FEBRUARY 1915 TYPHOID FEVER AND WATER SUPPLIES IN THE CITIES OF NEW YORK STATE Typhoid fever is spread by many other agents besides water supply. In the past, however, polluted water has been the cause of some of our most severe epidemics and one of the most important factors in the successful campaign which has been waged against this disease is an improvement in the character of public water supplies. The curves reproduced on the back cover of this number of HEALTH NEWS show in graphic form the history of typhoid fever in the New York State cities and villages of over 10,000 population, from 1904 to 1914, inclusive. Fifteen of the cities and villages have a record of typhoid rates almost uniformly below 20 per 100,000 for the whole period of eleven years: Albany, Amsterdam, Binghamton, Buffalo, Gloversville, Johnstown, Mt. Vernon, New Rochelle, New York, Olean, Rochester, Schenectady, Syracuse, Utica and Yonkers. It is gratifying to note that this list includes all the first and second class cities except Troy, and six cities of the third class. Eleven of the communities have had generally satisfactory typhoid rates in recent years, either with high rates during the early part of the period studied, or with occasional epidemics during the course of the eleven year period. All but one show rates under 20 per 100,000 for the year 1914. The list of communities in this class is as follows: Auburn, Cortland, Elmira, Hornell, Jamestown, Ogdensburg, Oneonta, Poughkeepsie, Rensselaer, Rome and Watertown. In the case of Auburn, Cohoes, Elmira, Niagara Falls, Poughkeepsie, Rensselaer and Rome the more recent decrease in the typhoid death rate was definitely associated with improvements in the public water supply. There remain seventeen cities and villages Corning, Dunkirk, Fulton, Geneva, Glens Falls, Hudson, Ithaca, Kingston, Little Falls, Lockport, Middletown, Newburgh, North Tonawanda, Oswego, Plattsburg, Troy and Watervliet-which show more or less consistently high typhoid rates. Taking the year 1914 alone, however, Fulton, Kingston, Little Falls, Lockport, Middletown and Plattsburg should be removed from this list, and in the case of Lockport, as pointed out elsewhere, the reduction in typhoid was directly due to chlorination of the public water supply. It may be noted that Ithaca, Newburgh, North Tonawanda and Oswego have recently taken steps to purify their supplies by chlorination. The highest typhoid death rates for 1914 were 33 for Watervliet, 34 for Corning, 33 for Hudson, 34 for Troy, 41 for Dunkirk and 61 for North Tonawanda. In each one of these cases, with the possible exception of Troy, the public water supply is known to have been subject to serious contamination. Typhoid fever rates in well-protected communities are rapidly falling to 10 per 100,000 or below. Any city which has a rate of 20 or over should give serious consideration to its water supply and to other sanitary conditions within its borders; for something is surely wrong. DISINFECTION BY CHLORINATION OF PUBLIC Director, Division of Sanitary Engineering The value of hypochlorite of lime as a general disinfectant and deodorant has been well known to the Medical and Sanitary Engineering professions for many years. Only within the past few years, however, has this knowledge been applied on a practical scale to the disinfection of large volumes of water such as public water supplies. The first practical demonstration was made in connection with the disinfection of certain public water supplies in England. Almost simultaneously in our own country, however, studies in connection with various purification processes made at the Massachusetts Institute of Technology demonstrated the utility of these chemicals for such purposes. The first public water supply in this country to be treated or disinfected by hypochlorite of lime, or "hypochlorite" as it is often called, was the Jersey City supply, in the year 1908. Here it was demonstrated, through a series of elaborate practical tests, that the addition of less than one part of "hypochlorite" to one million parts of water, would kill practically all of the bacteria present in the water, including, of course, all disease germs. Since 1908 the disinfection of public water supplies by this method has had a remarkable growth, and today we find "chlorination" plants quite generally in use, on every hand. Valuable as the discovery of this method of disinfection has proven to be in the protection of human life, it should not be inferred that this treatment is a panacea for all water supply troubles, nor that its practical application is in all cases a simple matter. On the contrary, there are some classes of waters which do not lend themselves readily to effective chlorine treatment, and in treating those that do, many difficulties have had to be overcome. One difficulty, for a long time of a serious nature, concerned the mixing and feeding devices for applying the chemical, which in the case of "hypochlorite" is added to the water in the form of a solution. It is necessary that this solution be of certain requisite strength, and that it be applied with precision, not only with respect to the changing rates. of flow of the water, but to its changing physical and chemical qualitya requirement that demands delicate but reliable regulating devices. The odor and taste of the chemical, even in the minute quantities used, may be sometimes detected by the sense of taste or smell if for any reason the proper rate of application