DISCUSSION OF PAPERS AT AMERICAN WATER WORKS CONVENTION

DISCUSSION OF PAPERS AT AMERICAN WATER WORKS CONVENTION

Among papers discussed at the recent Convention of the American Water Works Association was one on “The Purification of Water by Ultra-Violet Rays,” by Max von Recklinghausen, and “Use and Benefits of Pressure Recording Gages,” by J. M. Diven. The discussion of Dr. von Recklinghausen’s paper was opened by F, A. Dallyn, of Toronto, who said: “The Association is to be congratulated upon this paper from Dr. von Recklinghausen, He has been very modest indeed in his claims for the ultra-violet rays. He has certainly given us a most scientific paper upon the merits of the system. We in our own laboratory have tested it with a very small unit. The cost is certainly going to be a great element; yet when the cost turns out, as it appears to be, only about three times that of ordinary disinfecting agents, I think public opinion will demand its use. It will be very interesting to follow it up.”

The Ultra-Violet Ray

Shepherd T. Powell, Resident Chemist, Baltimore, Md., said that Baltimore is also training its men in the use of the ultra-violet ray, employing the apparatus which Dr. von Recklinghausen has described in his paper, namely, the small dometsic sterilizer, and said: “We got it about two and a half years ago direct from London. In this work we used Baltimore city water. That was before we had sterilization by hypochlorite of lime. Before applying this method the count of B. Coli ran from a few hundred to several thousand and up, but by the use of this sterilizer, although the comparative time of contact was very short, we found almost absolute sterility of the water resulted. The main thing that the speaker thinks this Association should consider in looking into the ultra-violet ray is the question of cost. This cost will come down undoubtedly. Dr. von Recklinghausen reports an average K. W. consumption of 30 to 125. Now if we place that average at say 75, and put the K. W. at 2 cts.—which I think most of you will agree is low enough except in a hydroelectric proposition—we have a K. W. consumption alone of $1 50, and there must be added to this depreciation and interest on investment, which 1 think will make a very considerable cost, especially when you consider that this is merely the sterilization of the water, and to this there must be added filtration, because a very slight amount of turbidity and color will reduce the efficiency of the lamp; so that simmering it right down, it is not so much the question of the efficiency of the ultra-violet ray as a bacteriacidal agent as it is the question of what it is going to cost. Of course the liquid chlorine method s getting more of a foothold, so that these amps will have to be very much reduced in cost and something done to bring them into such condition that they will not have to be reputnped so often, before the ultra-violet rays will be practicable.”

B. F. Shaw, Water Commissioner of Wilmington, Del., said he would like to ask if Dr. von Recklinghausen will state whether the results obtained in measuring the effect of the lamp on the bacterial culture by means of the time taken to kill the bacteria present are consistent in a number of cases using the same source of light and the same culture, and added that he had not attempted anything of that character himself, but from the work that has been published by Prof. Phelps of Boston and Mr. Chick of England, and others, on the character of curve of disinfection and its resemblance to the logarithmic curve, it would seem to indicate a priori that the time of disinfection would be a quantity difficult to determine closely, and rather unsatisfactory as a measure of the ability of the lamp to disinfect. He should, he said, be very much interested if Dr. von Recklinghausen would make a statement on that point.

Dr. Von Ricklinghausen Answers Questions

Dr. Von Recklinghausen, replied as follows: “The first question asked was in reference to the cost. Mr. Powell I think is quite right that the cost is high; especially when one considers, as has happened to every one of us, that the lamps will need repair and repumping after a short time. I may say that I had that experience myself with lamps used in the laboratory not in continuous uninterrupted service. The question of depreciation of lamps is evidently a cost factor, but I do not think that it should run very high. Now let us say that the ultra-violet ray application does cost more than treatment with hypochlorite or treatment with chlorine, is there not a great advantage in the possibility of overdoing the sterilization to an enormous extent without having any secondary reaction going along with it; that is to say, without producing bad water? What are we after? We want to produce good water. Now good water should evidently taste good, too, and should always taste good. I do not know whether this matter is to be really measured upon the basis of dollars and cents alone. As to results obtained in exposing Boston tap water, which has the color of 4, I know very well from my own experience that when you first start working with these lamps you sometimes get some strange results. Of course I cannot trace this particular case, but I have been able to trace most of these cases of irregular results down to the question of slight amounts of suspended matter. I do not know Boston water. Of course it may be beautifully filtered at the water works, but whether it gets in the same condition to the tap, I do not know. So that in your tests there might have been a little rotten ivy slipped in, I do not know, it is pretty hard to say; but in most cases I was able to trace irregularities down to slight differences in the suspended matter in the water. Some years’ experience with this agency has given me a feeling of absolute safety. If you have a physical agent in hand about which there is nothing mysterious, and if one follows the rule of taking water with no suspended matter, by carefully observing it one will get very regular sterilizing – results. That 20 c.c. amazes me very much, because I have worked not with natural color, but with color made from peat down to about 100 U. S. Standard, and found a sterilization of over 25 c.c. It is pretty hard to criticize one or two, or even a small series of results, and get an idea of the value of the sterilization thereby.”

