OAR 340-220-0170: Verified Emission Factors

(1) The owner or operator must verify emission factors before using them to determine emissions of regulated pollutants. To verify emission factors, the owner or operator must perform either source testing using the DEQ Source Sampling Manual or use other methods approved by DEQ for source tests. [NOTE: DEQ manuals are published with OAR 340-200-0035.] Source tests must be conducted using testing procedures on file at DEQ and DEQ approved pretest plan which must be submitted at least 15 days before the testing. All test data and results must be submitted for review to DEQ within 30 days after testing, unless DEQ approves otherwise or a different time period is specified in a permit. NOTE: DEQ recommends that the owner or operator notify DEQ and obtain pre-approval of the emission factor source testing program before or as part of the first source test notification. (2) The owner or operator must conduct or have conducted at least three compliance source tests. Each test must consist of at least three individual test runs for a total of at least nine test runs. (3) The owner or operator must monitor and record applicable process and control device operating data. (4) The owner or operator must perform a source test either: (a) In each of three quarters of the year with no two successive source tests performed any closer than 30 days apart; or (b) At equal intervals over the operating period if the owner or operator demonstrates and DEQ agrees that the device or activity operates or has operated for part of the year; or (c) At any time during the year if the owner or operator demonstrates, and DEQ agrees, that the process is or was not subject to seasonal variations. (5) The owner or operator must conduct the source tests to test the entire range of operating levels. At least one test must be conducted at minimum operating conditions, at normal or average operating levels, and at anticipated maximum operating levels. If the process rate is constant, all tests must be conducted at that rate. The owner or operator must submit documentation to DEQ demonstrating a constant process rate. (6) The owner or operator must determine an emission factor for each source test by dividing each test run, in pounds of emission per hour, by the applicable process rate during the source test run. At least nine emission factors must be plotted against the respective process rates and a regression analysis performed to determine the best fit equation and the correlation coefficient. If the correlation coefficient is less than 0.50, which indicates that there is a relatively weak relationship between emissions and process rates, the arithmetic average and standard deviation of at least nine emission factors must be determined. (7) The owner or operator must determine the Emissions Estimate Adjustment Factor (EEAF) as follows: (a) If the correlation coefficient (R2) of the regression analysis is greater than 0.50, the EEAF will be 1+(1-R2). (b) If the correlation coefficient (R2) is less than 0.50, the EEAF will be: [Equation not included. See NOTE.] (8) The owner or operator must determine actual emissions for emission fee purposes using one of the following methods: (a) If the regression analysis correlation coefficient is less than 0.50, the actual emissions is the average emission factor determined from at least nine test runs multiplied by the EEAF multiplied by the total production for the entire year; or [Equation not included. See NOTE.] (b) If the regression analysis correlation coefficient is greater than 0.50, perform the following calculations: (A) Determine the average emission factor (EF) for each production rate category (maximum = EFmax, normal = EFnorm, and minimum = EFmin); (B) Determine the total annual production and operating hours, production time (PTtot), for the calendar year; (C) Determine the total hours operating within the maximum production rate category (PTmax). The maximum production rate category is any operation rate greater than the average of at least three maximum operating rates during the source testing plus the average of at least three normal operating rates during the source testing divided by 2; (D) Determine the total hours while operating within the normal production rate category (PTnorm). The normal production rate category is defined as any operating rate less than the average of at least three maximum operating rates during the source testing plus the average of at least three normal operating rates during the source testing divided by 2 and any operating rate greater than the average of at least three minimum operating rates during the source testing plus the average of at least three normal operating rates during the source testing divided by 2; (E) Determine the total hours while operating within the minimum production rate category (PTmin). The minimum production rate category is defined as any operating rate less than the average of at least three minimum operating rates during the source testing plus the average of at least three normal operating rates during the source testing divided by 2; (F) Actual emissions equals EEAF x ((PTmax/PTtot) x EFmax + (PTnorm/PTtot) x EFnorm + (PTmin/PTtot) x EFmin.) (9) The owner or operator must determine emissions during startup and shutdown, and for emissions greater than normal, during conditions that are not accounted for in the procedure otherwise used to document actual emissions. The owner or operator must apply OAR 340-220-0170(9)(a) or 340-220-0170(9)(b), (c) and (d) in developing emission factors. The owner or operator must apply the emission factor obtained to the total time the device or activity operated under these conditions. (a) All emissions during startup and shutdown, and emissions greater than normal are assumed equivalent to operation without an air pollution control device, unless the owner or operator accurately demonstrates otherwise under OAR 340-220-0170(9)(b), (9)(c), (9)(d), and (9)(e), and approved by DEQ. The emission factor plus the EEAF must be adjusted by the air pollution control device collection efficiency as follows: [Equation not included. See ED. NOTE.] (b) During process startups a DEQ approved source test may be performed to determine an average startup factor. The average of at least three tests runs plus the standard deviation will be used to determine actual emissions during startups. (c) During process shutdowns a DEQ approved source test may be performed to determine an emission factor for shutdowns. The average of at least three test runs plus the standard deviation will be used to determine actual emissions during shutdowns. (d) During routine maintenance activity the owner or operator may: (A) Perform routine maintenance activity during source testing for verified emission factors; or (B) Determine emissions using section (a). (e) The emission factor need not be adjusted if the owner or operator demonstrates to DEQ that the regulated pollutant emissions do not increase during startup and shutdown, and for conditions that are not accounted for in the procedure otherwise used to document actual emissions (e.g. NOx emissions during an ESP failure). (10) A verified emission factor developed pursuant to this division and approved by DEQ cannot be used if a process change occurs that would affect the accuracy of the verified emission factor. (11) The owner or operator may elect to use verified emission factors for source categories if DEQ determines the following criteria are met: (a) The verified emission factor for a source category must be based on verified emission factors from at least three individual sources within the source category; (b) Verified emission factors from sources within a source category must be developed using this rule; (c) The verified emission factors from the sources must not differ from the mean by more than twenty percent; and (d) The source category verified emission factor must be the mean of the source verified emission factors plus the average of the source emission estimate adjustment factors. [NOTE: View a PDF of equations by clicking on the "Tables" link below.] [ED. NOTE: To view attachments referenced in rule text, click here to view rule.]