1880.] 



Water supplies of Galcutta. 



125 



The usual time for pumping up the water from the river into the 

 settling tanks is at five hours' ebb ; this is of course done so as to avoid 

 tlie possibility of taking in any tidal water and as far as possible to secure 

 only the true river water. The proposals for taking the water for these 

 two places appeared then to resolve themselves into two questions. 



(«) Whether at five hours of ebb the water off Cossipore, at all 

 seasons of flie year can be relied on as a safe source of water-supply. 



{h) Whether at five hours of ebb, the water at a distance of two or 

 three miles above Cossipore, at all seasons of the year, can be relied on 

 as a safe source of water-supiDly. For I think it will be generally admitted, 

 if at either place, at any one season of the year, the quality of the water 

 cannot be relied on, this would be equivalent to a condemnation of the 

 proposed place of supply. 



Before proceeding to deal with the actual results of the analyses 

 which have been previously made by the two gentlemen abovementioned, it 

 will be well to take a general review of the conditions of our river from which 

 the water-supply is to be derived. The river, as is well known, is a tidal 

 one to a considerable distance above its mouth, and it appears certain that 

 the tidal water does not at any season of the year, or under any ordinary 

 circumstances, reach higher than Chinsurah. I have already shown in a 

 previous part of this paper that the true river water, as it has been delivered 

 of late years in Calcutta, is a tolerably pure and reliable supply, and that 

 there has never been the slightest suspicion of any appreciable admixture 

 of tidal water with the natural river water, in the hydrant water now 

 supplied from Pultah. This of course, is because the water is collected 

 at a considerable distance up the river, and that it is taken at five 

 hours' ebb. 



The tidal water however, in flowing up past Calcutta undoubtedly, 

 must become contaminated with a variety of impurities. It may be true 

 that a large proportion, or perhaps nearly the whole of the sewage, as 

 collected in the drains of this town, is now carried to the Salt Water Lakes, 

 but no one, knowing the habits of the lower orders of the natives of this 

 country, will believe, that this represents the sum total of the sewage. 

 In all probability, there is a large amount of filth of various kinds, which 

 finds its way direct into the river. Again, on the banks of the river 

 numerous factories have now sprung up, and it will be quite tuilike the 

 usual experience in England if these factories, unrestrained by Acts of 

 Parliament, do not also send a large amount of filth, refuse, &e , into the 

 running stream beside them. I am not aware what sanitary arrangements 

 are made on the Howrah side of the river, but it has always appeared 

 to me, that a largo amount of drainage reaches the river from that 

 source. 



17 



