Common use of Data Quality Objectives Clause in Contracts

Data Quality Objectives. The data of primary interest in this verification are the reductions in emissions of the FTP primary pollutants: NOx, hydrocarbons (HC), PM, and carbon monoxide (CO). The DQOs of this GVP are the requirements of the test methods specified in 40 CFR Part 86 (highway diesel engines) or 89 (nonroad diesel engines) when conducting the number and type of tests called for by the approved test/QA plan for the SCR. ETV tests that do not meet the FTP and SET QA requirements are invalid. The number of and type of FTP tests (cold- or hot-start) required for ETV is determined from the following criteria: First, a minimum of three tests is required to provide the basic ETV result of a mean emission reduction and the 95 percent confidence interval on that mean based on measured variability for each of the measured emissions and test parameters. For highway engines, this minimum is satisfied with one cold start test and three hot start tests. For nonroad engines, three replicates of the appropriate test sequence (i.e., three 8-mode tests or three 6-mode tests) are required. A three­ test minimum is currently the same as is required by the State of California for its program. Second, additional tests may be required to meet the ETV requirement that the test/QA plan provide a 90 percent probability of detecting the expected emissions reductions when computed using the expected experimental errors for the various measurements. These criteria become controlling for low emissions reductions and/or high test variability. This is a planning requirement for the test/QA plan. Third, additional tests may be desired by the applicant to reduce the width of the 95 percent confidence interval on the mean emission reduction. This third criterion is a consequence of applying standard statistical procedures to the ETV test design and data analysis. At a fixed measurement variability, normal statistical procedures lead to a small number of tests giving a broader 95 percent confidence interval than would a larger number of tests. To any regulator or potential technology user, an emission reduction of 40 ± 5 percent is better than 40 ± 20 percent and will be given more credence. Noncritical measurements, including ammonia slip, will also be made as described in later sections. These are not considered critical, and the methods and DQOs for them will be stated in the test/QA plan. The FTP tests referenced above are conducted following test cycles specified in 40 CFR. As discussed in Section 5, other test cycles may also be required for verification of an SCR. A single data set for highway engines will consist of at least one FTP cold start cycle, plus three FTP hot start cycles and one SET. A single data set for nonroad engines will consist of triplicate multimode FTP tests. An applicant may conduct privately sponsored tests at a testing organization for development purposes with the same test engine prior to and/or after conducting ETV tests. Such testing is understood to be common and important to ensure that the technology is properly adjusted and tuned to the application. The ETV DQOs do not apply to privately sponsored testing. However, the applicant and testing organization must coordinate the entire testing effort with the APCTVC so that • preparation for the ETV test (submittal of the technology to the APCTVC, discussion of engine selection, and preparation of the test/QA plan) is completed prior to conducting the ETV test itself; • the APCTVC is notified of the ETV test dates in time to schedule QA activities at the discretion of the APCTVC; and • declaration of the test run that is to be the ETV test is made prior to starting the test, the engine is brought to a starting point in accordance with the test/QA plan, and the results of that test are documented and reported in accordance with the test/QA plan. An applicant may desire to run the baseline ETV test, conduct private developmental testing, and then complete the ETV tests following the private testing. This approach may be acceptable provided the baseline run is considered to remain valid for the duration of and for the activities that occur during the private testing. If not, the baseline case will have to be rerun. The data from all ETV tests will be retained and reported to the APCTVC, including invalid FTP test results. Data that meet the QA requirements of the FTP are considered valid and will be used to compute emissions reductions for ETV purposes. The SCR emissions reduction performance will be reported both as absolute emissions in the appropriate units (per applicable FTP) for the baseline and SCR cases and as percentage emissions reduction for a specific engine or engine family. The percentage emissions reduction reported will be the mean emissions reduction (relative to the baseline emission) with attendant upper and lower 95 percent confidence limits on that mean.