An aerial photo provides a different view of a treated wastewater discharge into Hawke Bay. Photo/Supplied
An aerial photo provides a different view of a treated wastewater discharge into Hawke Bay. Photo/Supplied
Aerial images of a Hawke Bay discoloured by large plumes of wastewater discharge have been revealed.
Photos showing discharge from the Napier City Council-owned sewerage plant into the sea - taken last Friday - were received by Hawke's Bay Today earlier this week.
Similar photos of discharge from the HastingsDistrict Council plant - taken this week- appear to be less dramatic.
Although the Hawke's Bay Regional Council are looking into the Napier discharge, the city council say this plume is nothing out of the ordinary.
Sewage from across Napier - excluding some areas - is pumped to the milliscreening plant at Awatoto. Sewage then passes through 1mm screens before being discharged from the plant into Hawke Bay via a 1.5 km outfall.
While the plant is owned by Napier City Council, the effluent discharged from the site is required to comply with their consent, issued by the Hawke's Bay Regional Council.
Napier council Manager Asset Strategy Chris Dolley said they did not believe the plume pictured was an adverse condition.
"We actually submitted a very similar photo, showing what the outfall could look like, as part of our consenting process and compliance application to HBRC, which was consulted on publicly. So no, it's not unusual, in our view."
Photos showing the discharge into the sea from the Napier City Council-owned plant were taken last Friday and received by the Hawke's Bay Today earlier this week. Photo/Supplied
When shown the image, a regional council spokeswoman said their compliance team would need to follow up on the discharge.
Under the conditions of the consent, the discharge of wastewater is not to cause effects beyond a distance of 300m from the outfall diffuser.
These effects range from undesirable biological growths, a change in the natural temperature of the receiving water of more than 3C, any emission of objectionable odour, or any significant adverse effect on aquatic life, among others.
The prohibited effects also include any conspicuous change in the colour or visual clarity beyond a distance of 300m from the outfall diffuser.
The spokeswoman said from the photo, the compliance team were unable to discern the actual distance covered by the discolouration, but would follow this up with the city council.
As the sea was currently "quite murky", the team would check the length of the plume as soon as it cleared.
The Hastings District Council treatment plant is located in Clive. In October a $3million project began which would see the replacement of their 300m diffuser, attached to the end of the 2.5km pipe.
The diffuser ensures that not all the water leaves the pipe in the same place.
The conditions of their consent to discharge wastewater were similar to Napier's - however some effects were not allowed beyond a distance of 500m from the midpoint of the outfall diffuser, and others from 750m of this point.
Waipawa resident Ross McDonald, sent Hawke's Bay Today the photos, although the one showing the Awatoto plume had been taken by a friend.
Mr McDonald said he himself had flown past the outfall at Awatoto several times, but had been unable to take a photo himself. When he had flown over the colour was more of a "murky brown".
He said he thought people needed to see "what happens in their aquatic playground" as it was a view not many Napier residents would have seen, or would even know occurred.
