Sewage filter tower has double load

Press, 10 June 1977, Page 17

Sewage filter tower has double load

The first of two filtei towers at the Bromley ; sewage treatment plant is handling twice as much sludge as it was designed for The Christchurch Drainage Board’s chief engineer (Mr P J. McWilliam) told the construction and treatment works committee yesterday that half the sludge now going through the tower would be redirected to several ponds so that the board could test the filter tower at its design load. “I am disturbed about the behaviour of the plant and its performance at this stage,” said the chairman of the committee (Mr C. H. Russell). Mr 1. G. B. Wilson said: “This filter is a bit of a toy. Until you have played with it a bit, you do not know how it will operate.” He said that 99 percent of the sewerage plants throughout the world did not work as designed and although he was

disappointed that the towers were not ready as desired, he thought the problems would be solved soon. Mr McWilliam said that winter was the worst time of the year to do this but if there were no problems, redirection of the sludge could continue until the second tower was ready. “This filter should be able to take the load of the higher-quality sludge,” said Mr Russell: “I am disturbed that if something goes wrong, one filter will not be able to carry the load.” Mr J. de C. Hanafin said it was unwarranted to express concern while the meeting was being reported and that it would be best to wait until the tower had been tried at design load. Contract Mr J. Ryan asked what was happening about an $BOO,OOO sewer contract let on Octo-

Iber 26, 1976, to March Con- [ struction, Ltd, and due for [completion on April 26 this year. There had been no pro- ! gress. : Mr McWilliam said that [there would be no increase in [cost to the board because of • increases in the price of materials during the delay. He thought that in time the company would apply for an extension to the contract even though the completion date had passed. Flow measure The board will buy a flurometer and dye to measure the flow patterns of the Waimakariri River, the Brooklands lagoon, the estuary, and pipes and channels. .' The flurometer itself will; cost just over $3OOO and I 1250 kg of dye will cost $3380,1 [prompting Mr Wilson to ask! ; that staff ,make sure they use| jit sparingly. '