Canton (O.) Sewage Disposal Works.
The very elaborate sewage disposal works at Canton, O., have attracted the attention of engineers and municipal authorities everywhere. The chief engineer of the construction of this remarkable plant is L. E. Chapin, assisted by Engineers Bender and Pfouts. We are indebted to Mr. Chapin for the very excellent illustrations that accompany this article. The story of the construction of the system is interestingly told by Mr. Chapin in a communication to the Board of Sewer Committee. Among other things he says:
The works have been designed and built for purification of house sewage by chemical precipitation, the precipitating agents, lime and sulphate of alumnia, being added to the crude sewage in certain specified quantities, and the whole thoroughly commingled, after which the sewage so treated is allowed to pass slowly through the precipitating tanks, where the heavier matters fall to the bottom and the clarified effluent passing off over a series of steps in the effluent chamber to the main effluent sewer and then to the creek.
The works are located in the northeast part of the twenty-eight acre tract of land purchased in 1888 for a sewage farm, the sewage being carried into the works by a by pass known as the inlet sewer,” and from the works by an effluent sewer back to the main sewer and thence to the Nimishillen creek. The plant consists of a building for machinery, an inlet screen chamber for removing papers and bulky matters, an inlet channel, leading from screen chambers, the four precipitation tanks, an effluent chamber and sewer and a sludge well. The building is a two-story frame structure divided into a mixing and press room, thirty by forty feet and twelve feet high in the clear, with a chemical storeroom of the same size above, and into which the chemicals are delivered by a bridge from the bank drive, also a boiler room twenty-eight by thirty-five feet, which is lined with brick, and under the floor of the boiler room and next to mixing room is located the screen chamber. The second floor of mixing room and the main roof is supported by heavy trusses designed to support a weight equal to fifty tons of chemical, a span of horses and wagon, as well as a 2000 gallon overhead water tank, in which is stored the water for steam and mixing uses.
The gate and screen chamber is three feet deep, eight and one-half feet wide and about fourteen teet long, divided by a longitudinal partition into two compartments, each having an iron screen, through which the flow of sewage is regulated by sliding flume gates, the rear of the gate chamber narrowing down to four feet in width and forming the inlet channel. The sides of Inlet channel and gate chamber are of twelve-inch brick masonry resting on an eight by twenty-inch brick footing course, the bottom of the channel having a pavement of five inches concrete, then one-inch sand, then paving brick on edge, the joints and spaces being grouted with Portland cement.
The tanks are four in number, with provision made for future requirements by opportunity to extend to the west. They are each fifty by ninety-six feet inside dimensions, and walls ranging from 5,75 to 7.58 feet high above the bottom pavement. The bottom of each tank has a slope of one in forty from rear to front, and also from sides to central sludge channel, which is two feet wide, being two inches deep at upper end and fourteen inches deep at lower end, below bottom of paving. This paving is hard burned shale paving brick on a one-inch sand cushion, with a five-inch concrete foundation, the brick being well grouted with neat Portland cement grout and forms a practically smooth surface.
(To be Continued.)