The Sewage Question at Chicago.
The following report upon the matter of sewage was recently submitted to the Mayor and common council of the city of Chicago, by John H. Rauch, M. D., secretary of the Illinois State Board of Health :
Owing to the increased quantity of sewage that empties into the Chicago river and the small amount removed by the Bridgeport pumps, the river during the past season was as offensive as at any time before the deep cut in the canal was made, and, in fact, in the history of the city.
Not only is the river a nuisance in its present condition, but it is a positive source of danger to the health of the citizens of Chicago, which will increase with its growth in population.
The sanitary interests of Chicago and the communities in the Desplaines and Illinois valleys imperatively demand that the sewage of Chicago, pumped into the canal, shall be diluted on the minimum scale of 14,000 cubic feet per minute for every 100,000 people who drain into the Chicago river. In winter, when oxidation is retarded by ice formations, shutting out light and air by low temperature and by impeded motion, a greater rather than less, quantity should be pumped. This is not surmise ; it is an absolute certainty, fully proved by careful investigations and recent analyses. As a matter of fact, the average quantity pumped during the period covered by the analysis referred to did not exceed 45,000 cubic feet a minute during the summer of 1888, nor was it more than 38,000 cubic feet a minute during the winter of 1888-9. The larger quantity is less than one-half the minimum dilution now necessary to prevent nuisance in the river and at Joliet.
The sanitary interests of Chicago require the increase of pumping to at least 120,000 cubic feet per minute, at this time. With comparatively small outlay the canal can be made to carry 100,000 cubic feet a minute, though probably one or two bridges would have to be raised.
Owing to the fact that the canal cannot carry off a sufficient amount, pumping works, for further relief, should be immediately erected at some suitable point of discharge on the Desplaines river, as recommended by this board in 1879, in addition to such an increase of the pumping plant at Bridgeport as may be practicable, to provide for the present necessities and augmented amount of sewage that will be discharged between the present time and completion of the waterway from Lake Michigan to the Illinois river.
With the sewage of more than 800,000 people already discharging into the Chicago river, the minimum dilution above specified—14,000 cubic feet per minute to the 100,000 people —requires at the present time that at least 120,000 cubic feet a minute be pumped.
The heavy rainfall of July 27-28, 1889, of over four inches, carried the accumulated sewage beyond the crib and polluted the water supply ; had it not been for the notice given to boil the water before using, and the remarkably low and equable temperature for more than a month after this heavy rainfall, the influence of this pollution of the water would have been much more marked upon health and life than it was. Under certain circumstances two inches of rainfall in twenty-four hours in this city is a menace to its water supply ; spring freshets also, and a rainfall in one day of three inches, with the present pumping capacity, always pollutes the water. As compared with the benefits to be derived from this work of diluting and removal of the sewage, the cost of this temporary undertaking should cause no hesitation.
It is, then, a matter of the most vital importance and an absolute sanitary necessity, that provision be made for pumping the amount of water mentioned, and this provision should be made without delay. The conditions that obtain are a constant menace to the health of the people. Delay in this matter by those in authority, so far as the people of Chicago are concerned, is simply criminal; and, as regards the adjoining communities that are imposed upon by this nuisance, an outrage.