WATER WORKS SYSTEM OF WASHINGTON

WATER WORKS SYSTEM OF WASHINGTON

The following is an abstract from a paper by the late Lieut. Col. A. M. Miller, Corps of Engieers, U. S. A., on the water-supply system of Washington: At the time of the original planning of the city, surveys were made under the direction of General Washington by Major L’Enfant to ascertain the practicability and feasibility of obtaining a full and good supply of water for the Federal capital. The Potomac river, Rock Creek and the Eastern branch were considered, as well as the numerous springs in and about the city. The first definite action in the matter was taken when in 1850 the 31st Congress appropriated $500, to which tne city subsequently added $1,000, to enable the War Department ‘‘to make such examinations and surveys as may be necessary to determine the best and most available mode of supplying the city of Washington with pure water, and to prepare a plan and estimate of the probable cost of same.” On January 25, 1851, the Secretary of War submitted to congress the report of Brevet Lt. Col. G. W. Hughes, corps of topographical engineers. This report discussed two sources of supply, the Potomac at Great Falls and Rock Creek; but owing to lack of sufficient funds surveys and detailed investigations were confined to the Rock Creek project. Col, Hughes proposed by building a dam to obtain front Rock Creek a possible supply of 8,000,000 gal. per dav and considered this adequate to supply the city for the following forty years, or until 1891. The population of Washington in 1851 was 40,027 and it was proposed to supply 1,500,000 gal. daily, or about thirty-seven gal. per capita. Col. Hughes said in reference to this: “This is the highest calculation I have seen, and is no doubt ample for uses for a city except for manufacturing purposes.” This project contemplated, in addition to the dam across Rock Creek, a sedimentation-basin on Meridian Hill and a distributing reservoir at nth and N streets, northwest. The surface of the water in the distributing reservoir was to be 147 feet above Ordinary low tide, or fifty-seven feet above the eastern base of the Capitol. Level in sedimentation basin 160 feet. The project and estimate for the present system, by which water is brought to the city from the Potomac at Great Falls, originated w-ith Capt. M. C. Meigs, Corps of Engineers, U. S. A., who, in the winter of 1852-3, made surveys and nrepared projects as authorised hy the 32nd Congress. Capt. Meigs’ report is embodied in Senate Ex. Doc, No. 48, 32nd Congress, 2nd Session. Projects with careful estimates and elaborate details were prepared showing the best mode of procuring this water supply. Congress agreed to a provision in the general appropriation bill approved March 3, 1853 appropriating “for bringing water into Washington, upon such plans as the President of the United States may approve, $100,000; provided, That if the water shall be taken from any place within the limits of Maryland, the consent of the State shall first be obtained.” The President of the United States adopted Capt. Meigs’ project, which contemplated a dam at Great Falls with a crest 145 ft. above high tide at Washington, a circular conduit of brick 9 feet in diameter with slope of 9 1/2 in. per mile, and two reservoirs; the first, or receiving reservoir, to be formed by damming Little Falls Branch about 4 1/2 miles above Washington, and the second or distributing reservoir to be located on the heights beyond Georgetown. The State of Maryland passed an act granting her consent, ceding jurisdiction over the lands to be acquired for the aqueduct, and authorising the appraisement and condemnation of lands in case the owners would not agree to sell on reasonable terms. The estimated daily capacity of the aqueduct as originally planned was 67,560,000 gal., and its estimated cost, including distributing mains to the various public buildings (which mains were to he used also for city supply) $2,271,244. The population in 1852, including Georgetown (8366) was 58,000. In 1859 the system was so far completed that water from Little Falls Branch was turned into the mains. On December 5, 1863. the conduit was completed and water supplied from the Potomac. Much trouble was caused by turbiditv in the receiving reservoir resulting from flood flow in Little Falls Branch; to avoid this trouble a by-conduit was built around the reservoir, the intention being to use the reservoir only when its water was in suitable condition. Subsequently, in 1845, this particular trouble was entirely cured by diverting the flow of Little Falls from