TOTAL COST OF £11,000

Taranaki Daily News, 25 October 1935, Page 11

TOTAL COST OF £11,000

HAWERA SEWER SYSTEM

FINAL REPORT BY ENGINEER. £5847 FOR OLD BOROUGH AREA. It is estimated by the consulting engineer engaged by the Hawera Borough Council to report on the sewer drainage scheme, Mr. R. Worley, Hamilton, that the cost of properly controlling the drainage system in the main portion of the town will be £5847. Although the survey for the Nolantovm drainage has not been completed, Mr. Worley estimates that the cost there will be When further information has been received, it is likely that the cost will be : - slightly reduced. The schedule of works considered necessary by the engineer includes the addition of 38 manholes, increasing the capacity r of the mains in Glover and South Roads, and relaying 16 sections of sewers in the original borough area. The cost in the Nolanfown area is made by the laying of six-inch main sewers and-four-inch connections, by manholes and lampholes, pumping main and station, small isolated tanks and engineering and contingencies. • ' Facts brought out by surveys are that existing sewers are not laid true to grade and are too flat, that insufficient manholes for the adequate maintenance <xL the system exist, that in two instances the existing sewers are not large enough to take care of the normal sewage discharge of the areas concerned and that, owing to the incorrect joining of pipes, ■’ large quantities of infiltration water find their way into the pipes. In his report Mr. Worley stated that > the survey had included a survey of all the existing installation, including loca-y'.-tion, grades, levels and manholes, and a gauging oL the quantity of infiltration water finding its way into the system. The involved shut! ng off the water supply section by se ition and gauging the quantity of the water flow- • ing into the sewers at each manhole. PIPES INCORRECTLY‘JOINTED. Owing to the pipes being incorrectly jointed and some of the manholes incorrectly built in the first instance, large quantities of infiltration water found its way into the system during the winter months when the ground water level v. as high, said Mr. Worley. The parts of the system responsible .for this infiltration had been located and the amounts gauged, and it was found that about 800 gallons a minute was finding its way into the system as against the total quantity being discharged into the systems from the connections of less than 400 gallons a minute. After careful consideration of the whole of the facts, the engineer recommended ameliorative measures as follow: The irregularity and flatness of the grades should be dealt with by the adoption of a more regular and intense system of maintenance and flushing. Additional manholes should be added to the system to ensure adequate maintenance. Replacements should be made .in the ' cases of the two sewers of insufficient capacity. In the areas where the bulk of infiltration was found, the sewers should be relaid by using a bituminous compound watertight joint in place of the usual cement compo joint. Slight infiltration was coming from all parts of the borough, but the 16 sewers mentioned , were responsible' for 750 of the 800 gallons and the engineer did not advise going to the expense of complete elim- • ination.

Although the estimates provided for the complete relaying of the sewers affected and though he thought the necessary funds should be provided, Mr. Wbr- , ley suggested that when it came to the carrying out of the work the sewers should be broken at each connection and a water test applied before tearing up the intervening length of sewer. A considerable saving might thus be effected. , '■ The schedule of necessary works showed the addition of four manholes ea'ch in Wilson, Union, Albion and Regent Streets, and in Fairfield Road, three each in Princes and Vogel Streets, two each, in Disraeli, Argyle, Victoria, Grey and Cambria Streets in Milmoe. and Cambria Streets. The total estimated cost was £532, or £l4 a manhole. The total estimated cost’s of increasing the capacity in Glover and South Roads , was £465, £225 being devoted to duplication in Glover Road from Camberwell Road to the pumping station and £240 to the extension of the South Road pumping main. r RELAYING OF 16 SEWERS.

The relaying of sections of sewers was estimated at £4350. The figures ip parentheses in the following figures - referred to the quantity of infiltration in each. section that would be stopped and total 790 gallons a minute. The sewers to be relaid were: Waihi Road, from Glover f Road to Turuturu Road (108), £450; Glover Road, from Turutvru Road to Waihi Road (115), £450; Camberwell Road (excluding cast iron section) (80)„ £420; Surrey Street, (50), £200; Disraeli Street, from South Road to near .High Street (68), £400;. Disraeli Street, from Surrey Street to High Sstreet (20), £200; Vogel Street (33), £500; Waihi Road, from South. Road to High Street.; (63), £540; Dixon Avenue, near Laurent V.C. Street (24), £200; Dixon Avenue, near Grant V.C. Street (20), £140; Grant V.C. Street (23), £300; Argyle Street (near South Road) (54), £100;. Milmoe Street (flow appears to be confined to one small area) (43), £5O; Caledonia Street, from Erin Street to High Street (45), £200; Erin Street, from Caledonia to Albion Street (24), £100; Wilson Street (unable to locate trouble due to no manholes) (20), £lOO. The engineering, overhead and contingencies were expected to absorb £5OO. He had not, said Mr. Worley, included any work in the Fairfield Road outfall sewer other than additional manholes because he believed that with the elimination of the stormwater and the infiltration water the present capacity of the nine-inch section was largq enough. Should the council desire to include the costs in the proposed loan so as to have the money available should it be required, the estimate for replacing- the existing nine-inch portion with 12-inch pipes was £985.' The survey of'Nolantown had not yet been completed, although sufficient information had been obtained to enable him to compile an estimate; of the cost of the work, said the engineer. The further information being obtained would probably enable this estimate to be reduced a little but for the purposes of the proposed loan the figure given below would be sufficiently accurate. The survey indicated that a litle more work would be necessary than anticipated as on the south side of Tawhiti Road it was not . practicable to install the sewers on the private properties. . The estimated cost, was as follows:— Six-inch sewers £3400, four-inch connections £460, manholes and lampholes £364, pumping station £250, pumping main £360, small isolated tanks £5O, engineering and contingencies £4OO. The costs of fully restoring all road surfaces and private property surfaces was included in the costs.