New biofilter complete, Drainage Board told

Press, 20 December 1985, Page 4

New biofilter complete, Drainage Board told

The new odour-combating biofilter at the Christchurch Treatment Works has been completed, the Christchurch Drainage Board’s chief engineer, Mr Peter Hunt, told the board this week.

A temporary biofilter system could, therefore, be working by Christmas, he said.

“All the pipework is complete and work on the manholes is nearly finished,” Mr Hunt said. “There is some work to do on the fan house but this will not stop. the system from being put into operation. “Manufacture of flexible ducting is in progress to enable withdrawal of some foul air from the base of the operating number two filter. This system will attempt to reduce odour emissions from the filter until the permanent cover is erected on number one filter.” Emergency discharge The board has applied to the North Canterbury Catchment Board for a right to discharge partly treated sewage in emergencies and is awaiting the outcome. The best option for these emergency discharges recommended by Mr Hunt is discharge into the oxidation ponds. Philpotts Road drain The board’s deputy chairman, Mr M. R. Carter, has indicated that the Christ-

church City Council is not willing to contribute funds towards piping the, Philpotts Road drain between the Dudley Creek diversion and Innes Road.

The board has completed an assessment of the benefits to surrounding properties from the piping which it will use when approaching property owners for contributions.

Timing of the works would be determined by the council’s and property owners’ response, Mr Hunt said.

“If the majority of property owners are willing to contribute and want the board to proceed the board may be able to use statutory powers to obtain all the necessary contributions,” Mr Hunt said. The board agreed to request a contribution from each property owner of $l6OO and a reply by February 28 of next year. Tidal control The board has. written to the Christchurch City Council seeking its urgent cooperation with road reconstruction to raise Clarendon and Richardson terraces. Since the Woolston Cut completion is targeted for mid-1986, a critical situuation had developed because of lack of progress with raising the terraces, Mr Hunt reported. “This situation is exacerbated by the Woolston Cut contractor’s need to partially open the cut by late February or early March, 1986, to allow the start of

control works at both ends of the Woolston Loop,” he said.

“This partial opening will allow a portion of the increased frequency of tidal effects and salinity to occur from that time.

“Unless suitable early programming for road raising can be achieved the board will have no alternative but to proceed with bank construction alone. This action would be undesirable and at variance with ■ the conditions recommended by the council.” Taylors Mistake A full sewer reticulation scheme is being designed for Taylors Mistake. If it is adopted by the board it will enable every existing residential sized section in the residential zone on the lower side of Taylors Mistake Road to obtain a sewer connection. Provision could be made for sewer reticulation to be installed by developers to connect to the main sewer system, Mr Hunt reported. “The outfall pumping stations and pressure mains will be designed to be capable of serving a potential residential area currently zoned rural,” he said. “This capability can be provided at small initial extra cost and the additional area has been indicated as a likely and logical change in Christchurch City Council planning.” Mr Hunt expects that a scheme can be finalised and costed before late February, 1986.