The Whakatāne District Council is to investigate whether any remedial work is required to prevent environmental exposure to contaminated wood waste at sites on Council-owned land.

A comprehensive report received by the Council’s Projects and Services committee on 4 September detailed the known contaminated sites throughout the Whakatāne District. Between 1950 and 1985, wood waste from the former sawmill operation at the Whakatāne Board Mill site was disposed of in some 31 separate locations, seven of which are on Council land.

Some of the wood waste contained timber treatment chemical residues, including sodium pentachlorophenol and dioxins, both of which are now known to cause cancer, in certain conditions. Sodium pentachlorophenol is readily mobilised by water and has long since dispersed, but because dioxin molecules bind to soil, they continue to represent a hazard, and any associated risk of exposure from the contaminated sites needs to be managed.

The Bay of Plenty Regional Council is responsible for monitoring and reviewing the management of the contaminated sites, while the District Council monitors land use activities, with a focus on any changes of use which may increase the risk of exposure to dioxin.

Concerns about two contaminated sites on Council land at 60 Bunyan Road were raised during District Plan hearings earlier this year and were also addressed in a Regional Council submission, which noted that while the most recent monitoring report did not indicate any issues with water, sediment or biota contamination, a recommended increase in the depth of cover material and canal edge protection works had yet to be implemented. The management plan for the sites recommends a minimum soil cover depth of 0.6 metres.

WDC Projects and Services Committee, Councillor Andrew Iles, says that as the responsible landowner, it’s appropriate that the Council should investigate any remedial works required to ensure that potential dioxin exposure pathways are addressed. A report on the scope and cost of any work required will now be undertaken and brought back to the Committee later this year.

In the meantime, the Council will also make information on contaminated sites more easily accessible by creating a page on its website with links to the relevant content on the Regional Council and Ministry for the Environment websites.