Up to 10,000 litres of partially treated sewage overflowed into a tidal tributary of Whaingaroa Harbour recently – and no health warnings were issued to the Raglan public because the Waikato District Council was oblivious to the spillage.
The council was in damage-control mode this week after revealing the potential size of the overflow, which earlier it was describing only as “a substantial amount”.
Council service delivery manager Tim Harty told the Chronicle on Monday: “We’re extremely disappointed this incident has occurred and we apologise for this operational failure. We want to reassure the community that it is not how we expect to do business.”
The up-harbour overflow came just before an “unscheduled” discharge of fully treated wastewater through the Ocean Beach outfall pipe on June 24.
That particular discharge – prompted by heavy rainfall at the time – complied with a consent that requires the wastewater to meet “bathing water” standards. Mr Harty said the Waikato Regional Council, the media and key stakeholders were all also informed at the time.
But it was a different story with the overflow of only partially treated sewage from the council’s pond at Raglan West. “While we did inform stakeholders and the public about the unscheduled discharge, unfortunately, because we weren’t aware of it at the time, we weren’t able to complete the same steps for the overflow,” Mr Harty said.
While the council isn’t saying as much, the overflow had potentially serious health implications because the tributary in question is understood to drain into the Kopua estuary, a popular swimming area which was the venue for Raglan’s annual midwinter swim only a week or so before the spillage.
The district council revealed late last week it had engaged an independent consultant to complete a full investigation into what caused the overflow, and had met with iwi and key stakeholders to apologise for the situation.
It added the Waikato Regional Council had received a full incident report and was also investigating the overflow.
“At this stage we’re unclear on all details so the independent consultant will complete their review promptly to help us establish how the incident occurred, the actual timeline of events and what changes we may need to make to improve our systems and processes,” Mr Harty told the Chronicle.
Under its consent Waikato District Council can discharge fully treated waste water “outside daily tidal periods” up to 20 days a year in the case of high rainfall.