148 



REPORT 1872. 



1871. Nov. 14 and 15. Eain part of the time. 



Greatest flow 1075 gallons per minute. 



Least „ 7G8 „ „ „ 



Average flow for the two days . 925 ,, ,, ,, 



1871. Nov. 30 and Dec. 1. Dry weather. 

 Greatest flow 768 gallons per minute. 



Least 



631 



Average flow for the two days 



•28 



824,796 gallons per day is the summer dry-weather flow of the sewage from 

 the Avhole of the district. 



The second examination was made by the Committee in the early part of 

 July last, when samples and gaugings were taken for a period extending over 

 eight days. The samples were taken, as in the previous ease, at the rate 

 of y77,^y y part of the flow at the time of taking. The following arc the 

 results of the gaugings on this occasion : — 



The samples of sewage and efiiucnt water taken were collected only during 

 the dry portion of the above period, namely, the afternoon of the 2nd July, 

 all the 3rd, 4th, and 5th, the morning of the 6th, and the afternoons of the 

 8th and 9th, when the rains could not be said to have had any effect on them, 

 and they may be considered fair samples of the dry-weather sewage and 

 effluent water. Selecting the entirely dry days from the above, it would 

 appear that the ordinary flow of dry-weather sewage may be stated as 650 

 gallons per minute, and that of the effluent water at 1425 gallons per minute. 

 Allowing one fourth of the sewage to be evaporated during dry weather, it 

 ■would appear that the effluent sewage is diluted during dry weather with 

 about twice its bulk of comparatively pure water from the river and other 

 sources. 



