BETTER DRAINAGE SYSTEM

Sun (Auckland), Volume IV, Issue 931, 26 March 1930, Page 8

BETTER DRAINAGE SYSTEM

GOOD water supply and an efficient system of drainage are the most valuable means of protecting large centres of population from disease. Auckland has the one, but while large quantities of sewage are discharged into the harbour almost at the City’s front door, it is doubtful if she has the other. Recent complaints against the present system of discharging treated sewage from the main outfall at Orakei, and the return of Mr. 11. 11. Watkins, Drainage Board engineer, who was sent abroad to investigate up-to-date methods of sewage disposal and treatment, lend this important question a new interest. It is fairly obvious that the Harbour Board, as a trustee of the Waitemata and its beaches, does not propose to allow the present system to persist without some very great improvements. The board would fail in its duty if it countenanced a continuance of the present, system. Whatever measures are taken, they are likely to be expensive. There are methods by which by-products can he obtained from the sewage, and the burden thus reduced, hut in view of the present active competition in fertilisers and similar products, and of the fact that even where modern plant is available to deal with the effluent it has not always been profitable, it is doubtful if this method is warranted in Auckland. Without such a system, or the adoption of sewage farms, to which, even in the best conditions, many people raise serious objection, the remaining choice is the disposal of the sewage far out to sea away from beaches and enclosed waters that may be contaminated. On the Hauraki Gulf side it is not possible to fulfil this ideal. Any outflow delivered there by pipeline would still be- delivered into enclosed waters which are the holiday resort of thousands of people. Even admitting that dilution minimises the unpleasantness o£ v the method now in vogue, the growth of the City presents the certainty of future trouble. The development in recent years of settlement to the north, in suburbs such as Avondale and New Lynn, has brought new problems of drainage. At present the main sewer follows a curve from Avondale to Orakei, roughly following the waterfront, though some distance away from it. Thus the Orakei outfall is the outlet for sewage which should properly be delivered in a different direction. The problem is complicated by the absence of any reasonable right to pollute the Manukau any more than the Waitemata, but the West Coast wii! in the final judgment be probably deemed the best outlet, particularly if the bulk of the outflow is purified, and the remaining effluent delivered into deep wale®, : ..