Contaminated sites

New Zealand has a legacy of soil contamination associated with past and present practices involving storage and use of hazardous substances, and disposal of hazardous waste. In order to help document where these activities have historically and are currently occurring the Ministry for the Environment (MfE) has put together a Hazardous Activities and Industries List (HAIL) to help identify potentially contaminated sites. This is a list of 53 specific land uses that are deemed to have a higher risk of contamination available on the MfE website.
Examples of sites in our region that may be contaminated include:

  • Timber treatment sites
  • Service Stations
  • Disposal of wastes, controlled and uncontrolled
  • Scrap yards
  • Gas works
  • Sheep dips

Contaminated sites may pose a threat to both the environment and our health. The inclusion of a site on a HAIL register does not necessarily mean it is contaminated. However, as the regional council, we have the responsibility to:
  • Control discharges to the environment, such as a discharges from a contaminated site to soil, air, groundwater or surface water; and
  • Investigate land for the purposes of identifying and monitoring contaminated sites.

HAIL sites in the Region

Horizons has a database called the Sites Associated with Hazardous Substances (SAHS) Register to record HAIL information and have an ongoing work programme to identify and record sites where HAIL activities have or currently are being carried out. This includes working with our local territorial authorities (city and district councils) to identify and record sites they think could qualify for the register.

These sites are divided into the following categories: Contamination Confirmed, Contamination Managed, Contamination Acceptable/Remediated, No Identified Contamination, Verified Site History and Unverified Site History. For more information about these classifications, please see the factsheet below.

HAIL classification category


This document provides more information on HAIL classification categories.



If you have any further questions beyond these FAQs, please contact our compliance monitoring team on toll free 0508 800 800.

Property information

To find out if Horizons holds any information about a HAIL activity or contamination on a specific legal site, please complete our online site enquiry form using the green button below.  Alternatively, any other HAIL questions or enquiries can be sent to

HAIL Information Request Form