RIVER POLLUTION.

RIVER POLLUTION.

The controversy between Chicago and St. Louis over the the pollution of the Mississippi river by the Illinois drainage canal turns on the old question as to how long a distance it is necessary for a river to How in order to purify itself. The sewage of Chicago is conducted to the Mississippi through the Des Plaines and Illinois rivers, and the people of St. Louis believe there will arise effects detrimental to the water of the Mississippi at that city. The United States Geological Survey has been called in to make a scientific study of the problem involved. The director of the Survey, Charles D. Walcott, says: “We know from chemical analysis and physical examination that a varying degree ot purification takes place in a river. In early days this was thought to be due to aeration, and the tumbling of water down mountain sides became the basis for poetic typitication of purity. The experiments of the Massachusetts State board of health, however, have shown that aeration has little or no effect upon the condition of organic matter in water—that is, the organic matter is not assisted in its oxidation by agitation in the air. It was also found that the highest degree of activity in oxidation process is to be found in quiescent or stagnant water, it, then, became clear that self-purification in a sluggish stream is far more effective than in a swift current, and that dams and other impediments have a beneficial effect upon the condition of water in river channels. The promulgation of these facts led to an entire change in the ideas concerning the distance necessary for stream purification, and it is now understood that no hard and fast rules can be set for guidance in determining the purifying power of any watercourse. A Royal Commission,appointed to inquire into the conditions of England’s rivers, reporting lo the English Parliament in the early seventies, held that no stream in the United Kingkom was sufficiently long to effect its own purification. The familiar and oftquoted principle is, that a stream purifies itself in twenty miles, but how this distance was ever determined on, or who was responsible for its general acceptance is a matter of doubt; certain it is that the statement is entirely wrong in the majority of cases. Pettenkoffer, Hering, Stearns, and others have given formulae which are undoubtedly,true for the rivers upon which these gentlemen worked, but which can in no wise be accepted for rivers in general, and it remains for the investigator to deter mine by actual experiment the purifying power of each stream with which he has to do.”

River Pollution

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River Pollution

An interesting lecture was recently given at the Manchester (England) Technical Laboratory by G. E. Davis, upon the above subject. According to an English contemporary the chair was taken by F. H. Walinsley, chairman of the rivers committee of the Salford corporation, who, in his opening remarks, said that though the state of the Irwell was bad now it would have been worse if the act of 1876 had not been passed.

Mr. Davis commenced by showing samples of neighboring streams which fed the Irwell—the colors varying from black to red—and said that the pollution had been increasing for over a quarter of a century, but the approaching completion of the Manchester Ship Canal made it imperative that something should be done to cleanse the river. Reviewing the act of 1876, he characterized it as a worthless measure, in that it made no, restrictions as regarded suspended matter or color. The clause providing for the discharge of chemical works etlluents into sewers was, in his opinion, a bad one. Treating with the various sources of pollution, sewage, he said, came first in point of magnitude. In Salford they had to deal with 10,OOJ.OOO gallons of sewage per day, and he showed by an experiment that to destroy the albumenoid ammonia chemicals would be required at the rate of 35 cwt. of alummo-ferric cake, or two tons of lime, per 1,000,000 gallons. Referring to the waste water from, the factories, he mentioned specially paper works, woolen mills, bleach, dye and chemical works, and stated that it was the users of the chemicals rather than the manufacturers who caused the pollution. The etlluents from chemical works consisted largely of calcium chloride, a salt in itself harmless to fish, but precipitation took place when this salt mixed with bleachers’ liquors in the bed of the river. There was no doubt that paper makers profited largely by the recovery of their soda, and he could instance works in the South of England where .£2000 a year was thus saved. No effort, however, had yet been made to deal with the acid sulphite liquors from the wood-boiling process.

As the effluents from various dye works differ so greatly, no general rule could be laid down for their purification, hut it would be an easy thing for each works to devise its own plan of procedure. Turning to gas works, the lecturer said that they sent out waste waters containing sulpho-cyanides, which, if they found their way into sewage intended for irrigation purposes, were, according to Dr. Voelecker, very injurious to crops. Acid or alkaline etlluents should not be allowed. These could be easily dealt with, and he instanced a case at Wolverhampton where the waste water, which formerly contained fifty per cent of free acid, was now turned out almost neutral. ‘They should bear in mind that the means of evaporating waste waters and of removing suspended matters by filtration were much improved since the bill of 1876 was passed, and really manufacturers in many cases had no excuse for the excessive pollution that took place. In conclusion he said the only remedy, in his opinion, was a law based on the proposed bill of 1886, to compel manufacturers to cleanse their etlluents to a certain standard of purity.

In the discussion that ensued, Mr. Fowler of Leeds objec ted fb laboratory experiments in these matters, and stated that at Leeds one ton per 1,000,000 gallons of sewage was found quite sufficient for purification. The chairman said that lime at thirteen shillings per ton was quite efficient as alum cake at forty-six shillings, and, in the case of large populations, the first cost of the chemicals was an item of considerable moment.

A CANINE Hf.RO.—A Chicago press dispatch says: “ liassan, a big Newfoundland dog, saved the life of his master, Frank Koppek, and the lives of five other persons early this morning at Hancock avenue and Cortland street. A fire started in Koppek’s house at half-past two o’clock. Hassan broke a chain which confined him, and jumping upon a table plunged into Koppek’s room through the transom. Koppek was choking, but the dog grabbed him by the night shirt and led him to the window, which Koppek broke, letting in the fresh air. Koppek jumped out to the ground, fifteen feet. He notified the firemen where his wife and five children were, and all were rescued. The dog was burned to death, being forgotten in the excitement.”

THAT ALUMINUM AIR SHIP.—A telegram of January 19 from Chicago says: “The Pennington air ship is safely housed at the office of the American Express Company, having arrived from Mount Carmel all right, and Inventor Pennington says it will be placed on exhibition in the Exposition building by Friday or Saturday at the latest. The model will cairy about 120 pounds without the machinery. Mr. Pennington said all the parts of the large machine, which will carry

forty persons, are on the ground at Mount Carmel, and will be put together at once. The inventor says the time between Chicago and New York will be reduced to five hours. ‘The first installment of ten per cent 011 the $20,000,000 capital stock is to be paid in at the stockholders’ meeting to-morrow.”

NEW ENGLAND WATER-WORKS ASSOCIATION MEETING.There were about 100 members and visitors at the adjourned meeting of the New England Water-works Association at Boston on January 14. President Albert F. Noyes was in the chair. Notification was received from the Connecticut Association of Civil Engineers and Surveyors that a committee had been appointed to confer with the New England Association regarding its coming annual convention at Hartford, and the subject was referred to the executive committee. Mayors Alger of Cambridge and Maybury of Waltham made addresses, hrederic Stearns, chief engineer of the Massachusetts State Board of Health, read a paper on “ The effect of storage on the quality of water,” which was discussed at length. A paper was read by William E. Davis, superintendent of water-works at Sherburne, N. Y., in which he described the manner in which he had moved about 700 feet of conduit pipe without disjointing it. New resident active membeis were elected as follows : S. Everett Tinkham, C. E., Boston ; X. H. Goodnow, assistant engineer Massachusetts State Board of Health, Boston ; John D. Shippy, superintendent Water-works Company, Ilolliston, Mass.; Geo. H. Barrus, consulting engineer, Boston ; Wm. W. Starr, Jr., Bridgeport Conn,; Frank H. Mills, Woonsocket, R. I.