New Zealand’s management of contaminated land is based on a mix of existing measures, from legislation to guidelines and local plans. These measures have been developed by central and local government and industry to ensure no new contaminated sites are created and existing contaminated sites are identified and managed or cleaned up appropriately.
The existing measures aim to protect the environment, including the health and well-being of people and communities, and to provide ways of obtaining information on the presence and effects of contaminated land.
There are seven main pieces of legislation that relate to contaminated land or the effects of contaminated land (see Figure 2). These Acts can be generally grouped by their relevance to contaminated land. The four main areas are:
- prevention of contamination
- contaminated land management, enforcement, remediation and liability (post-1991)
- protection of the environment, including human health, from the effects of contaminated land
- access to information about contaminated land.
Figure 2: Main legislation relating to contaminated land, and relevant areas
|Prevention||Management||Protection of the environment||Access to information|
Resource Management Act 1991
|Hazardous Substances & New Organisms Act 1996|
|Health Act 1956|
|Health & Safety in Employment Act 1992|
Building Act 2004
|Food Act 1981|
|Local Government Official Information & Meetings Act|
A number of Acts appear to overlap, especially for the protection of the environment. Within the environmental area there are five pieces of legislation, although (with the exception of the RMA) most of these Acts have quite separate and distinct functions:
- the Health Act relates to public health nuisance from contaminated land
- the Health and Safety in Employment Act relates to workplace safety
- the Food Act relates to food safety
- the Building Act relates to the suitability of land for proposed buildings.
The RMA, with its emphasis on effects-based management and a holistic definition of the environment, overlaps with most of this legislation.
Under the umbrella of each piece of legislation there are a number of tools, ranging from guidelines and funds to standards. The above Acts and their associated tools are described below. A summary table showing the main contaminated land Acts and their respective roles, agencies, agents and tools is attached as Appendix A.
2.1 Resource Management Act
The RMA provides for the sustainable management of natural and physical resources, and it is the core piece of environmental legislation for controlling the effects of contaminated land on the environment and people. The RMA contains a definition of contaminated land, requires planning controls for the effects of contaminated land, and defines functions for local government in relation to contaminated land.
Contaminated land is defined in section 2 of the RMA as:
Land that has hazardous substances [The RMA section 2 definition of “hazardous substance” includes, but is not limited to, any substance defined in section 2 of the Hazardous Substances and New Organisms Act 1996 as a hazardous substance.] in or on it and
(a) is more contaminated than an applicable NES,[(a) does not apply as there are no national environmental standards for contaminants in soil.] or
(b) has, or is reasonably likely to have, significant adverse effects on the environment.
The RMA defines the environment widely to include ecosystems, people and communities, natural and physical resources, and amenity values. The RMA is designed to protect the environment through local government’s control of activities through plans and resource consents. It requires that local government control the discharge of contaminants to land to ensure that no new contaminated sites are created, and controls the effects of contaminated land on the environment.
The RMA provides some clarity for local government in how to manage contaminated land. Sections 30 and 31 give local government the following functions in this respect:
- regional councils - “the investigation of land for the purposes of identifying and monitoring contaminated land”
- territorial authorities - “the prevention or mitigation of any adverse effects of the development, subdivision, or use of contaminated land”.
Section 43 of the RMA also specifically enables the use of national regulation for the management of contaminated land. Section 43(1)(a)(iv) states that a national environment standard (NES) can prescribe “soil quality in relation to the discharge of contaminants”.
Local government and the RMA
The majority of environmental management and regulation is undertaken by local government, consisting of regional councils and territorial authorities (see Box 1). Each council controls the activities in its area through policies and rules in district and regional plans. Business and industry must ensure their activities comply with the requirements of these plans. Resource consents may be required for changes in land use, activities that have the potential to contaminate land, and activities on contaminated land. However, the requirements and the thresholds will vary between districts and between regions.
