328
REPORT.
(i) The sample taken from the well in the infiltration gallery shows a great deal of pollution—fœcal bacilli Ain
of a cc. This, however, obviously cannot represent the real quality of the water because the pipe water shows fœcal back
10 cc.
(ii) The most likely explanation of this is either (i) dust is,kicked into the well,(ii) contaminated rainwater le
in under the door or (iii) a small trickle of highly contaminated water leaking in through a crack in the masonry of the
The last is the most likely suggestion. According to the above result the gallery water is much inferior to last quarter,b
pipe water is considerably improved.
The water is a very hard one. The presence of a large quantity of nitrates is probably due to the amount of
cultivated land there is in neighbourhood of the gallery.
.Recommendations.—Please ascertain and report to the Sanitary Commissioner (i) if rainwater could find its Iv
the well under the door ; (ii) if there is a crack in the masonry admitting ground water near the surface.
NOTE ON THE WATER-WORKS.
In the report on the water for the current quarter certain questions relative to the possibility of contaminatin
water in the infiltration gallery by either dust, rain water or pollute surface water, through a crack in the well were
As the answers given to these queries do not seem to explain the cause of the inferior quality of water in the gall(
investiation was made. From a careful inspection of the interior of the well there appears to be no crack whatever an
obvious therefore that the samples taken in the current and in the previous quarter represent the true quality of the WI
the gallery. The great difference between the bacteriological contents of the gallery water and that taken from the
pipes in the town is simply clue to the purifying action of the pipes. It will he observed that the further the water
in the pipes the better it becomes, or in other words, the best samples are taken from the most distant hydrant.
The quantity of water available in Dindigul is a much more serious problem than the quality, every year the
been increasing difficulty in supplying the town. At the time of my visit (November), after a deficient monsoon, the elf
is still acute and. it w ill increase as the hot weather comes on. The real fault in the Dindigul water-works is the fac
the galleries are sunk in the strata which are only very slightly porous. The consequence is that although there is ple
water in the immediate neighbourhood it does not run into the gallery in at anything like the same rate as it is carried
the town. in proof of the truth of this statement, the water level in the gallery well at the time of my visit was al
feet below the ground level. The irrigation wells situated between the tank and the gallery, and within 200 yards d
gallery itself, were full to within 2 feet of the coping. The tank itself is nearly dry, the water having been run off fora
Lion purposes. The worst feature of the scheme is that no extension of the gallery system would permanently lncrease
supply to the town.
The only possible way of improving matters seems to be to acquire the tank and store water in it, allowing
used for irrigation purposes, when the gallery fails the supply be supplemented 'from the tank. I am perfectly well
that in making this proposal objections will be raised on the ground of cost in compeasation to ryots whose irrigation
is cut off. But from a very careful inspection of the whole neighbourhood, it appears to cue the only possible solution.
difficulty. it is also possible that keeping a higher level of water in the tank might improve the supply in the galler
I am not hopeful of this, because irrigating the land in the neighbourhood of the gallery with well waters has little
influence on the quantity in the gallery. I recommend the Municipality to enquire into the probable cost of the
suggestion.
MADItAS,
30/h November 1908.