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170
The water is pumped from a point at the deepest part of
the Baths, passed under pressure to gravel filters, then
into a chamber or tank where it is aerated, and afterwards
chlorinated before returning to the Baths.
SWIMMING BATHS.
During the year the purity of the water received constant attention. In all, 78 samples were taken and submitted to bacteriological examination. Generally the
results were satisfactory, but on some occasions the bacterial
content was found to be unduly high.
The reports upon the water from the Open-Air Bath were
particularly good. On two occasions only did the bacterial
count exceed the maximum per cubic centimentre which
has been adopted as a standard.
On 5 occasions out of 29 the water from the First-Class
Bath, Lime Grove, gave counts in excess of this standard,
but on 14 occasions out of 29 the water from the SecondClass
Bath did not conform to the requirements, although
only on a few days was the count seriously in excess.
The chlorine content of the water was also tested from
time to time, and it was found generally that on those days
when the bacterial count was high, the chlorine was low.
The figures obtained for free chlorine varied from .2 parts
per million to over 1 part per million. When the latter
figure was shown the bacterial count was very low—3, 6
or 8 bacteria per c.c. The use of chlorine in this proportion, however, is unsafe and usually results in complaints
from bathers of discomfort and smarting eyes. If is recommended that the chlorine should not exceed .(5 pts. per
million nor fall below .4 pts.
ZOTOFOAM BATHS.
During the year the Council had under consideration the
desirability of the provision of remedial baths (Zotofoam
Baths).