There are two regulatory provisions that could significantly affect (reduce) your compliance requirements: (1) low use equipment exemptions and (2) Captive Attainment Area Fleets.
The regulation treats low use equipment is one of two ways:
Permanent Low Use
Year-by-Year Low Use
If you have equipment that ran less than 200 hours during the calendar preceding a compliance date that equipment's hp does not count towards your fleet size hp for that compliance date. This could have major implications to your compliance requirements.
For example, say you have 10,000 fleet hp. Hence, you are a Large Fleet and your first compliance deadline is Jan 1, 2014. Now say that 6,000 of your fleet hp ran less than 200 hours during calendar year 2013. In you Jan 1, 2014 compliance report you could declare that equipment (6,000 hp) as "Year-to-Year Low Use" and that hp would not count towards your fleet size on Jan 1, 2014. So 10,000 hp less 6,000 hp is 4,000 hp. That would mean that rather than being a Large fleet on Jan 1, 2014 you would be a Medium fleet for that compliance date. The first compliance date for Medium Fleets is Jan 1, 2017. Hence, you would have no compliance requirements for the Jan 1, 2014 deadline. However, say during calendar year 2014 7,000 of your hp ran 200 or more hours per year. That would mean for the Jan 1, 2015 compliance deadline you would again be large fleet and would have to meet the compliance requirements for that compliance date.
Also note that if you are subject to
Captive Attainment Area Fleet
Captive Attainment Area fleets are fleets or parts of fleets that operate entirely in one or more of the following counties: Alpine, Colusa, Del Norte, Glenn, Humboldt, Lake, Lassen, Mendocino, Modoc, Monterey, Plumas, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz, Shasta, Sierra, Siskiyou, Trinity, Tehama, Yuba, and the portion of Sonoma County that lies within the boundaries of the North Coast Air Basin. These fleets or fleet portions are classified as small fleets regardless of total hp of the fleet or fleet portion that operates entirely in the Captive Attainment counties. Note that there are special equipment labeling requirements for fleets that Captive Attainment Area equipment.