The EPA just got back to me. This is what they said:
Sorry for the late response due to the shutdown. Below is the regulation for applying for a testing exemption for a nonroad engine. In the attachment (more so for motor vehicles) this will provide information on the layout of the application letter.
§1068.210 What are the provisions for exempting test engines/equipment?
(a) We may exempt engines/equipment that you will use for research, investigations, studies, demonstrations, or training. Note that you are not required to get an exemption under this section for engines that are exempted under other provisions of this part, such as the manufacturer-owned exemption in §1068.215.
(b) Anyone may ask for a testing exemption.
(c) If you are a certificate holder, you may request an exemption for engines/equipment you intend to include in test programs over a two-year period.
(1) In your request, tell us the maximum number of engines/equipment involved and describe how you will make sure exempted engines/equipment are used only for this testing. For example, if the exemption will involve other companies using your engines/equipment, describe your plans to track individual units so you can properly report on their final disposition.
(2) Give us the information described in paragraph (d) of this section if we ask for it.
(d) If you are not a certificate holder, do all the following things:
(1) Show that the proposed test program has a valid purpose under paragraph (a) of this section.
(2) Show you need an exemption to achieve the purpose of the test program (time constraints may be a basis for needing an exemption, but the cost of certification alone is not).
(3) Estimate the duration of the proposed test program and the number of engines/equipment involved.
(4) Allow us to monitor the testing.
(5) Describe how you will ensure that you stay within this exemption's purposes. Address at least the following things:
(i) The technical nature of the test.
(ii) The test site.
(iii) The duration and accumulated engine/equipment operation associated with the test.
(iv) Ownership and control of the engines/equipment involved in the test.
(v) The intended final disposition of the engines/equipment.
(vi) How you will identify, record, and make available the engine/equipment identification numbers.
(vii) The means or procedure for recording test results.
(e) If we approve your request for a testing exemption, we will send you a letter or a memorandum describing the basis and scope of the exemption. It will also include any necessary terms and conditions, which normally require you to do the following:
(1) Stay within the scope of the exemption.
(2) Create and maintain adequate records that we may inspect.
(3) Add a permanent label to all engines/equipment exempted under this section, consistent with §1068.45, with at least the following items:
(i) The label heading “EMISSION CONTROL INFORMATION”.
(ii) Your corporate name and trademark.
(iii) Engine displacement, family identification, and model year of the engine/equipment (as applicable), or whom to contact for further information.
(iv) One of these statements (as applicable):
(A) “THIS ENGINE IS EXEMPT UNDER 40 CFR 1068.210 OR 1068.215 FROM EMISSION STANDARDS AND RELATED REQUIREMENTS.”
(B) “THIS EQUIPMENT IS EXEMPT UNDER 40 CFR 1068.210 OR 1068.215 FROM EMISSION STANDARDS AND RELATED REQUIREMENTS.”
(4) Tell us when the test program is finished.
(5) Tell us the final disposition of the engines/equipment.
(6) Send us a written confirmation that you meet the terms and conditions of this exemption.
David C. Hurlin
EPA Imports Line, Exemptions
Managed by Jacobs, Contractor to the U.S. EPA
Phone: (734) 214-4098 or 4100
Fax: (734) 214-4676