Major Hazard Facilities – TAOM

Eastland Group

Major Hazard Facilities and Regulations

In 2015 a new Health and Safety at Work Act was introduced, which included specific regulations for Major Hazard Facilities (MHFs). If a facility has certain hazardous substances present in quantities above a set threshold, then it is classed as a MHF under the MHF Regulations. The Regulations are overseen by a specialist group within WorkSafe New Zealand and are designed to provide oversight and safety assurance of MHFs.

Our Major Hazard Facilities

We operate two geothermal power stations which are classified as MHFs. MHF facilities may be either an upper tier or lower tier facility depending on the quantity of specified hazardous substances onsite.

Te Ahi O Maui

Te Ahi O Maui (TAOM) is a geothermal power station located outside the township of Kawerau in the Bay of Plenty. We use a liquid known as n-Pentane at TAOM to drive the turbines and produce power. The n-Pentane is fully contained in a closed-loop process which recycles the liquid through the system for continuous operation. Due to the quantity of n-Pentane onsite, TAOM is identified as an upper tier MHF.

Name of Operator Eastland Generation Limited
Location of Facility Statehighway 34 Kawerau
Person from whom information can be requested The Duty Operator 07 923 6040
General Description Te Ahi O Maui is a geothermal power facility utilising Ormat binary cycle energy conversion technology.  This technology uses n-Pentane as its motive fluid in a closed loop process. The site is situated in an isolated area on private land surrounded by indigenous and exotic forestry and is accessed via a private access road.
How will a major incident at the facility be notified
  • Audible alarm on site
  • Physical barriers prevent access to site
  • Specific, potentially affected parties will be notified by telephone
  • Due to its isolated nature, the general public will not be notified other than by regular news channels or social media
What should members of the public do if an incident occurs
  • Do not approach or try to access the facility
  • Follow the instructions of the Emergency Services, Duty Operator and security personnel

Safety Case Study

What is a Safety Case?

The MHF Regulations require upper tier MHFs to develop a Safety Case that demonstrates our ability to operate and maintain our power station safely. This means that we have identified all potential major incidents and we are using appropriate controls to minimise the risks of these incidents so far as is reasonably practicable.

A major incident is defined in the regulations as an uncontrolled event at a MHF that involves specified hazardous substances (e.g. n-Pentane) and exposes multiple persons to a serious risk to their health or safety.

We believe worker engagement and buy in is critical to achieving our goal of a safe site with zero harm to workers and visitors. We used a number of team-based methods for developing our Safety Case involving the entire team from operators through to senior management as well as specialists and external agencies such as Fire and Emergency New Zealand.

Our TAOM Safety Case was approved by WorkSafe New Zealand on 16th April 2018.

TAOM Safety Case

The TAOM Safety Case has four main parts:

  1. Facility description
    We believe in ‘safety by design’ and our Safety Case demonstrates how TAOM has been designed, manufactured and installed with safety at the forefront of each step. Likewise, our operating procedures and maintenance practices are all implemented toenhance safety and ensure that n-Pentane will remain contained onsite.
  2. Safety assessment summary
    The safety assessment process provides a comprehensive and systematic analysis of major incident hazards at TAOM. Our team of engineers and operators has worked together with consultants, specialists and external agencies using a variety of methods to evaluate risks and establish adequate risk control measures. The safety assessment demonstrates we have implemented the identified systems and controls needed to manage the hazards and reduce the major incident risks so far as is reasonably practicable. We also examined the risks to our close neighbours in the event of a major incident at TAOM. Through our safety assessment studies and computer modelling we show that it is extremely unlikely for a major incident to have a direct impact on the local community.
  3. Safety management system summary
    We have a strong commitment to a zero-harm approach to health and safety. Risks associated with our organisational activities are proactively managed so that workers, the local community and the environment remain safe. Our safety management system (SMS) provides a framework for the management of safety for TAOM. Through the SMS we are able to achieve a consistently high standard of health and safety performance. All aspects of the SMS are actively managed with performance verification systems in place. These systems are designed to help prevent a major incident occurring and minimise the effect of a major incident if one does occur.
  4. Emergency response plan summary
    Working with emergency services, we have developed a comprehensive emergency management plan (EMP) for TAOM which focuses on the preservation of life and safety for workers and the public. The EMP identifies the response we will take for each type of major incident which may occur onsite. We run regular drills to test the EMP and train our workers in emergency response. We also make sure we have the right resources (people, equipment and skills) available, or easily obtained, in the event of an emergency. Our safety assessment studies have identified an unmanaged pentane release as a potential major incident that could lead to asphyxiation, fire or explosion at TAOM. Evidence from other facilities suggests that most accidental releases of pentane do not result in asphyxiation, fire or explosion as they are quickly dealt with to prevent harm or environmental damage. Through our safety assessment studies and computer modelling we have demonstrated that it is extremely unlikely for a major incident to have a direct impact on the local community. However, some high consequence events have the potential for offsite impacts, although these are considered to have a very low probability of occurring.

In the event of an emergency at TAOM

Audible evacuation sirens are sounded to alert onsite personnel to follow the site evacuation procedures and activate the EMP. Fire and Emergency NZ will assume control of any major incident onsite, in collaboration with us, local authorities and other emergency service agencies.

Due to its isolated nature, people in the community do not need to take any immediate action if they hear these sirens. In the event of a major incident we will notify any potentially affected parties by telephone. In the case of an emergency Fire and Emergency NZand other emergency services will direct members of the public if any action is required.

It is important members of the public do not approach or try to gain access to TAOM. If required barriers will be erected to prevent access to site.

We will provide information to the local community via regular news channels or through our Eastland Group social media page.

Further Information

We have systems in place to ensure the safety case and its requirements are maintained, reviewed and revised in accordance with the MHF Regulations. This includes assessing the need for resubmission of the safety case when significant changes have occurred at TAOM. WorkSafe NZ will routinely review the safety case.

This document presents a summary of the safety case for TAOM power station. For further information please contact the duty operator on 07 923 6040.

More information regarding the requirements for major hazard facilities is available from the WorkSafe NZ website