Pressure Recording Gages

In connection with the reading of his paper Mr. Diven remarked that the written discussion contributed by Mr. Hazeltine was a most interesting addition to the use of the recording gage, being something to record exactly the precise time at which a fire alarm comes in.

W. E. Haseltine, G. M„ Ripon Light and Water Company, Ripon, Wis., discussed Mr. Diven’s paper in part as follows” “Several years ago the Ripon Light and Water Company got into a serious controversy with the officials of the City of Ripon, owing to a claim of inadequate pressure at a fire. Fortunately, the Company had in service a recording pressure gauge by which it was able to prove to the satisfaction of experts engaged by the city to make an investigation, that the fault did not lie with the company’s pressure, but with the lengths of run of hose and the attachments made by the fire department. The Ripon Light and Water Company furnishes domestic service by pumping into a standpipe, and fire service by shutting off the standpipe and pumping directly into the mains, and it seemed most desirable to have some method of proving beyond question how long it took to furnish this direct pressure after an alarm was turned in. For this reason the attachment described below was devised and put into service, and its operation as well as its effect upon the company’s relations with the city have been most satisfactory. It consists merely of an auxiliary hand “A” turning on a sleeve on the same axis as the recording hand of the pressure gauge ard adjusted to mark coincidentally tnerewith. Under normal conditions this hand draws a perfect circle near the outer edge of the chart, but when an alarm of fire is turned in a small electro magnet operating upon the armature attached to this hand jerks it to one side, making a mark at right angles to the regular curve, indicating indelibly upon the chart the exact instant at which this alarm was received. By observing the chart it is possible, without question, to determine what the pressure was at the moment the fire alarm was turned in and how long therafter direct pressure was furnished. The connection with the fire alarm system is made through a regular telegraph relay, the magnet on the gauge being operated by a single dry cell.”

Filing of Charts

A. A. Reimer, Superintendent, East Orange, N. J., said the use of recording gages is absolutely necessary in any up-to-date system, and added: “I consider that in our case one of the most valuable uses which we applied is in our fire flow test work. By placing a recording gage in any group of hydrants to be tested, you obtain a complete record of the loss of pressure in that group without having to station a man at every individual hydrant in the group. Thus you will eliminate the use of a large corps of men. With reference to packing away the charts, I think by taking oul one typical chart each month, any special chart with the necessary notes on that special chart the storage space required is very largely reduced.”

Mr. Diven here remarked: “If you will read the paper you will find that there is no objection made to filing away the charts so that they can be referred to, but merely that the diagramistic form was so much the easier for reference by pulling out the diagram. I would not destroy one of those charts under any consideration.”

J. Walter Ackerman, Superintendent Water Board, Auburn, N. Y., said: “In connection with this subject the author spoke of the ragged condition that sometimes exists of the charts in our own “system; our attachment for the office chart happens to be in the downtown district where the elevators are located; and in trying to eliminate the effect they have on the charts I took an ordinary hot water tank and placed it in the basement of the office building, arranged by-pass connections in such a way that I could use that for an airchamber or a cushion, so that the actual surge on your elevator systems does not give the gage the momentary thrust, but the air-chamber absorbs it. while any direct change in pressure gradually shows up. I do not know whether any one has had that particular experience or not, and just mention it as one of the things that can be added to a recording gage that will obviate some of the difficulty.”

Mr. Diven remarked that this was a novel suggestion, and added: “But doesn’t it do away with one of the uses of the chart* itself by failing to record the water hammer? It is good information to have; the very fact that that gage is fluctuating is an indication that something is abnormal on your system, that you have a 30 or 40-lb. water hammer, and you want a record of that, you don’t want to eliminate the record.”

Mr. Ackerman: “But if you have a number of elevators that are already destroying your gage record, you want something to try to eliminate that.”

Mr. Diven: “Your gage is telling you that what you want to do is to get rid of those elevators, or else put in a bigger main for them.”

