RESULTS OF WATER ANALYSES Abbreviations used to describe odors of water: 0, none; 1, very faint; 2, faint; 3, distinct; 4, decided; 5, strong; 6, very strong; a, aromatic; d, disagreeable; e, earthy; f, fishy; g, grassy; m, musty; v, vegetable CHEMICAL (PARTS PER MILLION) BACTERIOLOGICAL Color WATERVLIET The public water supply of the city of Watervliet has received a great deal of attention in the past from this Department. Numerous inspections, analyses, letters of advice and public addresses have been given in an endeavor to impress upon the citizens and officials the necessity of securing a water supply of safe and wholesome quality. In 1914 contracts were let for the construction of a new system of water supply consisting of a large impounding reservoir on the Normanskill at French's Mills, several miles west of Watervliet; a water power pumping station at this reservoir; 15 miles of wooden stave pipe line; a 15,000,000 gallon raw water storage reservoir, 2 miles west of the city; a gravity mechanical filter plant; clear water basin and a new pipe line to the distribution system. Pending the completion of this new system, the old supply derived by pumping directly from the Mohawk river at Dunsbach Ferry was continued and at times a supplementary supply was derived from the Hudson river by pumping from a point opposite the city. In 1916, at the urgent advice of this Department, liquid chlorine apparatus were installed at both the Mohawk and Hudson pumping stations. Several inspections of these plants were made during the year and advice given with respect to their proper operation. During the early part of July, 1917, inspections were made of the chlorination plant at the Mohawk pumping station and samples collected for analyses. Later in the month, information received through the daily press indicated that steps were about to be taken by the city officials to augment the supply from the Mohawk, which was proving insufficient for the needs of the city, by pumping from the Hudson river. A letter dated July 13, 1917, was accordingly sent to the board of water commissioners, pointing out the necessity for placing the chlorination plant for this auxiliary supply in proper operating condition, and warning against the admission of untreated Hudson river water into the distribution system. Following this letter, information was received from the board of water commissioners that action would be taken as suggested, but this Department was not informed at the time the Hudson plant was put into operation. On August 6, 1917, the results of the analyses of the samples of the chlorinated Mohawk suuply were transmitted to the city authorities and the need of increasing the amount of chlorine was pointed out. A letter was received from the local authorities, stating that our recommendations would be carried out. On September 15 a rumor reached the attention of the Engineering Division that an unusual number of typhoid fever cases had developed in Watervliet. The matter was at once taken up with the Division of Communicable Diseases, which immediately started an investigation, which soon disclosed the fact that a great many cases of typhoid had occurred in the city, although very few had at that time been reported. On September 17. the Engineering Division made an inspection relative to the water supply situation. It was found that the water from the Hudson river was being pumped, after treatment with liquid chlorine, directly into the distribution system from an emergency pumping plant located at the old electric light plant near the city hall. Analyses of samples from both supplies indicated that the sterilization of the Mohawk supply was somewhat inadequate and that the treatment of the Hudson supply was bringing about practically no purification. Upon further investigation it was found that not only was the capacity of the Hudson river pump larger than that upon which the rate of chlorine application had been estimated by the local authorities, but that the organic content of the river water was so high that the chlorine was immediately absorbed without producing bacterial reduction. In view of the seriousness of the situation, the investigation of the Division of Communicable Diseases indicating the occurrence of a large number of typhoid cases. directions were given for an assistant engineer to visit the Hudson river chlorination plant each day and the Mohawk plant somewhat less frequently. By careful checking the operation and by gradually increasing the amount of chlorine applied, the efficiency of the sterilization was improved, and on September 22, a practically sterile water was obtained with both supplies, the total bacterial counts being low and organisms of the B. coli type being absent. Thereafter satisfactory