Because each of these plans is prepared individually, there is a lot of variability between plans in terms of how they address contaminated land. A recent review of contaminated land provisions in district, regional and unitary plans highlighted the extent of this variability (Ministry for the Environment, 2006c). The review showed that:
- 33 percent of plans featured no specific provisions relating to contaminated land
- approximately 40 percent of plans have specific objectives, policies and rules relating to land use or remediation of contaminated land
- of the plans that have specific provisions, there is significant variability in how contaminated land is addressed.
Regional and unitary plans are more consistent in that most address contaminated land in their plans, with 88 percent having specific provisions. However, there is still significant variation in terms of how each plan addresses contaminated land.
Box 1 Local government and its role under the RMA
There are 16 regional councils, including four unitary authorities (which have dual territorial and regional council functions). Regional councils:
- are generally organised along major catchment boundaries
- prepare regional policy statements and regional plans
- regulate discharges to air, water and land
- have the contaminated land function of: the investigation of land for the purposes of identifying and monitoring contaminated land.
There are 74 district and city councils. They:
- prepare district plans
- regulate land use, subdivision and building control
- have the contaminated land function of: the prevention or mitigation of any adverse effects of the development, subdivision, or use of contaminated land
- also have a range of public health responsibilities under other legislation.
In the past 10 years New Zealand authorities have undertaken a work programme to address the risks from historical contamination, building on the policy foundation established under ANZECC (1992). The result has been a series of contaminated land management guidelines (CLMG) developed by the Ministry for the Environment, in consultation with industry and local government. These provide a theoretical framework to contaminated land management and support local government functions under the RMA.
A number of industry-based guidelines were also developed containing soil guideline values for specific contaminants of concern. These guidelines also contain values for water and air for certain contaminants.
The following guidelines published by the Ministry for the Environment represent a significant component of the existing policy framework.
- Health and Environmental Guidelines for Selected Timber Treatment Chemicals (Ministry for the Environment and Ministry of Health, 1997) - provides guidance on the assessment and management of timber treatment sites, including numerical values for selected timber treatment chemicals. As the first New Zealand contaminated land management guideline, this document also provides generic guidance on sampling strategies and investigation techniques that could be - and in practice have been - applied to all contaminated site types. This guideline also has, by presenting guideline derivation equations and exposure definitions, provided the generic approach that practitioners have used to derive guideline values for other substances or for site-specific situations.
- Guidelines for Assessing and Managing Contaminated Gasworks Sites in New Zealand (Ministry for the Environment, 1997) - includes numerical values for hazardous substances associated with gasworks sites.
- Draft Sampling Protocols and Analytical Methods for Determining Petroleum Products in Soil and Water (Ministry for the Environment, 1999a).
- Guidelines for Assessing and Managing Petroleum Hydrocarbon Contaminated Sites in New Zealand (Ministry for the Environment 1999b) - includes numerical values for hazardous substances associated with petroleum hydrocarbon sites.
- Identifying, Investigating and Managing Risks Associated with Former Sheep-dip Sites: A Guide for Local Authorities (Ministry for the Environment, 2006a) - provides guidance to help local authorities address the potential risks arising from contaminated sheep-dip sites.
The contaminated land management guideline series
- Contaminated Land Management Guidelines No. 1: Reporting on Contaminated Sites in New Zealand (Ministry for the Environment, 2003a) - provides guideline reporting forms and checklists.
- Contaminated Land Management Guidelines No. 2: Hierarchy and Application in New Zealand of Environmental Guideline Values (Ministry for the Environment, 2003b) - provides guidance on selecting criteria from domestic and international guidelines.
- Contaminated Land Management Guidelines No. 3: Risk Screening System (Ministry for the Environment, 2004a) - provides a system for doing a desktop risk screening of contaminated land. The guideline superseded an earlier draft, Rapid Hazard Assessment System, published by Ministry for the Environment in 1993.
- Contaminated Land Management Guidelines No. 4: Classification and Information Management Protocols (Ministry for the Environment, 2006b) - outlines a consistent method for local government registers and the release of information through relevant legislation (eg, land information memoranda through the Local Government Official Information and Meetings Act 1987 and project information memoranda through the Building Act).
