Good Effects From Storing Water.
The good results following the storage of water in reservoirs for a reasonable period before delivery in the mains either after or with out filtration has long been recognized. Laboratory research has confirmed the correctness of the idea. As the result of tests made with sewage polluted river water, Dr. A. C. Houston re ports to the Metropolitan water board of London, England, “That the merely mechanical effect of storage—that which results in the sedimentation of many of the microbes originally present in a water—is of far less importance than certain devitalizing processes, which occur under storage and which involve the ultimate extinction of specific bacteria in the water plus its sediment. Jt follows, therefore, that with efficient storage a water may become reasonably safe prior to filtration, a consideration which is of the highest importance in view of the possible breakdown of filtering apparatus.” In other words, the microbes of typhoid and cholera, the so-called water-borne diseases, are not at home in water, and become devitalized and incapable of transmitting disease if their stay in the water is sufficiently prolonged. Storage reduces the number of bacteria of all sorts, and diminishes the amount of suspended matter and color ; and analysis shows that the water becomes chemically purer. Storage prior to filtration prolongs the life of the filters. Dr. Houston states that raw river water should he stored for 30 days, if possible. before being subjected to filtration. Xinetyniiu per cent, of the organisms in raw water die after storage for a week, a few linger on for a fortnight, and still fewer struggle on for a month.