Use and storage of hazardous substances have left a legacy of soil contamination throughout Aotearoa New Zealand. 

Soil contamination has been largely caused by historic practices in which chemicals were manufactured, used, stored and disposed of in ways that are unacceptable today. Contaminated sites are often associated with industrial activities, but can also be caused by commercial, agricultural and residential land uses or activities. 

The long-term use of lead-based paints on buildings can cause soil contamination, but the use of lead-based paint is generally not recorded on our database unless we hold specific property information. 

Short-term and long-term exposure to soil contaminants can affect human health and the environment. It can also reduce the value of land and its potential for rural, residential or recreational use. Contaminants can migrate and contaminate other land, sediment, air, groundwater or surface water at the source and more remotely. We need to identify, prioritise, investigate and remediate or manage contaminated land in Otago. 

The ORC maintains a Listed Land Use Register of properties where we have information about current or past land uses that could contaminate land – also known as the HAIL database. This public database records sites of hazardous activities and industries in Otago. 

View map of available HAIL site information in Otago

To ask about a specific property or piece of land, please email contaminated.land@orc.govt.nz quoting the HAIL number as displayed in the map. 

The database is continually under development and should not be regarded as a complete record of all properties in Otago. The absence of available information does not necessarily mean that the property is uncontaminated; rather no information exists on the database. You may also wish to examine the property file at the relevant City or District Council to check if there is any evidence that activities occurring on the HAIL have taken place.

You need a resource consent if you want to disturb a contaminated site or discharge hazardous waste onto or into land that may end up in groundwater or surface water. If you are unsure whether you need resource consent, please contact consent.enquiries@orc.govt.nz. 

Disturbing contaminated soil and performing earthworks can pose serious risks to both the environment and people living and working on or near your site. It is crucial that everyone involved in your project understands their responsibilities and knows how to protect the health of site workers, neighbours and the environment. 

Chapter 5 of the Regional Plan: Waste (Waste Plan) has the regional rules and policies for contaminated sites. 

The Waste Plan defines a contaminated site as: “a site at which hazardous substances occur at concentrations above background levels and where assessment indicates it poses, or is likely to pose, an immediate or long-term hazard to human health or the environment.” 

To qualify as a contaminated site, a specific area of land must meet the following criteria: 

• The site must have a hazardous substance (contaminant) present in the soil or discharging from the site. 
• The concentration of the identified contaminant should be higher than what is typically found in a non-contaminated site. 
• The contaminant’s location and the concentration mean it poses a threat to people and/or the environment. 

If soil sampling results show that hazardous substances on a site does not exceed the natural or background levels, the site is not considered contaminated. 

Determining the concentration of naturally occurring trace elements in soil can be challenging due to the level of development that has taken place. Contaminant concentration levels in soil can be affected by factors such as discharges of contaminants from industries and uncontrolled landfill activities. Even run-off from roads can affect the concentrations of heavy metal in soils today. 

If soil sampling results demonstrates that the concentration of hazardous substances exceeds the relevant soil contaminant standards, there could be a threat to human health or the environment.  

Landcare Research (Manaaki Whenua) developed Soil Guideline Values to protect terrestrial biota. Called Eco-SGVs, these values are used to assess the potential environmental impact of contaminants. The predicted concentrations are displayed as filled contour plots so we can see how concentrations vary across the country. You can see them in the LRIS digital soil map. 

Predicted background concentrations of New Zealand

Small-scale disturbances, such as sampling surface soils and hand-drill sampling, are usually considered minimal. Larger scale works such as excavations, trenching, earthworks, groundbreaking and test-pitting or installing monitoring wells will require a consent.  

You also need consent to drill a contaminated site. This could be to determine whether the site is contaminated or – if it is known to be contaminated – to install permanent or temporary wells to monitor soil or groundwater or to drill a bore. 

A discharge to air consent may be required depending on the works, particularly if you don’t have dust or odour control measures in place (when needed). This should be outlined clearly in an application for resource consent.  

The relationship between the Regional Plan: Waste and the National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health (NES).

The National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health (NES-CS) is a nationally consistent set of planning controls and soil contaminant values relating to the disturbance, subdivision and land use change of contaminated and potentially contaminated land. 

The NES-CS is administered by city and district councils. Detailed information on the NES-CS can be found in the Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011, or by contacting your city or district council planning team. 

Some activities are allowed under the NES-CS, but you will need a resource consent for a controlled, restricted or discretionary activity. This is decided based on risk factors. 

The NES does not affect regional council functions. Even if the NES requires a resource consent from a city or district council, you may also need a regional resource consent for the same activity if it is required by section 15 of the RMA or a relevant regional plan.  

