Chapter M: E. Brian, Windsor, Ontario, city engineer (5)

Mr. POWELL. The flow is always out?

Mr. HATTON. Yes.

Mr. MAGRATH. I have an idea that the water works inward sometimes?

Mr. HATTON. Well, it comes down, as I say, on the west side, passes round Chicago, and comes up on the east side, and passes out in the straits; at least, that is my opinion.

Mr. MAGRATH. I may be wrong, but I had an idea that the current moved inward sometimes, and sometimes outward.

Mr. HATTON. Well, possibly so. This is the general tendency of it, but I think it does sometimes pass out and in, according to the direction of the winds.

Mr. POWELL. The Chicago Drainage Canal is not equal, I suppose, to the inflows from the surrounding country. It does not balance it?

Mr. HATTON. Well, I think not. It is claimed here very recently that the waters taken from the Chicago Drainage Canal have lowered the waters in the connecting streams some 5 or 6 inches. How true that is I am not prepared to say. Now, before deciding upon the method of sewage disposal for Milwaukee we built rather an elaborate experimental station, in which we tried to put all those modern methods of sewage disposal now prevalent in this country and abroad, and I think we had 23 different processes going on there at one time--one of the largest experimental stations carried on in this country for sewage disposal purposes.

Mr. MIGNAULT. When was it established?

Mr. HATTON. In the middle of 1914. We have been operating it just about two years. We tried out in that experimental station the Imhoff tank, so-called settling tank, sprinkling filters, colloidal tanks, electrolytic processes, chemical precipitation, chlorination, and finally, what we called the activated sludge process, which we have been trying out now for a year this month.

Mr. MAGRATH. Where did that process originate?

Mr. HATTON. Well, that is a question. Mr. H. W. Clarke, of the Lawrence experimental station of Massachusetts, claims he discovered it. Dr. Gilbert J. Fowler, of Manchester, England, now of India, has assumed the discovery of it and developed it in a laboratory way perhaps further than anybody else up to the time we took care of it in Milwaukee. He started his experiments in 1914, or late in 1913, and we started our experiments in 1914, late in 1914. But it has been developed in Milwaukee to a greater extent than anywhere else, either in Europe or United States. We started with a laboratory investigation. From thence we went to tanks, holding or treating 70,000 gallons a day each, and from thence we have gone to tanks treating 1,600,000 gallons a day, which are now being operated and have been operated since last January. The process, stated briefly, consists of, first, coarse screening the sewage, running it through coarse screens, then into tanks of any depth to suit the conditions and the situation, say from 10 to 20 feet.

Mr. POWELL. That is the residue after the first screening?

Mr. HATTON. That is the raw sewage after it has been coarse screened. Then the raw sewage is run into these tanks, which have in the bottom some method of diffusing air which is discharged into the bottom of the tank at low pressure, just sufficient pressure to keep the liquor agitated; while in there this liquor passes through this tank, taking a certain time in accordance with the standard of purification required, from two hours to four hours, during which time it is being agitated and aerated by the air. From these tanks it passes into a sedimentation tank. All of these tanks are practically one tank divided by a wall separating the aerating tanks from the sedimentation tank. After settling in the sedimentation tank from 45 minutes to an hour, or an hour and a half, according to the character of the effluent you require, it then passes out into the point of final discharge. The sludge which settles out of the liquor into the sedimentation tank is then pumped back and discharged into the raw sewage as it enters, or while passing into the beginning of the aerating tank. The surplus sludge which settles in the sedimentation tanks is treated otherwise, which I will describe later. The process is one of aeration and nitrification practically. The sewage does absorb a great deal of oxygen from the air which is forced into it through these diffusing methods. The sludge, however, which we return and keep intimately mixed with the sewage at all times is perhaps the chief medium of purification, because that sludge is filled with microorganisms and nitrifying organisms, which really do the purification work, and that is the reason that it is called activated sludge, because it is so filled with the nitrifying organisms, and the more active the sludge is the more rapid and higher degrees of purification you secure. It is a natural process entirely, simply intensified by artificial means. To show you the activity of that sludge, we got the raw sewage, perhaps a million bacteria per cubic centimeter, in the first aerating tank, within half an hour; the sludge contains anywhere from fifteen to twenty million bacteria per cubic centimeter. In this sludge we give the bacteria the natural environments for their work. We give them food, lodging, and air, and that is just exactly what aerobic bacteria need, and the desire is to have intensified the aerobic bacteria, which we have at all times when the plant is being properly operated. Now, that is a brief description of it.

Mr. POWELL. That is the only purpose of aeration?

