Information provided to Waikato Regional Council by Contact Energy indicates the holding pond discharge is unlikely to present any ongoing risk to water users, including swimmers.
While the council is still awaiting the analysis results of samples collected earlier this week by its staff, initial results from GNS provide confidence there will be sufficient dilution in the Waikato River.
This will have brought contaminant concentrations to well within those typically expected in the river, council scientists have concluded.
Based on this information, council scientists say concentrations of contaminants will be well below levels of concern for both ecological and human health.
While it's likely total suspended solids and turbidity will take longer to return to typical levels, members of the public are unlikely to see any further discolouration of the water as a result of this particular incident.
However, discolouration could occur if there is high rainfall over the coming days, as a result of the stream bank erosion caused by the initial incident. The council will continue to monitor this.
Meanwhile, the council is continuing to work with Contact Energy to investigate the incident and establish what caused it.
The discharge was reported to the council by members of the public late on Tuesday morning (19 February) as it had resulted in discolouration of the Waikato River downstream of the Waipouwerawera Stream tributary