DRAINAGE OF AUCKLAND.

New Zealand Herald, Volume XVI, Issue 6343, 17 March 1882, Page 6

DRAINAGE OF AUCKLAND.

TO THE EDITOR. Sip.,—ln the articles on the drainage of Auckland which have appeared in your paper lately, the desirability of preventing the ordinary water-carriage systems being adopted in Auckland has been urged, and theLisrneur Pneumatic system has been favourably reviewed ; and though I cannot agree with your sweeping condemnation of the former, I do not think that they are the beat suited for Auckland, situated as it is upon several watersheds, all falling towards the harbour, rendering unavoidable the construction of a long and costly interception and outfall sewer, as shown in Mr. William Clark's report. The Lierneur system is theoretically admirable, but most costly in practice. The committee appointed in 1875 in England to report upon the several modes of testing town sewage to the local Government Board condemned this system entirely after seeing it at work at Leyden, Amsterdam, and Dordricht, pronouncing it one of the most complicated and costly processes ; and though the design has been modified since that date, the addition of an extra set of pipes for slop water and other refuse only presents an extra cost. The earlier design as inspected by the above committee dealt only with the contents of the closet pans. I have not seen the Berlin Commissioners' report, but if the reason given in your article for its adoption is that the double set of conduits will cost less than a single set of ordinary sewers, it must be only on account of the cumbersome size of the brick and masonry sewers that are in vogue in Germany, as in all the German towns I have visited the modern English style of pipe drainage is unknown, except where introduced, as at Dantzic, by English engineers. An important action in ordinary drainage works, that of draining the subsoil of a town, is totally lost by the pneumatic system. I consider that a more systematic arrangement of pail collection would be sufficient for Auckland for a long time to come. The pails or tubs should be furnished in duplicate, with lids, and removed bodily, and no emptying into nightsoil carts allowed ; the house slops and rainfall being left to the street drains, with settlement tanks, cleaned weekly, before being discharged into the harbour. House slops and other refuse, where undesirable to be admitted into the street drains, might be removed by the Italian method, collecting into cisterns regularly emptied by suction into air-tigut vans, from which the air has been exhausted, the vans being then driven off without the slightest offensiveuess to the neighbeurhood. The same arrangement might be made in certain cases where buildings are unsuitable for ordinary pail collection. In the greater portion of Auckland there is sufficient ground around each house to absorb and purify the house slops by a natural disinfecting and filtrating action, the volcanic soil districts being specially favourable in this respect, all that is necessary being the laying down at a depth of not less than two feet of several lines of unglazed four-inch piping, within the garden, each line being about 30 feet long. In conclusion I would remark that the A.B.C. or Native Guano Company's mode of treating town sewage is alluded to in your article of the 22nd February, as if it were a drainage system, instead of being only a method of treating town sewage at the outfall.—l am, &c. W. K. Campbell, Assoc. M. Inst. C.E. Shortland-street, Auckland, March 11.