Mr. HATTON. No; there is another purpose of aeration, and that is the intimate mixture of the sludge with the liquor. That can be done mechanically with a little bit of air put in; but to do it mechanically would increase undoubtedly the cost and the operating expenses. In order to clarify the liquor it is not only necessary to nitrify it, but it is necessary, as we call it, to scrub it, and we remove the colloidal matter by means largely of scrubbing. To describe that in a layman’s way, not in a chemical way, the colloidal matter in sewage rests in the interstices between the globules of water, like water rests in the interstices of the sand at the seashore. Now, if you disturb that sand on the seashore, the water runs out and the sand becomes free of it. If you scrub the globules of water together violently, the colloidal matter is detached from the water and the water becomes clear. That is as near a layman’s description as I can give you, and we have tried the experiment out in our experimental station, to see whether there is any odor in that sewage, and we have thought that there is to a certain extent, not altogether. Now, the question as to how to dispose of this sludge is one of the greatest problems in sewage disposal in the world; and I think if any of you went over to Toronto, which I had the pleasure of visiting three weeks ago, you would see the difficulty that Toronto is up against in getting rid of its sludge, as are all other cities in the United States, whether it be Detroit or Buffalo, Cincinnati, Philadelphia, or New York--well, I will not say New York and Philadelphia, because they are out at the ocean, and they have a chance to get rid of it, but inland cities will have this difficulty.

Mr. POWELL. They are taking it up in New York.

Mr. HATTON. Yes; they may be able to discharge the sludge in the sea, but inland cities on the Great Lakes or rivers are going to be up against the proposition as to how to get rid of the sludge. Then any method of sewage disposal which will enable the cities to get rid of the sludge, whether it be at a profit, or whether it be to break even, or whether it be at a loss, and yet to get rid of it to the advantage of the agricultural element of this country and indirectly to ourselves, will be that system of sewage disposal which will undoubtedly meet the conditions of the large cities. That is the proposition which is primarily confronting us in Milwaukee, as I started out to say, and in all of this investigation there has been no doubt evinced in the last three months by the leading consulting sanitary engineers in the United States who have visited our plant that the purification of the sewage has been solved within reasonable cost, but there has been a great deal of doubt in their minds that the disposition of the sludge has been solved, and I have told them that within 90 days----

Mr. MAGRATH. Did you say that there was a feeling that the problem had not been solved?

Mr. HATTON. They felt that the question of the disposal of the sludge had not been solved, although we had solved the question of the disposal of the sewage.

Mr. POWELL. They all recognized that the purification of the sewage could be accomplished?

Mr. HATTON. They all recognized that the purification of the sewage could be accomplished in that method at a reasonable cost. But now we have solved practically the question as to the disposal of the sludge. It is true we have not reached those definite figures of cost which are necessary to convince the average municipal officer, but we are proceeding very rapidly, and we have our own figures which we feel are perfectly safe. In March for 10 days we dewatered this sludge by compressing. Now, for two weeks we have dewatered the sludge, and are drying the sludge, and reducing it into the form of a fertilizer of low grade, which is marketable anywhere in Chicago, and marketable along the eastern coast, through the chemical company--I forget the name of the chemical company there, but it is the largest fertilizing company in that district. They have offered us a yearly contract for all the sludge of the character that we have submitted to them that we could produce, based on the market value of the ammoniacal nitrogen contained in the sludge, the potash, and the available phosphoric acid. We have been testing this sludge day by day for two weeks, and we have averaged from that sludge 5 per cent of ammoniacal nitrogen--about sixty-seven one-hundredths per cent is available of phosphoric acid, and nine-tenths of 1 per cent of potash. Altogether that sludge is worth in the market, based on those ingredients alone, $15 a ton. There is no doubt about reducing it to a fertilizer basis. We have the apparatus and are doing it.

Mr. TAWNEY. Have you ever undertaken to extract anything else from this sludge, such as oils?

Mr. HATTON. We have, through the firm of Susenberger & Sons, of Chicago--no, it was a branch of Susenberger & Sons, of Chicago, which carries on the fertilizing end of the Susenberger & Sons’ business. They extracted the fats from the sludge, and turned the residue into fertilizer. But we do not have more than 2 or 3 per cent fats in our sewage, and that percentage of fats is not harmful to fertilizer, and it does not pay to take it away from the sludge. Unless you get at least 10 or 12 per cent of fat in your sludge, it does not pay to remove it, as I am told by those who are in the business of manufacturing fertilizers.

Mr. TAWNEY. Do you know that there is in operation in England now a plant where they are extracting from the sludge gasoline and lubricating oils and pitch?

Mr. HATTON. Well, yes; I have read of it in a casual way.

Mr. TAWNEY. And nitrates, and carbolic acid; is that right, Mr. Phelps?

Prof. PHELPS. Yes.

Mr. HATTON. I never go away without my box, and I want to show you some samples which I have here.

Mr. POWELL. You sell this stuff for $20 a ton?

Mr. HATTON. No; $15.

Mr. POWELL. What does it cost to put it in a salable condition after it is taken out?

Mr. HATTON. Six dollars a ton.

Mr. POWELL. You have a profit of $9 a ton?

