Mr. Hatton. No; except that——
Mr. Powell. Except extreme cold?
Mr. Hatton. Yes. We have to use more air in the cold weather than we do in the warm weather, in order to get the same quality of effluent, approximately this winter 12 per cent more air.
Mr. Powell. It means practically 12 per cent additional cost?
Mr. Hatton. Of the air alone; but this cost I have quoted is the actual cost of summer and winter conditions.
Mr. Fenkell. May I ask a question? To what extent would it be necessary to allow untreated water to escape because of rainstorm?
Mr. Hatton. We are anticipating at the present time, or will anticipate in this plant, 150 gallons of rain water per capita; that is all the rain water that will be carried to the plant, and that rain water will be treated the same as the dry-weather flow. The balance of the rain water will go into the river.
Mr. Powell. That is per diem?
Mr. Hatton. Per capita; 150 gallons per capita per day.
Mr. Dow. May I ask the witness whether I am correct in my summing up of the advantage of his method over the Imhoff tank method, in that it tends to reduce the net cost by producing a readily marketable fertilizer; that is the essential advantage. Am I correct in so understanding?