79
INTRODUCTORY NOTES
COMPARING THE ANALYTICAL RESULTS OBTAINED DURING THIS
QUARTER WITH THOSE OF THE CORRESPONDING QUARTER
OF 1909.
Ádóni.—There
is no evidence of progress in Ad óni. The Spring and the Tank
Water occasionally change places, but the general tendency is downward. In 1910
the tank was the better, but the filtration so faulty that the filtered water was much
worse. There is usually some improvement after passing through the pipes.
Cuddapah.—No unfiltered water could be got in 1910, but there is no reason
to suppose that it was any worse than the water of the Infiltration Gallery. This
Gallery produces little or no improvement in the quality of the water. The
astonishing improvement caused by passage through the pipes in the Yerramukku
- p a l l i s e c t i o n w a s n o t m a i n t a i n e di
n 1 9 1 0 .
Madras .—Both the difference of date and the climatic conditions have
combined to bring about a great difference in the Madras water-supply, which in
1910 was better than it had previously been. As regards the head-works it would
appear that little is wanted beyond good conservation of the gathering grounds to
p r o d u c e a v e r y f a i r s u p p l y . T h e w a t e r a s d i s t r i b u t e d i s n o t s o g o o d . P o s s i b l y
the long open channel gives a means whereby pollution can be introduced into
the water.
Trichinopoly .—Much the same climatic conditions appear to have prevailed in
the two years, and the condition of the river water was on both occasions
remarkably alike and unfortunately remarkably bad. In 1910 passage through the
Infiltration Gallery and pipes did not produce the same good effect as in 1909,
though the water was slightly improved. The increase in hardness, pointing to
admixture with subsoil water, is again evident after the water has passed through
the Infiltration Gallery.
Tanjore .—Owing to the drought comparatively very bad water was being got
from the river-bed in 1910, so that the Infiltration Gallery having equalised matters
is a good performance. The improvement was not however maintained in the
distributary system in the later year.
Guntúr.—The water of the Spring was very much better in 1910 than in 1909.
As this fact is associated with drought in 1910, it looks like as if surface pollution
can get access to the spring if there be a little rain. This should be easily remedied.
Passage through the pipes in 1910 brought about a woeful deterioration, so these
should be attended to. Chemically there is nothing to note except the high solids.
which seem to be mainly sulphates. This is a constant feature.
Coonoor.—The water was very much worse in 1910 which is not very easy to
explain as there was no lack of water either year. The 1909 samples were taken
three weeks later in the year so possibly the gathering grounds had got more
efficiently cleansed. If properly conserved such an effect would not be apparent
because there would be no pollution to clean away.
Nellore.—The water of the Pennar River seems to be characterised by high
total counts, which are not greatly reduced and are sometimes largely increased
by filtration. This is curious as filtration does bring about a great reduction in the
fæcal germs. The pipes do not seem to be in good order as in both years fœ cal
germs of the susceptible Class I appeared in the distributary system.
Tirupati.—The water was very much better in 1910, a state of affairs probably
due to the drought, so that surface washings can get access to the water. Can
this not be prevented ? The pipes would appear to be in a far from satisfactory
condition.