Mr. HATTON. Approximately $9 a ton. You understand the ammoniacal nitrogen varies, of course, and that cost is based upon the ammoniacal nitrogen, and our average is 5 per cent so far. In wintertime I imagine it will grow less. In July, August, and September it will grow more. It is true we have a very strong sewage, containing, for the last month, for instance, 369 parts of suspended matter. That is a good deal stronger than the average municipal sewage. It is industrial sewage, largely. Now, I do not want you to think these samples I am showing you are picked out samples. These are samples which a good many gentlemen present will tell you they have seen in our plant that they have visited day by day. This was taken yesterday at noon and delivered to me in the afternoon. This is a bottle of the raw sewage, after passing through the half-inch screen. I am now showing you a bottle of the sewage taken from the aerating tanks, containing about 25 per cent of activated sludge, the nitrifying media which purifies the sewage, and I am now showing you the effluent passing away from the sedimentation tank 4 hours and 45 minutes after it passed into the influent tank. So far as we can determine, there is a trace of suspended matter in that sewage. Of course we could not determine whether it was stable or not, because that takes time. It was taken out yesterday, but my chief chemist, who brought the samples to me, told me there was no doubt about the stability of that liquor.

Mr. MIGNAULT. Have you analyzed it to determine whether there subsists a certain amount of B. coli?

Mr. HATTON. No; this was taken yesterday; but we do get some B. coli; we do not get complete sterilization. We attempt to get 95 per cent reduction of bacteria in our effluent. We have not had occasion yet, except when our plant was broken down, or the lake was so high that it backed into our plant, to reduce our standard. We could always get 95 per cent, and we more often got 98 or 99 per cent. I do not know whether I should show you this box I have here very closely, because it does not smell very well.

Mr. TAWNEY. You do not deodorize your sludge?

Mr. HATTON. No. I am showing you now a sample of the pressed sludge.

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.

Mr. TAWNEY. What is this process called?

Mr. HATTON. Activated sludge. We tried out the Imhoff tank process with chlorination in this same sewage, and found the cost a little bit less than the cost of this process, without finally disposing of the sludge. We also tried out Imhoff tank, followed by sprinkling filters, and found the cost much more than this process. We also found, in our climate of Milwaukee, that, instead of averaging two and a half million gallons, or getting two and a half million gallons per acre per day through sprinkling filters in wintertime, there were three months that we could not get more than a million and a half. We also found that up to the present date we have not been able to dry sludge in the open air coming from the Imhoff tank from the first of last November up to the present day, and in making our estimates, we do not believe we could get three months in the whole year in this climate--I am speaking of Milwaukee--when we could dry sludge effectually from the Imhoff tank or any other sedimentation process. We have too much rain in June to dry sludge, and the only way we could possibly dry Imhoff tank sludge was by covering with glass, heating the place, as suggested by a gentleman in Cleveland, Ohio.

Mr. MIGNAULT. How long does the drying process last?

Mr. HATTON. Well, that is all according to the weather. If the weather is very nice and warm, and we have the sun, and not too damp, it will dry out in about two weeks; it will dry into a spadable condition in five to six days in good dry weather, but if there is a little bit of rain comes along overnight, or if it is alongside a lake, and there is considerable moisture or damp, it may take two or three days longer.

Mr. POWELL. How do you dry the sludge?

Mr. HATTON. In a drier, an industrial drier, just the same as they use in the packing houses in Chicago and many of the breweries and many other places throughout the United States in industrial works.

Mr. MIGNAULT. Does it require much space?

Mr. HATTON. No; the amount of land which we have laid out to treat a hundred million gallons a day, which is the quantity we will have to treat, is 20 acres; that is, including our pumping stations, our ministration houses, sludge-disposal houses, and everything concerned. In fact, to be distinct, this system can treat from ten to twelve million gallons of sewage per acre per day.

Mr. TAWNEY. What does it cost?

Mr. HATTON. The cost of the treatment?

Mr. TAWNEY. The installation?

Mr. HATTON. About the same as the Imhoff tank. I say that because we worked out the Imhoff tank layout, and also our activated sludge layout, upon the same ground, and it broke even as to cost.

Mr. MIGNAULT. When you say you make a profit on the sludge, in the disposal of it, what cost do you consider?

Mr. HATTON. I did not catch that.

Mr. MIGNAULT. When you say you make a profit out of the disposal of the sludge, what cost do you consider? The cost of the drying----

Mr. HATTON. The cost of the drying, the cost of the dewatering, the cost of the freight and the overhead charges of the machinery necessary to dewater and to dry, and the attendance cost--all those have to be taken into consideration.

Mr. POWELL. You take the raw sewage that comes from the tank?

Mr. HATTON. We take the raw sewage as it comes from the sedimentation tank containing 97 per cent of water and deal with that.

Mr. POWELL. That all enters into cost?

Mr. HATTON. Yes.

Prof. PHELPS. That is $6?

Mr. HATTON. Yes.

Prof. PHELPS. Would you tell us the cost of the aeration in preparing the sludge?

Mr. POWELL. That would be taken into account as against some other system.

