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Land use near a major hazard facility


When a proposal to build an aged care facility was received by a local council, a nearby major hazard facility lodged an objection to it. The council asked Broadleaf to investigate whether or not the objection was justified, and to be an expert witness in a formal public hearing.

Our expertise in land use safety planning and regulatory requirements was useful in this process. In particular, we were able to guide the council to ask the right questions of the owner of the refinery to achieve a satisfactory planning outcome.

The proposal

A local council had received a planning application to develop a parcel of land for use as an aged care facility.

The land was within a predominantly undeveloped area. The majority of the area was owned by a nearby oil refinery, which was classed by the planning regulator as a Major Hazard Facility (MHF).

After giving notice of the planning application, the council received public submissions. One of these was an objecting submission from the owner of the refinery, which stated, among other things, that the proximity to a MHF of such a sensitive land use as an aged care centre would be inappropriate based on risk and safety.

General advice had been received by the council that risks to people and property at the site from the refinery were negligible, based on similar ‘typical’ facilities. Based on risk, the advice was that there was no reason to prohibit building an aged care facility in the proposed location.

To properly consider the objecting submission, the council convened an Expert Panel and scheduled a formal public hearing. At the hearing, representatives from the council, the aged care proponent and the refinery would present their cases, including providing their own expert evidence.

The council asked Broadleaf to act as an expert witness. Our tasks were to:

  • Review the available risk-related information
  • Provide an opinion on whether the risk to the site was satisfactory and defensible
  • Appear at the Expert Panel hearing if necessary.

We planned to provide the council with a verbal expression of the adequacy of the available information and the defensibility of the council’s initial view that the aged care proposal could be approved, prior to producing a formal Statement of Evidence.

Major hazard facilities


A Major Hazard Facility (MHF), as defined in occupational health and safety (OHS) regulations in many jurisdictions, is a facility that stores, handles or processes large quantities of chemicals or dangerous goods. An OHS approval authority may also determine that a facility is a MHF if it forms the opinion that there is potential for a major incident to occur at the facility. Examples of MHFs include:

  • Oil and gas processing plants and refineries
  • Chemical, petrochemical, fertiliser and explosives manufacturing sites and storage facilities
  • LPG facilities
  • Some warehouses and transport depots.

MHFs create, use or store significant quantities of hazardous materials. A physical or procedural failure could involve a fire, explosion or the release of a hazardous substance, with the potential for catastrophic harm to employees, the community or the environment.

OHS regulations typically mandate duties for operators and employees of MHFs to prevent major incidents that may lead to injury, death or environmental harm. They impose specific legal responsibilities on operators and employers for the safe management and operation of MHFs.

Safety Case

The operator or owner of a MHF has a legal duty to control risks at the facility. To obtain a licence to operate a MHF, operators are required to submit a Safety Case that sets out how the facility will be operated safely.

A Safety Case demonstrates to the approval authority that the facility is safe to operate. It provides the authority with a safety assessment that investigates and analyses the potential for major incidents, including their severity and likelihood, and lists the range of control measures to ensure it is being managed satisfactorily.

A Safety Case should provide enough information to the regulatory authority to satisfy it that the MHF is safe and will remain that way. It is a means of both ensuring and demonstrating that the primary objective of safe operation is being met, including continuous improvement to safety.

A Safety Case documents most or all of the following components:

  • A comprehensive hazard identification, considering the materials and unit operations that will be present on the facility; depending on the facility, this may involve a selection of techniques and analyses including brainstorming, reviewing historical incident data, Hazard and Operability Studies (HAZOPs), Failure Modes and Effects Analyses (FMEAs), task analyses, and fault tree and event tree analyses
  • Detailed analyses to determine the consequences and likelihoods of potentially harmful events and major incidents; this may involve modelling loss of containment scenarios, dispersion modelling through air or water, overpressure modelling for explosions, fire safety studies, and fault tree and event tree analyses
  • The basis for safe design and construction of the facility, including any engineered control measures
  • The basis for safe operations and maintenance of the facility including safety management systems that are control measures
  • Arrangements for managing emergencies, both inside and outside the site
  • A description of the technical and management processes to ensure the procedures and assessments will be maintained as current in response to changes in facility design and operation.

