This paper was presented by Marija Batistich to the Environmental Law and Regulation Conference on 30 April 2012.

Executive Summary

New Zealand has an estimated 20,000 contaminated sites, with the major contaminating activities being from agriculture, the chemical industry, gasworks, the petroleum industry, timber treatment and waste disposal. Many of these sites have been sold or abandoned by the polluters, leaving the task of remediation to new owners or occupiers, or to central and local government in some instances.

The previous, largely unregulated regime for controlling the effects of contaminated sites was ad hoc and varied across district boundaries, especially between territorial authorities with large rating bases, and smaller and less well-resourced authorities. There was little national guidance on identifying, managing and remediating contaminated sites. This inconsistency and lack of guidance resulted in the risk that potentially contaminated land could be used in a way that compromised the safety of those exposed to the soil.

In particular, there was no set of standards to which a site should be remediated, or at which it was recognised that a site was contaminated. In 2005, to address the lack of action at a district level, the prevention or mitigation of adverse effects of the development, subdivision, or use of contaminated land was added to the functions of territorial and unitary authorities under section 31 of the Resource Management Act 1991 (the RMA). However, a Ministry for the Environment (the Ministry) review of district plans in 2007 showed that contaminated land controls continued to vary widely, and that most did not reflect the statutory function.

To address these issues, the old regime has been replaced with the new Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (the NES), which provides national planning controls and technical standards for specified contaminants, and which applies to all potentially contaminated sites in New Zealand.

Certain activities on land that is potentially contaminated are now subject to the NES, and might require resource consent. Of note, for a change in land use or a subdivision, a resource consent for a restricted discretionary activity may be required unless an investigative report provided to the territorial authority shows that the levels of contaminants on the land fall within specified standards. Specific exemptions to the NES are provided for production land which will remain production land, and for land that falls under the Resource Management (National Environmental Standard for Electricity Transmission Activities) Regulations 2009.

The soil contaminant standards (SCS) referred to in the NES relate to 12 contaminants that are considered to be of priority, and levels vary according to the relevant exposure scenario. Should the contaminant and/or exposure scenario not be provided for, the NES provides a methodology for deriving an appropriate standard.

Current Regime

The NES came into effect on 1 January 2012.

The NES provides a nationally consistent set of planning controls and SCS that all territorial authorities are required to give effect to and enforce.

The policy objective of the NES is to ensure land affected by contaminants in soil is appropriately identified and assessed when soil disturbance and/or land development activities take place and, if necessary, remediated or contained to make the land safe for the intended use.

These controls will be engaged when potentially contaminated land is to be developed, but will not affect existing land uses or resource consents. As the NES is largely untested, it is not yet clear how it will apply in practice.

The role of the Ministry for the Environment

The NES regulations are administered by the Ministry, which will take on a monitoring and advisory role for territorial authorities in relation to the NES. To this end, the Ministry proposes to undertake a full evaluation of the NES within five years, as well as developing and implementing a preliminary monitoring plan, which is currently underway. The Ministry's intention is that monitoring required for the NES will be incorporated into its wider 'Monitoring and Review' project.

Land covered

The NES will only apply where there is reason to suspect that the relevant piece of land could be contaminated, with the current version of the Ministry's Hazardous Activities and Industries List (HAIL) being the reference document.

A piece of land will be covered if an activity or industry described in the HAIL is being, or has been, undertaken on it, or if it is more likely than not that an activity or industry described in the HAIL is being or has been undertaken on it.

Where the activity that raises the likelihood of contamination was undertaken on only part of the land parcel, the NES will only apply to that part. This recognises that uses that are associated with contamination can be confined to a small area of a land parcel, e.g.a sheep dip on a farm.

The NES provides two ways in which the person undertaking the activity may elect to determine whether the land is covered by the NES: either through council records; or as a result of a preliminary site investigation.

Where the council records do not suggest that there is a risk of contamination, the person undertaking the activity is entitled to rely on this, and will not be required to commission a preliminary site investigation. Conversely, where the records suggest that the land could be contaminated, a person can undertake a preliminary site investigation to show that this is not the case. However, the Council will be the one that decides whether there is such a risk from the records or from the conclusions in the report.

Activities regulated

The activities that will be regulated by the NES on land that is, or is potentially, contaminated are:

  • Removing or replacing fuel storage systems, or parts of a fuel storage system;
  • Sampling soil;
  • Disturbing soil;
  • Subdividing land; and
  • Changing the use of land.

Where the land is 'production land' (a term that is not defined in the NES), the NES will only apply where the subdivision and/or change in land use will result in land no longer being production land, where a fuel storage system is being removed or replaced, or where the soil being sampled or disturbed relates to specified residential or farmhouse garden uses.

A further exemption applies to soil disturbance on land which falls under the Resource Management (National Environmental Standard for Electricity Transmission Activities) Regulations 2009.

Planning controls

Nationwide controls that direct the requirement for consent for the above activities on contaminated or potentially contaminated land are contained in eleven regulations in the NES. Where the land is not covered by the NES, these controls will not apply.

These have been automatically incorporated into district plans, which must not be inconsistent with the NES. However, the district plans can legitimately control other effects of contamination, meaning that the relevant district plan will still have to be considered. For instance, a district plan might control the effects of the activity on the non-human environment, which is not the focus of the NES.

