In view of the many complaints against the city's water supply Engineer De Varona today, made the following statement:

To judge of a water properly it is necessary to know (1) its source and environments, (2) its physical properties, (3) its chemical composition, (4) the result obtained from its biological examination.

The first and second points concern the engineer, the third and fourth are more particularly the duty of the chemist and biologist, whose special functions are the determination of the quality and adaptability of the water for public use. The chemical and biological examinations are not only necessary in first selecting a source of supply, but they should to continue to guard against pollution or contamination, or to advise the proper remedy to apply whenever the water may be unfavorably affected from any cause. This bureau, over two years ago (see pages 73 and 74 of the annual report for the year 1894), recommended the creation of a laboratory for the express purpose of making the necessary chemical and biological analyses of our water, color tests, etc., as well as other investigation in connection with the subject of water supply, and realizing the importance of such a necessary adjunct to the department in the report for last year just issued (see page 110), the necessity of this laboratory is again shown and the matter discussed quite at length.

"Biological examinations should be regularly made, not only of the Hempstead stream, but wherever there is any suspicion of pollution. The results shown by the chemical analysis may indicate danger, but should be interpreted in connection with the biological conditions which obtain." Pending the creation of such a laboratory, which it is to be hoped will not be delayed much longer, and the necessity for which needs very little additional demonstration at the present time, chemical analysis have been made for us weekly by the board of health for the last two years, the results of which are satisfactory, as often stated before. The insufficiency of chemical analysis alone has already been pointed out, and the only biological investigations which are now available are those of a quantitive character, which have been made weekly of the tap water by the board of health, who, we understand, are now working with zeal and activity to differ the species and accurately diagnose the evil, so that the remedy to be applied may be effective. We must be advised whether the trouble arises in the distribution system or in the sources of supply; and if in the latter, whether the trouble is local or general.

The bad odor and color of water is and has been unfortunately a frequent cause of complaint in many of our cities, and each case must be studied by itself to determine whether the odor is the result of the existence or decay of plant or animal life, and the remedy is to be applied only after careful experiment and examination. Popular judgment of water is apt to be very erroneous and takes into account only color and odor; and yet perfectly clear and odorless water may be saturated with the worst elements. In all water there are found quantities of varieties of plant and animal life, the former furnishing food for the latter, and they in turn accomplishing a great amount of good in purifying the water.

The greatest and most frequent evil is due to the decay of plants, a difficulty, which, instead of being exceptional, is of very common occurrence in water works and one of the worst evils with which managers have to contend.

In regard to the objectionable odor, Mr. Elwyn Waller states that when he was connected with the New York board of health he investigated 150 water supply systems and that one-half of the number were similarly troubled. The presence of "algae" produced odors which were characterized as "cucumber," "fishy," or "rotten eggs."

These algae are liable to appear in all waters whether or not the same are in all respects all that could be desired. Their appearance in new works is quite common. None of the species is poisonous except one variety, which has never been found in this country but the unpleasant odors given off at certain seasons are undoubtedly very offensive. Again the bacteria and other forms or low plant or animal life are not injurious except those of the disease producing type, such as cholera, typhoid, etc. These can get into the supply only as sewage and their entrance into any supply can only be guaranteed against by rigid inspection. It is, therefore, apparent that a water cannot be hastily condemned, and if bad, cannot be improved without due investigation. Some time ago the New York health inspectors found that hundreds had been drinking water from a so called "healing spring" in the part of New York state, which gave forth as clear and apparently perfect water as anyone could ask for, but this, upon investigation, was found to come entirely from an adjoining sewer. Again chemical analysis does not prove the water good or bad until it accounts for all the components foreign to it in the pure state.

Further referring to the objectionable odor and color, the report of the Massachusetts state board of health for 1890 states that it may be remedied by boiling or by filtration and boiling. Their chemist remarks that they are due either to organisms or their decay, he does not know which, and their biologist concludes that their cause is the decay of such organisms. Professor Mason, in his work, states that the decay of organisms produce the odors, which have not been proven to be productive of disease, and that these odors are prevented by aeration. The algae, he adds, depend on the presence of nitrogen, which is often found in deep water supplies; hence the algae develop in storage.

The sulphur in the algae, he says, produces the characteristic odor of sulphuretted hydrogen, or rotten eggs. Rochester, New York, Boston, Jamestown, Poughkeepsie, New Britain, Hoboken, Long Island City and many other localities that could be named, have been subject to this evil, in their water supply, and in the case of Hoboken the chief engineer.

Mr. Brush, states that in 1884, owing to the odor in the water, bitter prejudice broke out against it, and to quote from his report: "The mayor of our city called public meetings, and I was informed that I was expected to explain why the water was bad, and to remedy it, or suffer the consequences. Instead of considering the subject as a matter which was incident to water supplies generally, and which would have to be examined in a scientific way, it was treated with intemperance and ignorance. The trouble was very satisfactorily and thoroughly overcome by forcing air in the pipes." Dr. Leeds was consulted in this case.

In some cases where it has occurred it is permanent; others have obtained relief by aeration or by cleaning the storage basins. Some localities are troubled with it at long intervals, and there are instances where the difficulty is not more or less marked. While it seems idle to theorize on the present difficulty, before the facts are laid before us by the board of health, and the proper remedy devised, it may be proper to state that should it be due to the presence of algae it seems quite likely that this may have developed in the driven well water when exposed to light, as this has been of frequent occurrence, owing to which it has been advised that water from deep wells should either not be sorted or stored under covered reservoirs. If that be the case, the remedy would be either the aeration of the water at the Ridgewood reservoir or still boater pumping around the same so that the water would not be exposed to light before reaching the consumers.

To sum up. In order to correct the present evil it is indispensable to ascertain whether the cause exists in the supply or distribution; whether the trouble is local or general; what is its character and what the remedy. It has already been stated that this department is not equipped to do this work and that we depend on the services of our board of health, who is thoroughly and diligently investigating the matter. On the completion of its labors this department will immediately act on its report and recommendations.

In the meantime, we have its assurance that there is nothing deleterious in the water. If the trouble be in the supply and is due to the algae "it would not be at all surprising if it were to disappear as suddenly as it came and before any remedy is applied.