- Contaminated Land Management Guidelines No. 5: Site Investigation and Analysis of Soils (Ministry for the Environment, 2004b) - provides best practice for the sampling and analysis of soils on sites where hazardous substances are present or suspected in soils, and guidance on the principles governing the interpretation of the data obtained.
In addition, the following guidelines are widely used to assess the effects of hazardous substances on air, surface water and sediment:
- Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC and ARMCANZ, 2000)
- Ambient Air Quality Guidelines (Ministry for the Environment, 2002a).
All of the above guidelines are widely used in New Zealand, at least by regional councils and unitary authorities [The findings of a June 2006 survey of council officers at 14 of the 16 regional and unitary councils indicated that the guidelines were used by most respondents. The contaminated CLMG series was used by 85-100 percent of respondents, while the main industry guidelines (timber treatment, oil industry and gasworks) were used by most (79-83 percent) respondents (Ministry for the Environment, 2006d).], and have been found to be technically robust. Although the level of use by territorial authorities has not been surveyed, it is likely to be much more variable.
The Ministry has also supported the development of Guidelines for the Safe Application of Biosolids to Land in New Zealand (NZWWA, 2003) through the Sustainable Management Fund. These guidelines are designed to provide a framework for biosolids management that enables their application to land to maximise the benefits and minimise the risks of adverse effects on human health, the environment and the economy. In contrast to the other contaminated site guideline values, plant toxicity or food residue concentrations are often used as the basis for the biosolids guideline values.
Environmental guideline values
Numerical hazardous substances values that are protective of human health and the environment, and the methods used to derive them, are important tools in the assessment of contaminated land. Without these values and methods we would not be able to assess the effect of contaminated land on the environment or on human health.
Typically, New Zealand practitioners rely on a mixture of national and international guidelines from which to select numerical values. However, the various New Zealand and international guidelines used contain:
- different terminology (eg, acceptance criteria, trigger values, maximum acceptable values, environmental quality guidelines, intervention levels) (Cavanagh and O’Halloran, 2002)
- different receptors
- different methodologies and assumptions for deriving values, particularly different toxicity values, receptors accepted and exposure pathways considered (Cavanagh and O’Halloran, 2003).
To reduce the confusion created by these differences, the Ministry for the Environment produced a guideline in partnership with local government called Contaminated Land Management Guidelines No. 2: Hierarchy and Application in New Zealand of Environmental Guideline Values (Ministry for the Environment, 2003b). CLMG No. 2 provides a best-practice hierarchy for selecting guidelines from the range of New Zealand and international guidelines available. CLMG No. 2 states a preference for New Zealand guideline values over international guidelines, and a preference for risk-based guideline values over threshold values. Based on these preferences, CLMG No. 2 sets out the following hierarchy for selecting guideline values:
- New Zealand-derived, risk-based guideline values
- rest-of-the-world-derived risk-based guideline values, with a preference given to those that employ risk assessment methodologies and exposure parameters consistent with what is already used in New Zealand
- New Zealand-derived threshold values
- rest-of-the-world-derived threshold values.
Figure 3 shows the purpose for which each of these guidelines is applied (human health or ecosystem) and the media the values are derived for (soil, water or air). Appendix D contains tables from CLMG No. 2 that show the hierarchy of documents containing guideline values for soil and water. Appendix E contains summary information on each of the guidelines identified.
Notes: MfE = Ministry for the Environment; MOH = Ministry of Health. For simplicity, this figure excludes the NZFSA Food Standards for produce.
Text description of figure
The figure shows the methods and numerical values for ecosystems and the methods and values for human health, for water, soil sediment and air. Gaps are filled by various international guidance.
