The log cabin Democrat., 1920-06-24

The tests show the water to be at present in a satisfactory condition. Although gas-producers were present, none of them could be proved to be harmful. All the other tests were satisfactory. except the positive test for alum. This must be remeded be- fore our water service can be consid cred perfect.
 Respectfully submitted,
 M J. McHenry, City Chemist.
 On account of conflicting engage ments, the city council committee has not yet held a meeting to consider the installation of a purification pro- cess in the waterworks system, but the matter will be taken up at once, the Log Cabin Democrat was inform ed today.
 D. l. N. McCollum, city health of- ficer, said today that settling basin should be installed and provision made for treating the city water at once T have felt for more than year that something should be done about this, and it certainly should be delayed no longer" he said. Dr. McCollum said the treatment with chlorine was the most economical and the most posi- tive method of rendering water free from disease producing organisms.
 Many citizens are unfamiliar with the chlorine qualification process as applied to city water, although it is the one in most general use. The most common method is the application of chloride of lime, commonly known as bleaching powder, which is produced by mixing chlorine with slacked lime. The city water at Little Rock is treat ed with this preparation before be- Ing pumped into the mains Some in teresting references to this chemical With reference to municipal water SUD- plies are found in a textbook on gen. eral chemistry written in 1916 by Dr. Alexander Smith, head of the depart ment of chemistry in Columbia Uni versity, from which the following quo- tatlon is taken:
 Many river waters contain large amounts of clay and organic matter (often due to admixture of sewage) suspended in them. It is not the or ganlc matter which is deleterious. but the bacteria of putrefaction and dis ease, which are present also, and are usually for the most part attach ed to the particles Of suspended mat ter Cholera and typhoid fever are often spread by the drinking of water into which sewage, infected by other patients suffering from these diseases, has been allowed to enter. Clay can be seen, and renders the water tur- bid, but organic matter and bacteria may be present in water which looks perfectly clear.
 The suspended impurities may be removed by filtration On large scale, beds of gravel are employed, but this treatment will not remove al bacteria. In many cases small amounts of alum, or alum and lime, or copperas and lime, are added. These produce slimy precipitates which assist in the elimination of fine, suspended inorganic and organic mat ter, including practically all the bac- teria. This is called the coagulation treatment (the treatment now em- ployed in the Conway system). The whole suspended matter is then al- lowed to settle, which it does very quickly, in large reservoirs. The re- maining organisms may be destroyed by adding little bleaching powder before the water is distributed"
 In another section of his book the same authority says; "In the purifica- tion of city waters the organisms which give rise to typhoid fever are destroyed by adding a small propor- tion of bleaching powder solution