Haw. Rev. Stat. § 340E-4: Imminent hazards.

The director, upon learning that a contaminant is present in or is likely to enter a public water system or an underground source of drinking water and may present an imminent and substantial danger to the public, may take such actions necessary to protect the health of the public. The actions which the director may take include but are not limited to:

(1) Issuing such orders as may be necessary to protect the health of persons who are or may be users of such system (including travelers), including requiring the provision of alternative water supplies by persons who caused or contributed to the endangerment; and

(2) Commencing a civil action for appropriate relief, including a restraining order or permanent or temporary injunction.