Work needed on sewage ponds

Ruapehu Bulletin, Volume 13, Issue 630, 2 April 1996, Page 15

Work needed on sewage ponds

A number of improvements to Ohakune' s sewage oxidation ponds will have to be made for the council to meet the requirements of the Resource Management Act. In a report to the Waimarino Community Board to be heard this Thursday, chief engineer Bruce Dobson said the improvements included the installation of aerators on the ponds and the construction of small wetlands prior to the discharge into the Mangawhero River. "There were a number of objections to the resource consent particularly from the residents in Bums Street," states Mr Dobson in his report. "One of the main objections was that the construction of the wetlands involved the removal of some of the native trees that screen the ponds from Burns Street. Other concerns were the quality of the effluent and possibility of floatable objects discharging from the ponds into the river without being intercepted." "It is probably going to be possible to make the wetlands slightly longer and narrower to avoid the removal of any of the trees," he writes. "As far as the removal of floatable ma-

terial is concerned it is proposed that a steps screen be inserted in the line before the sewerage is discharged into the oxidation ponds. Such a unit has been installed in the Taumarunui sewerage treatment plant and effectively removes particle sizes down to three millimetres." "Further consultations have yet to take place with the Iwi to ensure that they are happy withtheproposals," saidMr Dobson. He said getting a power supply to the site is presenting some difficulties. "There has been considerable bank erosion on both sides of the stream in the vicinity of where we intend to take our power across the (Mangawhero) river and we are concerned that any power pole near the river bank would be subject to destabilisation by erosion." This erosion could also undermine the bank on the oxidation pond side of the river, into the wetlands area. "Discussions have been Held with the Regional Council regarding methods for correcting the river channel. However, this is undoubtedly going to cause us some additional expenditure perhaps of the order of $30,000."