(a) This section describes emission standards and certification requirements for auxiliary power units (APU) installed on highway tractors subject to standards under 40 CFR 1037.106 starting in model year 2024.

(b) You may apply for a certificate of conformity under this section if you manufacture APUs, or if you install emission control hardware to meet the standard in this section.

(c) Exhaust emissions may not exceed a PM standard of 0.02 g/kW-hr when tested using the steady-state test procedures described in subpart F of this part for the duty cycles specified in § 1039.505(b)(1). Your APUs must meet the exhaust emission standards of this section over the engine's useful life as specified in § 1039.101(g). These emission standards also apply for testing with production and in-use APUs.

(d) The APU is deemed to have a valid certificate of conformity under this section if the engine manufacturer certifies the engine under 40 CFR part 1039 with a family emission limit of 0.02 g/kW-hr or less.

(e) The APU may draw power from the installed engine to regenerate a particulate filter, but you must not make any other changes to the certified engine that could reasonably be expected to increase its emissions of any pollutant.

(f) Sections 1039.115, 1039.120, 1039.125, and 1039.130 apply for APUs as written. You must exercise due diligence in ensuring that your system will not adversely affect safety or otherwise violate the prohibition of § 1039.115(f).

(g) All your APUs are considered to be part of a single emission family; however, you may subdivide your APUs into multiple emission families if you show the expected emission characteristics are different during the useful life.

(h) Testing requirements apply for certification as follows:

(1) Select an emission-data APU representing a worst-case condition for PM emissions. Measure emissions from the test engine with the APU installed according to your specifications.

(2) We may require you to provide an engineering analysis showing that the performance of your emission controls will not deteriorate during the useful life with proper maintenance. If we determine that your emission controls are likely to deteriorate during the useful life, we may require you to develop and apply deterioration factors consistent with good engineering judgment.

(3) Collect emission data and round to the nearest 0.01 g/kW-hr for comparing to the standard. Calculate full-life emissions as described in § 1039.240(d) if you need to apply a deterioration factor.

(4) You may ask to use emission data from a previous production period instead of doing new tests as described in § 1039.235(d).

(5) Additional testing provisions apply as described in § 1039.235(c), (e), and (f).

(i) Your APU certificate is valid for any engine certified under this part 1039, as long as the engine has a maximum engine power no more than 10 percent greater than the maximum engine power of the engine used for certification testing under this section.

(j) The following provisions apply for determining whether your APU complies with the requirements of this section:

(1) For purposes of certification, your emission family is considered in compliance with the emission standards of this section if all emission-data APUs representing that family have test results showing compliance with the standards.

(2) Your engine family is deemed not to comply if any emission-data APU representing that family for certification has test results showing a full-life emission level above the PM standard.

(k) At the time of manufacture, affix a permanent and legible label identifying each APU. This applies even if the engine manufacturer certifies a compliant engine as described in paragraph (d) of this section. The label must meet the specifications described in 40 CFR 1068.45(a). The label must—

(1) Include the heading “EMISSION CONTROL INFORMATION”.

(2) Include your full corporate name and trademark.

(3) State: “THIS APU ENGINE COMPLIES WITH 40 CFR 1039.699.”

(l) [Reserved]

(m) See §§ 1039.201, 1039.210, 1039.220, 1039.225, 1039.250, and 1039.255 for general requirements related to obtaining a certificate of conformity. A certificate issued under this section may apply for a production period lasting up to five years. Include the following information in your application for certification, unless we ask you to include less information:

(1) Describe the emission family's specifications and other basic parameters of the APU's design and emission controls. List each distinguishable configuration in the emission family. For each APU configuration, list the maximum engine power for which the APU is designed to operate.

(2) Explain how the emission control system operates. Identify the part number of each component you describe.

(3) Describe the engines you selected for testing and the reasons for selecting them.

(4) Describe the test equipment and procedures that you used. Also describe any special or alternate test procedures you used.

(5) Describe how you operated the emission-data APU before testing, including any operation to break in the APU or otherwise stabilize emission levels. Describe any scheduled maintenance you did.

(6) List the specifications of the test fuel to show that it falls within the required ranges we specify in 40 CFR part 1065.

(7) Include the maintenance and warranty instructions you will provide (see §§ 1039.120 and 1039.125).

(8) Describe your emission control information label.

(9) Identify the emission family's deterioration factors and describe how you developed them, or summarize your analysis describing why you don't expect performance of emission controls to deteriorate. Present any emission test data you used for this.

(10) State that you operated your emission-data APU as described in the application (including the test procedures, test parameters, and test fuels) to show you meet the requirements of this part.

(11) Present emission data for PM.

(12) Report all test results, including those from invalid tests, whether or not they were conducted according to the test procedures of subpart F of this part. We may ask you to send other information to confirm that your tests were valid under the requirements of this part and 40 CFR part 1065.

(13) Describe any adjustable operating parameters as described in § 1039.205(s).

(14) Unconditionally certify that all the APUs in the emission family comply with the requirements of this part, other referenced parts of the CFR, and the Clean Air Act.

(15) Provide additional information if we say we need it to evaluate your application.

(16) Name an agent for service located in the United States. Service on this agent constitutes service on you or any of your officers or employees for any action by EPA or otherwise by the United States related to the requirements of this part.

(n) If a highway tractor manufacturer violates 40 CFR 1037.106(g) by installing an APU from you that is not properly certified and labeled, you are presumed to have caused the violation (see 40 CFR 1068.101(c)).