Mr. HATTON. I think I have that. I will read to you from a copy of the Second Annual Report of the Sewage Commission of the City of Milwaukee of 1915:

The cost of the activated sludge, continuous flow, with a
removal of 95.5 per cent bacteria--

I say that because the cost of the operation and the plant depends entirely upon the character of effluents you want to secure. A lower grade of effluents lowers the first cost and operating cost, so this is based on a removal of 95.5 per cent, which is our standard----

The disposal of sludge in cost per million gallons, $3.
The interest and depreciation on the cost of the plant,
based at 7½ per cent, $2.81. Cost of operation, exclusive
of sludge, $2, making a total cost of $7.81 per million
gallons treated.

From this $7.81 must be taken the value of the recoverable sludge, which, as I stated to you, so far in our investigations has been $3 per million gallons, or making a total net cost of $4.81 per million gallons, which includes overhead charges.

Mr. TAWNEY. What was the cost of your Milwaukee plant?

Mr. HATTON. Well, we have a 1,600,000-gallon plant now. The aggregate cost of our total plant is estimated to be about two and a half million dollars--will be that much.

Mr. TAWNEY. And that will take care of----

Mr. HATTON. A hundred million gallons.

Mr. POWELL. What is your population?

Mr. HATTON. The present population, 450,000; we are building a plant to provide for a population of 800,000.

Mr. MIGNAULT. What is the per capita cost?

Mr. HATTON. I have not worked it out.

Mr. POWELL. Does the cost decrease relatively in larger plants?

Mr. HATTON. Quite so; yes, sir.

Mr. POWELL. It is not adding simply a unit?

Mr. HATTON. No. Of course, the cost of this plant largely depends upon the cost of the air. The larger the air plant the less the cost of air. We figure our cost of air based upon a cost of electricity of seventy-seven one-hundredths per cent per kilowatt hour, which is the rate fixed by the Wisconsin Railway Commission for that sort of power; so that that rate is actually fixed.

Mr. POWELL. Is that power quite an item in the cost?

Mr. HATTON. Quite an item; the biggest item in the cost; the cost of power for compressing the air--that and the overhead charges, such as the interest on the money invested.

Mr. MIGNAULT. Are you aware whether power is more expensive in Milwaukee than in Detroit?

Mr. HATTON. I am not; I do not know what the cost of power is in Detroit.

Mr. POWELL. About what is the cost of horsepower? What is the cost to you people?

Mr. HATTON. I say it costs us seventy-seven one-hundredths of a cent per kilowatt hour, and horsepower is about three-quarters of a kilowatt in round numbers--six-tenths of a cent, I should say.

Mr. MIGNAULT. Is there any nuisance resulting from the drying process?

Mr. HATTON. No. The gases must be washed, and then after passing through the washer are taken into the plant itself--into the liquor, and the liquor is a deodorizer; so there is no odor arises from the cooking of the sludge, as we call it.

Mr. MIGNAULT. That is the drying of the sludge?

Mr. HATTON. Well, that is what we call cooking.

Mr. POWELL. This is not the same principle of the two tanks where the material is taken into one tank and has a certain bacterial operation, and then passes into another tank, and then finally into beds?

Mr. HATTON. No.

Mr. POWELL. You know the system to which I refer; they had it in England in one place, and then started it in Canada, and it was not a success?

Mr. HATTON. That is, they passed from aerating beds----

Mr. POWELL. No; they passed first into an inclosed chamber, where the bacteria destroyed it.

Mr. HATTON. I should imagine, from what you say, that must be the process by which both the aerobic and the anaerobic bacteria are the destroyers.

Mr. POWELL. Exactly.

Mr. HATTON. We do not want any anaerobic bacteria in our process, because it produces septic action, which is inimical to our process, because it absorbs the oxygen and interferes with the efficiency of the process.

Mr. POWELL. Can you take the sludge from the Imhoff tank and use it, or treat it the same as you are treating the sludge there in Milwaukee now?

Mr. HATTON. We can; but the trouble is that the sludge from the Imhoff tank, as we have found it in Milwaukee, only contains about from 1 to 1½ per cent of ammoniacal nitrogen at most, and that does not pay for its recovery. I want to say another thing about this which is of interest. There is no odor about the operation of the plant at all. You can stand over one of the tanks as it is being aerated and have no odor come to you, or no odor throughout the entire plant, unless you let the sludge stay undried.

Mr. TAWNEY. To what do you attribute the lower percentage in the sludge taken from the Imhoff tanks?

Mr. HATTON. The fermentation process removes the ammonias from the sludge. Well, practically all the reduction of the sludge in the Imhoff tank proposition is the fermentation process, and of course that removes a large portion of fertilizer values in the sludge.

Mr. MAGRATH. Are there any weak features in this process that you look forward to correcting?

