WATER FILTRATION. XLV. 



cases the cost of maintenance ranges from 10/6 to 14/6 per 

 million gallons. 



The cost of operating an American or rapid filtering 

 plant will vary according to whether coagulant is used or 

 not; if used, the quantity per gallon of water will influence 

 the cost. The Jewell Company state that the average cost 

 of operating a plant of this description when one grain of 

 sulphate of alumina per gallon of water is used, exclusive 

 of labour, is about 3*5 dollars per million gallons. The re- 

 ports of engineers in charge of plants at different places as 

 to cost of operating varies considerably. At Lexington, 

 N.Y., where alum is used, the cost per million gallons is 4 

 dollars. At Wilkesbarre, Pa., the cost of filtering 9 million 

 gallons per day did not exceed one dollar per million gallons 

 — the maximum cost works out at 2*30 dollars per million 

 gallons. In Sydney the cost of operating, for labour alone, 

 would be about 3/4 per million gallons where a coagulant 

 is not required. The cost of installation, as given by Mr. 

 Fuller for a complete going plant, is 15,300 dollars per U.S. 

 million gallons (about £3,060), or about £3,672 per million 

 Imp. gallons. 



It would be difficult to compare prices in America with 

 this country, as the conditions under which the filtration 

 plant would have to be constructed and worked may con- 

 siderably vary. It is, however, beyond question that the 

 American rapid filtration is much cheaper in first cost for 

 dealing with turbid waters than the European method, 

 whether the cost of working the former will be more than 

 counterbalanced by the greater yearly charge for interest 

 of the latter, can only be demonstrated by two installations 

 working under the same conditions. The experience gained 

 by the author leads him to the conclusion that the American 

 system is eminently suited for dealing with the turbid 

 waters of our inland rivers, more especially where land 

 resumption is an item. 



