Hazardous substances and land contamination
Hazardous substances are encountered as part of everyday life but they also have the potential to cause contamination that is harmful to people and the environment.
Land can become contaminated with hazardous substances because of human activities or natural processes. Water soaking through contaminated soil can become degraded, and contaminated water and sediment can get into waterways and impact aquatic and marine ecosystems. Managing contaminated land can sometimes be expensive and difficult.
Some activities that use, store or dispose of hazardous substances can cause the contamination of land. These activities are included on a national list called the Hazardous Activities and Industries List (HAIL).
Here are the current issues faced around hazardous substances and land contamination in Canterbury/Waitaha.
Issue: Contaminated land can adversely impact our environment
Past land use (including, for example, landfills and farm dumps, former gasworks, fuel service stations, horticulture, timber treatment, and sheep dips) has left a legacy of contaminated sites across the region. Soil and water that is contaminated may have limited use and can harm ecosystems and human health.
Over the past ~150 years, some of the land in Canterbury/Waitaha has become contaminated from land use activities. For example, disposal of household and industrial waste has left the landscape dotted with old landfills. The use of persistent pesticides, most of which are now banned, has contaminated soil.
Old industrial sites such as scrapyards, and rail yards have also left a legacy of contamination. Contamination of land is still occurring in Waitaha, as a result of the use, storage, or disposal of hazardous substances and waste to land, ranging from accidental fuel leaks, to a chemical spills, to the burying or burning of rubbish.
When water soaks through contaminated soil, the underlying groundwater can become contaminated. When water (such as stormwater) or wind picks up contaminated soil, contaminants can move to other areas of land, or into nearby lakes and rivers. In some cases, such as a landfill breach, waste itself can be released back into the environment.
Climate change projects and risk from natural hazards
Contamination can be released from sites because of natural hazards, such as flooding or sea level rise.
Increased extreme events such as heavy rainfall and floods may result in erosion of contaminated surface soil or encapsulation systems (such as landfill capping), causing contaminated material to be dislodged.
In Waitaha, we have many HAIL sites in low lying areas, such as wastewater treatment plants, bulk fuel storage, and landfills.
Climate change may require councils to relocate critical infrastructure, in a bid to adapt and improve community resilience.
This may result in the decommissioning of currently operating HAIL activities, and their establishment in new areas.
Identifying and monitoring contaminated land
The Resource Management Act (RMA) sets out functions for managing contaminated land for regional councils and territorial authorities. Regional councils investigate land for the purpose of identifying and monitoring contaminated land, while territorial authorities prevent or mitigate any adverse effects on the environment that may arise from the use, subdivision, or development of contaminated land.
The Listed Land Use Register (LLUR) is used to manage information about contaminated and potentially contaminated land, or HAIL sites, in the region.
The public can obtain individual property information using the LLUR portal.
When land that has previously been or is currently being used for an activity detailed on the HAIL is identified, it is recorded on the LLUR with contextual information on the dates of the activity/ies and any other relevant information.
Not all HAIL sites will be contaminated, and the only way to confirm whether contamination has occurred requires a detailed site investigation. Most known HAIL sites have not had this done.
New HAIL sites are still being discovered, even if the activities that caused the contamination happened many years ago. We have a programme of proactive identification of HAIL sites that has been in operation since 2008.
This shows the type and frequency of known or potential HAIL activities within Waitaha. Data is limited to include only what is currently captured on the Listed Land Use Register.
Current actions and approach
Sometimes the legislation doesn't give councils the ability to require contaminated land to be cleaned up. In these situations, where the landowner is eager to remediate the land but may not have the financial ability to pay for it, we can apply for funding via the Ministry for the Environment’s Contaminated Sites Remediation Fund (CSRF).
This fund can provide financial support to investigate and clean up sites that are significantly high risk. We have successfully worked with landowners and other agencies to remediate a number of high profile contaminated sites, and are currently involved in CSRF projects in the region. Details of funded projects can be accessed at Contaminated Sites Remediation Fund / Ministry for the Environment.
National regulations
The National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health 2011 (NESCS) addresses the management of contaminated land from a human health perspective. City and district councils are responsible for administering the NESCS, which sets out the requirements for dealing with contaminated land. This means they require actions to be taken to resolve contamination issues when specific activities are proposed on that piece of land (such as subdivision or earthworks). The NESCS does not address the management of contaminated land for environmental or ecological reasons, nor does it address contamination of groundwater or surface water.
This means territorial authorities require actions to be taken to resolve contamination issues when specific activities are proposed on that piece of land (such as subdivision or earthworks). The NESCS does not address the management of contaminated land for environmental or ecological reasons, nor does it address contamination of groundwater or surface water.
Regional regulations
We have responsibility for regulating discharges to air, land and water, including those to and from contaminated land.
For example, regional rules and associated resource consents regulate the discharge of stormwater into or onto contaminated land. Regional rules also require that discharges of hazardous substances from contaminated land are managed to avoid adverse effects beyond the site boundary.
Issue: Preventing the contamination of land can avoid adverse impacts on our environment
The use of hazardous substances and contaminants has become a part of everyday life and they are important for the social, cultural, and economic well-being of people and communities. However, these substances have the potential to cause significant adverse effects if they are not properly managed.
Adverse effects from the storage, use, disposal, or transport of hazardous substances or contaminants can include things such as the contamination of land, air, and water, which can in turn lead to adverse effects on human health and ecosystems.
Pathways by which contaminants in soil can affect human health and the environment. Source: Ministry for the Environment/ Manatū Mō Te Taiao
Such adverse effects may come about because measures to store, use, or dispose of hazardous substances or other contaminants are inadequate. For example, spills or leaks can occur when hazardous substances or contaminants are loaded and transported, even if precautions are taken.
The prevention of contaminated land is dependent on the adequate management of potentially contaminating industries and practices including, waste minimisation disposal of contaminants and contaminated material, and pollution prevention procedures.
If land is contaminated, it can limit the future use or development of that land and can even render the soil itself unsafe. The best way to avoid the risks associated with land contamination is to avoid the land becoming contaminated in the first instance. Avoiding the future contamination of land is the most efficient way of safeguarding our land and soil resource, and our social, economic, and cultural values associated with these resources.
Current actions or approach
National regulations
The Resource Legislation Amendment Act 2017 (RLAA) removed the explicit function of regional and territorial authorities under the RMA to manage adverse effects of the storage, use, disposal and transportation of hazardous substances in order to avoid the duplication of controls of other legislation such as the Hazardous Substances and New Organisms Act 1996 and the Health and Safety at Work Act 2015. Additional controls are only necessary under the RMA to control environmental effects that are not covered by other legislation. For example, management within sensitive or high risk areas and the control of discharges of contaminants into or onto land, air, or water as these are not controlled through other legislation.
Regional regulations
The regional planning framework has the broad function of achieving integrated management and this sits alongside other agencies managing hazardous substances, such as the Environmental Protection Authority (EPA) and WorkSafe.
The Canterbury Regional Policy Statement (CRPS) includes directions to regional and district plans to protect sensitive areas and activities (such as high hazard areas, community drinking water protection zones and others) from the effects of the use, storage or disposal of hazardous substances, including the contamination of land.
The Canterbury Land and Water Regional Plan (CLWRP) manages discharges from activities using hazardous substances and waste management activities such as municipal waste, farm pits and offal pits.
District plans
District Plans manage the effects of subdivision, use and development of land and include provisions to ensure activities that use hazardous substances are provided for and appropriate controls are in place to manage adverse effects on the environment consistent with national direction, and the direction provided by the Canterbury Regional Policy Statement (CRPS).