Module Three: An Overview of the HFSP
What, why and how|Overview of the HFSP
What, why and how
What
- overview of the HFSP - how does it work?
- the key building blocks of the HFSP
- how the HFSP can be used to assess the effects presented by several hazardous substances
Why
- to appreciate the principal elements of the HFSP
- to see how the HFSP enables the screening of hazardous facilities for consenting purposes
How
- presentation
- exercise and report in
What
I hear I forget, what I see I remember, but what I do I understand
Confucius, circa 500 BE
Overview of the HFSP
Background
The storage, use and transport of hazardous substances are normal parts of many industrial activities. However, if these activities are not properly managed, significant damage to the environment, human health and property may result when hazardous substances are accidentally released.
Adverse environmental effects caused by hazardous facilities may affect a range of sensitive resources such as:
- stream, estuaries, harbours and lakes
- wetlands
- hospitals, schools, rest homes, residential housing
The purpose of the HFSP is to assess potential off-site adverse effects of a proposed hazardous facility at a particular location, taking into account:
- the types and quantities of hazardous substances stored or used on a site
- the hazards posed by the intrinsic properties of the hazardous substances in question
- substance-specific factors such as physical form and mobility in the environment (for example, whether a substance is solid or liquid)
- site-specific factors such as the sensitivity of neighbouring land uses, or the proximity to sensitive environmental resources, i.e., wetlands, lakes, or aquifers.
Assessing Hazardous Substances: Effect Types and Hazard Ratings
To be able to apply the HFSP, hazardous substances used or stored by a hazardous facility must be assessed first in terms of the hazards they present. For example: Are they flammable? Are they explosive? Are they toxic?
HSNO Act provides framework for assessing hazardous substances
The HSNO Act provides the framework for assessing and classifying the different hazardous properties of hazardous substances and how these need to be controlled.
Because the HFSP is meant to be simple screening method for resource consenting purposes, the HSNO classification framework has been simplified for use with the HFSP. This involves using two fundamental concepts:
- Effect Type
- Hazard Level
Effect types and hazard levels
The HFSP assesses hazardous substances broadly and simply in terms of three Effect Types. These are:
- Fire/Explosion Effect Type
- Human Health Effect Type
- Environment Effect Type
Each of the above Effect Types is divided into three Hazard Levels:
- High
- Medium
- Low
Based on this approach, each substance is given a hazard rating for each Effect Type. As follows:
| Effect type | Hazard level | ||
|---|---|---|---|
| Fire/Explosion | High | Medium | Low |
| Human Health | High | Medium | Low |
| Environment | High | Medium | Low |
The Hazard Level for each hazardous substance is based on the hazard classification system established under the HSNO Act. This is further described in Module 6.
Assessing cumulative effects
If more than one hazardous substance is present on a site, the assessment for the HFSP is carried out for all substances so that their joint (cumulative) effects in relation to their surrounding land use and the environment can be evaluated. This is done in terms of the tree Effect Types outlined above.
The key building blocks of the HFSP
The key building blocks of the HFSP comprise:
- Base Quantities
- Adjustment Factors
- Adjusted Quantities
- Quantity Ratios
These elements are further described below.
Base Quantities
A Base Quantity is the maximum quantity of a hazardous substance which is deemed, in terms of the off-site risks it presents, to be acceptable on a site in a heavy industrial zone .
Different Base Quantities apply for each of the above-described Effect Types and Hazard Levels, reflecting the different levels of off-site risk this present.
Experts in the field have based the development of appropriate Base Quantities for the different Effect Types and Hazard Levels on scientific research and professional judgement.
The Base Quantities used for the HFSP are shown in Table 3.1. This Table shows Base Quantities for each Effect Type and Hazard Level. Examples of applicable Base Quantities are:
- 100 tonnes for combustible liquids (HSNO Class 3D) with a LOW Hazard Level for the Fire/Explosion Effect Type (for example, diesel)
- 10 tonnes for flammable liquids with a HIGH Hazard Level (HSNO Class 3.1A) for the Fire/Explosion Effect Type (for example petrol)
- 3 tonnes for ecotoxic materials with a HIGH Hazard Level (HSNO Class 9.1A) for the Environment Effect Type (for example, pesticides)
Adjustment Factors
Site and substance conditions are not always ideal, and sometimes these factors can influence the level of off site risk presented by some hazardous substances. The HFSP enables key site- and substance-specific factors to be taken into account when determining the status of a hazardous facility. This occurs through the use of a series of Adjustment Factors that are applied to the Base Quantities for each substance.
