The Water System of Columbia, S. C.

The Water System of Columbia, S. C.

For the past five years the inhabitants of Columbia, S. C, have enjoyed water second to none in purity and quantity, and if the expressions of water experts visiting the plant are to be valued, Columbia has an ideal water supply which would be a credit to many cities several times its size. When the plant was first put into operation the daily consumption of the city was only 1,500,000 gallons, but the daily consumption has now increased to 4,250,000 gallons which shows that the public has either learned to use more water in recent years, or that the city is growing very rapidly. Both probably account for the increase in consumption, for when such water was furnished as the old plant produced, no one had the desire to use any more than was absolutely necessary. While the plant is furnishing pure water it is also supplying it in such quantities and at such pressure as to attract the attention of the insurance underwriters. It has been on rare occasions during the past year that the steam fire engines were called upon to extinguish fires. During last year the filters were thoroughly overhauled and cleaned in order to preclude any possibility of contamination. The system of filtration is based upon the most scientific principles of modern construction. Sulphate of alumina is used as a coagulant to break up the muddy water; the alumina coming in contact with natural lime forms a hydrate which is insoluble. This insoluble matter in forming entraps whatever organisms may be in the raw water and is finally retained on the filter beds of sand and gravel and thousands of miniature siramers. Much work has been done on the uistribution system, principally of which are two intercommunicating eight-inch mains on Gervais street, and a 12-inch main on Huger street from the plant to Green street. This arrangement gives an increased volume of water in the western part of the city and also affords an auxiliary pumping main in case of accident to the main 24-inch line to the standpipe. Waterworks lot Columbia were first authorized in 1818, but a more modern plant was constructed in 1855, and the city replaced this w ith the present plant which w as put in operation December 26, 1906. The city occupies an area two miles square and is quite uneven in topography, the highest point being 150 feet above the Congaree river, which flows near its western boundary. The water supply is taken from the Saluda river, the water shed of which has an estimated area of about 2,475 square miles and contained in 1900 population of 127,000. The hydraulic power plant comprises two turbine water wheels of 300 horsepower, which operate two centrifugal pumps, each having a capacity of 12,000,000 gallons per day, and two power pumps having a capacity of 3,500,000 gallons per day against the maximum pressure head of 125 pounds contributed by the standpipe and friction in the distribution system. In addition to the hydraulic power plant there is an auxiliary steam power plant equipped with two pumping engines, each having a capacity of 5,000,000 gallons per day, the boiler plant for operating these being contained in the same building. This building also contains electrical generators which furnish power to operate the auxiliary machinery in the filter plant and for lighting the works. In addition to these pumping plants there are, immediately adjacent to them, a sedimentation reservoir, mechanical filter plant and filtered water basin; and at another portion, the city standpipe. The intake crib is constructed of concrete and is supplied with two 30 x 30-inch sluice gates, the opening being nro vided with screens constructed at the outer face of the wall. From the intake crib a 36-inch suction main is laid in the bed of the Congaree river for a distance of about 1,000 feet, w_____ch ends at the pumping station in a suction chamber, which also is constructed of concrete. The power station is a brick structure 29 feet 8 inches by 97 feet 2 inches. Here are two horizontal turbines, each capable of developing 309 horsepower when operating with full gate under a head of 18 feet and at a normal speed of 150 or 160 revolutions per minute. These turbines are duplicates and work independently of each other, having separate draft tubes discharging into separate tail-water chambers. Kadi of these turbines operates one centrifugal pump of the onestage type and having a capacity of 12.000,not) gallons per 24 hours against a total head of 75 feet (including 21 feet of suction) when running at a speed of approximately 500 revolutions per minute. These pumps lift the water from the suction chamber into the raw water reservoir constructed on a knoll at one side of the plant. The high duty pumps are two in number, of the horizontal, duplex, double-acting, plunger type, each with a capacity of 3,500,000 gallons per 21 hours against a head of 300 feet. The pumps are connected by gear wheels to the shafts of an independent turbine water wheel. The)’ pump the filtered water into the distribution mains and standpipes, taking il from the clear water basin. The reservoir which serves as a sedimentation basin has an approximate capacity of sixty million gallons when filled to within three feet of the top of the banks. It is built partly in excavation and partly in embankment, the banks having a top width of lu feet and side slopes of two to one. At its highest part the main embankment has a concrete core wall ranging in thickness from two to six feet. At one side is constructed a concrete gate chamber five feet square inside and 36½ Uet high, equipped with four 20 x 29-inch sluice gates. A tin-inch cast iron drain pipe is laid for the entire length of the reservoir and to this are connected a 24-inch outlet pipe and a 24-inch waste pipe. From the reservoir the water flows by gravity lo a coagulation basin 52 feet wide, 100 feet long and 18 feet deep. Sulphate of alumina is used as a coagulant. which with lime arc applied to the raw water wrere it enters the coagulating basin, the amount of coagulant being accurately regulated by automatic appliances. Close to the coagulation basin is the filter house, in which are two chemical tanks six feet in diameter and six feet high, with crates for holding the sulphate of alumina to be dissolved and an indicator gauge to show the amount of solution used per hour. The filter house is a brick structure 128 x 54 feet, with concrete floors. Here, in addition to the chemical tanks, are located the filters, which are six in number, of the mechanical gravity type, each having 490 square feet filtering area and designed for a capacity of 659,000 gallons per unit per 24 hours. The filtering material consists of 30 inches of sand on a 6-inch bed of gravel. The filtered water from these is discharged into the filtered water reservoir, and from this is drawn the wash water, which is pumped to and through the filters by means of two 50 horsepower centrifugal pumps, each direct connected to direct-current variable speed electric motors. The filtered water reaches the reservoir through a conduit beneath the center line of the building and a 24-inch pipe. The filtered water reservoir is oval in shape, with inside diameter of 211 and 171 feet, and a total depth of 14 feet, with a capacity of approximately 3,500,000 galons. The walls and bottom of this reservoir are constructed of concrete. The auxiliary steam pumping station is a brick structure divided into two sections, a pump room 14 feet by 60 feet and a boiler room 41 feet by 60 feet. The stack is of brick, five feet in diameter and 120 feet high. There are four horizontal, duplex, compound, condensing, direct acting pumping engines, each with a net capacity of 5,000,000 gallons per 24 hours against a pressure head of 288 feet, the suction lift being 12 feet. In this station is installed a direct-connected generating set, having a capacity of 500 kilowatts at 250 volts, the engine being of the horizontal type. From the highduty pumping engines the water is forced through a 24-inch rising main to the standpipe, which is located about one mile from the plant. This standpipe is of steel, 25 feet in diameter and 100 feet high. A cut-off valve is located near the standpipe to provide for direct pumping to the distribution system should this be necessary. The distribution system consist of 45 miles of cast iron pipe ranging in size from 6 to 20 inches.

OIL POWER WATERWORKS AT (OPEN HAGEN.

The two fire engine companies of Ovid, N. Y., have consolidated under the name of the Croton Hose Company. Charles P. Seeley was elected chief; his assistant is Dr. Harry Ogden.

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