Mr. HATTON. There are some problems which we are investigating, with a view of getting a more economical use of the air, and thus a lower cost of operation, and that problem concerns the diffusion of the air in the tanks. We are trying out three methods of diffusion. We are not prepared to say yet which is the most economical. I am giving you the figures based upon that which we have used, and our whole efforts now are being directed to reducing the amount of air used. That is the principal point which we are investigating at the present time.

Mr. TAWNEY. How does the operating cost of your system compare with the operating cost of the Imhoff tanks?

Mr. POWELL. The operating cost of the Imhoff tank is considerably less than the operating cost of our tanks. They have no air to pay for, and very little plant attendance to pay for.

Mr. MAGRATH. As I understand you, the cost to the municipality under your system is less than the cost under the other system?

Mr. HATTON. The cost of the Imhoff tank, you mean?

Mr. MAGRATH. Yes.

Mr. HATTON. That is true of installations of any magnitude.

Mr. TAWNEY. Installation, but not operation?

Mr. HATTON. On both--that is, taking into consideration the value of the sludge recovered.

Mr. MAGRATH. Your system costs the municipality less than the other system?

Mr. HATTON. Providing they sell the sludge. I want to make it plain to you gentlemen that I am not giving you this information as it may pertain to Detroit or Buffalo or any other city, but as it concerns Milwaukee, because I am not in a position to speak of it here, not knowing your situation.

Mr. TAWNEY. You state that you recently had your plant examined by a number of the leading consulting sanitary engineers of the country, and that while they all agreed that your system was successful, so far as purification of sewage was concerned, they expressed doubt as to the disposing of the sludge. On what do they base their skepticism or doubt with reference to the sludge disposal?

Mr. HATTON. Past experience.

Mr. TAWNEY. Your past experience?

Mr. HATTON. No; past experience of the sanitary engineers who have expressed that doubt. As I started to say, or I think I did say at the beginning of my remarks, that disposition of the sludge was the greatest problem, both in Europe and America, and this was so easy, apparently, to dispose of, that they were from Missouri and had to be shown.

Mr. TAWNEY. After seeing the way in which you disposed of sludge in Milwaukee plant, did that satisfy them or remove their doubts as to the efficiency of your method?

Mr. HATTON. They have not seen it yet.

Mr. TAWNEY. I thought you said they personally visited it.

Mr. HATTON. They have personally visited it. We put it in operation, but our press broke down. We have only put this portion of it in operation in the last two weeks, and it is only now we have begun to dry it; we did not have a dryer before.

Mr. MIGNAULT. Do you use the rotary dryer?

Mr. HATTON. The rotary direct dryer.

Mr. MAGRATH. I interrupted you when you were about to say that in 90 days you would demonstrate something, and you stopped.

Mr. HATTON. I told these engineers that in 90 days I would demonstrate the possibilities of disposing of the sludge, but I have already demonstrated it before the end of the 90 days. I think I said that at Syracuse some time ago in an address I delivered.

Mr. MAGRATH. In an address made, I think, in 1915 you expressed some doubt as to the efficacy of your method in winter months?

Mr. HATTON. Yes; I did; and in order to try out this system in Milwaukee during the winter months was the purpose of building this 1,600,000-gallon plant which we are now operating; that was the primary object of building that plant, which cost us $65,000, and we got it in operation the first week in January and we have operated it since continuously with temperatures as low as 20° below zero, with a clear effluent during the cold winter months coming out of the plant as that effluent which you see there in that bottle. We had no freezing and no trouble with ice. We had, of course, much lower nitrates in our effluent than we had in the summer months; in fact, we had very little nitrates, but we kept up the stability about 104 to 110 hours’ average; some of them went up higher. We go on the basis of 5 days’ stability test instead of 10 days. The American Public Health Association suggest that five days is all we need.

You ask me about the relative cost of the Imhoff tank installation and operating as compared with the activated sludge. Our investigations in Milwaukee show that the cost of the Imhoff tank, without sterilization, is $6.20 per million gallons--that includes all overhead charges--as against $7.81 for the activated sludge. The cost of the Imhoff tank----

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.

Mr. POWELL. That is, by treating the sewage as you treat it, and disposing of the product, the fertilizer, Milwaukee is the gainer, as against dumping it in its raw condition into the lake?

Mr. HATTON. Decidedly.

Mr. POWELL. That is something consequential.

Mr. HATTON. Yes.

Mr. TAWNEY. Financially, it is disposing of the sewage at a profit, as I understand?

Mr. HATTON. Oh, no; I do not want you to think that. We do not get enough profit out of our sludge to pay for the treatment of the sewage.

Mr. TAWNEY. That is the inference I drew from your answer.

Mr. MIGNAULT. What you say is that it pays to dispose of the sludge after the treatment process?

Mr. HATTON. Yes; there is a profit in it, but not sufficient to pay for the whole cost.

Mr. MIGNAULT. When the sludge has been treated you calculate the cost of drying it and disposing of it, and you make a profit out of it?

Mr. HATTON. Yes.

