Areas where RMA controls may be necessary

In most circumstances, the HSNO Act and HSW Act provide an appropriate level of management of hazardous substances.  However, there will be some situations where RMA controls may be justified.  

The need to place controls in RMA plans to manage the effects of use of hazardous substances will differ according to local circumstances and is generally only warranted when hazardous substances are located within sensitive environments and/or incompatible activities. The need for any controls must be justified through a robust section 32 evaluation that demonstrates why a degree of environmental protection over and above that provided for under other legislation, such as the HSNO Act or the HSW Act, is necessary within that particular local context. The following guidance provides information on circumstances where it might be justified and appropriate to include controls in RMA plans and policy statements to manage specific and local environmental effects of managing, handling and storing hazardous substances. The focus of any such provisions should be on ensuring the risk of adverse effects is acceptable, rather than on risk avoidance. 


Where land uses are incompatible

The use and handling of hazardous substances is usually a subset of the risks and effects associated with a particular land use activity and, as such, the anticipated adverse effects of the activity is typically addressed by zone provisions it is located in.

The HSNO Act and HSW Act have a generic consideration of surrounding land uses, by including different clearances with respect to specific substances (HSNO Act) or hazardous facilities according to surrounding land uses (HSW Act). Most of these controls apply regardless of where that substance is stored or used and apply a precautionary approach, which provides an acceptable level of safety, including in respect of separation distances, in most circumstances. Generally, the HSNO and HSW Acts will be adequate to ensure risks, including cumulative effects, associated with hazardous facilities (activities that use, store, manufacture and/or dispose of hazardous substances) are contained on a site. However, some hazardous facilities, may have potential for off-site effects, despite compliance with HSNO and the HSW Act, for instance some Major Hazardous Facilities (MHF).   

Where necessary and appropriate, managing the effects of activities that use, store, manufacture and/or dispose of hazardous substances in relation to surrounding land uses may be achieved under the RMA by:

  1. Managing the establishment of hazardous substances/facilities adjacent to and within sensitive environments to ensure acceptable levels of risk of off-site adverse effects; and
  2. Preventing sensitive or incompatible activities establishing in areas where hazardous facilities/activities are located where these activities have the potential to constrain or curtail the operation of a lawfully established hazardous facility.

Major Hazard Facilities (MHF)

Particular attention should be given to potential land incompatibility issues associated with MHF. As noted above, MHF are defined under regulation 19 and 20 of the Health and Safety at Work Regulations 2016 (the MHF Regulations). They are workplaces that have significant inherent hazards due to the storage and use of large quantities of specified hazardous substances. Failure to control risks associated with these facilities could result in catastrophic consequences. The MHF Regulations mandate specific duties relating to process safety for existing and potential MHFs.

Specific requirements in the MHF regulations include:

  • Operators of proposed MHFs are required to notify WorkSafe that their facility is likely to equal or exceed the threshold quantity for an MHF. The notification needs to include information about the land use and other activities in the area surrounding the facility or proposed facility (regulation 12)
  • The operator of each MHF must prepare and test an emergency plan – which must include a map showing the site of the MHF and land use and occupancy, any MHF and any hazardous substance storage sites that are known to the operator, within a 2 km radius of any point on the perimeter of the MHF (regulations 31 and 32)
  • Operators of an Upper Tier MHF are required to prepare safety cases and submit them to WorkSafe for acceptance. An Upper Tier MHF must have an accepted safety case to operate. A safety case is a document that summarises and describes process safety related systems and controls in sufficient detail to demonstrate their adequacy.  The safety case must include demographic information about the local community, including authorised land uses, within a 2 km radius of any point on the perimeter of the UTMHF.  (regulation 45 and schedule 7)
  • The operator of a MHF has a duty to provide plain English information to the local community about their MHF including contact details, how they would inform the local community if a major incident occurs and what to do if there is a major incident (regulation 66).

For sites or operations that store or use particularly large volumes of hazardous substances (including MHF), councils may want to consider controls that extend beyond HSNO Act, whereby a wider assessment of the surrounding land uses and environment will be required.  Any assessment matters or restriction of discretion in relation to these types of activities (e.g. bulk fuel storage, large scale chemical or explosive storage and manufacture etc), will need to consider what the risks are and what information council will need to assess these risks.

Where there are sensitive receiving environments 

The HSNO Act and HSW Act have a generic consideration of surrounding land uses, by including different clearances with respect to specific substances or hazardous facilities according to surrounding land uses. Most of these controls apply regardless of where that substance is stored or used, which provides an acceptable level of safety in most circumstances.

However, to within or adjacent to particularly sensitive receiving environments, additional controls under the RMA may be justified to appropriately manage the adverse effects and risks associated with hazardous substances. For example, a rule might be imposed in a plan imposing permitted activity conditions or requiring resource consent for hazardous facilities within a certain setback distance from sensitive areas, such as wetlands or sources of reticulated potable water. This would allow site-specific requirements to be imposed to ensure the potential adverse effects on these receiving environments from hazardous substances are appropriately managed. Any such controls should only address matters not appropriately addressed under other legislation.

Reverse sensitivity issues

For the purposes of this guidance note, reverse sensitivity can be defined as the potential for the operation of an existing lawfully established activity to be constrained or curtailed by the more recent establishment or intensification of other activities which are sensitive to the established activity. Under the RMA, new activities may be restricted where they have the potential to result in reverse sensitivity effects in order to protect established activities and their operations.

