Report on the Waters of Illinois.
Edward Bartow, of the Illinois water survey, has brought out an exhaustive report of the results of analyses of the various waters used by the people of the State who live in towns of whose population exceeds 1,000. In these analyses such problems as the following have been studied: 1. Tests of the purity of water delivered by waterworks plants. 2. Comparative tests of the waters from several possible sources for cities intending to put in a new supply, or to extend an old one. 3. Tests of the efficiency of filters by analyses of water before and after filtration. 4. The determination of the suspended matter and the soluble mineral content of streams of the State, in order to obtain data from which can be calculated the size and expense of filter-plants or water-softening plants. 5. The determination of the mineral content of well water supplies, to obtain data concerning the character of the soluble mineral content that, where necessary, the proper treatment for such waters may be learned. The water problems of the State were divided into four subdivisions as follows: (1) Epidemics; (2) sewage purification; (3) water supplies; (4) streams. As to the first: Cholera and typhoid fever are the principal water-borne diseases. The first may now be eliminated from consideration, so far as concerns inland towns. Unfortunately, the second as yet cannot be written off as a negligible quantity, and it is the function of the State board of health to investigate places where the typhoid rate is high and of the State Water Survey to analyse the samples collected by the health authorities and to report them. As to sewage purification and its disposal: These come under the same two bodies as to samples of sewage and effluent, systems, plants and all sewage works and their inspection. As to water supplies: It is the’primary function of the water survey to oversee all that are in the Slate—(1) municipal; (2) institutional; (3) individual. Analyses of muncipal supplies involve the following data: Population, and rate of increase; on what branch of river system; chemical or physical character of the river water; ponds, lakes or reservoirs, and their character; ice industry; character of wells and springs ;• sewer system established; the municipal water supply, when established—source of water, ownership, cost, changes since installation; description of reservoirs, pumping station, and pumps, daily consumption, character of the water, chemical and physical, if treated, how, and at what cost, if supply from wells, the geological strata, diameter and depth, the annual cost of maintenance. The analytical analyses involve bacteriology and chemistry and are both qualitative and quantitative. The division of hydrography of the United States Geological Survey has been making a study of the quality of water in the streams. The work in Illinois was done under a co-operative agreement between the Geological Survey, the State Geological Survey, the Engineering experiment station of the University of Illinios and the State water survey. Samples were collected daily from twenty-seven stations on the principal streams within the State and sent to the laboratory of the State water survey for analysis. Ten samples were compounded and an analysis made of the composite sample. The report states that there are 227 cities and villages having a general water supply, of which eleven obtain their supplies from other cities. This leaves 216 separate sources of supply, classified according as they are derived from streams, springs, shallow wells (less than 50 ft. deep), deep wells in drift and deep wells in rock. It is interesting to note that the larger part of the supplies north of a line drawn from Quincy to the point where the Indiana State line touches lake Michigan are from deep rock wells. Between this line and a line drawn from just below St. Louis to Danville, it is found the deep drift wells predominate; south of the second line practically all are surface supplies. There are in the State ninety-nine cities supplied from deep wells in rock; fifty-one, from deep wells in drift; seventeen from shallow wells; ten from springs; sixty from streams, lakes or ponds. There are ten which are supplied from two different sources, such as river and deep rock wells, springs and deep rock wells, springs and reservoirs, deep drift wells and creek, creek and deep rock wells, river and shallow wells, springs and creek.