The Rapid Filter Plant at Evanston, Illinois

The installation of a filter plant was urged because of the poor condition of the water in Evanston, both from the hygienic and aesthetic standpoints. The intake is only one and one-sixth miles offshore, well within the range of drift for the sewage of Evanston and Wilmette, the greater portion of which is discharged on the lake front. In the winter of 1911-1912 a severe threatened epidemic of typhoid was averted only by the emergency use of chloride of lime.2 From time to time breaks in the intake pipe have been found, thereby receiving water nearer inshore. When the matter was agitated in 1912, Mr. W. W. Jackson and the writer made a report, in August of that year, recommending the construction of a plant of the rapid-filter type. By a popular vote, in the same fall, a bond issue was authorized. Plans ajid specifications were prepared by Mr. George W. Fuller, of New York City, and the writer, on which bids were received in April. Active construction work commenced in June, 1913, under our direction, with Mr. C. G. Gillespie as the resident engineer, the work being substantially completed in August, 1914. Since that time, Mr. Gillespie has been in charge of the operation of the plant. Doubtless the water works man will ask why the plant was made of 12,000,000 gallons capacity for an estimated population of about 30,000. The reason for this is the abnormal daily average pumpage in the summer time, the daily average frequently running 12,000,000 gallons per day for a continued period of hot weather, with peak loads for four hours as high as 17,000,000 gallons per day in the afternoon, and on one day after the plant went into service lasting twelve hours. The average daily pumpage by the year has been about 6,000,000 gallons per day for the last ten years (Fig. 1), the effect of increase in population having been taken