoring agencies. In this case, the instrument manufacturer would not initiate an equivalency determination since he is no longer selling the item; hence, EPA may initiate the determination if deemed warranted. After EPA determines that a candidate method satisfies the requirements for either a reference or equivalent method, it must notify the applicant, and send a notice of acceptance to the Federal Register within 15 days. EPA is required to maintain a current list of designated reference or equivalent methods and provide the list to any person or group upon request. The list will also be available in each EPA Regional Office. When an applicant's method has been designated as a reference or equivalent method, the applicant must agree that the method offered for sale will be accompanied by a comprehensive operational or instructional manual. The applicant must also assure that any method offered for sale will generate no unreasonable hazard to either the operators or the environment during normal use or when malfunctioning. In addition, a continuous analyzer offered for sale must continue to meet the performance specifications (discussed in Subpart B) for a period of one year after delivery to the purchaser, provided the analyzer is maintained and operated by the purchaser in accordance with the operating manual supplied with the analyzer. Cancellation or modification of equivalent or reference methods are also covered in Subpart A. In the event EPA finds it necessary to cancel a reference or equivalent method determination, a prescribed procedure will be followed (Figure 3). In the event an instrument manufacturer finds it necessary to modify a method previously declared to be a reference or
equivalent method, the process delineated in Figure 4 is required. in either case, if the applicant is not satisfied with an EPA determination, his appeal routes have been established (Figure 4). Specifications for automated methods Subpart B gives the requirements and procedures for test performance characteristics of automated methods. To satisfy the requirements, a test analyzer representative of the candidate automated method must exhibit performance better than or equal to the specified value for each performance specification (except range). The performance specifications for automafed methods for measuring sulfur dioxide, photochemical oxidants, and carbon monoxide are given in Table 1. Because of its unique nature, reference and equivalent method requirements for suspended particulates are not included in the new regulations. Nitrogen dioxide and hydrocarbons corrected for methane are also not covered because of technical problems with the designated reference methods. A companion document entitled "Guidelines for Determining Performance Characteristics of Automated Methods for Mea-
suring Nitrogen Dioxide and Hydrocarbons Corrected for Methane in Ambient Air" (EPA-650/4-74-018) is available. Once the problems in reference methodology for these two pollutants are resolved, these guidelines will be incorporated into the equivalency regulations. For each performance specification listed in Table 1 (except range), the test procedure must be repeated seven times. Each result is then compared with the specifications listed in Table 1; a value higher than the specification constitutes a failure. The seven results for each parameter must be interpreted as given in Figure 5. The results of the individual performance specification tests, including recorder chart tracings, records, test data, and other documentation obtained from or pertinent to these tests, must be identified, dated, signed by the analyst performing the test, and submitted with the application. Suggested formats for reporting test results are also presented in Subpart B. One of the significant parameters for which performance specifications are included is the interference equivalent specification. This requirement will discourage the use of nonspecific analyzers that respond to pollutants other than the
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