Three-year plan for sewerage

Press, 6 May 1983, Page 5

Three-year plan for sewerage

Bromley residents plagued by smells from the sewage-treatment works may have to wait for a “slow but sure” answer. Members of the Christchurch Drainage Board yesterday decided on a treatment process that will cost about $1 million and take up to three years to implement.

Mr J. G. Freeman said the “slow but sure” option was best.

The first proposed stage is the installation of a pilot wet oxidation process to treat smells from the plant filter/ If that worked, a dome would be built to trap smells, and experiments begun to decide the most economical volume of air to treat. Installation of a full-scale treatment process is the final stage. The process has been recommended by the English firm of Mather and Platt Anti-Pollution Systems, Ltd. The board’s chief engineer, Mr H. P. Hunt, told its operations and services committee that the option would allow each stage of treatment to be proved to work and eventually save operating costs. It would take longer to implement than other options but smells would be reduced before then, when the dome

was built. Overseas results were encouraging, although none had tried the process for treating smells from trickling plant filters as was intended. He cited one case where an office block had been built on top of a Swiss plant using the process. The committee agreed with his recommendation. It

also authorised a letter to Mather and Platt stating the board’s intention to buy a pilot treatment plant, subject to board approval.

Mr H. W. Thompson opposed the recommendation because he said the board needed to look at overseas plants using the process before making any decision.