REPORT ON THE RESULTS OF AN EXAMINATION OF THE WATER SUPPLY 



OF PHILADELPHIA. 



]!y Dr. J. H. WuKiHT, Scalt Fellow in Hi/yienc, ruiro-siti/ of J'eiin.iijlvairui. 



The following is a report of a cbemical and bacteriological study of the water supply of the 

 city of Philadelphia, exteudiiig from October, ISttl", to August, 1893. The iiivestigntiou has been 

 carried on iu this laboratory under the direction of Dr. J. S. Billings and Dr. A. C. Abbott, whom 

 the writer thanks for their active interest and many valuable suggestions. 



The objects in view have been to determine the amounts and variation of those chemical 

 constituents of the water which are of chief importance from a hygienic standpoint and the 

 variation iu the number of bacteria per cubic centimeter, together with the description and 

 enumeration of their species. 



The water supply of Thiladelphia is derived Irom the Schuylkill and the Delaware rivers. 

 The water of the Schuylkill, which constitutes the greater part of the supply, is obtained from 

 two i)rincipal points on that river about G miles ai)art, and both within the city limits. The water 

 taken at the upper one of these two points is distributed to that part of the city which includes 

 the localities known as Germantown, Chestnut Hill, and Manayunk. This area is unequally 

 divided into three distribution districts designated on the map of the water bureau as the " IJox- 

 boio" and the two "High Service" districts. (See Annual IJeport of the Bureau of Water for 

 1891.) The lower Schuylkill water supplies the central part of the city and all that portion 

 lying between the two rivers, together with West Philadelphia. On the map above mentioned 

 West Philadelphia constitutes the "Belmont" district, while the remainder of the area supplied 

 from tiie same source is divided ux> into the distribution districts named " Direct Pumi)age," 

 "East Park," and "Fairmount." The water of the Delaware is distributed through the north- 

 eastern section of the city and also supplies a part of the central i)ortion. This area forms what 

 is called the "Frankfort" district. The immping station is at Lardner's Point, within the city 

 limits. In the results of analyses these names have been used to indicate the sources of the 

 samples of water. The general scheme of the work has been as follows: After some isolated 

 determinations had been made iu October and November of the water of the laboratory (Belmont 

 district), in the latter month, the systematic analysis of samples of water collected from taps in 

 the various districts was begun. From January onward the analyses have been limited to samples 

 from four districts, which were considered as representative of the different sources of the supjjly. 

 These were the "lioxboro" district, representing the water of the upper Schuylkill, the " Fair- 

 mount," and the "Belmont" districts, representing the lower Schuylkill, and the "Frankfort" 

 district, representing the water of the Delaware. 



Two to four times each month four samples, one from each of these districts, have been 

 analyzed simultaneously. 



Tlie analyses have consisted in the determiuation of the chhniiie, oxygen consumed, free and 

 albuminoid ammonia, nitrogen as nitrates, aud the number of bacteria iu 1 cubic centimeter. In 

 the earlier part of the work the nitrogen as nitrites was also determined. 



Tlie water lias usually been collected by an assistant. That which was intended for chemical 

 analysis was brought to the laboratory iu large bottles; that for bacterological determination 

 422 



