120
8. The total quantity of water supplied was 870,041,470 gallons so that the cost of maintenance per 1,000,000 gallons supplied, neglecting Engineering supervision but including the expenditure incurred in the prevention of waste, has been $8.13 as compared with $7.81 the previous year.
Tables A., A1., A2. shew the quantity of water supplied from each source each month during the years 1889, 1890, 1891 the average minimum temperature and the rainfall from which diagrams No. 1 * and 1^ * have been prepared.
I shall refer to this later on when dealing with the question of the consumption of water.
9. The Quality of the Water supplied.--I am indebted to Mr. W. E. CROW, the Government Analyst, for a monthly analysis of the water supplied from the Pokfoolum and Tytam reservoirs before and after filtration from which Tables B. and B1. have been compiled.
Though the analyses speak for themselves there is an apparent anomaly in the total solids before filtration being less than those after filtration during the months of January, February and December in the case of the Tytam water, and January, February, March, May, October and December in the case of the Pokfoolum water. This seems due to the increased hardness of the water after filtration which is accounted for by the quantity of lime existing in the sand composing the filtering material. The ultimate hardness is so small that this slight increase is no detriment to the quality of the water either for domestic or dietetic purposes.
Speaking generally the water supplied during the past year has been of exceptional purity for a public water supply and compares most favourably with the public water supplies of the United Kingdom.
10. During the month of May on the first heavy rains occurring, after probably the severest drought experienced in this Colony within the memory of any one living, the water assumed tempora- rily a milky white appearance of so noticeable a character that public attention was called to it and a special report was made by Mr. E. W. LUCAS, the Assistant Government Analyst, a copy of which I attach.
11. The entire absence of ammonia in the filtered samples of the Pokfoolum water is a notice- able fact. The analyses of the filtered samples in the case of the Tytam water is not so satisfactory in this respect.
The difference is probably due to the fact that the water after filtration in the case of the Pokfoo- lum supply is stored in a covered reservoir whilst in the case of the Tytam supply, it is stored in an open reservoir in close proximity to the City.
12. The reduction of free ammonia and albumenoid ammonia by filtration is satisfactory evidence of the efficiency of the filters.
The covering over of the Tytam Service Reservoir has received my attention and detail plans and estimates have been prepared.
13. Consumption of Water.-As will be seen on reference to tables A., A.1, A.2, the approximate total consumption of water during the past year has been 870,041,470 gallons as against 823,019,012 gallons in 1890, and 778,146,993 gallons in 1889.
That the consumption should have increased is by no means to be wondered at when it is borne in mind that previous to the commencement of this year water was only very imperfectly distributed and the greater part of the eastern and western portions of the City now supplied with filtered water were previously supplied with unfiltered water from various sources (the yield of which there was no means of ascertaining) and what distribution works existed had been far out-reached by the rapidly increasing population and extension of the built area necessitating the collection of water from streams on the hill-side.
Since the month of June the whole City has practically without interruption been provided with a constant supply and water is now readily accessible not only to the residents in the City but also to those in the hill district.
14. The introduction of a constant supply at a high pressure following on an intermittent supply naturally led in the first instance to considerable waste; persons who had been accustomed to leave their taps open all night so as to secure, during the few hours the water was obtainable under an intermittent system of supply, sufficient water for their daily wants scarcely realised the fact that such a precaution was no longer necessary and doubtless much waste was occasioned in this manner.
15. The additional pressure obtained with the new system of pipes increased the waste of water through defective fittings and leaky pipes. J
16. The sources of waste have received my careful attention and in May last Mr. DRAPER was engaged for the purpose of making an house-to-house inspection. Such an operation though absolutely necessary in the first instance is, as is well known to those who have had work of this nature to perform, a very tedious one, and compliance with the necessary rules and regulations for the prevention of waste is by no means easy to obtain. However good work has been done upwards of 1,900 Houses Services
* Not printed.