Site Investigation

A site investigation is likely to be required if your site has been used, or is suspected to have been used, for an activity or industry associated with probable ground contamination (for instance has historically been used for industrial practices or broad scale horticulture), and you intend on developing the land in one of the following ways:

  • Subdivision.
  • Change of land use.
  • Earthworks.
  • Removal or replacement of a fuel storage system.

An overview of potentially contaminating activities has been provided by the Ministry for the Environment in the Hazardous Activities and Industries List (HAIL) available here.

If you are unsure if your site will require a site investigation please feel free to contact our knowledgeable team.

Preliminary Site Investigations (PSI)

The purpose of a Preliminary Site Investigation (PSI) is to review the history of the site in order to determine the likelihood of ground contamination.

  • During the PSI all available site information is reviewed to identify any activities that may contaminate the site and to locate any areas that have potentially become contaminated due to these activities.
  • If the PSI can demonstrate that the site activities were unlikely to lead to ground contamination, further investigation may not be required.
  • However, if the potential for ground contamination exists, a Detailed Site Investigation (DSI) may be necessary to determine the level of contamination at the site.

The PSI is essential in assessing whether the site is covered by the National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health (NESCS) and the Contaminated Land rules of the Auckland Unitary Plan: Operative in Part (AUP OP), or applicable Regional Plan.

If you require further information on the above, or if your local council have requested a Preliminary Site Investigation report, please get in touch with our expert team today.

Detailed Site Investigations (DSI)

The purpose of a Detailed Site Investigation (DSI) is to, based on the findings of the PSI, confirm the level of contamination at the site and assess if the land is safe to use. The DSI will also assess the potential for surface water, groundwater and air quality (vapors/fibres) at the site to be impacted by ground contamination.

  • The level of contamination at the site is determined by way of an intrusive investigation where soil samples are collected and analysed at a laboratory.
  • Any investigation undertaken should comply with the Ministry for the Environment’s Contaminated Land Management Guidelines No. 5: Site Investigation and Analysis of Soils (Revised 2021) (CLMG No. 5).
  • The results of the sampling and analysis are then compared with guideline values relevant to the proposed development of the site.
  • In the event that the level of contamination at the site is found to be unsafe for site users, or is found to have the potential to impact the receiving environment, appropriate remedial actions or site management practices are necessary to make the land safe to use and to prevent discharges to the environment.

For further information or if your local council have requested a Detailed Site Investigation report, we would love to help you out. Please contact us today.

To find out what site investigation is necessary for your land development project, contact our specialist team today