This table shows when regional or district consents are required: 

Policy 5.4.4 of the Waste Plan applies the ANZECC guidelines for assessing and managing contaminated sites.  However, since the Waste Plan became operative, these guidelines are largely superseded by a series of guideline documents published by MfE in 2001, called the Contaminated Land Management Guidelines. 

Contaminated site management can be broadly classified into the following reporting stages: 

• Stage 1 – Preliminary site investigation (PSI) report   
  • This is often referred to as a desktop study because it does not usually involve sampling and analysis. The main objective of a PSI is to gather information about a piece of land to determine whether it could be contaminated. 
• Stage 2 – Detailed site investigation (DSI) report 
  • Further investigation, including soil sampling and analysis within areas of concern identified by stage 1. 
• Stage 3 – Site remedial action plan (RAP)
  • Documenting the remediation (actions taken to stop or reverse environmental effects) and management strategy to mitigate the risk posed by contaminants 
• Stage 4 – Site validation report (SVR)
  • This demonstrates that objectives in the remedial action plan have been achieved and documents the site’s mitigation status following remedial action. 
• Stage 5 – Ongoing monitoring and management plan 
  • If contamination remains, this plan sets out how will it be monitored and managed. 

Asbestos can harm human health, and disturbing it can discharge it to the air. Managing and removing asbestos must follow the Health and Safety at Work Act 2015 (HSWA) and Health and Safety at Work (Asbestos) Regulations 2016. You may also need a consent under our Waste Plan. 

Disclaimer: Otago Regional Council has prepared this information to help businesses and individuals select a contaminated land consultant for contaminated site investigations and remediation. Otago Regional Council has prepared this information in good faith exercising all reasonable care and attention, but no representation or warranty, express or implied, is made and Otago Regional Council expressly disclaims any such representation or warranty that might be deemed to have been given, as to the relevance, accuracy, completeness, exhaustiveness, currency, suitability, reliability or fitness for purpose of this information in respect of any particular user’s circumstances. Otago Regional Council reserves its right to make changes to this information at any time. 

Sites that are potentially contaminated or contaminated often present several challenges that require specific technical skills. It’s important to note that not all environmental consultants are qualified to perform assessments and investigations. It’s vital to select a suitably qualified and experienced consultant who has the required expertise and experience to address your specific needs.  

You may waste time or money and face legal issues if a site investigation and/or remediation works do not meet the appropriate environmental, planning and reporting standards. Poor quality contaminated site reports usually result in further work at an additional cost and create delays in obtaining resource consents. You can save time and money by making sure you choose a consultant who can provide the services you need from the outset.  

We cannot recommend specific consultants, but the following information might help you choose the best service for your needs. 

The simplest place to start looking for a contaminated land consultant is to do an internet search typing ‘Contaminated Land Consultants’. The list of environmental consultants is extensive, but not all consultants have relevant experience or qualifications in contaminated site assessment and remediation. Contact people or businesses you know who have engaged a contaminated land consultant in the past and ask whether they can share their experience or make a recommendation. 

To do a site investigation as a requirement of the NES for contaminated land, your consultant will need to be considered a ‘Suitably Qualified and Experienced Practitioner’ (SQEP). New Zealand consultants can be accredited as a Certified Environmental Practitioner (Contaminated Land Specialist). Your city or district council may use its discretion to consider a consultant who doesn’t have this accreditation as “suitably qualified”, but it is worth checking with them before you make a final decision. 

You might like to ask prospective consultant(s) the following questions: 

• Do you have Certified Environmental Practitioner (CEnvP) accreditation? 
• Who will be working on my project? Do they have relevant skills and experience? 
• Does the company have prior experience with similar sites and similar project purposes (e.g. meeting regulatory requirements)? 
• Does the company hold sufficient public liability and professional indemnity insurance? 
• Is the company familiar with the local legislation (NES, District Plan, Regional Plan?) and national best practice guidelines? 
• Has your company worked with local government previously, and have experience with their expectations? 
• What are your health and safety procedures? 
• What is the breakdown of costs, and what might be potential additional costs? 
• How long will the project take, including any field work, laboratory analysis, report writing and review? 

It is important to all parties that you clearly define what you want them to achieve. Are you conducting due diligence, confirming whether it’s safe to consume home-grown vegetables, or trying to satisfy NES requirements for a subdivision proposal?  

Gather as much background information as you can about the site’s historical activities, potential contamination and previous practices. The better the background information and specific goals you can provide, the more accurate the quotes are likely to be.