Drinking- Water and some of its Impurities. 123 



Let us now look at these results and see what they in- 

 dicate. The total hardness of the water supplied to the 

 three cities is about the same, the difference being no 

 more than would exist in the same water on different 

 days. In permanent hardness the Troy water is much 

 better than that of Schenectady. The nitrates indicate the 

 sewage contamination perfectly, increasing as we go down 

 stream from Schenectady to Albany. Above Schenectady, 

 there is very little sewage flowing into the Mohawk, until 

 we reach Utica, eighty miles above, that being the only 

 place on the river with a system of sewers. The river 

 itself passes over many rifts and shallows between these 

 places, affording every opportunity for the oxidation of the 

 organic matter. At Troy the river has received the 

 sewage of Cohoes, Waterford, Lansingburgh, etc., and at 

 Albany that of Troy and West Troy in addition, and the 

 nitrates accordingly increase. The water of Tivoli lake 

 having received no sewage is consequently purer than 

 that from the river, and is the best water supplied to these 

 cities. As far as the analyses go, however, the river 

 waters are perfectly safe and wholesome, being far purer 

 than any well-water analyzed. 



In the analyses of the well-water from Schenectady we 

 find nothing more than would naturally be expected. 

 The city is a very old one, situated in a valley, and with- 

 out the slightest attempt at a system of sewers. For over 

 two hundred and fifty years the inhabitants have been 

 pouring their refuse on the ground, and the contents of 

 their privy vaults have been soaking into the earth. 



In old cities the ground becomes almost honey-combed 

 with vaults. As fast as one is filled, it is covered up and 

 another is dug. When the property is sold, the first vault 

 is forgotten or unknown. Finally a well is to be dug on 

 the place, and it is easily seen that there is some possi- 

 bility of striking an old vault. 