Methods and numerical values for ecosystems
- Ambient air quality guidelines (MfE, 2002a)
Soil & Water
- Water quality guidelines for fresh and marine waters (ANZECC/ARMCANZ, 2000)
- Timber treatment (MfE and MOH, 1997)
- Gasworks (MfE, 1997)
Methods and numerical values for human health
- Drinking-water standards 2005 (MOH, 2005)
- Water quality guidelines for fresh and marine waters (ANZECC and ARMCANZ, 2000)
- Timber treatment (MfE and MOH, 1997)
- Gasworks (MfE, 1997)
- Oil industry (MfE, 1999a, 1999b)
- Sheep-dip draft (MfE, 2006a)
- Lead-exposed persons (MoH,1998)
- Workplace exposure standards (OSH, 2002)
- Ambient air quality guidelines (MfE, 2002a)
- Oil industry and gasworks (MfE 1997, 1999a, 1999b)
- Air Quality National Environmental Standard
Contaminated Sites Remediation Fund
Since 2003 the Government has made up to $2 million per year available for the Contaminated Sites Remediation Fund (CSRF) [The fund was originally called the Orphan Sites Remediation Fund. This name is not appropriate since the definition of an “orphan site” rests on a legal liability regime that does not currently exist.]. The funding has been made available in two parts:
- $1 million per year is allocated to the clean-up of New Zealand’s highest-risk contaminated sites (eg, Mapua)
- $1 million per year is available as a contestable fund to assist regional councils to investigate and clean up high-risk contaminated sites. To qualify, the sites must pose a known or potential risk to human health and the environment within their regions.
Contaminated sites that are posing or likely to pose a high risk to human health, and that are prime candidates for the CSRF, are those that are:
- located in environmentally or culturally sensitive areas or
- where the landowners do not have the financial resources to undertake the work themselves but want to do something about the problem.
The CSRF plays a key role in encouraging action on contaminated sites, especially where the responsibility for contamination is difficult to establish. Since 2003 the fund has supported 33 projects. Most of these projects (26) have been for assessment and remediation planning rather than actual remediation (seven). The remediation of the former Fruitgrowers Chemical Company property in Mapua, near Nelson, is the largest and most notable of these remediation projects.
There are, however, obstacles to achieving clean-up, such as the size of the fund and the limited financial resources of local government. The budget announcement in May 2006 allocated an additional $1.7 million per year[GST inclusive] to the fund for the next three years (2006–2009).
New Zealand Waste Strategy
The New Zealand Waste Strategy (Ministry for the Environment, 2002b) was developed in partnership with local government in 2002. The strategy provides a series of targets for contaminated land, which guide the activities of central and local government over the next decade. The targets for contaminated land are as follows:
By December 2008, all sites on the Hazardous Activities and Industry List will have been identified and subject to a rapid screening system in accordance with the Ministry’s guidelines.
By December 2010, all sites on the Hazardous Activities and Industry List will have been subject to a rapid screening system, in accordance with Ministry guidelines, and a remediation programme will have been developed for those that qualify as high-risk.
By December 2015, all high-risk contaminated sites will have been managed or remediated. A timeframe will have been developed to address the management or remediation of remaining sites.
The targets involve the identification, management and remediation of high-risk contaminated land according to the Ministry’s guidelines. Local government is making progress towards achieving these targets.
Agrichemicals collection and disposal
New Zealand has a legacy of unwanted agrichemicals in farm sheds around the country which pose a risk to the environment. Many of these unwanted agrichemicals are persistent organic pollutants (like DDT) which are now banned from use. Under the Stockholm Convention, New Zealand is obliged to remove stockpiled persistent organic compounds (intractable agrichemicals) by 2013.
Since 2003 approximately 270 tonnes of agrichemicals have been collected and removed from rural properties across New Zealand. Of these, over 220 tonnes were “intractable” agrichemicals, requiring high-temperature incineration. So far the programme has cost $2.5 million. The Ministry for the Environment will continue to work with industry and councils to collect and safely dispose of unwanted agrichemicals stockpiled on farms throughout New Zealand for the next three years. The Ministry for the Environment also intends to assist industry and councils to establish appropriate ongoing collection programmes in each region to ensure that stockpiles of unwanted agrichemical do not build up again.
2.2 HSNO Act and regulations
The Hazardous Substances and New Organisms Act 1996 (HSNO) is administered by the Ministry for the Environment but is implemented by the Environmental Risk Management Authority (ERMA) and enforced by various agencies, including local government and the Department of Labour.
HSNO controls are established to prevent future land contamination. Under the HSNO Act, life-cycle controls on the manufacture, use, storage, and disposal of hazardous substances are set by ERMA through regulations.
