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(c) Number of water boats and their sanitary condition:—
Inspector Madeley, who carried out during the year an enquiry into the water
supply to ships in the Port, says:—
"There are twelve water boats working in the Port. All are of steel construction
and of the 'single skin' type, i.e., the skin of the boat forms the sides and bottom
of the tanks and the deck forms the top. The manholes are raised from 6 inches to
1 foot above the level of the deck and the steel covers are fitted with locks and should
be secured whenever the boat is unattended, to prevent unauthorised persons dipping
water from the tanks in buckets which may be dirty. Each boat should be provided
with a small domestic tank for use of the crew, as otherwise they will obtain water
from the main tank usually by lowering a bucket into it. Manhole covers should have
proper filling caps, so that there is no need to open the tanks during loading. It is
particularly undesirable that the manhole covers of tanks should be opened when
a water boat is lying alongside a ship, as there is risk of foul water from the ship's
scuppers being accidentally discharged into the tanks. For the same reason all hoses
not actually in use should be kept under cover. It is the usual practice to clean tanks
every three months and to cement-wash them every six months, and the boats come
under the supervision of your Inspectors at these times."
All water boats must be registered annually with the Port of London Authority,
and before a certificate is granted they must be inspected as to their fitness for
navigation in the river and docks. The Port of London Authority notify the Port
Sanitary Authority when water boats are coming up for re-registration, and will not
issue a certificate to any water boat until your Medical Officer has certified that it is
fit for the carriage of drinking water. This arrangement has now worked quite
smoothly for several years, and has enabled your Officers to get repairs and
improvements carried out without difficulty.
Special Inquiries in regard to Water Supply.
During August there occurred on board a ship in the Mediterranean a number
of cases of enteritis. The possibility of the water on board being contaminated was
considered, and samples examined bacteriologically at two ports abroad were
unfavourably reported upon. This water was taken on in the Port of London, but on
enquiry was found to have been derived from a large public supply, which is kept
under the closest supervision and in regard to which there had been no other complaint,
though it is distributed over a very large area ashore. However, a thorough
investigation was carried out by a Medical Officer and a Chemist, representing the
Shipping Company concerned, the Bacteriologist to the Water Company, the Medical
Officer of the Port of London Authority and myself. The situation of the mains and
hydrants was carefully inspected, and there appeared to be no risk of contamination.
Three samples were drawn from each of the following points : a tap on the main in
the meter house; the hydrant on the quay where the ship referred to had taken on
water; the same hydrant after sterilisation; the end of a length of hose, as used for
supplying ships, attached to this hydrant; a tap on an adjacent quay. The three
series of samples were submitted to three different Bacteriologists. All the samples
were reported as satisfactory except that from the end of the hose. This contained
"coliform" organisms, but no typical bacilli coli. The hose was ordinary canvas
hose, which is handled and stored with reasonable care. It therefore appears that
coliform organisms may gain access to pure water during its passage along a length
of hose from a hydrant ashore to a ship. These organisms will, under favourable
conditions, multiply during storage in the ship's tanks. The question then arises as
to the hygenic significance of these coliform bacilli. They are not pathogenic, but
they are regarded by Bacteriologists as indicating the possibility of dangerous
contamination. Their importance can only be gauged in association with the results
of chemical examination and some knowledge of the source of the water. Actually
the bacteriologists abroad did not, in this instance, differentiate between coliform
organisms and typical bacilli coli. It is suggested that this distinction should always
be made, and that in the absence of typical bacilli coli, Bacteriologists should not
unhesitatingly condemn a sample of water from a ship simply because coliform
organisms are present. It is right that they should express some doubt in regard to
the sample, but they should indicate that their findings are not conclusive and that
they could only express a definite opinion if they were in possession of data as to the
source of supply and the possibilities of pollution. It is probable that coliform