In relation to hazardous substances, this can occur where sensitive activities (such as residential activities or places of assembly) are allowed to locate in proximity to existing hazardous facilities. This can be of concern, because these activities are particularly sensitive to the operation of hazardous facilities, which can have adverse effects, or risks beyond the sit boundary that may not be able to be completely avoided or mitigated.  For most activities, this is often achieving through the underlying zone or overlay provisions, such as a non-complying status for sensitive activities within industrial zones.

Reverse sensitivity effects are not specifically addressed under the HSNO Act or HSW Act as these Acts do not provide regulatory powers or controls in relation to land use planning. The MHF Regulations only control the hazardous facility itself, not surrounding land uses.  Therefore, it is important that land use planning minimises exposure to people close to a hazardous facility (particularly a MHF). Historically, the focus has been on the management of hazardous substances themselves, and not issues regarding encroachment around hazardous facilities.

MHF have requirements under the HSW Act (and associated regulations) to ensure the safety of workers on the site and those nearby. Encroachment of sensitive activities around MHF can therefore significantly impede their ability to meet their regulatory requirements. Any such constraints are potentially significant, noting that the list of MHF (found on the Worksafe website), includes infrastructure of national and regional significance. These facilities involve significant investment, and often have a functional need to be located in a particular location. In the worst case scenario, reverse sensitivity effects may result in MHF sites having to stop operating, which would have significant implications for communities and their well-being. 

Councils need to be fully aware of the significance and potential risk from a MHF, when considering sensitive land uses or intensification of existing activities near an MHF. Depending on the risk, it may be appropriate to consider land use restrictions on land in the vicinity of a MHF, to enable the MHF to carry out its operations, including maintenance and upgrades, without being unreasonably constrained by sensitive activities subsequently locating near a MHF.

Cumulative risks of multiple hazardous facilities

The HSNO Act and the HSW Act controls are substance and location-specific and do not address cumulative risk in the case of an accident.  Cumulative risks may result from similar types of risks presented by neighbouring facilities, or from potential multiple adverse events through time. For most small to medium hazardous facilities, cumulative risks are generally not a significant issue that warrant controls in RMA plans, but they may be for larger facilities to ensure risks are acceptable. 

Areas prone to natural hazards 

Many plans contain natural hazard risk overlays to control the development of land to avoid or reduce the risks of natural hazards.  In these areas, risk assessments are often required to determine the potential risks of an activity and how it may be be affected by, the relevant natural hazard event (including in respect of frequency and consequences).  These risk assessments should also determine the effectiveness of mitigation, if any, to protect the environment and human health. The proximity of activities which use hazardous substances to areas subject to natural hazards can increase the likelihood of a release of a hazardous substance into the environment should a natural hazard event occur. The location of hazardous facilities in relation to areas prone to natural hazards is therefore something which councils may consider addressing through RMA plan provisions if there is evidence that the existing regulatory controls are insufficient to adequately address risk in those areas. Consideration should also be given to climate change effects which have the potential to increase the frequency, magnitude, and consequences of natural hazard events. 

Councils may find that the requirements within their RMA plans relating to buildings and development in areas identified as being subject to natural hazards, combined with the HSNO Act and HSW Act requirements and requirements under other legislation such as the Building (Earthquake-prone Buildings) Amendment Act 2016, are sufficient to protect the building or site in which a hazardous substance is used or stored from the natural hazard risk. Where the risk of a natural hazard is greater, councils may place additional controls on the location of certain activities (such as industrial activities) or hazardous substances within the specified natural hazard risk area. It is not warranted to impose blanket controls on all hazardous substances on land considered hazard prone as this would likely result in significant consenting requirements without adding significant benefits.


The HSNO Act and HSW Act do not directly manage discharges of hazardous substances/contaminants to land, water and air. In controlling how these substances are stored and used, they do however have an important role to play in mitigating potential for discharges. For example, in relation to petroleum refuelling facilities, despite management in accordance with the HSNO Act, there remains potential for discharges to land, water and air from refuelling activities. It is therefore appropriate that the potential adverse effects of these discharges se are managed by regional councils, for instance through industrial and trade activity provisions. Regional councils need to consider the HSNO Act and HSW Act controls and any relevant controls under the Agricultural Compounds and Veterinary Medicines Act 1997 (ACVM Act) when including controls on discharges from hazardous substances in their plans to avoid unnecessary duplication or confusion. Use and disposal of hazardous substances still must comply with the HSNO Act, HSW Act and where relevant the ACVM Act or any other relevant legislation. 

For example, regional plans may require resource consent for the use and discharge of agrichemicals such as fertilisers and pesticides. However, fertilisers, agricultural herbicides and other pesticides have existing controls under HSWA and the HSNO Act, and the ACVM Act.  Councils should review the controls imposed under the HSNO Act, HSW Act and ACVM and only include additional controls in their plans where these Acts are considered insufficient to avoid, remedy or mitigate adverse effects on the environmental and public health.

Substances outside HSNO

Under the RMA, the definition of hazardous substances  includes, but is not limited to, any substance defined in the HSNO Act as a hazardous substance. This means that under the RMA, hazardous substances can encompass a wider range of substances and hazardous properties, than under HSNO.

RMA plans and policy statements may control substances which, due to particular properties, can have adverse effects on ecosystems and wildlife but are not considered eco-toxic under the HSNO Act. Such properties include the potential to cause high bio-chemical oxygen demand in natural waters when the substance enters such waters, leading to rapid oxygen depletion, for example some agrichemicals. Other environmentally damaging properties include the potential for smothering effects, for example those caused by certain oils.