History of the Kopeopeo Canal
The Kopeopeo Canal extends from the Rangitāiki Plains to the west of SH30. It runs east where it joins the Orini Stream and then discharges into the Whakatāne River. It was built in during the 1920s to convey drainage and floodwaters from low-lying farmlands in the Rangitaiki Plains into the Whakatāne Estuary.
The canal was contaminated between the 1950s and late 1980s as a result of stormwater discharges from a former sawmill, which treated timber using Pentachlorophenol (PCP). While unknown at the time, PCP imported into New Zealand for use in the timber processing industry also included a percentage of impurities that contained dioxins.
Led by the late Joe Harawira, Sawmill Workers Against Poisons (SWAP) and Ngāti Awa sought solutions to clean up dioxin-impacted sites, restore mauri and bring attention to the human health issues contamination has caused. As kaitiaki, SWAP and Ngāti Awa needed to find ways for people to help Papatūānuku heal herself and restore mauri. The story of the Green Chain tells of the impact on the canal and the community of the contamination from the stormwater discharges from the former sawmill.
SWAP inspired Te Ohu Mō Papatūānuku, a collaborative project that tested whether natural resources such as plants and fungi can decontaminate sites, soils and sediments through bioremediation. Kopeopeo Bioremediation Trials Project: Te Ohu Mō Papatūānuku was completed in 2011 and demonstrated the ability of bioremediation to degrade dioxin in sediment from the Kopeopeo Canal in small-scale trials.
The results of recent investigations show some sediment was excavated from the canal from the 1950s-1980s and has resulted in dioxin-impacted soil being placed on stopbanks on the southern side of the canal. This land is subject to a separate investigation and is not part of the sediment remediation project. The area has restricted access and is considered to be low risk. However a review of long-term management or remediation options will be prepared and discussed with the community in the future.
Understandably, there are strong feelings in the community about the state of the canal. In May 2013, Campbell Live reported on some residents’ concerns regarding the project and a petition was made to the Local Government and Environment Committee. The final report on the petition is available here. (93.8KB, pdf)
The project team is working closely with the community and has resource consent to use a staged approach to remove, safely store and clean up the contaminated sediment using bioremediation. The selected bioremediation method breaks down contaminants using a combination of fungi, bacteria and plants to degrade dioxin.
Click the image below to see The Green Chain documentary.
Read more about the results of a smaller-scale project of this kind at the Omokoroa Boatyard.