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(b) Water Supplies - Miscellaneous
Pour samples of sub-soil water were taken.
(c) Swimming Bath Water
Fifteen samples were taken for bacteriological examination. All were reported
to be satisfactory.
By courtesy of the Chief Superintendent and Engineer of Baths and Wash-houses
the following information is included in this year's report.
There are six Swimming Pools at present under the control of the Council. The
Swimming Bath at Hornsey Road is being reconstructed. Upon completion, which it is hoped
will be in 1963, there will be two Swimming Baths at this establishment.
The Metropolitan Water Board supply the water for these Baths:-
The method of treatment for purification is by chemical dosage: alumina ferric is the
coagulant used to fulfil the function of forming a film on sand. Soda ash is the
alkaline salt to counteract acidity. A pH value of between 7.4 and 7.6 has proved most
satisfactory to the swimmers using these baths.
Aeration is maintained by means of an air compressor.
Sterilization: Chlorine gas is used a residual of 0.5 to 0.75 p. p.m. being
strictly adhered to. In the summer months when heavy loads are to be expected it is
kept at 0.75 p. p.m.
The frequency of changing the baths water is governed by the flow through the
filters which in the case of these establishments is approximately once every four
hours. In the summer months when the baths are open for 12 to 14 hours daily a complete
turnover of three times per day is necessary.
One sample of the water at Highbury Fields open air swimming pool which is
controlled by the London County Council was taken during the summer season for
bacteriological examination. The London County Council was informed of the result which
was satisfactory and is included in the figure given at the head of this section.