ROCHESTER AND LAKE ONTARIO WATER PLANT
Specially written for FIRE AND WATER ENGINEERING.
The city of Rochester. N. Y., has two sources of water supply, the municipal from Hemlock lake, and the Rochester and Lake Ontario Water company, the latter supplying the suburbs of the city and several large railway and other companies. The industries in and about the city consume 22.000,000 gal. of water daily. Those within the city limits are supplied from Hemlock lake by the Rochester city system; while those without the city limits receive their supply from the Rochester and Lake Ontario Water company. Between the two systems the supply is almost limitless and the quality superior. It may fairlv be claimed for the Rochester and Lake Ontario Water company that it is responsible for the great growth of the number of large manufacturing plants just outside the city limits. The company is but a little over three years old; but it now supplies to its patrons over 3,500,000 gal. daily and has contracts that by July of this year will add another 1,500,000 gal. to its output. At present the capacity of the plant of the Rochester and Lake Ontario Water company is 10,000,000 gal. daily and the work of development is being constantly pushed. This company must necessarily be considered one of the great factors in the future development of the city’s manufacturing interests. The company’s source of supply is lake Ontario and, therefore, unlimited. The quality of the water is excellent for all purposes ; but, to make assurance doubly sure, the company has the finest known modern methods of filtration, and the whole of the filtration is supervised by Prof. James M. Caird, of Trov, New York, one of the most eminent bacteriologists in the State. The 24-in. intake-pipe goes 4,coo ft. into the lake to a depth of 35 ft. of water. The pumping plant consists of the following: Two Corliss engines, cross-compound, flywheel type, direct-connected pumps; eight Ledoux mechanical force-filters, direct-pumping to the standpipe, which acts as an equaliser of pressure. At the pumping station the start is made with a pressure of 210 lb.; at the highest point it is 60 lb.: the rest of the system is 90 lb. The standpipe is 410 ft. above iake Ontario; it is constructed of steel; it is 150 ft. in diameter, 20 ft. high and is erected on a stone and concrete foundation. There are 12 miles of 20-in. forcemains and 7 miles of 12-in. There are, also, 15 miles of lateral mains consisting of 6-in.. 8-in. and 10-in. The territory the company supplies consists of the towns of Greece, Gates, Brighton, Pittsford and Penfield; also, the villages of East Rochester and Pittsford, which have their own systems of piping and furnish their own fire hydrants—about eighty in number. The company supplies ty-first ward in the city of Rochester, in which ward it has set 26 fire hydrants. There are also twenty-four hydrants set in various parts of Brighton and Gates. At the present rate of pumping there are used 3,500,000 gal. per day; but the company has contracts booked that will use up to 5,000,000 gal. during the coming summer, and it expects very speedily to enlarge the plant, as its total capacity is only 7,000,000 gal. per d a y. The plant was designed by Mr. J. W. Ledoux, chief engineer of the American Pipe Manufacturing company, of Philadelphia, and constructed by that company under the superintendence of Mr. James H. Dawes in 1904. It is certainly a credit to all concerned, as it is one of the most efficient and up-to-date plants in the country. The officers and directors are as follows: President, H, B. Mingle, New York City; vicepresident, Joseph S. Keen, jr., Philadelphia, Pa.; secretary and treasurer, George K. M. Clarke, Rochester, N. Y.: directors, H. B Mingle, Joseph S. Keen, jr., George M. Bunting and Horace A. Doan, Philadelphia; William F. Balkani, George E. Merchant, Edward Harris, sr., Jacob Gerling and Bernard Dunn, Rochester, N. Y. The following data were furnished by Mr. J. W. Ledoux. The suburbs of Rochester are supplied with water by the Rochester and Lake Ontario Water company whose works were designed and constructed by the American Pipe Manufacturing company, of Philadelphia, Pa., in 1903. The pumping station is located on the shore of lake Ontario, about 2 miles west of Charlotte. Water is taken from an intake-crib located at a point about 3,800 ft. from the shore, where the water is 30 ft. deep. The intake-pipe is 24-in. in diameter and is laid in a trench averaging 4 ft. deep. The Buffalo Dredging company had the contract for laying the pipe. Each section containing six 12-ft. lengths of pipe was jointed complete on a scow and lowered in place, and the connection between this and the succeeding section consists of a flexible joint made by divers. Close to the pumping