Mr. Dallyn. Yes.
STATEMENT OF MR. F. A. DALLYN,
OF TORONTO.
Mr. Dallyn. I am the provincial sanitary engineer, attached to the Provincial Board of Health of Ontario.
Mr. Tawney. Have you anything to add to what Dr. McCullough has said regarding the policy of the Province with respect to the purification of sewage and water for domestic and sanitary purposes in these boundary waters?
Mr. Dallyn. There is one matter, I think, that is worthy of further note, and that is as to whether it would be any advantage to either the municipalities, the Provinces, or the States, to be restricted, as they are in the report of the commission, to a specific method of meeting the commission’s requirements. There seems to be some doubt as to the proper way to interpret the reference—as to whether the commission is supposed to report some definite way in which a standard is to be attained or whether the two Governments meant that a prescribed standard could be reached at a reasonable expense through at least one method. Speaking as an engineer, not as the engineer of the Province, I would say we do not want to be hampered by any restriction in that respect on the part of the commission. We do need a standard of purity for sewage effluents. It is very necessary. We can hardly advance any further without one, but we do not want to be hampered by any particular way of arriving at any desired result. As to whether we will adopt two hours’ sedimentation and Imhoff tanks, or a different type of tank, and one, two, or four hours’ sedimentation is a question that requires study for each separate municipality. It will depend upon the character of the local sewage. And with the developments that are taking place in sewage disposal it is quite conceivable that half an hour’s sedimentation may be a practical limit, with some particular type of tank. We do not want to be tied down to two hours’ sedimentation. And then as to the method of sterilizing the effluent, your report indicates that bleaching powder, or liquid chlorine, will be the agents to effect this. Possibly we will not want to be hampered by a provision as to these. The experiments at Milwaukee indicate that a higher bacterial removal than you are calling for on these waters can be obtained by aeration of sewage by the activated sludge process. This method may not be practical at all centers; it will be practical at some.
That is just the position, I think, that most of us engineers will take with reference to your report upon remedial measures. We are very much in sympathy with the effort toward setting a standard of purification for these boundary waters. It is needed. Some of us feel that the only feasible and practical way of accomplishing the desired end is by standardizing the sewage effluent, by saying just what percentage of matter in suspension you want removed and what bacterial removal you want. I think the sewage treatment standards suggested by Prof. Phelps are practical ones and will occasion very little disputing.
Mr. Magrath. You do not want to be hindered from going as far as possible?
Mr. Dallyn. We certainly do not, sir. As to the construction and location of interceptors, of course, it is recognized by the engineers that the commission has had a very difficult problem, and that, with the time available, they have made a very valuable report as to the feasible way of handling the question, but there are a great many studies that will be required to be made before a municipality should be tied down to any particular route. Your proposal may show the natural route to utilize, but there might be difficulties in construction which can not be anticipated, without a great deal of survey work, by testing the substrata, finding what is below, whether sand, rock, quicksand, or clay, which might be overcome by deviating from the prescribed route, even though the excavation were heavier. Surveys can not be made in a short time. I feel also that our municipalities heretofore have not had appropriations with which to make investigation as to whether the routes suggested by you are practicable. The money that the commission has expended on this work, of course, is not adequate to make a very minute survey; and when you realize that in order to examine this report properly each of these municipalities has to spend from $10,000 to $20,000 you realize that it is quite a large undertaking for them to do at a very short notice. It is work that will require probably a year to investigate. I believe that is all I desire to say.
Mr. Powell. You mean, by further investigation, having soundings and test pits along the route?
Mr. Dallyn. Oh, yes; and by cross sections of sewer, whether it is cheaper to use brick, or concrete, or vitrified block. There is a good deal of research work to be gone into before deciding upon work costing large sums of money.