The HSNO Act provides for ERMA to establish exposure limits for hazardous substances for the protection of human health and ecological receptors. An exposure limit is defined as the maximum amount of a hazardous substance that can be legally present in a particular environmental medium such as air, water or soil, or deposited on a plant surface (such as plant foliage), although exposure limits may also be set as guideline values (ie, not legally enforceable).
There are two types of exposure limits that may be set for hazardous substances.
- The tolerable exposure limit (TEL) is designed to protect humans from the adverse effects of toxic substances. It is the concentration of a substance in an environmental medium that will present a low risk of a toxic effect occurring in people exposed to that substance.
- The environmental exposure limit (EEL) is designed to protect organisms other than humans (including plants) from the adverse effects of ecotoxic substances. It is the concentration of a substance in an environmental medium that will present a low risk of adverse environmental effects in non-target areas.
TELs and EELs may be set for new toxic and ecotoxic substances which are assessed under the HSNO Act, and may also be set for existing substances as they are transferred to the HSNO regime, as required by the Hazardous Substances (Classes 6, 8 and 9 Controls) Regulations. Where a legally enforceable TEL or EEL has been set for a substance, it is an offence to use that substance in a way that causes the concentration to exceed the exposure limit set for that specific environmental medium. A limited number of TELs and EELs have been set and are available at www.ermanz.govt.nz.
2.3 Health Act
The Health Act 1956 is the principal health statute. It is administered by the Ministry of Health and enforced by public health agencies and territorial authorities. The Act establishes public health management arrangements for communicable disease, and covers some generic environmental health risks and other miscellaneous issues.
The Health Act is relevant to contaminated land where it provides powers and sets a duty for territorial authorities to abate public health nuisances. Health nuisances are defined by the Act as conditions that are “offensive or likely to be injurious to health” [Section 29(a) and (o) of the Health Act 1956.]. It is understood that the use of these powers for contaminated land is unusual and that they are only likely to be applied if there is a possibility of immediate harm.
In 1998 the Ministry of Health published Environmental Case Management of Lead Exposed Persons: Guidelines for Public Health Services (Ministry of Health, 1998). These guidelines provide practical advice for the investigation and environmental case management of people with elevated levels of lead, and are particularly aimed at risks arising from lead-based paint. The guidelines include recommendations for protecting children from lead in soil, and are principally taken from United States guidance. Guidance is also provided on dust and soil-sampling techniques for residential situations.
2.4 Health and Safety in Employment Act
The objective of the Health and Safety in Employment (HSE) Act 1992 is to promote the prevention of harm to all people at work and others in, or in the vicinity of, places of work. The HSE Act is administered and enforced by the Department of Labour. To support workplace safety the Department of Labour has produced a number of guidelines.
The Health and Safety Guidelines on the Cleanup of Contaminated Sites (OSH, 1994) published in 1994 concern the occupational health aspects of site clean-up and focus on the procedures and methods necessary to protect the workers involved. The guidelines complement existing guidelines, such as those published by the Ministry for the Environment. The Workplace Exposure Standards (OSH, 2002), last revised in 2002, assign standards for concentrations in air for approximately 700 substances.
The Workplace Exposure Standards (WES) are intended to be used as guidelines for those involved in occupational health practice. Although the WES are called “standards”, they do not have the force of regulation that national environmental standards and food standards have.
Other guidelines published by OSH that contaminated land practitioners, as part of their investigations, should be aware of are:
- Safe Working in Confined Spaces (OSH, various dates), a series of information sheets on safety in confined spaces
- Code of Practice for the Design, Installation and Operation of Underground Petroleum Storage systems (OSH, 1992), which provides environmental site-sensitivity ratings and processes for carrying out environmental sensitivity and hydro-geological surveys.
2.5 Food Act
The Food Act 1981 is administered by the Ministry of Health and implemented by the New Zealand Food Safety Authority (NZFSA). The NZFSA ensures the food New Zealand produces, exports and imports is safe and suitable for domestic and international consumers.
