Land contamination, what does it mean?

From time-to-time regional councils receive information about current or historical activities that may have led to contaminated land. This can be caused by using, storing or spilling hazardous chemicals and the soil can remain contaminated for many years afterwards.

Hazardous chemicals haven’t always been as well controlled as they are now and contamination may have occurred if land was used in the past for an orchard, a market garden, a service station, a timber treatment plant or a motor vehicle workshop. These are just some of the activities which appear on a national hazardous activities and industries list (HAIL).

Regional councils must identify where past contamination may have occurred, using historical aerial photos and other records. When a site is identified, it is added to the council’s register of potentially contaminated sites within their region and the owners are advised.

A month after new information is added to the register it is forwarded to the local district council and becomes part of the property file (and the LIM or land information memorandum) for each property where contamination may have occurred.

There is no need to worry though. Being on the register doesn’t mean that your land is unworkable or that there is definitely contamination present. It’s simply an official notice in case you are planning an activity that will disturb the soil, such as sub-dividing, adding an extension to an existing building, building a shed or garage, or changing the land use.

If you think the reginal council’s potential contamination information relating to your property is incorrect, you must provide evidence that there is no contamination before the regional council passes on its information to your district council.

If you want to develop your land after it’s been added to the HAIL register, you are responsible for managing potential risk to the environment and to people’s health. This isn’t difficult to arrange. You’ll need to start with a site investigation by a suitably qualified and experienced practitioner specialising in environmental engineering – such as Kirk Roberts. If the investigation indicates contamination, then you will need to address the contamination before you can do anything else. This may mean removing or diluting contaminated soil, capping and sealing in the contamination, or treating the contaminated soil. In some cases you may need a resource consent before proceeding.

If no contamination is found, no further investigation or action is required.

Even if you have no plans to develop your site, you can also get a site inspection to find out if residual contaminant concentrations from historical land uses are below the guideline values for the current land use
If your inspection indicates no contamination, the Listed Land Use Register entry for your property will be changed from ‘verified HAIL, not investigated’ to ‘below guideline values for residential / recreational / commercial land use’ and the site record will be updated with the results of the investigation.

If contamination is found, you don’t have to do anything about it unless you want to develop your site. Potentially contaminated properties are occupied, bought and sold every day, all around the country.

If you’ve been notified of possible contamination on your land and want to know more, Kirk Roberts Environmental Engineering team can help you. Whether you want peace of mind or are looking to develop your property/land we can apply our expertise to:

• test your land to the required standard (NESCS)
• do any remediation work that may be required
• develop a site management plan or an environmental management plan if required
• monitor any construction on your site to ensure requirements are met.

“Most contamination we find can be easily remediated,” says Jens Zollhofer, Senior Environmental Scientist at Kirk Roberts. “We specialise in cost-effective remedial action plans that are tailored to your development.”