WATER AND DRAINAGE.

Manawatu Herald, Volume XXXI, Issue 464, 15 July 1909, Page 3

WATER AND DRAINAGE.

ANALYST’S REPORT OF AR TESIAN AND RIVER WATER

The following is Dr MacLaurin’s report on the analysis of ‘the samples of water submitted to him by the Borough Council. No. iis the water from Mr Ross’ artesian well 165 ft deep, and No. 2 is from Messrs Devin and Co’s. 196 ft deep.

On standing, No. 1 gave a minute deposit, consisting of vege- * table debris and siliceous particles. No, 2 gave a minute deposit, mainly vegetable debris. None of the larger organisms (protozoa, etc,,) so often found in water were present in either sample. No. 1 is very free from organic impurity, and its hardness, although appreciable, is not excessive. It is of good quality for household use. No. 2 is a much less pure water than No. 1. It is hard water, containing an excessive amount of solids.

s His report upon the water obtained from the river about threequarters Of a mile above the wharf was as follows : .

On standing, the sample gave a small deposit, consisting mainly of vegetable debris, with a few waterfleas and diatoms. This • water contains a considerable amount of dissolved organic matter. It is only of fair quality for household purposes.

Dr. Mackill’s report was as follows :—The result of Dr. MacLaurin’s analysis as regards the artesian waters is varied—'but the sources are about half a mile apart. The one from Messrs Levin and Co., is driven on the beach just where the wharf is, yet I can scarcely think that the high amount of chloride and the hardness are due to sea-water soakage, for the analysis of the river threequarters of a mile higher up—where it is still tidal —shows so little chloride that one can exclude seawater, the rise and fall ,of tide being evidently due to backing up of river water. The river water analysis is surprisingly good considering. I visited Foxton on June 22nd and took bacteriological samples at the place in the river from which this chemical sample was taken, and from the artesian well at Levin and Co.’s premises. The river has very little fall for many miles up, and there is no possibility c f a pressure supply from this source without incurring an enornlous expenditure. Therefore, the question being one of pumping from the river neat the town, a sample taken from the spot three-quarters of a mile up gives a fair idea of available water. Dr. MacLaurin’s results exclude sea water admixture.. (I also.

noticed cows drinking from the river here), so we may regard the water there as typical of the river water, for a mile or two up at least. My results were as follows: River Water. Organisms per c.c. normal temperature. ... 3760 Organisms per c.c. at 37 oc. 195 In glucose media, and anaerobically in milk, a large number of gas producing organisms were found .in the deposit from xo ounces of this water, but no b. coli. Levin and Co’s artesian water — Organisms per c.c. normal temperature practically none, only ope colony, and that a mould, being found in any of the plates. Grown at 37 oc., also, the plates were sterile. No growth or gas production in 2 c.c. of the water ,in glucose agar.

The river—therefore, even at mid-winter, shows a considerable degree of pollution, and the water was muddy and unpleasant looking. It could only be used for domestic purposes after sand filtration ; so the cost of filters and their supervision, added to the cost, of pumping, at once puts this water out of court for so small a community as Foxton.

The artesian water on the. other hand is practically sterile, ( and there seemed to be so good a flow from the 2m; pipe that I think it probable that there is an abundant supply available. The somewhat unsatisfactory chemical results with this water, which is so pure bacteriologically, seems to me to suggest the possibility of an error in the method of collection. This, might arise easily, enough since there are several branches to the artesian pipe which are used to convey the water to various parts of the buildings, and the arm from Which the sample was collected is often screwed off and laid, .aside. Enough dirt might have been in this arm to vitiate the results. When I took my sample I removed all the movable branches and took the water direct from the fixed pipe. Another reason for thinking that there may have been an error in collection is that the report shows it to be hard water; whereas, trying it roughly with a bit of soap, the artesian flow seemed to be fairly'soft., As this bore is conveniently situated to the town, it would be a pity to put it out pf court without a further analysis.