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1 Introduction

This is the fourth in a series of five guidance documents for contaminated land[Terms in bold are defined in the Glossary.] management produced by the Ministry for the Environment. The other four guidance documents are:

  • Contaminated Land Management Guidelines No. 1: Reporting on Contaminated Sites in New Zealand (Ministry for the Environment, 2003a)
  • Contaminated Land Management Guidelines No. 2: Hierarchy and Application in New Zealand of Environmental Guideline Values (Ministry for the Environment, 2003b)
  • Contaminated Land Management Guidelines No. 3: Risk Screening System (Ministry for the Environment, 2004a)
  • Contaminated Land Management Guidelines No. 5: Site Investigation and Analysis of Soils (Ministry for the Environment, 2004b).

Under the RMA, regional councils have the function of investigating land in order to identify and monitor contaminated land. Territorial authorities have the function of preventing or mitigating any adverse effects from the development, subdivision or use of contaminated land.

Both regional councils and territorial authorities acquire large amounts of information in the course of carrying out their functions. In addition, due to an increasing public awareness of land contamination issues, local authorities [The term 'local authority' refers to regional councils, city and district councils (territorial authorities) and unitary authorities.] receive enquiries for information, particularly associated with property transactions or development. The quality of information available, together with the legal liability issues that arise from inappropriate release or inaccurate interpretation of information, mean there is a need for careful information management.

1.1 Purpose

The purpose of this guideline is to promote a practical, nationally consistent framework to assist local authorities to investigate and monitor contaminated land. The guideline promotes best practice among local authorities for identifying and classifying sites, and for providing information to landowners and other interested parties.

The classification system promoted here groups sites according to the adverse effects or risk − or potential risk − they pose to the environment, including people. The system helps to identify sites that require investigation or remediation. Local authorities are encouraged to adopt the classification system and procedures provided. Having a nationally consistent system will enable everyone involved in the management of information about land contamination to 'talk the same language', and ultimately should encourage better outcomes for everyone involved in the sale, purchase, investigation, remediation and use of sites.

1.2 Scope

This guideline covers sites where hazardous substances are, or may be, present in the environment, and where there is the potential for those hazardous substances to pose risks to people or to have wider environmental effects.

The guideline does not cover environmental contaminants such as micro-organisms or radioactivity, although there may be some circumstances (eg, if the risks posed by the presence of contaminants on the site are not addressed in another way) when it is appropriate for information about such a site to be placed on the register.

Note that local authorities or other agencies may choose to address issues of widespread contamination, such as historical pesticide use or cadmium contamination, through specific strategies rather than by the systems in this guideline.

1.3 Relationship to other documents

Some regional councils and unitary authorities have developed information management strategies for land contamination linked to regional policy statements and plans. Such strategies typically:

  • define the region's priority site types and preferred outcomes for sites
  • provide policy and methods for site identification
  • define the requirements for site investigation, risk assessment, site remediation and site management
  • define information management policies and procedures, including database development and information entry, storage, manipulation, retrieval and release.

Territorial authorities may also have developed policies and plans to address potential land contamination, either in conjunction with regional councils or in the absence of regional land contamination policies.

This guideline is not intended to replace local authority strategies or policies, although parts of it may usefully replace sections of local authority documents where site classification systems and information management procedures are required. This guideline should be read in the context of the entire suite of Contaminated Land Management Guidelines produced by the Ministry for the Environment, along with some industry-specific guidelines, which are available on the Ministry for the Environment's website (

This guideline is not intended to provide a precise recipe for creating a particular type or form of database for storing information on land contamination. Rather, it provides an overall information management strategy that, together with a set of categories and procedures, can be applied to achieve consistency between local authorities.