The Choice in Potable Waters.

The Choice in Potable Waters.

Professor Sanderson, of the department of geology in the University of Minnesota, recently spoke as to the choosing of the best kind of potable water. He said in part (his talk referring to the betterment of the supply of Minnesota):

“There are two possible sources of procuring suitable water for the city, and these are the river and artesian wells—all wells which are less than 200 ft. deep are useless. Scientific analysis shows that drinking water must be free from excess of germs and excess of mineral matter. Well water is freer from germs than river water, and deep wells are almost entirely free from germs. As regards mineral matter, however, river water is better, containing but 130 gr. per 1,000,000 gal., whereas in well water there are 300 gr. in the same amount.” For manufacturing and general purposes outside of drinking, Professor Sanderson inclined to the belief that river water was the best, having the additional advantage of always being possible to obtain in sufficient quantity. As to the possibility of being able at all times to obtain sufficient artesian water, he differed from Professor Winchell, of the same university, the latter holding that a sufficient supply was always possible a statement to which Professor Sanderson would not agree. As to the cost, Professor Sanderson said that a filtration plant would cost the city close upon $1,000,00. One filtration of river water removes (he stated) 80 per cent, of the germs, which was more than Philadelphia could do for its water supply by two filtrations.