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DISCUSSION OF PAPERS AT AMERICAN WATER WORKS CONVENTION

1

DISCUSSION OF PAPERS AT AMERICAN WATER WORKS CONVENTION

Among the papers discussed at the recent convention of the American Water Works Association at Philadelphia, was a paper by Dr. Arthur Lederer and Frank Bachman, on “The Efficiency of Household Filters in Chicago,” and one by Dr. Frederick D. West, entitled, “Disinfecting Two Hundred Million Gallons of W’ater Daily.” When the discussion opened on Dr. Lederer’s and Mr. Bachman’s paper, J. M. Diven, superintendent, Troy, N. Y., said: “If the city is not going to filter its water supply, the speaker believes that it is its duty to furnish pure water. If they arc going to rely on household filters to furnish this pure water, it is up to the city to take care of the filters and see that they are properly sterilized and kept in condition. We do all that at our filtfr plant. We see that the filters are clean, that the clear water reservoirs are clean. No one in ten thousand domestic consumers will see that their filters are in a sterilized condition; they are satisfied if the water comes through clear; if the turbidity is removed and the small fish taken out and the water is cool and palatable. The filter is forgotten. It would probably be vastly cheaper for the city to filter the entire supply rather than to attempt to send inspectors to take care of several thousand household filters.”

Mr. Diven related the following story: The lady of the house was getting her morning glass of water and asked the maid what was the trouble with the water that gave it such a peculiar taste. The maid replied: “The water is all right; there are none of those live bugs or bacteria in it; I killed them.” The mistress asked: “What did you put in to kill them?” “I put nothing in it. What did you do?” “I ran the water through the meat chopper twice before I put it in the cooler.”

F. L. Rector, M. D., of New York City, said he had some experience in testing these household types of filters mentioned in the paper, having tested five different kinds of them, only one of which was found to be of any practical efficiency. The others gave a count of above 27 to 30, running up to several times what there was in the raw water.

Shepherd T. Powell, chemist, Baltimore. Md., said he was rather startled at some of the results shown in that paper. His experience with household filters, of which he has tested out several kinds, was, he said, the same as Dr. Rector’s, that nine times out of ten the water is worse after it goes through than it was when it entered the filter. You take the general run of household filters that are left to the servants, very little attention is given them and you will generally find the effluent bad, because of the lack of care given to the filter rather than to any defect in its mechanical construction.

Wilson F. Monfort, chemist of the Water Department, St. Louts, Mo., said: “After a sufficiently long period of time has elapsed without cleaning sttoh filters, there is no doubt whatever but what the organisms do go through as mentioned in the paper; but prohablv the idea is that the results are better if the filters are taken care of properly. The sneaker’s experience some years ago was that the household filter is often left unattended, and one can get a nice slimy growth in the outlet. It is necessary that they be sterilized at least once or better twice a week, which seems to obviate the difficulty. The speaker has tried that in his own case and finds that it works out very nicely.

The discussion of Dr. West’s paper on “Disinfecting Two Hundred Million Gallons of Water Daily,” was opened by Wilson F. Monfort.

Mr. Monfort said he had been very much interested in Dr. West’s paper, and regretted that at St. Louis they were unable to contribute anything, because the water that was treated with liquid chlorine so rarely showed any indications of the R. Coli. He said: “We had negative results before treatment regularly, almost universally, and the disinfecting action was almost nil. There is one question that has been brought up with regard to the relative efficiency of hypochlorite of lime and liquid chlorine that I think should be pushed a little farther. It is not the matter of cost, it is the matter, perhaps, of uniformity application as affecting after-growths that have been commonly noted for a number of years where hypochlorite of lime is used. want to raise that question and hope that Mr. West may be able to give us an answer, as to whether he has discovered any aftergrowths in the use of hypochlorite or when using liquid chlorine? It has occurred to me that the liquid chlorine diffusing so very rapidly, thhere is a possibility of much more efficient sterilization of the water; whereas the hypochlorite solution as often made is diluted and may be diffused much less rapidly, and the efficiency of application is considerably lower. If it be true that hypochlorite diffuses more slowly than chlorine, and I think that is true, then we should expect some organisms to get by. In our testing, out of every 100,000 gallons we are collecting a sample probably of 100 c. c., and we need a larger number of samples perhaps in order that a fair test may be made. With the liquid chlorine so far as my observation goes there are no after-growths to be found. It seems that the bacilli that remain afterward are of such a class that they do not rapidly increase in the distribution systems, and that these may be due in large part not only to the efficiency of the liquid chlorine itself, but to the superiority of its diffusion and its improved quality of mix that one gets by using the chlorine solution as against the hypochlorite solution with its extreme variation in strength of solution, even when the same chloride material is used, as Mr. West has shown. I think due also to this inferior quality of diffusion it is the hypochlorite it has been shown to possess.”

