Mr. Tawney. The reason I ask that is that I saw a sample of pressed sludge recently, treated by the process I mention in operation in England, where there was absolutely no odor to it at all.
Mr. Hatton. There is no odor in this sludge until it has been out in the air 24 hours. Then it begins to get very odorous. That is the pressed sludge ready for the dryer. When that came out there was no odor except an earthy odor. I am showing you now a sample of the dried sludge ready for the fertilizer.
Mr. Tawney. That is in ground form?
Mr. Hatton. No; that is not ground. That is just as it comes out of the dryer. Some of it would have to be ground no doubt; we are expecting to grind it.
Mr. Mignault. The dried sludge has no smell?
Mr. Hatton. The dried sludge has no smell. There it is; it has been on my desk for a good long while. We obtain about half a ton of this dried sludge per 1,000,000 gallons of sewage treatment. It means that we would get about $7.50 per 1,000,000 gallons out of our sludge, and spend from $3 to $4 getting it out of the sewage, making a profit of from $3 to $4.
Mr. Powell. The process of sedimentation in that bottle has just taken three minutes and a half.
Mr. Hatton. That is where we were deceived in designing our sedimentation tanks. As a matter of fact, there is a lot of finely suspended matter, and it is that finely suspended matter which takes the time to settle. But I want to draw your attention to the absence of colloidal matter, and I want to say also that, outside of broad land irrigation, or slow sand filtration, I think I am justified in saying there is not any other method of sewage disposal process which will so effectually take the colloidal matter out of sewage, and make the sewage at least satisfactory, ethically, to all the cities and municipalities. I am quite sure if you can discharge an effluent of that kind in any of the rivers and waters between Canada and the United States that no citizen of Canada or no citizen of America can possibly object. He goes largely by what he sees, not by the ingredients which some chemist tells him are in the water.
Mr. Tawney. Have you any of the by-products you extract from the sludge?
Mr. Hatton. We do not attempt to extract any by-products. We propose to sell the sludge as a fertilizer in the shape I have shown to you in this box. I might say that there is no other process of sewage disposal at present in common use in America favorable to this locality comparable with this process, except Imhoff tank and sprinkling filters, followed by final sedimentation.