station is a suction-well, the bottom of which is 14 ft. deeper than the intake-pipe which turns down at this suction-well, and, by exhausting the air at the top, enables the intake to act as a syphon and supply the maximum capacity. The pumping station is built of Medina sandstone. The floor of the pumpingroom and its basement are of cement, the former being laid on I-beam construction. The floor of the boilerroom is of brick, of the filterroom, of cement. The roof is of slate, the roof trusses, of structural steel. The pumping machinery consists of two horizontal, condensing, cross-compound crank and flywheel Corliss pumping engines, having a capacity of 3,000,000 gal. each; the water-plungers being ti in. in diameter and the stroke 30 in. The condensers are of the surface-type located on the suction-pipe. There are three Babcock & Wilcox water-tube boilers, which contain approximately 3,000 sq. ft. of heating surface. Connected with the discharge-piping system in one corner of the pumpingroom is an airchamber 6 ft. in diameter and 12 ft. high, kept full of air by means of a small Westinghouse locomotive air-compressor. The top of this airchamber is also connected by means of small pipes with the individual air-chambers of each pumping engine; the result is that the variation of pressure itt the long pumping-main is reduced to a minimum, and this danger is further reduced by means of a relief-valve located on the puntp ing-main and discharging into the suction-well. The usual pumping water-pressure is approximately 275 11). per sq. in., and the steam-pressure is maintained at about 150 lb. per sq. in. The filters are of the pressure-type, eight in number, each 8 ft. in diameter by 25 ft. long, containing approximately 1,528 sq. ft. of filter-surface. The strainer-system is composed of perforated brass pipes covered with brass gauze, and the sand known to the trade as between No. 16 and No. 30 gauge. Washing is done by simple reversal of current, one filter being washed at a time. The stack is of brick, too ft. high and 5 ft. in internal diameter, constructed by H. R. Heinicke. according to their standard designs. The pumping engines and filter plant were furnished and erected by Robert Wetnerill & Co., of Chester. From the pumping station to and through the city of Rochester to Cobb’s Hill, the pipe is 20-in. cast iron. From the eastern city limits of Rochester the pipe is of t2-in. diameter, the total distance from the pumping station to Fairport being 20.4 miles. At Cobb’s Hill is erected a steel reservoir 150 ft. in diameter, and 20 ft. high, holding approximately 2,600,000 gal.; the elevation of the water, when full, being 650 ft. above tide. The main elevation of the lake is 246, and the elevation of the floor of the pumping station is is quite 255 ft. During the flood-season the Genesee river which flows through Rochester, carries a great deal of sediment and impurities, and with a strong west wind the lake becomes seriously roiled for several miles west of Charlotte, so that the complete purification of the water is hard to accomplish by filtration alone during several weeks of each year, the main trouble being that the coagulant does not affect the water immediately. To obviate this difficulty, it is decided to erect at a point near the pumping station a coagulating basin, and, until this could be accomplished, a temporary wooden structure 200 ft. long, 50 ft. wide and 6 ft. high was constructed, and, in connection with this, a low-lift centrifugal pump was placed in the basement of the pumping station. Water is drawn from the intake-main and pumped into one end of this wooden tank, and coagulant in the form of sulphate of alumina is discharged into the same point. The water then circulates past baffles to the oposite end of the tank, from which it is drawn out and discharged into the suction-well. This apparatus has proved very successful and will accomplish the purposes for which it is intended until the large sedimentation-basin is later built. Some of the principal large consumers of the water company arc the New York Central railway, which takes water at several points within the city of Rochester— also, at b’airport, Despatch, Brighton and Charlotte; the B. R. St P. railway; the Eastman Kodak Works, and many other large manufactories. I’hc present consumption of water averages about 3,500,000 gal. per 24 hours. An analysis of the raw lake water is as follows: Total solids, 141.5; silica, oxide of iron and alumina, 11.34; calcium sulphate, 21.64 • calcium carbonate, 62.6; magnesium carbonate. 25.78; sodium chloride, 13.18; nitrogen as nitrates, traces; nitrogen as nitrites, none; free ammonia, none; albuminoid ammonia, traces. The number of bacteria per cubic centimetre in the raw water of the lake varies from 1,500 to 12,000.