SOUTH KARORI STREAM

Dominion, Volume 26, Issue 149, 20 March 1933, Page 11

SOUTH KARORI STREAM

Pollution Said to be of General Origin

CITY COUNCIL’S DEFENCE

Further evidence for the defence in the application by John Allen Kirkealdie, farmer, of Makara, for an injunction against the Wellington City Council in connection with the Karori drainage system, was heard by Mr. Justice Ostler in the Supreme Court on Saturday. Plaintiff alleges that the City Council is causing or permitting the South Karori Stream to be polluted by offensive matter from the septic tank at Karori. In addition to the injunction, plaintiff is seeking to recover damages for loss of stock, alleged to have been sustained by the restriction of his dairy activities owing to the condition of the stream, and general damages. Mr. E. K. Kirkcaldie is appearing for plaintiff, and Mr. J. O’Shea and Mr. J. Lockie for the Wellington City Corporation. Evidence was given by Mr. H. F. Toogood, civil engineer, who said that it was the designer’s intention that the Karori tank should serve 3000 people, and that this calculation was based on an average flow of 30 gallons per head per day, and 18 hours’ detention when the tank was clean.

‘‘The designer’s anticipations with regard to the amount of sewage to be dealt with have been proved correct,” said Mr. Toogood. “This is evidenced by the fact that the metered water supply to the borough shows the consumption of water per head is approximately 33 gallons per day, and as the total of this amount will not find its way into the sewerage system, 30 gallons of sewage appears to be correct. Attention Required. ' “The time considered necessary for detention of the sewage in septic tanks has beeu greatly modified in recent years, and, whereas 18 hours and up to 24 hours was deemed necessary some years ago, more recent experience has shown that long detention is not only unnecessary, but in many instances very unwise.” Mr. Toogood said he was of opinion, after recognising the general limitations of septic tanks, that the tank now installed Jin the Karori Stream was suitable for the disposal of sewage from a population of at least 4500 people giving a sewage at the rate of 30 gallons per head per day, and if reasonable opportunities to desludge were given, they might possibly be used with fairly satisfactory results by a greater number of people. The tank in its present condition, Mr. Toogood said, required attention both by desludging and by the reduction of mat. As the Karori Stream cleared itself within half a mile from the tank, this should be considered satisfactory from the viewpoint of sewage disposal. His Honour pointed out that the evidence of witness showed that the effect of septic tank treatment was by no means complete, but that the tank was acting reasonably well in the circumstances. The existence of pollution of the stream was shown by witnesses’ own evidence. The common law did not allow that. It seemed that the only question was whether the common law had been altered by the statute law.

Mr. E. R. McKillop, assistant engineer to the city corporation, said that the septic tank was completed some seven years ago at considerable expense to the corporation, and was installed in its present position with the full approval of the Department of Health. It was situated on a stream already highly polluted, and down which development was proceeding. The condition of the stream was now approximating that of some which flowed through built-up areas within the city itself, and it would appear to be just as impossible to maintain the purity of this stream as it would be to obtain potable water •in the lower reaches of any of the streams now cuiverted through the city. “Unfit For Drinking.”

It would appear, said Mr. McKillop, that the whole of this stream from the septic tank to Karori was polluted and was becoming more polluted. It was unfit for drinking and ordinary domestic use, and the effect of the septic tank effluent was only to make this fact more apparent to the casual observer, and thereby removed the danger which the stream above the tank constantly presented. In regard to the stream below the tank, no matter what improvements were made to the septic tank, or indeed what form sewage treatment at the site took, the stream below the tank would not be fit for use. To Mr. Kirkcaldie, witness said that he considered that the sewerage system of Karori, at the present time, was operating in a very efficient manner. At the conclusion of the evidence, his Honour suggested that he should find a statement on the facts. His statement would be that a nuisance had taken place, and that the city corporation had polluted the stream to a greater extent than it was before. He did not think that counsel for the defence could deny that. The question of law, then, was left to lie determined, and that could be referred to the Court of Appeal. The case was adjourned until Saturday next.