Mr. POWELL. Take a million gallons of sewage at the point of delivery here in Detroit, and assume Detroit to be circumstanced or conditioned just the same as Milwaukee is from a sewage standpoint, what would it cost to bring that sewage up to the point at which you take it for the purpose of manufacturing into fertilizer?

Mr. HATTON. It costs $7.81 per million gallons, and we get therefrom practically $3. I am taking the lowest estimate now, making a cost of $4.81 for the treatment of sewage. I think that answers the question.

Mr. TAWNEY. For 1,000,000 gallons?

Mr. HATTON. Yes; per million gallons.

Mr. POWELL. Where does the $3 come in?

Mr. HATTON. It is the profit from the sludge.

Mr. TAWNEY. Deducting the cost of treating it?

Mr. HATTON. Yes.

Mr. POWELL. The actual cost is $4.81.

Mr. HATTON. Yes.

Mr. POWELL. Following up the question Mr. Magrath asked you, to anticipate any necessary outlays you made for improvements, without regard to this, taking the machinery as it is to-day, is there anything that you think would come in to disturb these features and upset them in the present conditions?

Mr. HATTON. As to the process?

Mr. POWELL. Yes.

Mr. HATTON. Nothing that has been discovered so far.

Mr. POWELL. You do not anticipate anything?

Mr. HATTON. Nothing at all; if I did, sir, I would hardly be warranted in recommending to my board the expenditure of two and a half millions for this process. That is the best way to answer that. We have adopted this process, and are going ahead to build it as soon as we get our land, which has to be condemned partially.

Mr. MAGRATH. Before you leave the subject, many municipalities, as you know, dump crude sewage into flowing water, and consequently they have not arranged their collecting sewers at any particular point. In the application of this system of yours is it necessary that there should be a collection of the sewage at some particular point, or could it be applied quickly to those existing municipalities?

Mr. HATTON. That is one of the features about the process. While it is always desirable to get one point to dispose of your sewage, where the cost is considerable for intercepting sewers to get at that one point it is better to divide up those numbers of points, providing you can do so without nuisance and at less cost than the intercepting sewers, and with this process it can be built and operated in the heart of the city without any nuisance arising. I think that answers the question, does it not?

Mr. MIGNAULT. Is there any difference in that respect between your treatment and the Imhoff tank treatment?

Mr. HATTON. I think not. There is no odor that is objectionable about an Imhoff tank.

Mr. MIGNAULT. I mean as to the necessity of intercepting sewers?

Mr. HATTON. I think not.

Mr. MIGNAULT. In either case, the question of intercepting sewers is a question to be considered, according to the layout of the ground?

Mr. HATTON. No; not altogether that; according to the layout of the ground and according to the process which you propose. If, for instance, you should go beyond the Imhoff tank process and put in sprinkling filters or nitrifying beds, then you would have to get outside of the city, in order to prevent the nuisance arising from those beds.

Mr. MIGNAULT. Perhaps I did not make my meaning clear. Is there any advantage in your system as to the multiplying of the treatment works, in order to avoid the construction of intercepting sewers?

Mr. HATTON. Between the two works?

Mr. MIGNAULT. Yes.

Mr. HATTON. No; I think not.

Mr. POWELL. Your process is not affected by atmospheric conditions at all?

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?

Mr. HATTON. Not altogether, sir. As far as your statement goes, it is correct, but to get a removal of 95 per cent of bacteria from the raw sewage, it costs considerably more to do it by the Imhoff tank and sterilization than it does by this process. I just quoted the figures.

Mr. DOW. Then initially, the advantage is that, with equal operating costs a higher removal of bacteria is possible by this process?

Mr. HATTON. Yes.

Mr. DOW. And in addition thereto, there is a certain commercial advantage, in that the product is readily marketable?

Mr. HATTON. Yes.

Mr. DOW. Much more readily marketed than the Imhoff product?

Mr. HATTON. Yes; that is true.

Mr. DOW. As regards the latter phase of the situation, am I correct also in my supposition that the present prices for fertilizers are abnormal, having regard to the prices prior to the war, say 1914?

Mr. HATTON. No; the price of two and a half per unit is the price that existed prior to the war; the price of ammoniacal nitrogen to-day is considerably higher than that.

Mr. DOW. The figures given are based upon what might be considered normal markets, and not upon the present very abnormal prices?

Mr. HATTON. Yes; for instance, phosphoric acid is worth to-day 10 times as much as the quotations I have used in making my valuations.

Mr. TAWNEY. Have you any questions, Prof. Phelps?

Prof. PHELPS. No.

Mr. DALLYN. Just one point that Mr. Mignault brought out. Comparing the results of your process with the Imhoff tank, Mr. Mignault rather concluded that the Imhoff tank could be used in the same location as your plant. Is it not true that the effluents from the two types of treatment compare as the two samples on the table, activated sludge effluent being clear, and that from the Imhoff tank turbid and discolored, similar to raw sewage?

