MUNICIPAL WATKR SUPPLIES. 



BY C. M. BROOM ALL. 



The health of a conimunity varies in more or less direct 

 ratio with the purity of its water supply. The obtaining of 

 such a pure supply and its subsequent preservation from pol- 

 lution is, therefore, of extreme importance. The matter of 

 such examination of the proposed water supply and its pre- 

 servation against contaminatioti, is usually placed in the 

 hands of a municipal committee of non-technical men, none 

 of them overly competent to pass upon the chemical and 

 biological questions to be decided. This committee may have 

 before it the reports of engineers, chemists and bacteriolo- 

 gists and yet unfortunately its members may not fully under- 

 stand the purport of the various technical terms used. The 

 writer has had some little experience in this direction and 

 has more than once seen his reports fall upon unreceptive 

 ears. This and other considerations indicate the necessity 

 that the layman, as well as the expert, should have a know- 

 ledge of such subjects. It is hoped, therefore, that what 

 follows may be of interest and aid to the non-technical 

 reader. No attempt is made at originality, and the only 

 object is to give a summary of the minimum of knowledge of 

 principles and laboratory practice necessary for the intelli- 

 gent operation of a municipal water supply. 



Naturally the examination of a given water hinges largely 

 upon laboratory work, and the number of laboratory tests 

 that might be applied to the water is very large. It is, 

 therefore, necessary from this host of tests to sort out those 

 which are best and then to choose from these the least 

 number consistent with the necessities of the case. In 

 describing the laboratory work, no attempt is made to give 

 the full techniqtie of the operations, as this is amply treated 

 of in the laboratory manuals. 



The consideration and examination of a water supplv 

 may be taken \.\\) under three heads: l-'irst, the waterslied ; 