The Food Act 1981 enables the setting of food standards. Food Standards Australia New Zealand (FSANZ) develops food standards for both New Zealand and Australia. In New Zealand the NZFSA enforces these standards. It is important to consider food standards when setting soil quality targets for the remediation of land which will be used for food production, although there is no direct (or easily determined) link between food standards and soil contamination.
2.6 Building Act
The Building Act 2004 enables the setting of building regulations in the form of the Building Code. The Act is administered by the Department of Building and Housing and is implemented by territorial authorities.
Clause F1 of the Building Code specifically requires building sites to be assessed to determine the presence and potential threat of any hazardous agents or contaminants [Clause F1 of the New Zealand Building Code, “Hazardous agents on-site”, is contained in the First Schedule of the Building Regulations 1992.]. Clause F1 is supported by the Approved Document for New Zealand Building Code: Hazardous Agents on Site (Building Industry Authority, 2001). This provides a contaminated land investigation methodology derived from the now outdated Australian and New Zealand Guidelines for the Assessment and Management of Contaminated Sites (ANZECC, 1992).
Also, under the Building Act an owner contemplating building work may apply to a territorial authority for a project information memorandum (PIM) in respect of the work. Like land information memoranda (see below), PIMs must include information on the likely presence of hazardous contaminants.
2.7 Local Government Official Information and Meetings Act
Under the Local Government Official Information and Meetings Act 1987 (LGOIMA), any person may apply in writing to a territorial authority for the issue of a land information memorandum (LIM) containing matters affecting any land in the district of that authority. Territorial authorities are required to disclose everything they know about a parcel of land, including any information they hold about the “likely presence of hazardous contaminants”.
LIMs and PIMs have become an important mechanism for the release of contaminated land information. People and communities, as well as business and industry, benefit from this information because it allows them to make informed decisions when buying or selling property.
In response to recent uncertainty by councils and landowners over the interpretation of “likely presence of hazardous contaminants”, the Ministry for the Environment released two Crown Law opinions to clarify what should be included on the LIMs for former horticultural land [These legal opinions can be downloaded from 'What should be included on LIM for former horticultural land – legal advice'].
2.8 Tax incentives
A June 2005 amendment to the Income Tax Act created a mechanism to facilitate tax deductions for business expenditure on the clean-up of contaminated sites. A key element of the amendment is a provision for business taxpayers to establish site restoration funds. Businesses can choose to divert some of their tax payments into a restoration fund, which will give rise to tax deductions over the operating life of the business. When a taxpayer incurs expenditure to rectify discharges of contaminants, they will be able to apply for a refund from the restoration fund.
The following remediation activities are also now eligible for tax deductions under the amendment:
- expenditure on investigating and testing locations and methods for an activity or improvement that is intended to avoid, remedy or mitigate detrimental effects on the environment from the discharge of contaminants
- expenditure related to monitoring discharges and their effects, and the effectiveness of solutions
- capital expenditure, including the planning and construction of tanks, pipes, impermeable surfaces and machinery, in addition to costs associated with the planting of trees and other vegetation for the purpose of avoiding, remedying or mitigating effects on the environment from the discharge of contaminants.
2.9 International agreements: Stockholm Convention
The Stockholm Convention on Persistent Organic Pollutants aims to protect human health and the environment by banning the production and use of some of the most toxic chemicals known to humankind. The Convention became international law in May 2004, was ratified by New Zealand in September 2004 and entered into force for New Zealand on 23 December that year. Persistent organic pollutants (POPs) are chemical substances that persist in the environment, bioaccumulate through the food chain, and pose a risk of causing adverse effects to human health and the environment.
The Ministry for the Environment consulted on a National Implementation Plan during June to August 2006. The Plan sets out how New Zealand proposes to meet Stockholm Convention obligations, such as reducing dioxin releases, completing the phase-out of Polychlorinated biphenyls (PCBs), undertaking the environmentally sound management of POPs wastes such as obsolete chemicals and contaminated soils, and environmental monitoring. New Zealand’s final plan is to be submitted to the Stockholm Convention Secretariat by December 2006.