Mr. HATTON. That is true. I answered that with the idea of nuisance to the adjacent neighbor.

Mr. DALLYN. What is your actual saving, as you actually contemplate placing interceptors, collecting the sewage, in the adoption of your method?

Mr. HATTON. We are saving about $2,000,000 in carrying out the subaqueous tunnel a mile and a half out to sea, as the original board of engineers suggested.

Mr. POWELL. I understood you to give that as the esthetic feature?

Mr. HATTON. Yes; not only esthetic feature, but the purification feature; in other words, the local engineer has indicated that he would not permit, with his sanction, any sewage disposal plant which would deposit that much suspended matter in the harbor.

Mr. MIGNAULT. The question I put to you was to ascertain, in case they decided to establish other treatment plants in order to avoid constructing sewers, whether your system had any advantage over the Imhoff-tank system?

Mr. HATTON. As I answered your question before, I was looking upon it with a view to nuisance to the neighborhood. As to nuisance which might arise from the discoloration of the water, I should say the Imhoff tank would be far more deleterious in that respect than our process; but as to nuisances arising in the waters due to decomposition, assuming that the sterilization of the Imhoff tank liquor is complete, then the two plants would be practically equal, as to nuisances arising outside of the discoloration of the water.

Prof. PHELPS. In regard to the matter which Mr. Mignault has brought out, I think it should be stated that, as far as the city of Detroit is concerned, and also as far as Buffalo is concerned, the question of interceptors, or of local plant, was not determined by the character of the treatment, but was determined solely by the physical conditions--that is, it was impossible for us to locate the local plants and thus save the interceptors, by reason of the levels of the sewers and the inaccessibility of available land. We did consider local treatment, and if it had been feasible it would have represented considerable saving. The determination is not conditioned by the character of the treatment.

Mr. TAWNEY. Have you anything further to say?

Mr. HATTON. No.

Mr. TAWNEY. On behalf of the commission, I desire to extend to you our sincere thanks for your appearing before us, coming from Milwaukee for that purpose, and giving us the very interesting and clear statement you have concerning the operation of your plant in Milwaukee and the process of it.

Mr. POWELL. We can all assent to that.

Mr. GARDNER. Without any question.

Mr. MIGNAULT. You refer to the published report of the city of Milwaukee. Is that available?

Mr. HATTON. I would be glad to give it to the commission. I am sorry to say it is the last one.

Mr. TAWNEY. That is the only one you have?

Mr. HATTON. Except our own office copy.

Mr. MIGNAULT. And the process is described?

Mr. HATTON. Quite well; and the results.

Mr. MAGRATH. I suppose it is impossible to get copies of this any place?

Mr. HATTON. Well, there are some of them in public laboratories throughout the country and among engineers; but we had a pretty lively demand for them and we only had 500 copies issued, and they are all gone. That is a copy I picked up on my desk yesterday.

Mr. RICH. Mr. Chairman, I have a brief statement here regarding lake currents which would elucidate what Mr. Hatton was not quite familiar with.

Mr. Goddard, assistant engineer at Grand Rapids of the United States engineer office, read a paper before the Engineers’ Club, of Grand Rapids in April, 1916, which included his own experience, as well as a compilation of the results of the studies of others and covering a number of years. His conclusions were that the currents in the Lakes are produced primarily by the winds and secondarily by variation in barometric pressure.

Wind currents follow the direction of the wind.

Pressure currents flow from high to low pressure areas.

The flow through the Straits of Mackinac in either way, according as the above conditions prevail.

STATEMENT OF MR. THEODORE A. LEISEN, GENERAL SUPERINTENDENT
OF THE WATERWORKS OF THE CITY OF DETROIT.

Mr. TAWNEY. Mr. Leisen, you are the president of the Great Lakes Pure Water Association, are you not?

Mr. LEISEN. No, sir.

Mr. TAWNEY. Are you connected with that association?

Mr. LEISEN. I have a letter from the secretary asking me to represent the association at this meeting.

Mr. TAWNEY. Have you examined this report of the consulting engineer of the commission?

Mr. LEISEN. I regret to say that I did not see that report until yesterday at noon, and I think you can realize that I have not. While I had endeavored to read over a part of it I have not been able to digest it.

Mr. TAWNEY. What are the functions of your organization?

Mr. LEISEN. The functions are largely the questions from the sanitary point of view of preserving the purity of the waters of the Great Lakes.

Mr. TAWNEY. It is a voluntary organization?

Mr. LEISEN. It is a voluntary organization without any official standing. It is simply an auxiliary to the health departments in an unofficial way, I should say.

Mr. TAWNEY. Where are the headquarters located?

Mr. LEISEN. Practically they have no headquarters.

Mr. POWELL. Who are the officers?

Mr. LEISEN. Mr. Paul Hansom, of the Illinois State Board of Health, is the secretary; and Dr. Charles J. Hastings is president.

Mr. POWELL. Has your organization followed the work of the International Joint Commission in this investigation?