is even slightly exceeded. Especially with some waters containing considerable amounts of organic matter, the suitable apportioning of the amount of chemical is difficult; the organic matter present having the power of absorbing and rendering ineffective the "hypochlorite," with the resulting possibility of applying too little, on the one hand, with ineffective sterilization, or too much, on the other hand, with the causation of taste and odor. Many improvements have been made in the past two years in chlorination plants, especially with reference to the devices for applying the chemicals; but the most important of these has been the substitution of chlorine gas for the "hypochlorite." When we consider that chlorine is fully as effective as the "hypochlorite" we can readily understand how, if the gas can be applied directly to the water, the method of treatment may be simplified. This in fact is just what has been done, and now certain manufacturers are able to furnish chlorine in liquid form, under pressure, in portable cylinders, for this purpose. The water works official is thus enabled to connect these cylinders of chlorine to the water works intake pipe, or to the suction or discharge conduits from the pumps, and apply the chlorine gas directly to the water in these mains. through the necessary regulating devices. A number of such devices for applying chlorine gas are now upon the market, and while somewhat complex in their mechanical working, they are durable in material and construction and quite positive in operation. Up to the present time, and until its efficiency had been clearly demonstrated, the disinfection of water by chlorine has been largely limited to the treatment of water which had first been passed through sand filters. Unfortunately there are many supplies in this and other States which are subject to continuous sewage contamination, and therefore unsafe, where the municipalities or companies are financially unable at once to meet the expense of sand filter plants. When one considers therefore that the cost of a chlorination plant is only a very small fraction of the cost of such a filter plant and that the cost of the minute quantity of chlorine necessary to disinfect the water is almost negligible, there would appear to be no plausible excuse now for any municipality or water company to furnish its people or patrons with unsafe water. It must not be expected that a chlorination plant will make a roily or colored or otherwise physically objectionable water, attractive; but where properly installed and operated it can be relied upon to destroy disease bacteria and thus to safeguard the people against water-borne diseases and epidemics. In the State of New York at the present time practically all of the larger and many of the smaller water filtration plants are equipped with chlorination apparatus for disinfecting the final effluents from the filters before the water is sent to the consumer. In addition to these there are many municipalities, including New York City, Buffalo, Lockport, Auburn, Newburgh, New Rochelle, and a number of smaller places where the water supply is not filtered, but where a chlorination plant is installed and the water disinfected before use. Two striking examples of the efficacy of chlorine treatment for the protection of life and health, illustrating the value of this method in cases of emergency, may be cited. The cities of Lockport and North Tonawanda are situated side by side and both take their water supplies from the Niagara River, a few miles below the city of Buffalo, which pours its raw sewage into the river. Both water supplies have for many years been known to be unsafe, not only through. laboratory tests, but also from the high typhoid fever rates that have existed at both places. Some six months ago the city of Lockport installed a chlorination plant and within a month the typhoid rate dropped, and since that time there has hardly been a case of typhoid fever in the city. North Tonawanda on the other hand, continued to use its same sewage-contaminated water supply and has continued to have not only its usual high typhoid fever rate, but, during the months of October and November, 1914, had an undue prevalence amounting almost to an epidemic. Realizing the importance and seriousness of the situation at North Tonawanda, Dr. Biggs authorized the Engineering Division to purchase a chlorination apparatus and immediately install and operate it for the city for a period of about six weeks. The plant, which was of the portable type, was installed under the immediate supervision of the writer on short notice. In fact, it was installed and put in operation within 24 hours from the time work was begun upon it. The cost of the apparatus and installation was less than $300, and the cost of chlorine was about $1.00 per day for the population of about 12,000. Before the plant was started a series of water samples were collected CHLORINE DISINFECTING PLANT INSTALLED AT NORTH TONAWANDA at five different points of the water supply system and sent to the State Laboratory for analysis. Five subsequent series of samples were collected from the same sampling points after the plant was put in operation. The first series of samples, before chlorination, showed total bacterial counts ranging as high as from 1,200 to 1,400 per cubic centimeter, with the presence of sewage bacteria in all samples tested. In the five series of samples collected after the chlorination plant was in operation, |