Past industrial, domestic, agricultural and horticultural activities have left a legacy of contaminated sites in our District. It is important to know where contaminated land is located so people are not exposed to contaminants that may affect human health. Waikato District Council is committed to working with land owners, developers, regional council and health authorities to reduce the risk associated with contaminated sites.

What is contaminated land?

A site is considered to be contaminated when hazardous substances are found at significantly higher concentrations than their normal levels, and there is likely to be a risk to human health or the environment.

Potentially contaminated land is land that has been used for an activity that is more likely than other activities to cause contamination i.e. is contained within the HAIL.

Background levels

It's important to know that many hazardous substances occur naturally in our soil.

Many chemicals, particularly trace elements, are needed by living organisms in order to live and grow1.  However, above a certain level even these chemicals can become toxic, interfering with the complex biochemical reactions of plants and animals.

Other hazardous substances do not occur naturally. Over time, some of these have become widespread in our environment. One example is the organochlorine DDT, which was previously used as a pesticide.

The National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health

The National Environmental Standard (NES) for Assessing and Managing Contaminants in Soil to Protect Human Health came into effect in January 2012. The NES provides a nationally consistent set of planning controls and soil contaminant values and ensures that land affected or potentially affected by contaminants in soil is appropriately identified and assessed before soil disturbance and/or land developments take place and, if necessary that the land is remediated or the contaminants contained to make the land safe for human use.

The standard means that if your land is or has been used for a hazardous activity or industry as described in MfE’s Hazardous Activities and Industries List (HAIL) and you want to undertake specified activities (below) you will need to comply with the NES.

  1. Removing or replacing of fuel storage systems or part of a fuel storage system
  2. Soil sampling
  3. Earthwork activities/soil disturbance
  4. Subdivision of land
  5. Change of land-use

For information on what this means for you, see the NES regulations which clearly set out the steps to follow.

Fertiliser use on rural properties

Note that if you want to establish a residential activity on rural land (e.g. a farm house), Council may also require additional information surrounding the use of superphosphate fertiliser on your property. This is because superphosphate fertiliser contains the heavy metal cadmium as an impurity and with sustained application over the years, it has the potential to raise the level of cadmium above the contaminant standard for a rural-residential setting.

Buying or selling a property on potentially contaminated land

A series of four brochures have been developed to help guide you through the process of buying and selling a potentially contaminated site.

Information includes why contamination is a problem, how to find out if land is contaminated, who is responsible for a contaminated site, regional and unitary council role in contaminated land as well as advice for prospective buyers, sellers, lawyers and valuers.

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