An acceptable Safety Case is a pre-requisite to the granting of a MHF licence by the OHS approval authority. The Safety Case is required to be kept up to date, with regular reviews before licence renewals.

Safety restrictions on land use

OHS authorities restrict land use near MHFs, to reduce potential harm to people, assets and the environment. The restrictions typically include a set of quantitative criteria and maps that represent the extent of notional risk boundaries around a MHF as planning advisory areas (Figure 1). For example:

  • Inner planning advisory area – the individual risk of fatality from potential foreseeable incidents is greater than or equal to 1 x 10-7 per year (one chance in 10 million years)
  • Outer planning advisory area – the consequence of a credible incident is not likely to cause a fatality, but persons present may suffer some adverse effects or have difficulty responding to an emergency that may result in injury or harm.

Figure 1: Indicative safety advisory areas for MHFs

OHS authorities generally advise against land uses or developments within the inner planning advisory area, apart from low density industrial uses such as non-retail warehousing. They also generally advise against land uses or developments within the outer area for residential, business or other purposes where the people likely to be present are not able to respond safely to a potential emergency.

Environmental restrictions on land use

In many jurisdictions environmental authorities also have statutory referral powers for some land use planning proposals. In particular, environmental guidelines for industrial residual air emissions often recommend minimum separation distances between industrial land uses and sensitive land uses.

Environmental guidelines typically apply only to pollutants that cause odour and dust, rather than to hazardous chemicals (which are covered by OHS regulations). However, hydrogen sulphide, a gas that is present at most oil refineries, is odorous in low concentrations and therefore subject to these guidelines.

Regulations applicable in this case

Buffer zones in this jurisdiction

For the jurisdiction in which we were working, approval requirements and associated land use restrictions for MHFs were set at state or provincial level, taking into account the specific advice of specialist OHS and environmental regulators.

Until the objection was received from the owner of the MHF, the council had been intending to allow the aged care facility proposal to go ahead. It had been given general advice from consultants that it was safe to proceed, although this advice had been based on similar ‘typical’ facilities, rather than the specific MHF.

The council had some knowledge of the risk and safety laws pertinent to MHFs but was unaware of the relevance of a Safety Case. With the experience of land use safety planning, and relevant legal aspects and the processes involved, Broadleaf was aware that the refinery would need a Licence to Operate and, in order to obtain that, the refinery owner would have had to submit a Safety Case to the OHS regulator.

The council and the OHS regulator had communicated about the inner and outer advisory areas specific to the oil refinery. The OHS regulator indicated that the inner and outer advisory areas were to be measured 300m and 500m, respectively, from the edge of the oil refinery processing facilities, and 185m and 300m respectively from the tank farm bunded areas.

From the perspective of the safety regulator, the aged care centre would need to be located at least 500m from the oil refinery and 300m from the tank farms.

From the perspective of the environmental regulator, the required minimum distance between a petroleum refinery and land in a residential zone is 2km, and this would apply to the aged care facility. This requirement could be varied, but any variation would be based on specific information about the refinery.

Proximity of the site to the MHF

The extent of the inner and outer safety planning advisory areas (the specific boundaries in a map like Figure 1, but tailored for this specific MHF), and in particular whether these areas included the proposed aged care site, was considered critical information required to determine whether the risk to the site would be tolerable. So too were the minimum separation distances mandated by environmental authorities.

The proposed aged care facility was to be located about 1.65km from the refinery and 750m from the nearest tank farm (Figure 2). The MHF operator’s submission was that the aged care facility was within its buffer zone and would be inappropriate based on risk and safety.

Figure 2: Location of the site relative to the MHF

Figure 3 shows the indicative location of inner and outer planning advisory areas in relation to the MHF and the aged care site. The proposed site is clearly located outside these advisory areas.

Figure 3: Indicative safety advisory planning areas

Separately, the environmental authority had provided a letter to the council that stated that it had no concerns with the proposed development.

