NEW PLYMOUTH SEWERAGE.

Taranaki Daily News, 22 June 1920, Page 7

NEW PLYMOUTH SEWERAGE.

GENERAL MANAGER'S RECOMMENDATIONS. The general manager of the New Plymouth borough reported to last night's meeting of the Council as follows: I had previously recommended that an officer he employed to take the levels and prepare a contour map of the borough, and that when this- was completed a report be obtained upon a comprehensive scheme for the sewering of tlic whole borough. This is necessary in order- that any future extensions may not be made haphazard and may be partof the comprehensive scheme. The Council adopted the recommendation, and provision was made in the new loan for funds to carry out the work. Apart from the above, however, there are one or two matters in connection with the sewerage system which require attention. The most important if. in connection with the septic tank. The original schema provided for the installation of two tanks of the same capacity. The first was installed, but the second was left over until the number of connections to the sewers made a second tank necessary. This number was reached years ago, but the second tank was not installed. The consequence is that the present tank, being considerably overtaxed, really acts merely as a collecting chamber. When the comprehensive scheme is submitted it will probably be found that the sewage from the present installation will be collected at the Qxisting tank and pumped to an outfall a long way from the central portion of the town. It is not, therefore, desirable to instal the second tank, but as it will be soveral years before the comprehensive scheme can be undertaken, something should be done at once to (leal in a more satisfactory way with the effluent from the present tank. I therefore recommend that the borough engineer be instructed to report upon the advisability and also, the cost of laying a pipe along the bed of the Huatoki to low water mark 011 the beach, to carry the effluent from the tank direct to the sea instead of discharging, as at present, into the river. As this work would not be of any permanent uge in connection with the comprehensive scheme he should also report whether any other method, at a lesser cost, could he adopted to meet the position. I do not wish to say tno iniich in regard to this matter, but I think it will be realised that although the cost may be considerable, something must be done to remedy the present state of affairs. A very important part of the sewerage system is the connections upon private property. These arc not lqjd by the borough, but must be laid in accordance with the by-laws and the materials Ufisd must be passed by the borough sanitary inspector for the time being. I am advised that in past years sufficient attention lias not been paid to the class of pipes used, /and inferior pipes were permitted to be put in. Whilst the Council itself used first-calss pipes for its mains, ji appears that the use of first-class pipes for connections upon private property was quite the exception. Too much care cannot be taken in the laying and inspection of pipes used for private drains, as they are an integral part of the sewerage system and every bit as important as the mains in the streets. The present inspector realises this, and quite a large number of- pipes have been condemned by him which would have been passed as quite satisfactory a few years ago. Another rather important matter brought under my notice, was that when the sewer mains were laid in the streets a large unmber of the manholes were covered with concrete slabs instead if easily removable cast iron covers, These slabs are. covered in some cases with several feet of soil and macadam. This means that the manholes cannot be in* speeted periodically, and incipient blockegas detected and removed. Inspection becomes absolutely necessary at times, and this entails a certain amount of labor in (figging up the streets to get at the manholes. A very large proportion of the initial cost saved by the substituting of concrete slabs for the proper manhole covers is therefore lost 'every year, to say nothing of the inconvenience caused and the very essential ventilation of the sewers lost by the method adopted. Another weak point in the system to which I had intended to direct attention was the practice of permitting more than one house to be connected to the one branch drain, and the large number of blockages and consequent expense caused thereby. This matter was, however, the subject of a special report by the borough engineer to the last meeting of the General Purposes Committee, and steps have been taken to prohibit the practice in future. It will be noticed that throughout this report I have only dealt with the weak points of the' system. The good points of a system are generally well known, but I take it that- the Council.desires to know if and where the system is any-' wise defective. The report has, therefore, been based* upon this assumption, my object being to show, firstly, that when a comprehensive scheme is being prepared later a very careful inspection muts be made of the present system, in order that provision may be made in the new loan for the remedy of any defects entailing a heavy expenditure; and, secondly, that any minor defects

I may be remedied forthwith.