Christchurch City Council hold a resource consent to discharge treated wastewater, from the city’s wastewater treatment plant, to sea via an ocean outfall. As part of their consent, they are required to undertake sediment and ecological monitoring of the area surrounding the outfall. Bioresearches were contracted to undertake monitoring of macroinvertebrates living in and on the sediment, and of contaminants in the sediment.
In partnership with a team of professional divers, Bioresearches collected samples from the sea bed around the ocean outfall diffuser as well as from a control location further north. Results from each location were then compared to each other, and to results from previous years sampling to determine if the ocean outfall was having an effect on the sediment and benthic ecology of the area surrounding the diffuser. Results and discussions were presented to CCC and then passed on to the Canterbury Regional Council to fulfil resource consent obligations.