32 



SEWAGE-POLLUTED OYSTERS AS CAUSE OF TYPHOID. 



pound of slacked lime to 2,500 gallons of raw sewage. Four-ounce 



samples of sewage, one collected before and one after treatment, were 

 examined, with the following result: 



Examination of sewage samples before and after treatment. 



i Chemical analyses ma.it- by W. W. Skinner. Water Laboratory. Miscellaneous Division, who eommnt8 

 as follows: " In the rast> of sewage, the results of the analysis show this to be probably a raw product, both 

 fore and alter treatment. But the examination, so far as m;-do, seems to indicate 



be 



has little etYeel upon the character of (lie material." 



impossible to make further chemical analyses. 



e that the treatment 



to the small amount of the sample, it was 



The bacteriological results show that one sample of sewage at the 

 time of collection contained more bacteria at 25 C. before treatment 

 tli.-in after treatment ; however, the sample after treatment with lime 

 contained a higher total number of organisms at 37 C. The number 

 of B. coli was unchanged. 



The results, both chemically and bacteriologically, would indicate 

 practically no change resulting from treatment of this sewage at this 

 disposal plant. It was said that in addition to the lime used there 

 was also about 50 gallons of crude phenol used per month in washing 

 down the walls of the sedimentation basins during denning. 



In the accompanying illustration is shown the disposal plant in the 

 background, with the flume some 26 feet wide in the foreground. 

 The Hume is reenforced with crossbeams, which cause its peculiar 

 appearance (see fig. 6). 



Besides the Ilendrix Street disposal plant, the Jamaica and Far 

 Kockaway plants arc operated in a similar manner; the output, 

 however, is only a few million gallons daily. 



The Paerdcgat sewer, having a daily discharge of about 2,000,000 

 gallons, empties into Jamaica Bay, a short distance to the west of 

 Indian Creek, where nine oyster dealers, including dealer A, float 

 their oysters. To the east of the mouth of Indian Creek empty the 

 IS, 000, 000 gallons of sewage from the Ilendrix Street sewer (see lig. (>). 



In addition to the effluent from the public trunk sewage systems of 

 Brooklyn and vicinity, there aje numerous small sewers located all 



