The Iowa City Water

The Iowa City Water

In a paper read before the Baconian Club, of Iowa City, Ia., J. Hinman, Jr., bacteriologist and chemist, laboratory for the Iowa State Board of Health, State University of Iowa, spoke of the results of an investigation of the city water which has been carried on in the university laboratories for more than a year. According td Mr. Hinman, although the water furinshed to residents of Iowa City is all right most of the time, as far as conditions with regard to the bacteria are concerned, yet there are times when the water supply seems to become suddenly contaminated and the city water supply is very bad. In drawing a chart to illustrate conditions for the year, Mr. Hinman indicated the line of one hundred bacteria per cubic centimeter at 2 inches above the base line. But on some occasions the number of bacteria jumped so high that the point on the chart would have been nearly sixty feet above the base line, according to this scale. On the chart, he had changed tin scale as the figures mounted higher. The highest point reared was on January 20, 1915, when 36,000 bacteria to the cubic centimeter were shown in tests conducted on a 20 degree centigrade plate. At body temperature, 37 degrees centigrade, the tests showed 12,000 bacteria to the cubic centimeter. On other occasions at about the same period the amount ran nearly as high. I his was the time when the laboratory issued its warning against drinking the water without boiling. On the other hand during the months of July and August, 1915, the water was truly in excellent condition. At no time did the number of bacteria per cubic centimeter exceed 10, and on some days the tests showed that the water going through the mains was absolutely sterile. On 142 days out of the year there were direct evidences of sewage pollution showing in the tests. The chief need at the present tune to better the condition of the water which is supplied to the mains is an extension of the clear well in which the filtered water is stored, according to the investigations which have been made by Mr. Hinman. At the present time the well is filled with filtered water at night, when consumption in the city is less rapid, but in the dav time the water is drawn off so rapidly that the rate of filtration has to be changed in order to keep the clear well filled with filtered water. If the well were enlarged it could be filled at night and the supply would he great enough so that bv filtering at the same rate during the day there would always he a supply of pure water on hand with an amount in reserve that could be turned into the mains in ease of fire.

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