I received an EPA notice

They have different statutory triggers. A clean-up notice under section 91 of the Protection of the Environment Operations Act 1997 can direct specified clean-up action where the authority reasonably suspects that a pollution incident has occurred or is occurring. It can be addressed to an owner or occupier of affected premises or to a person reasonably suspected of causing or contributing to the incident. A prevention notice under sections 95–96 is forward-looking: it directs an occupier or person carrying on an activity to take specified action where the authority reasonably suspects the activity is being carried on in an environmentally unsatisfactory manner. The issuer, addressee, requirements, service date and statutory section on the document should be checked rather than treating either instrument as a generic 'EPA notice'.

The notice sets its own compliance period. Separately, section 289 of the Protection of the Environment Operations Act 1997 gives a person served with a prevention notice 21 days after service to appeal to the Land and Environment Court. The appeal does not automatically stay the notice; a stay operates only to the extent the Court directs. A clean-up notice has no equivalent statutory merits appeal, although judicial review may be available for a legal error. Asking the authority for clarification, variation or more time, or commencing review proceedings, does not itself suspend compliance, so compliance and review need to be managed in parallel.

Potentially, but not merely because a person is a director. The Protection of the Environment Operations Act 1997 contains offence-specific executive-liability provisions. It also permits supplementary clean-up or prevention notices in defined circumstances to be issued to specified current or former directors, people concerned in management and related bodies corporate after corporate non-compliance. The provision, alleged conduct, person's role, company response and available statutory defences all need to be checked before personal exposure is assumed.

Part 5.7 of the Protection of the Environment Operations Act 1997 requires immediate notification to every relevant authority when a pollution incident occurring in the course of an activity causes or threatens material harm and the relevant person becomes aware of that fact. Material harm includes non-trivial actual or potential harm to human health, safety or ecosystems, or aggregate actual or potential loss or property damage above $50,000. Duties can apply to the person carrying on the activity, employees, employers and the occupier. Notification is verbal to each listed authority and is followed by written notification within seven calendar days of the incident. There is no fixed safe number of minutes or hours, and notification should proceed alongside containment and any applicable pollution incident response management plan.