the reservoir and discharging it directly into the Potomac. At first the diverting dam at Great Falls of rip-rap. extended across the Maryland channel only. At low stages of the Potomac constant difficulty was encountered in obtaining a sufficient supply of w’ater. This was partiallv obviated bv extending temporary dams above Conns Island, which was on the west side of the Maryland channel, and clearing out this channel by the removal of rock from the bottom. In 1886, this dam was replaced by a masonry structure extending to the Virginia bank of the river at a level of 148 ft. above mean tide at Washington and finally, in 1896, the crest of the dam was raised to a height of 150.5 ft. above the same datum. Under these conditions the capacity of the conduit was found to be 75,500,00c gal. per day when the water level in the distributing reservoir was held at 144 ft. In the report of the District Commissioners for 1907 appears the following: “The bill introduced in the last Congress providing for the transfer of the Washington aqueduct and filtration plant to the commissioners failed to become a law, and the commissioners earnestly recommended that such a law be passed at the next session of congress. The jurisdiction over the water-supply system is now placed by law under the chief of engineers of the United States army, while the jurisdiction of the water-distribution system is under the Commissioners. It would tend to much better administration if the entire water system was under one control. The division causes a division of responsibility, the duplication of work, and the employment of a duplicate force. Part of the water mains are under the control of the War Department and part under the control of the Commissioners. The water distributed flows from one set of mains to the other and back again in the supply of government and private buildings. The chief of engineers has recommended such a transfer.” This certainly was a very unsatisfactory method for administering the affairs of the water department and a change from it must tend to the betterment of the service. The present distribution system is under the control of W. A. McFarland, M. E. superintendent, who is assisted by J. S. Garland, C. E., and P. G. Melbourne, assistant engineer on construction The report of the committee of twenty of the Board of F’ire Underwriters gives the following description of the system: All water supplied to the District of Columbia is taken from the Potomac river at Great Falls, 14 miles above the city. A masonry conduit conveys the supply front a diverting dam at Great Falls to storage distributing reservoirs within the District. Owing to a range of elevations of about 400 ft., distribution is accomplished in five separate services. The low service is supplied by direct gravity flow from distributing reservoirs, the higher services by puntpage front low service reservoirs and mains, two of the latter services having equalising and distributing reservoirs of considerable capacity. The drainage area of the Potomac river above Great F’alls is 11,000 sq. miles, with a minimum stream flow of about 700,000,000 gal. per day. The river drains narrow precipitous valleys of the Allegheny mountains, and is subject to freshets, which render the water at times excessively turbid. A diverting dam spans the river above the Great Falls of the Potomac, crossing an island. It is a masonry structure of rectangular section. 7 ft. 9 in. to 8 ft. 3 in. wide, with rip-rap backing on upstream side, is 2,877 ft. long; average height 8 to 10 ft. with extreme of 20 ft. Length of spillway about 2,000 ft. at elevation 150.5. Water passes at the dam through a feeder and gatehouse to the conduit which leads to the city. The feeder is of masonry 256 ft. long, 9.5 ft. in diameter with invert at elevation I39-5terminating in a masonry gatehouse of substantial construction, where flow into the conduit is controled bv sluice gates, 2 ft. by 4 ft., at ten openings in a cross wall. The conduit for the greater part of its length is constructed 9 ft. in interior diameter either of rubble masonry, plastered, or of three rings of brick ; but where the soil was particularly firm the inner ring of brick wa; omitted, making diameter 9 ft. 9 in. Where the conduit is an unlined tunnel through rock the ex cavation is sufficient to contain an inscribed circle 11 ft. diameter. Masonry section built in excavation with a minimum depth of 3 ft. of earth cover. About 9½ miles below the gatehouse, the conduit connects with Dalecarlia reservoir at its northern end; thence flow is through this reservoir to its southern