40 CFR §1074.101

1. (a)California must request authorization from the Administrator to enforce its adopted standards and other requirements relating to control of emissions from nonroad engines or vehicles that are not preempted by § 1074.10(a) or (b). The request must include the record on which the State rulemaking was based.
2. (b)After receiving the authorization request, the Administrator will provide notice and opportunity for a public hearing regarding such requests.