You are here: The issues Hazardous substances Contaminated land

Frequently asked questions about contaminated land

What is contaminated land?

Under the Resource Management Act, contaminated land is land with hazardous substances in or on the land that are reasonably likely to have significant adverse effects on the environment (including human health).

The full definition of contaminated land under section 2 of the Resource Management Act is:

“Contaminated land means land of 1 of the following kinds:

(a)if there is an applicable national environmental standard on contaminants in soil, the land is more contaminated than the standard allows; or

(b)if there is no applicable national environmental standard on contaminants in soil, the land has a hazardous substance in or on it that—

(i)has significant adverse effects on the environment; or

(ii)is reasonably likely to have significant adverse effects on the environment”

How does land become contaminated?

The inappropriate storage and use of hazardous substances and disposal of hazardous wastes can result in the contamination of the environment. Contamination is not always limited to a specific site: hazardous substances may seep through the soil into groundwater, or be carried to nearby land and waterways in rainwater or via small dust-like particles. Hazardous gases can also pollute our air.

Some land in New Zealand has been contaminated as a result of industrial, domestic or agricultural activities. In particular, the manufacture and use of pesticides, fertilisers, production of coal and gas, mining, timber treatment and sheep dipping are activities that have led to the creation of contaminated sites in New Zealand. Many of these activities – for example, the use of DDT in sheep dips and to kill insects in the 1940s to the 1960s – were not known to be hazardous at the time.

When is contaminated land a problem?

Contaminated land is a problem when the hazardous substances are at a concentration and/or are located where they have, or are reasonably likely to have, a significant adverse effect on human health and the environment. Contaminated land is a greater problem when contaminants are close to buildings and people, or close to water-bodies and important habitats.

People, animals and the environment can be exposed to hazardous substances on contaminated land in a number of ways, including:

direct contact with contaminated soil
swallowing food or water from contaminated environments
breathing vapours or contaminated dust

As well as endangering health, these substances can:

limit the use of land,
cause corrosion that may be threaten building structures and
reduce land value.

As land is increasingly developed in New Zealand, it is important to know where contaminated land is situated so people are not exposed to contaminants that may affect their health.

To assist identify potentially contaminated land the Ministry of the Environment has compiled a list of activities and industries that are considered likely to cause land to become contaminated. This list is called the Hazardous Activities and Industries List (HAIL).

Local authorities may use the HAIL to identify potentially contaminated sites. Further investigation of an individual site is required in order to determine whether the site is contaminated.

What can I do if I am concerned my land is contaminated?

There are a range of things you can do to find out whether your land is contaminated.

Who manages contaminated land?

Local government (regional councils, city and district councils) are responsible for the day-to-day management of contaminated land and have specific functions under the RMA. Local government is in charge of controlling the effects of contaminated land, and also for controlling activities that cause land to become contaminated. Sections 30 and 31 of the RMA give local government the following functions:

regional councils - “the investigation of land for the purposes of identifying and monitoring contaminated land”
district and city councils – “the prevention or mitigation of any adverse effects of the development, subdivision, or use of contaminated land.”

These functions generally mean that regional councils work to identify and monitor land that is contaminated within their region. District and city councils usually get involved to make sure that no health or environmental effects occurs when land is subdivided, developed, or the land use changes.

In addition to the RMA functions, district and city councils also have responsibilities under other Acts to provide information about the presence of hazardous substances on land.

The Ministry for the Environment is responsible for administering the Resource Management Act (RMA) 1991. The RMA is the core piece of environmental legislation for controlling the effects of contaminated land on the environment and people.

More information on the roles and legislative responsibilities see management of contaminated land in New Zealand

Where can I find out more information?

For the public

For information about contaminated land in your region, contact contaminated sites staff at your Regional Council. Links to council websites can be found from the Local Government New Zealand website. The following regional council websites also have good information about contaminated land:

For regional and district councils

Guidance for regional and district councils can be found Ministry for the Environment’s contaminated land web pages.

For more information about any of the Ministry’s work on contaminated land please see: ‘Contaminated land’ or email Contaminatedlandinfo@mfe.govt.nz.