The Press WEDNESDAY, AUGUST 10, 1966. Harbour Pollution

Press, Volume CVI, Issue 31134, 10 August 1966, Page 14

The Press WEDNESDAY, AUGUST 10, 1966. Harbour Pollution

Lyttelton’s Harbour Board and Borough Council and the Mount Herbert County Council were last week alerted once again to the menace of harbour pollution. The evidence is quite sufficient to persuade the Health Department to recommend that notices be erected to warn against fishing and swimming in the inner harbour, at Corsair Bay, Rapaki, and Purau Bay, This is a blow to valuable assets of Lyttelton and Christchurch. The recommendation is based on one check on the harbour waters. A series of tests taken under a variety of conditions might show that pollution beyond acceptably safe limits is rare.

The local bodies are alive to the dangers. The Lyttelton Borough Council already plans to alter the public lavatories at Corsair Bay so as to prevent pollution by direct discharge into the bay. Its planning of the newest sewer outlet, which discharges the greater part of the town’s sewage into the harbour east of Cashin Quay, envisaged the eventual installation of a treatment plant. Without pumping, the rest of the town’s sewage will not easily be treated, although some temporary reduction of pollution might be possible. New sewerage systems at Diamond Harbour and Cass Bay avoid further pollution of the harbour. The Harbour Board is concerned about all aspects of pollution, especially by oil and sewage from ships.

Pollution from shipping in harbours has been the subject of international study. No promising solution is offering. The piping of sewage from most ships is impracticable. Shore latrines are not popular among seamen. Holding tanks aboard ships for use in harbours and docks may be the best answer; but several decades might pass before all ships could be equipped. Warships and coastal vessels present snecial difficulties. The waters of three harbours in New Zealand—Auckland, Whangarei, and Ohiwa in the Bay of Plenty—are classified under the Waters Pollution Act: that is to say, standards related to usage are set for the purity of the water, discharge points are registered and policed, and pollution is an offence. The Pollution Advisory Council which administers the regulations, aims to advise and persuade rather than to force local bodies and others to accept measures to preserve the purity of inland and coastal waters. Classification is a long process and it must allow time for practical, and often expensive, steps to be taken before standards are rigorously enforced. Tentative as the recommendations of the Health Department may be, now is the time fully to assess the pollution of Lyttelton Harbour, which may be worse rather than better than the recent single sampling revealed. The contamination of fish, the fouling of pleasure craft, and the endangering of swimming are threats to public health not to be taken lightly.