connection with the conduit about three-fourths mile distant, and conduit con tinues from latter ccnnection to the Georgetown reservoir about 2 miles farther south and the same distance north of the city. A gatehouse with valves is located just south of Dalecarlia reservoir. There is a by-pass conduit around Dalecarlia reservoir 2,730 ft. long and 9 ft. in diameter and one around Georgetown distributing reservoir 2,274 ft. long and 7 ft. in diameter. Conduit is under small pressure, being constructed just below its hydraulic grade line at a uniform slope of 9 in. in 5,000 ft. The water level is permanent ly maintained at the upper gatehouse at elevation 151. The normal elevation of water level at Georgetown reservoir (at the lower end of conduit), is 146, and when water stands at this level the capacity of conduit is about 65,000,000 gal. daily. With the level of Georgetown reservoir drawn down to elevation 144 the capacity of the conduit is about 76,000,000 gal. and with the water level at 140.7 the capacity increases to about 95,000,000 gal. To afford a distributing centre within the city limits a reservoir and tunnel to supply it from Georgetown reservoir were begun in 1884, but construction was suspended in 1888, resumed in 1898 and work completed in 1901. The tunnel is of horseshoe section, 9 ft. 2 in. by 9 ft. 10 in., about 4 miles long, lined with brick throughout. As it is under a static head amounting in places to 150 ft., lining was securely backed with stone and all interstices grouted with cement under 150 lb. pressure. As a further protection against ill effects of internal pressure the portion under Rock creek is lined with iron. Shafts at low points are provided with pumps so that the tunnel may be entirely drained. Capacity under 2 ft. head about 78,000,000 gal. a day, and under 4 ft. head 120,000,000 gal. a day. The tunnel is provided with gatehouse and shaft at each end. The combined area of the gate openings at upper gatehouse 62 sq. ft. There are five storage and distributing reservoirs and one standpipe, with combined capacity of 624,430,00c gal.; all but one service, provided with reservoirs. The first three reservoirs are in charge of Washington Aqueduct, the remaining smaller distributing reservoirs arc controled by the wafer department, District of Columbia. The Dalecarlia reservoir is located about 4)4 miles aoove Washington on conduit line; formed by damming Little Falls Branch, a tributary of the Potomac, with drainage of this stream diverted from reservoir. The dam is of earth with clay puddle core, 50 ft. top width, 40 ft. maximum height; slopes 2 to 1 unpaved, but exterior slope well sodded. The spillway is 75 ft. long at elevation 146.5, independent of dam. The reservoir receives supply from the conduit through a chamber at north end, provided with stop planks, so that the reservoir’ may be cut out of service and supply carried around it by by-pass; a similar connection is also made at south end. The masonry tunnel is 3 ft. in diameter under the dam, controled by a 48-in. sluice-gate provided for emptying reservoir. It has a capacity of 150,000,000 gal. The Georgetown reservoir is located 4 miles west of the city at the lower end of masonry conduit. It is constructed with three sides embankments and one side excavation. It is divided by a division wall with a 12-ft. opening closed by sluice gate. A 48-in. pipe across the lower basin provides for taking the water from the upper basin if necessary. The supply from the main conduit is through a gatehouse at the northeast corner and at the south end of the reservoir is another gatehouse through which the supply is discharged into the low service distribution pipes. The capacity of this reservoir is 150,000,000 gal. Washington city reservoir is located in the northern part of the city and is formed by damming a small valley and excavating at upper end diverting the surface drainage. The dam is 40 ft. high, 140 ft. wide on top and 1,200 ft. long. It is built of earth with puddle core. This reservoir supplies the low service distribution and Trumbull street pumping station. Its capacity is 285,000,000 gal. Brightwood reservoir has an elevation of 276 ft. and was constructed in 1901. It is formed of concrete retaining walls with heavy earth embankments and has a capacity of 34,000,000 gal. Reno reservoir has an elevation of 423 ft., the highest point in the district, and has a capacity of 4,500,000 gal. It is of concrete construction and gatehouses on two sides control the inlet and ontlet pipe. Water is furnished the high pressure fire system from this reservoir. The Reno