Leeston sewers almost ready

Press, Volume CXIV, Issue 33448, 1 February 1974, Page 19

Leeston sewers almost ready

A sewerage scheme for the town of Leeston which aroused speculation that it might pollute Lake Ellesmere is almost completed. The ecological questions have been met by a compromise.

The contractors are ready I to start work on the oxidation pond in which the , sewer effluent will be treated. It was the proposal , for the discharge of all the treated sewage into the i Leeston Creek that made the ’ North Canterbury Acclimati- . sation Society challenge the . original plans of the Elies- ■ mere County Council. The society argued in a Town and Country Planning Appeal Board hearing that ' the discharge would hasten the eutrophication of Lake Ellesmere, and its destruction as a fishery and wildlife breeding ground. After hearing conflicting evidence, the board ruled that the council could discharge direct to the creek during the autumn and winter, but that it must use the effluent for irrigation during the spring and summer. The

work has proceeded on this basis.

The pond, of three acres and a half, will be 300 yards from the southern boundary of the town on a five-acre block owned by the council. There is no reason to expect problems or nuisances, and there have been no comments to the council from residents.

Between May and August, the pond will discharge into the creek. Between September and April, the effluent will be used to irrigate the farm of Mr G. W. Amyes, who has border-dyked his land, and will get the effluent free.

If, for any reason, he cannot take the effluent, the council has the right to discharge it on a 10-acre paddock near the pond. Although the scheme was planned in 1967, delays in getting financial and technical approvals, and the appeal, held up the start of work until March last year, when the Ashburton firm of Crum Brothers, Ltd began the excavation of 28,000 ft of main trenches, and 10,000 ft for side lines. “The contractors ran into! trouble with the excavating,” said the County'

Engineer (Mr D. J. May). “The water-table in parts of Leeston is only 18in below ground level, and this caused flooding. In places, the trenches were Bft to 9ft deep.” The council staff designed the scheme, and laid the mains. The capacity of the scheme is 1200 people, and Leeston now has a population of about 850. Rapid housing development is expected when the sewers are in operation, particularly at the south end, where, in what the “locals” call Monkey Town, is a large block of residentially-zoned land. Mr May said the whole scheme would cost about $280,000. The next job after the pond would be the installation of two pumping stations—just 6ft pipes sunk 15ft to house submersible pumps. The sewage would run by gravity to the pumps, and be pumped to the pond. “I can’t actually give a finish date—it will depend on the speed with which property-owners connect to the mains,” said Mr May. “This work is at their exjpense, and it should be possible to start it, working in grotms, in perhaps two months.’’