results were obtained for the most part. At times, however, owing to the carelessness on the part of the local authorities, or due to accidents of the chlorination apparatus the supplies were inadequately sterilized. Nevertheless, it may be stated that from the 22d of September until the new supply was put into service, about the first part of December, the water supply of Watervliet was reasonably safe the greater part of the time. About the first of December, however, difficulties were experienced with the operation of the pumping plants and with the operation of the chlorination apparatus, but about this time the new supply was being put into service, and the water in the distribution system was derived in part from the relatively safer Normanskill supply. During the supervision of the operation of the chlorination plants by the Engineering Division, the epidemiological investigation by the Division of Communicable Diseases was proceeding. Some 169 cases of typhoid fever were found to have occurred in the city of Watervliet during the outbreak. The information secured pointed to the public water supply as one common source of infection and a certain public well as another possible source. Watervliet, owing to the unsatisfactory condition of the public supply, had been provided with numerous public and private wells which are sunk for a comparatively few feet through porous shale, and in nearly all cases seriously polluted. On November 1 the Engineering Division was directed to make a survey of these wells and immediately proceeded to do so. Samples were collected from every public well in use and upon the receipt of the results of analyses, made by the Division of Laboratories and Research, steps were taken on November 3, through the local officials, to close these wells found to be most grossly contaminated. are In connection with the typhoid outbreak the following dates are significant: On July 24 the Hudson river water was first pumped into the mains; on September 15 the first information regarding the typhoid outbreak reached this Department; on September 21 the well, which the evidence indicated as being the source of infection for a large number of cases, was closed, and on September 22 the first effective sterilization of the public water supply was obtained. In June and July only 5 cases of typhoid were reported from Watervliet, while there were 35 cases with onsets in August; 96 in September, and 38 in October, whereas only 8 were reported in November. About the middle of November, the work on the new waterworks had reached the point where water had been delivered to the raw water reservoir near the filter plant. It was found. however, that owing to leaks which had developed in the coagulation basins of the filters. it would be impossible to operate immediately. In order to secure a supply of better quality, and in order to obviate, if possible, the use of the grossly polluted Hudson at the earliest moment, it was suggested that the city secure permission from the State Conservation Commission for a temporary by-pass around the filter plant. This permission was obtained, but some time elapsed before advantage was taken by the city of this permission. It was advised by this Department that the unfiltered Normanskill supply be sterilized with liquid chlorine or hypochlorite, but no immediate action was taken to follow out this advice for some little time after the admission of the Normanskill supply into the city distribution mains, despite the fact that the city was experiencing a most serious outbreak of typhoid, due to the use of contaminated water. Finally, the filters were put into shape and used without the preliminary coagulation basins being in service. About the first of December it became impossible to operate the pump at the Hudson river plant, and about the 10th of December operation of the Mohawk plant was given up. On December 6, the chlorination plant for the sterilization of the Normanskill supply was put into service and has been in use, presumably, ever since. STATE DEPARTMENT OF HEALTH-ENGINEERING DIVISION WATERVLIET - PUBLIC WATER SUPPLY MOHAWK RIVER SUPPLY CHLORINATED WATER B. Coli MIXED AND MISCELLANEOUS B. COLI Remarks P. M. 3+0 10.10 A. M. 3+0 2.30 P. M. 3+0 3+0 10.45 A. M. 3 +0 3 +0 15 0+3 3+0- 45 0+3- 0+365 0+3- 0+3 0-3 19) 1+2 0+3 0+3 Tap, 2d ave. and 19th st. 9.2 1.300 2+1- 1+2 0+3 Tap, Menands. Tap, 7th ave. and 19th st. 3+0- 3+05,500 3+0- 1+2— 35 0+3 1+2 0+3 0+3 0+3 Tap, 3d ave. & 8th st. 4,800 2+15,300 3+0- 1+2 2+1 6,800 3+0- 1+2 2,500 1+2 0+3 2,700 3+0- 0+3 Difficult to operate Mohawk pump during entire month of Nove.nber. Amount of chlorine used not as large as advised. Probably no water pumped from Hudson river after Nov. 30. Ob ervers: E. S. Chase and C. M. Baker. |