Adjustment Factors vary for the different Effect Types and take into account the following:
Substance-specific factors such as:
- the state of the substance (whether solid, powder, liquid, or gas)
- the type of storage proposed (above ground or underground.
Site-specific factors such as:
- distance to site boundary
- proximity to any sensitive water bodies.
There are three Adjustment Factors for each Effect Type.
Adjustment Factors are listed in Table 3.2.
Adjusted Quantities
Adjusted Quantities are calculated by multiplying the Base Quantities of a hazardous substance with the appropriate Adjustment Factors. This is done for every Effect Type so that the full range of effects can be assessed for each substance.
An Adjusted Quantity reflects the quantity of a hazardous substance(s) which is deemed, having considered site and substance-specific factors, to be acceptable on a site in a heavy industrial zone (i.e. it will not generate or present any significant off site risk in that environment).
Quantity Ratios
The Quantity Ratio is a ratio that is derived from dividing the quantity of a particular hazardous substance that is proposed to be used or stored on a site, by the Adjusted Quantity calculated for that substance.
The reason for calculating Quantity Ratios is so that the effects of different hazardous substances which may be proposed for a particular site can be added up within each Effect Type. In this way, cumulative effects of hazardous substances, to be used or stored by a proposed facility, can be assessed. By using this approach, the HFSP fulfils one of the key requirements of the RMA.
The Quantity Ratio calculated by the HFSP creates the link into the District Plan, by establishing a numerical figure that can be matched against the numerical limits or Consent Status Indices that are listed in a plan to determine the consent status of an application for a hazardous facility (Refer Module 4 - Exceptions and exemptions).
Case study
A case study for calculating a Quantity Ratio is shown below: An applicant proposes to store 60 tonnes of a highly flammable liquid (HSNO Class 3.1a; UN Class 3 PGI) in two underground storage tanks, which are located less than 30 metres from the site boundary.
- Base Quantity (Table 3.1) = 10 tonnes
- Applicable adjustment factors: (Table 3.2)
- FF1 = 1 (liquid)
- FF2 = 1 (distance <30 metres)
- FF3 = 10 (underground storage)
- FF1 x FF2 x FF3 = 10
- Adjusted Threshold Quantity = 100 tonnes
- Proposed Quantity = 60 tonnes
- Quantity Ratio \ = 60 ¸ 100 = 0.60
Note: as the substance is flammable, the above calculation has been carried out for the Fire/Explosion Effect Group. If the hazardous substance also exhibits other hazards – for example it may be toxic or ecotoxic, then the same exercise may have to be carried out for the Human Health and Environment Effect Groups.
Figure 3.1 shows an example of a completed HFSP calculation for a hypothetical print shop in a mythical business zone. Quantity Ratios have been calculated for each proposed hazardous substance and the three Effect Types (Fire/explosion, Human health, Environment).
The Quantity Ratios calculated for each substance have then been added up within each Effect Group to show t the combined Quantity Ratio for all the different hazardous substances that will be used by the facility.
The example illustrates how the cumulated Quantity Ratios for this facility exceed the critical levels for a resource consent for the Fire/Explosion and the Environment Effect Types.
Module 4 will deal further with how the HFSP links into the actual controls stipulated by a district plan.
Figure 3.1 Illustration of the consent status of a print shop in a business zone
See
Figure 3.1 at its full size (including text description)
Exercise
3.1
- Describe below, with a few bullet points, the following terms:
- Base Quantity
- Adjustment Factor
- Adjusted Quantity
- Quantity Ratio
- In Figure 3.1, which hazardous substance is the major contributor to the Quantity Ratio in each of the Effect Groups?
- What do you think could be done to reduce the Quantity Ratio in each of the Effect Groups?
Key
application
Identify a key application of the information you’ve learnt in your day-to-day working environment.
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