14
Madras Corporation .—The sand filters at Kilpauk did well at both the examinations.
At the first examination in February the filtrates showed an 87 per cent bacterial reduction
on the average over the raw water, while at the second the average reduction was 75 per cent.
The final product as supplied is, however, not quite up to the mark and cannot be expected
to be any better until the full requirements of the city can be filtered, before supply.
Madura.—Of the two galleries which supplied this town during the year, the Kochadai
one was found to have been laid in quite different strata and to yield water definitely superior
in quality to that from the Arapaliem gallery. In May, vibrios were detected in some of the
samples of water and at the instance of the Surgeon-General, an Assistant of this Institute
was detailed to investigate the matter ; about seven cultures of water vibrios were isolated on
the spot and brought to the laboratory. Luckily, none of these responded to the reactions of
the true cholera vibrio.
Masulipatam.—In March the filtered water was just as bad as the raw water as the
dosage of alum was exceedingly small (0.07 grain per gallon). In October there was definite
improvement. As distributed the water was found to have gained in solids, chlorine and
organic matter, probably derived from sub-soil water through leaks in the pipeline.
Negapatam .—When the Vettar river was dry in March the infiltration gallery yielded a
supply of a very fair quality. In September when the river was in floods the gallery supply
was poor in quality. The water improved in distribution to a slight extent.
Nellore .—The water-supply to Nellore was found to be in excellent order on both the
occasions on which samples were examined. In 1919 also, equally good results were
recorded.
Ootacamund.—In January, the supply was in excellent condition but in June samples
were drawn immediately after the first heavy showers and found to compare unfavourably
with those of January, though still passable.
PeriyaKulam .—In June, there was a slight falling off in the quality of the filtrate as
compared with the previous examination. In December, the results of filtration could not be
judged, as the filter had been started on the day preceding sample collection. The supply
was, however, potable.
Rāmē
swaram Union.—At the instance of the Sanitary Engineer the water-supply to this
union was included in the list of periodical examinations. At both the examinations the
supply was found to be quite satisfactory. In February the service reservoir and pipeline
were found to contaminate an initially good supply and the necessity for a thorough cleaning
was pointed out.
Salem.—The raw water of the Panamarattupatti reservoir was found at both the exami-
nations to be of a very fair quality. The filtered water was worse than the raw water in
April and only slightly better in October, showing that the process of sand filtration was not
efficient.
Tanjore .—In June, when there was a mere trickle in the river the gallery supply was fair,
but deterioration was noticed at several points in the town distribution, showing that the
service reservoir and pipeline required cleaning. In December the water-supply was distinctly
poor, as the infiltration gallery probably also suffered as a result of the very heavy floods
this year.
Tirupati .—In January, the supply was in very good order and in August it was still fair
though not quite so good as in January.
Trichinopoly .—The supply to this town was in fair order at both the examinations, but
deterioration in transit was observed at one or two points.
Tuticorin .—The water-supply to this municipality was in a very unsatisfactory condition
as revealed by the results of both the examinations. Water from an impounded reservoir,
situated about six miles away from the town in close proximity to wet fields and manure heaps,
is led by a masonry conduit into a service reservoir in the town from whence covered masonry
channels draw off the water into masonry pits. People draw their supply from these pits by
means of vessels tied to ropes. Gross organic and bacterial pollution was detected at both the
examinations and the necessity for introducing a regular protected. water-supply with filtra-
tion arrangements was pointed out.
Vellore.—The results of sand filtration were not satisfactory.
Vizagapatam .—There has not been any improvement in the unsatisfactory state of affairs
that was reported last year. The filters have been functioning indifferently and several
cracks and leaks were noticed in the filtered water chamber and in the filters themselves.
A defect in the arrangement of the pipes which affected the efficiency of filtration was also
pointed out.
Vizianagram.—In July, the supply just passed muster and in December, it had improved
to a very marked extent.