Mr. Tawney. Is that an estimated or actual cost?
Mr. Hatton. That is the cost from the operation of our plant.
Mr. Tawney. Actual operation?
Mr. Hatton. Actual operation.
Mr. Tawney. Is it not an estimated cost?
Mr. Hatton. No. The cost of the Imhoff tank with sterilization, reducing the bacteria 85 per cent, was $9.51 per million gallons, as against $7.81 for the activated sludge. Mark you, the bacterial removal in the activated sludge was 95.5 per cent for that cost, whereas the bacterial removal in the Imhoff with chlorination was 85 per cent; and we attempted—and the report is in here—to sterilize our Imhoff tank effluent to that point comparable with the activated sludge, and found that the cost of the process was about $14.50 per million gallons.
Prof. Phelps. How much chlorine does that represent?
Mr. Hatton. Eight and five-tenths parts, which costs $5 per million gallons, based on 7 cents per pound; that is 3 cents per pound less than we were paying for it; and we believed—in fact, we were assured—that if we bought it by carload lots we could get it for 7 cents per pound at that time.
Mr. Powell. Now, circumstanced or conditioned as Milwaukee is, how does the cost of disposing of your sewage, as at present carried on, compare with what it would be if you dumped it in its raw state into the lake, that is taking the raw sewage when it comes from the end of the sewage pipe? Is Milwaukee the gainer or the loser by disposing of the sewage as you suggest?
Mr. Hatton. Well, undoubtedly the gainer.