Haw. Code R. § 11-60.1-5
In addition to the conditions authorized in sections 11-60.1-68 and 11-60.1-90, the director may impose more restrictive conditions in a noncovered or covered source permit to further limit the air pollutants and operation of the source. In determining whether to impose more restrictive conditions, the director shall consider the relevant circumstances of each individual case, including the availability of a reasonable control technology, cleaner fuels, or a less polluting operating process; the consideration of the existing air quality and the resulting degradation; the protection of the public health, welfare and safety; and any information, assumptions, limitations, or statements made in conjunction with a permit application.
Haw. Code R. § 11-60.1-5