173
INTRODUCTORY NOTE .
Trichinopoly.—The river was in high flood in 1910, so it is not surprising to.
find the water more polluted than in the previous years. In neither of the latter
two years has the presence of oxytocus perniciosus been demonstrated. The exact
significance of the presence of this germ in drinking-water supplies is unknown,
but as it is remarkably sensitive to the action of sunlight, we cannot but class it
as a sign of recent pollution. In 1909 the infiltration gallery was producing a
good. effect on the water, but the same cannot be said of the previous and following
ears Exactly the reverse is the case with the so-called pipe action. Deterioration
in 1909, improvement, in 1908 and 1910. Chemically the water is fair in 1908 and
better in 1909-10.
Tanjore.—The Tanjore water-supply maintains a fairly good record. The
river is usually flooded at this season and the water relatively impure. The
infiltration gallery however brings about a marked improvement and this is main
-
ined throughout the distributary system. Chemically the water is fair, but.
curiously enough acquired a considerable amount of oxidised nitrogen from the
gallery or pipes in 1908-09. This was not seen in 1910.
Madras.—The
results got in the last quarters of the years would almost support
the idea that there is a tendency to improvement in the Madras water-supply. The
improvement is however probably illusory and due to varying meteorological
conditions. There was more rain in. 1908-09 than in 1910, so in the last year the
water at the head works was very definitely better. It still contained. however a
most undesirable amount of organic matter of animal origin. It is a pity that
more successful attempts to keep the gathering grounds clear of animals are not
carried out by the Corporation. The .appearance of B. Coli Communis in 1908 and
of vibrios in 1910, both in the same section of the distributary system would
appear to indicate defects in the pipes of this section.
Adóni. —In 1910 only the spring water was in use which enables us to show
that the excessive amount of animal organic matter is mainly derived from the
tank water. The increase shown in the pipe water in 1910 as compared with the
spring water is probably derived from residual water in the system which came
from the tank. The great purity of the spring water in 1909 is difficult to account
for and unfortunately was not in evidence in the previous or following years. The
tank water, considering its chemical features, can be remarkably free from bacterial
impurity, ride 1909, but unfortunately again the reverse may be true, as in 1908.
Cuddapah.—The river is usually in flood this quarter with somewhat variable
results. In 1908 pollution of a most objectionable kind was in evidence, in
1909–10 the water was, under the circumstances, extraordinarily good. Passage
through the infiltration gallery and pipes does not materially improve the water.
Chemically the water seems to have a slight tendency towards improvement, but the
variations in the amount of nitric nitrogen are remarkable and difficult to account for.
Guntúr.—The
water-supply of Guntúr cannot be said to be on the upgrade,
It was better in 1908 than in the following years ; it was greatly polluted in 1909,
but more specifically and objectionably polluted. in 1910. Possibly the heavier
rainfall of 1910 has to do with the specific pollution, but this cannot be definitely
stated. The filtration of the water as carried out exerts no beneficial effect on the
water.
Bezwada. — B e z w a d a
b e i n g a n e w s u p p l y n o c o m p a r i s o n w i t h p r e v i o u s y e a r i s
a v a i l a b l e . J u d g e d b y t h e r e s u l t s o f t h e p r e v i o u s q u a r t e r t h e r e i s a t e n d e n c y f o r
silt to accumulate in the pipes and to give rise to objectionably high total counts in
the water of the distributary system.
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