Government has refuted claims that disinfected water containing chemicals has been released into the Takuvaine stream.
The claims have been made by anti-chlorine group Te Vai Ora Maori who say the treated water “released from the Takuvaine intake” has flowed down the stream, “effectively killing the fragile stream life”.
The group has also shared a video in which a resident living nearby the intake have claimed of dead koura (shrimps) and eels trying to get out of the stream.
But financial secretary Garth Henderson assured the public, especially the landowners up at the Takuvaine intake, that “no calcium hypochlorite has been disposed into the stream”.
Te Vai Ora Maori president Anna Rasmussen said landowners Tere Carr and Diane Holford visited the Takuvaine intake the day disinfection of the sedimentation tank took place on December 16.
Rasmussen said the disinfected water should have been held for long enough to allow the chlorine to evaporate (three to six weeks), but rather “it was released the same day”.
“Some of it flowed down the stream, effectively killing the fragile stream life,” she said.
The following day, Rasmussen said Te Vai Ora Maori spoke to the family who live next to the intake. She said the family reported a flood of water coming down the stream.
“One of the children said that he had seen dead koura (shrimps) and that he had seen tuna (eels) trying to get out of the stream,” Rasmussen said.
“Their way of life has been altered and they are very concerned about the impact Te Mato Vai will have on them and their whole village.”
Garth Henderson said National Environment Service and landowners’ representatives would be invited to be on site to witness the “zero chlorine reading” as agreed, before any discharge of the treatment water into the stream.
They could also monitor the discharge and testing of the release of the de-chlorinated fresh water into the stream, Henderson said, adding this will be done in the New Year.
The disinfection part of
the commissioning process
at the Takuvaine intake
started last week after giving landowners 48 hours’ notice, Henderson confirmed.
Prior to the disinfection process, he said all pipes and structures were flushed out with raw untreated water from the stream to remove all sediments and dirt build up before the disinfection.
The flushing of the pipes from the intake to the sediment pond was by a flushing pipe which discharges directly into the stream, Henderson said, adding that flushing took about two hours.
“The storage tank was also flushed to a discharge point in the stream, again only with raw untreated stream water, and that took about six hours. It is that flushing that the landowners may have seen discharging into the stream.”
After the flushing was completed, Henderson said the infrastructure was isolated and then disinfected by adding high concentrations of calcium hypochlorite to the settling tank where it remained for the day.
A further top-up dose was applied about three hours later. The chlorinated water remained until test results showed no E.coli. The treated water remained in the settlement tank and structures, he said.
“Because the settlement tank and the fact that it is open to the atmosphere and suns UV rays the chlorine breaks down relatively quickly so that by the following day there was a much lowered concentration of chlorine. The treated water remained in the settlement tank for the following 24 hours or thereabouts and I understand has now been pushed through to the storage tank.
“No treated water or chlorine has been or will be discharged into the stream.”
Henderson said as this matter was before the Court, the project management unit was in the process of working up affidavits to be sworn by the employees of McConnell Dowell. These will be ready in the New Year, he said.