Summary of separation distances

Table 1 summarises the information about separation distances for the aged care facility and the refinery. It shows that the aged care site is only affected by the 2,000m minimum distance required by the environmental authority. As noted above, the environmental authority had no concerns about the location and had waived this requirement.

Table 1: Summary of separation distances



Description to sensitive sites




Minimum distance from crude storage tanks with floating roofs




Minimum distance from crude storage tanks with fixed roofs




Minimum distance from crude storage tanks




Minimum distance from refinery




Actual distance from proposed site to Tank Farm 2



Actual distance from proposed site to Tank Farm 1



Actual distance from proposed site to refinery



Minimum distance from refinery, waived in this case


Actions by the council and the refinery owner

The council had to consider the objection from the refinery owner and ascertain whether or not – on a risk basis – the refinery owner’s grounds for objection were reasonable.

To be satisfied that the risk to the proposed aged care facility from the refinery and storages would be tolerable, it was necessary to perform a risk assessment specific to the actual facilities. This could be done by obtaining information from the owner about the refinery itself, including the materials on site, the types and amounts of storages, the conditions of storage, the safety management systems in place and a large amount of other site-specific information.

The alternative would be to ask the oil refinery owner to provide their existing specific risk assessment, which would have the relevant information that could be used to demonstrate the level of risk at various distances from the refinery, including at the aged care site.

It seemed reasonable, therefore, to request a copy of the Safety Case for the refinery, so that the effect of potential major incidents at the plant on the proposed aged care facility could be assessed.

For that reason, as part of the Directions Hearing, Broadleaf requested that the oil refinery owner or the safety regulator provide a copy of the Safety Case, or relevant portions of it, to provide assurance, on a risk basis, that an aged care facility to be located at the proposed site would have sufficient protections.

The refinery owner strongly resisted the request for a copy of the Safety Case and questioned the relevance. Also, they insisted that the Safety Case was a document that was inwardly focused and not relevant to off-site effects.

Given this resistance, Broadleaf moved to say that the alternative to receiving the Safety Case was that we would have to conduct a risk assessment. Accordingly, we requested access to detailed process information about the site.

This was also resisted strongly by the refinery owner.

As a result, the refinery owner amended their submission and backtracked their safety concerns for an aged care facility in what it claimed was its buffer zone. They said that they referenced the MHF legislation in their submission merely to say that it provides general planning guidance for land use near MHFs, and that they did not intend to suggest that the site fell within the regulatory authority’s areas for restricted land uses.

For these reasons, they suggested, the Safety Case and any other issues related to safety or potential hazards or risks were considered irrelevant and they withdrew their objection on those grounds.

At this point, council understood that there was now no need for Broadleaf to provide evidence at an Expert Panel hearing. We provided a formal Statement of Evidence to council to ensure the relevant legislation and evidence, and the process that was followed, was recorded and available for future reference if necessary.


Generic and specific analyses

When dealing with any analysis, it is common to start with a generic, conservative analysis that is quick and simple, as was undertaken in this case with an analysis of a ‘typical’ oil refinery. As long as the analysis makes conservative assumptions, then this may be sufficient to make a justifiable decision.

If the simple, conservative analysis indicates that there is insufficient certainty about the level of risk for a defensible decision to be made, then a more detailed and site-specific analysis is required.

The general principle is to keep the process as simple as is necessary to achieve the outcomes and to make the decisions that are needed.

Domain-specific knowledge

When providing expert advice, it is necessary to have the appropriate information. In this case, it was useful that Broadleaf had a sound understanding of the planning process and the relevant regulatory context in the jurisdiction. This assisted in knowing what to ask for and what information to expect to be available.

In this particular case, the refinery owner possessed relevant information but was not prepared to provide it. Therefore they dropped their opposition to the proposal. We don’t know the reason for their opposition, but it is likely to have been because the Safety Case contained information that was considered commercially sensitive, such as plant throughputs, capacities or intellectual property that they did not want to make public.

Other reasons may have played a part. For example, revealing information about the extent of the risk contours around the refinery, and their proximity to neighbouring properties, would probably be sensitive in the community. Such information might reduce nearby land values, leading to media attention, negative publicity for the refinery owner, and possibly legal action from the owners of affected properties.