40 CFR § 1039.250 - What records must I keep and what reports must I send to EPA?
(a) Within 45 days after the end of the model year, send the Designated Compliance Officer a report describing the following information about engines you produced during the model year:
(2) If you produced exempted engines under the provisions of § 1039.625, report the number of exempted engines you produced for each engine model and identify the buyer or shipping destination for each exempted engine.
(b) Organize and maintain the following records:
(1) A copy of all applications and any summary information you send us.
(2) Any of the information we specify in § 1039.205 that you were not required to include in your application.
(3) A detailed history of each emission-data engine. For each engine, describe all of the following:
(i) The emission-data engine's construction, including its origin and buildup, steps you took to ensure that it represents production engines, any components you built specially for it, and all the components you include in your application for certification.
(ii) How you accumulated engine operating hours (service accumulation), including the dates and the number of hours accumulated.
(iii) All maintenance, including modifications, parts changes, and other service, and the dates and reasons for the maintenance.
(iv) All your emission tests, including the date and purpose of each test and documentation of test parameters as specified in part 40 CFR part 1065.
(v) All tests to diagnose engine or emission-control performance, giving the date and time of each and the reasons for the test.
(vi) Any other significant events.
(4) Production figures for each engine family divided by assembly plant.
(5) Keep a list of engine identification numbers for all the engines you produce under each certificate of conformity.
(c) Keep required data from emission tests and all other information specified in this section for eight years after we issue your certificate. If you use the same emission data or other information for a later model year, the eight-year period restarts with each year that you continue to rely on the information.
(d) Store these records in any format and on any media, as long as you can promptly send us organized, written records in English if we ask for them. You must keep these records readily available. We may review them at any time.