Woodwaste sites in the Whakatane District
From the 1950s through until the 1980s, woodwaste from the former sawmill near Whakatane was used as infill on farms and low lying areas. The woodwaste was often a mixture of clean fill and sawdust and often included waste from treated timber and the treatment process.
There are around 30 of these known woodwaste sites. Some are in private ownership, some are owned by Bay of Plenty Regional Council or Whakatane District Council (WDC).
Contaminated sites may pose a threat to both the environment and our health. They may limit land use and can also reduce land values. It is important that a contaminated site is investigated and managed to reduce any potential risk.
The sites were investigated in 2005 using ground penetrating radar and soil borings to determine the extent of the wood waste and the thickness of cover material over the waste at each site. Some sites had waste and soil samples collected for analysis. In addition, a human health risk assessment was carried out to determine what levels of contaminants were considered acceptable and did not pose a risk to human health.
There is a wide variety of different sites with different levels of contamination at each. Therefore the key way to manage the risk to human health is to ensure that there is a good layer of clean cover material in place over the wood waste at all times. This acts as a barrier between the woodwaste and people who use the site. That is also why it is so important that activities that might disturb the soil are managed on these sites.
Hazardous Activities and Industries List (HAIL)
The Ministry for the Environment (MfE) has put together a Hazardous Activities and Industries List (HAIL) to help identify potentially contaminated sites.
Bay of Plenty Regional Council has created a database called the Selected Land Use Register to record HAIL information. We have been working with our local territorial authorities (city and district councils) to identify and populate the register with sites that have had past or present hazardous activities located on them.
The Selected Land Use Register currently holds approximately 900 sites from across the region, and includes the known woodwaste sites in the Whakatane District.
Contaminated Land Working Party
A number of parties are currently working with the Regional Council and Whakatane District Council to record and manage these known hazardous sites. The Contaminated Land Working Party is made up of members from a number of agencies:
||Whakatane District Council
||Bay of Plenty Regional Council
||Te Runanga o Ngati Awa
||Toi Te Ora Public Health
||Sawmill Workers Against Poison (SWAP)
Contaminated sites are a national issue and the Ministry for the Environment has developed guidelines for how sites should be managed.
Owners of the woodwaste sites have in place a management plan to ensure the sites are controlled and the contaminated fill is not disturbed. New management plans are required to align with the National Environmental Standards (NES) and the Contaminated Land Working Party is currently working with landowners to update these.
It is important to note that the contaminated sites pose a potential risk if the material is uncovered. Currently, most sites are covered by a layer of clean fill (non-contaminated soil), isolating the exposure pathways. While these sites are known and the management plans ensure that the contaminated fill is not disturbed (for example by digging, erosion or earthworks), and that the cover over the contaminated site is maintained to a minimum depth, the risks of exposure are minimal.
Example of public signage