April 10, 1913: Engineering News article. Conditions of Small Water Purification Plants in Illinois. By Ralph Hilscher. “In Illinois there are about a dozen water purification plants with rated capacities of about 2,000,000 gal. per day, or less, which involve the use of coagulants, settling basins and filters. Of these, with possibly two or three exceptions, It can be said that none produce an effluent that attains at all times the standard of purity that any municipality should demand for Its public water-supply. Some of these plants yield an effluent during the major part of the time, which is of quite satisfactory quality, but fall far short of successful operation during periods of excessive turbidity and color in the raw water. Others produce an effluent at no time that is of good appearance and satisfactory from a hygienic standpoint.
The poor results realized are due largely to certain faults in design and operation, which are more or less common to these small installations. Many of the plants are of obsolete design and in practically all the plants, too great economy was attempted in building and certain essential features were omitted. The operation has usually been deficient due to lack of experience and expert advice In such matters. Certain faults largely responsible for the short-comings of these plants will be discussed [in the larger article].
Reference: Hilscher, Ralph. 1913. “Conditions of Small Water Purification Plants in Illinois.” Engineering News article 69:15(April 10, 1913): 707.
Commentary: The image of the double-plunger angle blowoff valve has nothing to do with the article about small water treatment plants. It was just a cool drawing in the same issue of Engineering News.