Dr. West, Torresdale, Pa., replied to the question as follows: “I had intended, at a later date, to take up that very subject of apparent difference in the bleach and the liquid chlorine affecting the permanent action, that is, the after-growth. I delayed that purposely, because I wanted to get results when our water is of a high temperature. I have used the liquid chlorine in water at as high a temperature as 80 degrees, and as far as I have gone, when I used the bleach the number of bacteria developing in the district that we sampled which was taken at a distance of perhaps fifteen or eighteen miles from our plant, was considerably above the number in the basin, the latter on an average being perhaps four or five. At the city of Philadelphia I get counts of 200. At the present time I have had counts at the Pennsylvania Saw Works, the farthest point away, which almost compare identically with those in the basin. At the present time the action seems to be decidedly superior; in other words, instead of apparently drugging the bugs, we have killed them: but I want to bring that out a little later when I have more complete data. My general conclusion-now is that the action is more permanent and lasting with the bleach than with the use of chloride of lime.

Robert Spurr Weston, consulting S. E., of Boston, Mass., said he had read Dr. West’s paper with a great deal of interest, and said: “We are now conducting some experiments in connection with the cost of the New Haven filter plant. At Exeter, N. H., we have been making experiments on the relative efficiency of bleaching powder and liquid chlorine. While our experiments are not complete, the relative efficiencies found per pound are in the ratio of somewhere between 5 or 6 to 1; that is, 1 pound of liquid chlorine will do as much work practically as between 5 and 6 pounds of liquid chlorine. The chief reason why chlorine was used at Exeter and was first used in the form of bleaching powder, was the importance of coagulating the water to a satisfactory degree by the use of sulphate alumina alone. The water is from an impounding reservoir which has been enlarged by raising the dam within the last three four years. That has flooded a large area which is overgrown with vegetation, which imparts a sort of collidal vegetable matter, a cucumber juice or quince seed juice, which it is impossible to wash out of our filters, although we have improved the washing arrangements and have done everything we could. We have had this collection of gelatinous matter imperfectly coagulated on the surface of the sand, which bothered us a great deal. We could, of course, remove it by the addition of an excessive amount of alum, but the alkalinity of the water was such that we did not wish to put in any additional soda. Therefore we tried the bleach, and we found that we could accomplish more work by using say .4 p.p.m. of bleaching powder than we could with 17 p.p.m. of alum; and as the cost of the chemicals is about the same, the conclusion is obvious. We were never able reduce the color of the filtered water below 20 with the use of sulphate of alumina. We now get it practically to zero, and we are getting the bacteria down to 8 and 5 per c.c.”

J. Walter Ackerman, superintendent, of Auburn, N. Y., said Dr. West had written him in relation to what they were doing at Auburn and unfortunately he was not able to give him any particular results, for the reason that at the time they were applying the hypochlorite and did not have the advantage of a bacteriologist on the job. Mr. Ackerman continued: “We now have a bacteriologist employed constantly. In October of last year we began the application of liquod chlorine by means of one of the Leavitt & Jackson apparatus. Of course I was very glad to know that Mr. West had had some of the difficulties of the application of hypochlorite that had been my experience; notably, our pump packings went to pieces, and, of course, stopped up the orifices of the tanks and we were under some uncertainty as to whether the piping was not stopped up also. That I believe is experience common to all of us in that line. While we are on perhaps the border line of the places that can afford to have all this apparatus and the smaller places, our daily use being a little over 6,000,000 gallons, as to the matter of cost which has been mentioned so many times, is not the cost a comparatively small matter, that is, the relative cost between one and the other, if you can get any better results from one than the other? The cost per million gallons is so small Chat it is practically negligible; and when you take into consideration the benefits that you get. the cost is so little that I do not believe it should hardly be given consideration. The water which we have is an unfiltered raw water. And although normally it is from a lake of ten square miles in area and our sedimentation under normal conditions is fair, our raw water running, excepting during the spring floods, under 100, of course in the spring floods we sometimes get as high as 5,000; but I do not remember that we ever get above that. As to the after-growths, while I cannot say anything about the aftergrowths with hypochlorite. I do note a slight difference at the present time when we take our samples. If we take a sample immediately in the pump discharge we are apt to get a slightly higher count than down in the city. The author has well spoken of the labor connected with it. There is one thing I believe he omitted to speak of, and that is when you use hypochlorite of lime you have an accumulation of empty cans that you do not know, what to do with. This in our own case quite a problem. We have a pumping station that is located right out in the lake. One of our workmen decided that one of our old cans needed disposing of, and I told him dispose of it, because it was old and uncertain in content. So he dumped it into the creek, and it killed I don’t know how many fish., We paid $100 to the State Service Commission as a fine for killing the fish. But in general liquid chlorine has proved very satisfactory with us, and I am sure I would not want to go back to the hypochlorite of lime.”