Mr. LEISEN. My familiarity with the organization is almost nil. As I say, I had a conversation with Mr. Hansom in New York relative to the matter a few weeks ago, and he asked me if I was still a member of the association. As a matter of fact, that did not come to a definite point until I got his letter asking me to represent them here. Officially, I am not in a position to say very much about the association or what they have done. It is a newly organized body.

Mr. POWELL. When was it organized?

Mr. LEISEN. Some time during the past years.

Mr. POWELL. What are its purposes?

Mr. LEISEN. I think the preservation of the purity of the waters of the Great Lakes.

Mr. TAWNEY. And also the connecting rivers, I suppose?

Mr. LEISEN. Well, yes.

Mr. TAWNEY. Have you any statement which you desire to make to the commission in respect to the pollution of these waters?

Mr. LEISEN. As you understand, I am the general superintendent for the board of water commissioners here in Detroit, and as such have charge of the water supply. So, naturally, my interest from that point of view would be toward----

Mr. TAWNEY. You appeared before the commission two years ago, when we were here, did you not?

Mr. LEISEN. Yes, sir.

Mr. TAWNEY. And at that time you gave us full and detailed information concerning the water purification?

Mr. LEISEN. I believe the points were generally covered then.

Mr. TAWNEY. Have you the same process now that you had at that time?

Mr. LEISEN. With this difference: At that, time we were treating the water with hypochloride of lime as a disinfectant. We have since changed to liquid chlorine treatment.

Mr. TAWNEY. What has been the result?

Mr. LEISEN. There has been no radical difference in the result. The results obtained from the use of hypochloride of lime have been almost identical with those obtained from the use of liquid chlorine; possibly some elimination of the taste in the water. I do not believe the complaints of taste of chlorine have been of any moment at all since the liquid-chlorine process was adopted. To that extent I consider it an improvement and it is a little more cleanly. It is a nicer process, more methodical, and more mechanical in its methods.

Mr. TAWNEY. You have only one intake?

Mr. LEISEN. Yes.

Mr. TAWNEY. What is its capacity?

Mr. LEISEN. It is 10 feet in diameter and a little over 300 feet long. Its capacity, of course, would vary with the head permissible on the shore end.

Mr. TAWNEY. How many gallons are you consuming per day?

Mr. LEISEN. We are consuming at the present time about 130,000,000 to 160,000,000 gallons per day.

Mr. TAWNEY. That is, a day of 24 hours?

Mr. LEISEN. Yes. Our highest hourly capacity for any one period was at the rate of about 190,000,000 gallons per day of 24 hours.

Mr. TAWNEY. The hour consumption was at that rate?

Mr. LEISEN. That was the peak load, yes; for one hour during the past year.

Mr. TAWNEY. Have you studied this problem in connection with the matter of sewage disposal at all, or do you deal entirely with the water end of it?

Mr. LEISEN. I have no official connection with the sewage disposal proposition; but my interests are simply those of an engineer in the problem, and as a citizen.

Mr. TAWNEY. Have you had any cases of typhoid fever in the city of Detroit in the last year or two?

Mr. LEISEN. Yes; there have been cases, not abnormal. The typhoid-fever death rate has been reasonably constant for the last few years and comparatively low.

Mr. TAWNEY. Have you gentlemen any questions to ask? If not, that is all, Mr. Leisen. Are there any other gentlemen here representing the city of Detroit who wish to be heard on this subject? I see that the mayor of the city has just come in, in time to witness the closing of these hearings. He may have something to say. If he has we shall be glad to hear from him.

Mr. MARX. I do not know really what you have done this morning.

Mr. TAWNEY. Well, gentlemen, it seems that this closes the hearing. In concluding the hearing I have been requested, on behalf of the commission, to extend to the mayor of the city of Detroit and the council of the city our sincere thanks for the courtesy which has been extended to us in giving us the use of this council chamber. I can assure the mayor and the council that the commission sincerely appreciates, not only the courtesy that has been extended to us, but also the hearty cooperation which we have received from the officials of the city since the beginning of the investigation, and we sincerely hope that when our final recommendations are made to the two Governments they will receive the approval and support of the city of Detroit and of the neighboring cities as well. Thanking you gentlemen for your appearance and courtesy, I will state that the hearings are now closed.

Mr. MARX. I want to assure you of our continued cooperation.

(Thereupon, at 12.30 o’clock p. m., the hearings were closed.)

INTERNATIONAL JOINT COMMISSION,
_Ogdensburg, N. Y., Friday, August 25, 1916._

The commission met at 10 o’clock a. m.

Mr. Gardner presided.

Mr. GARDNER. Gentlemen, you will kindly come to order. In August, 1912, the Governments of Canada and the United States jointly referred to the International Joint Commission for investigation and report, under the terms of Article IX of the treaty of January 11, 1909, certain questions relating to the pollution of boundary waters. Briefly stated, these questions are: What are the extent, causes, and localities of such pollution? How may such pollution best be remedied?