CITY SEWAGE OUTFALL

New Zealand Herald, Volume LXXI, Issue 21755, 21 March 1934, Page 13

CITY SEWAGE OUTFALL

FUTURE TRANSFER OF SITE

CHLORINATION IN SUMMER HARBOUR BOARD INSPECTION The measures being taken by the Auckland and Suburban Drainage Board to minimise any nuisance caused by the Orakei sewage outfall were explained to members of the Auckland Harbour Board yesterday in the course of a visit to Orakei at the Drainage Board's invitation.

Mr. G. W. Hutchison, chairman of the Drainage Board, in an address to the visitors, said that the outfall undoubtedly would have to be transferred elsewhere, although not until after a period the length of which would depend upon the ratepayers' ability to find the necessary finance.

The present outfall, Mr. Hutchison said, was by no means an intolerable nuisance. A chlorination plant was being installed, and Would have been in use already had it not been- necessary to have certain parts made locally to replace some that had been broken in transit. When it was put into operation a few weeks hence the effluent would be entirely deodorised. This would remove 50 per cent of the present disability.

Actually, the effluent was more innocuous than the raw sewage that was being discharged into the harbour from the North Shore reticulation systems and from ships which, it was estimated, had a population of between' 2000 and 3000 people. Mr. H. H. Watkins, engineer and secretary to the Drainage Board, explained the present situation by means of maps and diagrams. Copies of a typewritten memorandum, giving statistics of the board's operations, were also distributed. This showed that the present sewerage system, serving 18,731 acres and an estimated population of 157,000, had been designed for an ultimate population of 280*000 on a basis of six times the assumed dry weather flow. Mr. Watkins stated that there was never less than lift, of water over the outfall. No solids were discharged. The chlorination plant would be used for only live months of the year, at a cost of about £IOOO per annum. Chlorination would not be needed in winter, owing to the greater rainfall and the absence of pleasure craft from the harbour.