Permitted activities

The NES classifies certain activities as permitted, meaning no resource consent will be required if the stated standards and requirements are met. These activities are:

  • removal or replacement of fuel storage systems and associated soil, and associated subsurface soil sampling;
  • soil sampling for the purposes of determining the presence of contaminants;
  • small-scale (no greater than 25 m 3 per 500 m 2 of affected land) and temporary (two months' duration) soil disturbance activities; and
  • subdividing land or changing land use where a preliminary investigation shows it is highly unlikely the proposed new use will pose a risk to human health.

Controlled activities

If a permitted activity requirement for one of the above activities is not met, the relevant activity will be classified as controlled under the NES, meaning that resource consent must be granted, but that control can be exercised over certain matters by the consent authority.

To be a controlled activity, the following requirements must be met according to regulation 9(1):

  • a detailed site investigation of the piece of land must exist;
  • the report on the detailed site investigation must state that the soil contamination does not exceed the applicable contaminant standard;
  • the consent authority must have the report; and
  • conditions imposed according to the matters of control, must be complied with.

Restricted Discretionary and Discretionary Activities

If the detailed site investigation report states that an applicable contaminant standard (usually the Soil Contaminant Standard (SCS) will be exceeded, or one of the other conditions above is not able to be met, the activity will become restricted discretionary according to regulation 10.

Discretion is restricted to specific matters, for example, whether the land is suitable for the proposed activity, given the amount and kind of soil contamination present. Again, the consent authority must be provided with the detailed site investigation report, and the consent conditions imposed must be complied with.

The applicant can propose either remediation or management as options to make the land safe for its intended use. The Users' Guide states that remediation to the SCS level (or the standard derived through the NES Methodology1) will be sufficient. Where remediation is not feasible or cost-effective, the applicant can put forward management controls that will reduce the risk of exposure. There is no guidance in the NES as to when remediation would be preferred over management controls, or what methods would be acceptable in either instance, only that they be 'appropriate'.

Where this is not the case, for example, the consent authority is not provided with the detailed site investigation report, or no report has been commissioned, the activity will default to discretionary activity status.

Method for determining applicable soil contaminant standards

The NES sets 'exposure scenario' for twelve 'priority contaminants', which are those contaminants that are most commonly associated with historical uses that result in contaminated soil.2 Each combination of exposure scenario and priority contaminant has an associated SCS.

The Users' Guide states that the SCSs perform two functions:

  • Health-based trigger values – SCSs represent a human health risk threshold above which:
    • the effects on human health may be unacceptable over time; and
    • further assessment of a site is required to be undertaken.
  • Remediation targets – where contamination is above the SCS, then the SCS represents the maximum target concentrations of contaminants at or beneath which the land can again be considered "safe for human use" and the risk to people is considered to be acceptable.

The scenarios are based on five land uses that have different risks of exposure to contaminants in soil attached to them. These are rural/lifestyle block, residential, high-density residential, parks/recreational, and commercial/industrial outdoor worker (unpaved).

Where the contaminant of concern is not a priority contaminant, the NES mandates the approach to take to determine the appropriate standard (which the NES defines as a 'guideline value'). Either a site-specific soil guideline value can be derived according to the Methodology, or a guideline value can be chosen from national and international literature in accordance with the Ministry's guidelines.3

Where the exposure scenario is not one of those identified in the NES, the NES states that the applicable standard will be the 'guideline value' derived in accordance with the methods and guidance on site-specific risk assessment provided in the Methodology, or the SCS for the priority contaminant of the exposure scenario adopted in the Methodology with greater assumed exposure than the actual exposure.

Implications for property acquisition and development

Increased reliance on experts

The NES is likely to lead to increased reliance on contaminated sites experts (usually environmental consultants), referred to in the NES as 'suitably qualified and experienced practitioners'. This term is not defined in the NES, and the Users' Guide notes that the territorial authorities will have the discretion to decide this in each instance. If the practitioner chosen by the landowner does not meet the Council's criteria, the report can be rejected.

The Users' Guide suggests that the practitioner will essentially be "an expert in some specific and relevant fields and experienced in drawing together multidisciplinary inputs and drawing conclusions about site contamination".4 The person certifying the report will have, as a guide, at least 10 years' experience. However, the Guide considers that the person who undertook the fieldwork or drafting of the report could be more junior than this.

Involvement of technical experts will be required at a number of stages, and will result in an increase in the cost of development. Advice may be required for:

  • Determining whether the NES applies;
  • Preliminary site investigations, including for the purposes of assessing what contaminants are likely to be present, and whether the land is covered by the NES;
  • Determining the appropriate SCS where the contaminant and/or exposure scenario is not specified in the NES; and
  • Detailed site investigations, to be submitted with a resource consent application.

Increased significance of a HAIL listing

Whether a property is on a regional council's HAIL list will likely weigh more heavily into a purchaser's decision to acquire land, especially given the breadth of the Council's discretion in assessing whether records show a likelihood of contamination on site. Given the uncertainties as to whether the NES would apply, which could depend to a large extent on the approach of the relevant territorial authority, there could be an increase in landowners objecting to a HAIL listing, or commissioning technical reports to refute a HAIL listing.

Uncertainty as to acceptable remediation and/or mitigation

The Users' Guide states that remediation, where required for a discretionary or discretionary restricted activity under the NES, will be acceptable where contaminant concentrations are brought below the relevant SCS.

However, where the standard is a derived one and not stipulated for a priority contaminant, a decision-maker under the RMA might disagree with the standard that has been calculated.. Further, where a combination of mitigation and remediation is proposed, the uncertainty as to what would be acceptable is increased.  

Click here to view table.

Figure 3 from page 12 of the Ministry for the Environment's Users' Guide, National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health, April 2012.