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3. No sufficient evidence has been found to condemn the area either from inspection
or from Bacteriological examination provided reasonable precautions are taken.
4. The results given by the unfiltered water taken from the various intakes and streams seem to show that the area is liable to some intermittent contamination with fecal matter,
5. The contamination however does not appear to be either continuous or large in amount. It certainly does not appear to be in sufficient amount to render the water incapable of being converted into a good drinking water.
6. The Pine Wood Nullah shows twice as much contamination as the other intakes,
the reason for this requires to be found, and put a stop to.
7.
The method of running the water direct from the intakes on to the filter beds with no preliminary storage is very undesirable as if there was any infection of the water with pathogenic organisms, they would not have time to die out.
8. This method is even more undesirable if the water happened to be filtered by a
new filter bed which was not yet efficient.
9. If water must be used directly from intakes with no preliminary storage, a very strict supervision must be kept over the area drained by the intake, to prevent its being contaminated with human excreta, and it should only be filtered by a Bed which is known to be efficient.
10.
The whole water should be stored as far as practicable before being filtered.
11. The Filter Beds appear to require at least a week before they become efficient;
during that time the water is used as far as I know and is not run to waste.
12. Therefore when several filters are in use, they should be changed one at a time
and not all at the same time.
13. The filters, as far as they have been tested, never give such good results as
are apparently obtained at Home.
14.
15.
The rate of filtration of 400 to 500 yards gallons appears to give as good results (for a tropical filter) as 300 to 400 yards gallons; but it by no means follows that an increase of the rate up to 700 to 800 yards gallons as is sometimes done (see table of filtration for year 1910) would give a satisfactory filtrate.
As a whole, with the exception of the No. 6 Filter Bed, the filtration results are disappointing showing far too much fluctuation, the importance of prelimi- nary storage of the water is therefore more evident.
16. A standard equal to the results given by No. 6 Bed should be maintained for
all filter beds.
17. The remarks on the Bacteriological results of the water are based on the presence of organisms giving the reaction of true Bacillus Coli Communis (Escherich). Further investigations will be required before the exact signifi- cance of the other Lactose Fermenters can be determined.
18.
19.
It is desirable that an investigation of the habits of the nightsoil coolies in the Peak District in the early morning should be made from time to time. Even negative evidence on this point would be of great value.
From the results given it should be possible to produce a filtered water with a total agar count of 30 to 40 per c.c. and with Lactose Fermenters absent from 20. c.c.
This result would be, for the Tropics, a very good one. At present, though samples equal to or even better than this are from time to time obtained, still a steady standard is not maintained.
20. For drinking purposes, of the unfiltered water, the best would be the water
which has been stored in the Reservoir for some time.