Economic Value of Public Water Supply
The October Bulletin of the North Carolina state board of health contains the following article by W. H. Booker, C. E., assistant secretary to that body:
It is the purpose of this brief article to touch upon the economic side of the question of public water supplies. For this purpose, no standard of value or comparison lends itself so readily as the dollar. For the purpose of discussion, the reader’s attention is respectfully called to the difference in sanitary value between the average public and the average private water supply of our state. It will be readily understood that the difference, if any, between any two supplies, front a strictly sanitary viewpoint, will be a difference in health and mortality among the users of the two supplies. To get the value of such a difference in terms most easily understood, we will, therefore, endeavor to put at least a partial or conservative value in dollars and cents on the difference in health and mortality among the users of the two supplies. The most general value placed on a human life in cold dollars and cents is $5,000. To be sure, this value varies greatly with the individual, but in damage suits for fatal accidents, in the case of life insurance, and in general, the productive value of the average man is taken to be about $5,000. This, of course, represents only what the average person is worth to his community, and not his intrinsic value or what he is worth to his friends and relatives. The difference in value between a pure water and an impure water is very frequently measured by the typhoid fever death and case rate when all other conditions in the town or towns to be compared remain practically the same, the quality of the water supply alone being changed. Therefore, for every death from typhoid fever that can be shown to be due to a polluted water supply we must necessarily place a charge of $5,000 against that supply. But deaths from typhoid fever are not all. F’or every death from typhoid fever there are perhaps on an average 16 cases of the disease. The value, or rather the cost, of having a case of typhoid fever may be assumed to be equal to the value of from four to six weeks’ work in addition to the cost of medical attention and nursing. For the purpose of this discussion, let us assume this cost to average $125 a case, or a total of $2,000 for the 10 cases. Therefore, the total loss from each death from typhoid fever may be assumed to be equal to $7,000. But the value of a good water over a polluted water does not consist entirely in the reduction of the death rate and the case rate of typhoid fever. Where vital statistics have been kept, the reduction of typhoid fever following the substitution of a pure water for a polluted water has been found to be accompanied by a drop in the death rate from many other diseases. For example, take the two similarly situated towns of Albany and Troy on the Hudson river, in New York state. Albany installed a filtration plant in 1898-9 and secured a pure supply. Troy did not. Note the difference from table I. It has also been found that in the case of live other cities in which the quality of the public water supply has been more or less improved, other sanitary conditions remaining equal, that the decrease in the total death rate attributable to the change in the water supply was 803 per 100,000 population, while the decrease in the typhoid fever death rate was only 71 per 100,000. From a little study of the statistics it will be seen that in the case of Albany and Troy the decreased in total number of deaths due to the introduction of pure water in Albany was three and one-fifths times as great as the “decrease in typhoid fever deaths. In the case of the other five cities mentioned the reduction in the total death rate was four and one-fourth times as great as the reduction in the typhoid fever rate. For the purpose of this discussion, it would seem that we might safely assume that the reduction in the total death rate in a town due to the introduction of a pure water supply is about three times the reduction in the typhoid fever death rate. If we may assume the decrease in the morbidity rate for other diseases to be the same as that of typhoid, we have a saving of three times $7,000, or approximately $21,000, to the community for the reduction of every death from typhoid fever. From the figures already given it would seem that when vital statistics have been accurately kept, the decrease in the annual death rate due to the introduction of pure water is about 70 per 100,000 from typhoid fever alone. This in turn means a saving of 70 times $21,000, or $1,470,000 annually, for a town of 100,000 people, or an annual saving of $14.70 per capita.
Therefore, pure water, from a sanitary point of view alone, is worth $14.70 more annually per capita than impure water. Can you afford to be without it? What can your city afford to pay for it? The individual householder having an average family of five now using impure water would be justified from a sanitary viewpoint alone, in expending annually a sum of five times $14.70, or approximately $70 to secure a pure water supply. In the case of cities or towns in our state, however, only a part of the private supplies are polluted, and therefore only a part of the inhabitants would be benefited. Table II, taken from the last annual report of the directors of the state laboratory of hygiene, shows the relative frequency of pollution of various water supplies throughout the state: In other words, the percentage of bad or polluted water is reduced 85 per cent, by using a municipal supply, while the percentage of good waters is increased 37 per cent. Again, to be conservative in our discussion, let us assume that on an average, only 25 per cent, of the population will be benefited by a change from private supplies to municipal supplies. This means that a municipal supply from a sanitary point of view alone is worth 25 per cent, of $14.70 or $3.67 annually per capita more than a private supply. Of course, it is impossible to state even approximately what the cost would be for a public water supply in your particular city or ttown. A fair estimate may be secured from a competent civil or sanitary engineer. In general, where accurate records have geen kept of the cost of public water supplies it appears that the annual cost per capita for a municipal supply, including maintenance and operating expenses, interest on the bonded indebtedness, together with the yearly payments into the sinking fund for liquidating this bonded debt, and into a depreciation fund for renewals, etc., besides the yearly cost of extensions and improvements, ranges from about $1.50 to $3 or more per person using, where the public supply is generally used.
The reader is cautioned to bear in mind that these figures are necessarily only approximate. However, it is believed that the existing error is probably on the side of conservatism. Furthermore, the reader is reminded that this comparison between a probable cost of from $1.50 to $3 and a saving of approximately $3.07 represents the ratio of the total cost to the sanitary saving alone. It was not the object of this brief article to discuss the value of a public water supply for. fire protection, for commercial purposes, for street and lawn sprinkling or for any of the other purposes for which such a supply is available. After determining the value of these various items for yourself, or by the aid of your engineer, ask yourself, your city authorities and the influential people of your citty or town how much longer you can afford to be without a good public water supply.