standpipe is an elevated steel tank supported and enclosed by a circular brick tower 70 ft. high and walls 24 in. thick below the tank carry eleven 24in. steel beams and concrete arches, forming floor for support of stanapipe 27 ft. above the ground. The walls closing the tank are 18 in. thick. Bed-plates and plates in the lower half of tank are 1/4 in. thick; above this thickness is 3-16 in. The tank is filled by pumps worked by gas engine, located beneath the tank, a single 8-in. pipe serving for both influent and effluent. The pumping plant consists of four engines at U street station with a combined capacity of 16,000,000 gal. per day; two engines in’Trumbull street station of 20,000,000 gal. capacity each, also an 8,000,000 Barr engine to supply the second high-level service; a 5,000,000 Nordberg pump to supply second or third high-service and a new Holly pump of 2,500,000 gal. capacity in reserve. The total pumping capacity in this station is 50,500,000 gal. Reno pumping station has two small triplex gas engine pumps of 540gal. combined capacity per minute and the filter station pumping plant has centrifugal pumps of an aggregate capacity of 40,000,000 gal. Two pumps of 2,500,000-gal. capacity each furnish water for washing filters and fer fire protection. The pumps at the Reno station standpipe are of the Gould pattern and the new engines at the Trumbull street station were furnished by the AllisChalmers company. The pumping engines at the Trumbull street station discharge in a 48-in. cast iron force main in Le Droit avenue, which extends 3,000 ft. in Florida avenue, where it supplies two 36-in. pipes, one extending easterly 10,000 ft. to the distribution system on Capitol Hill, the other westerly 800 ft. to a connection with a 48-in. main. 1 he pumps at U street discharge into the distribution system through mains varying from 12 in. to 20 in. diameter with connection to Brightwocd reservoir through a single 36-in. force main 2 miles long; to Reno reservoir through 2 1/2 miles of 12 in. and 1 3/4 miles of 20in. cast iron pipe. The average daily consumption is 67,000,000 gal. and the population which is a little ever 300,000 gives a daily per-capita consumption of 221 gal. This excessive use of water in a non-manufacturing city is attributed to leaks and waste, over twenty-five per cent, of the services have leaky fixtures. The average normal prsstirc in the business centre is 40 lb. There arc five services in the system as follows: The low service supplies the greater part of the city, including the congested value and minor mercantile districts as well as practically all of the manufacturing establishments, the latter in this city comparatively unimportant in extent and value. The high-pressure fire main system for the protection of this district has been designed by the water department. The first high-service system is supplied by direct pumpage from Trumbull street station and furnishes a thickly settled residence section 011 Capitol Hill in the easterly part of the city, with an estimated population of 45,000. The second high-service system is supplied from Brightwood reservoir at an elevation of 276 ft. and furnishes a large section in the northern part of the city, with a population of 70,000. The third high-service is supplied from the Reno reservoir and the fourth high-service supplies a section in the western part of the district from the Reno standpipe too high to lie served from the reservoir. There are 430 miles of pipe in the distribution from 48 to 3 in. in diameter; 4,958 gatevalves of the Eddv pattern and 2,458 hydrants, of which 1,120 arc McClelland pattern; 500 Harg, 400 Dent, 130 Glamorgan and 300 of the A. P. Smith high pressure type. These latter have gate in connection between street main and hydrant and an auxiliary foot valve which opens with first turn of stem and relieves pressure, which enables one man to open the hydrant against 300 lb. pressure. The Smith hydrant is specially designed for use on the proposed high-pressure fire mains.

INTERIOR PUMPING STATION, WASHINGTON, SHOWING 20,000,000-GALLON ENGINES.ONE OF THE BRIDGES ON LINE OF WASHINGTON AQUEDUCT.

WASHINGTON FILTRATION SYSTEM.

The new sand filtration plant is situated in the rolling hill lands lying to the north of the city, some 2 miles distant from the Capitol. It covers a space of forty acres comprising twenty-nine lillerbcds. pumping stations, gatehouses, storehouses and a chemical laboratory where daily analyses of the water are taken. The construction, which took two years and a half to complete, was supervised by the Engineer corps of the United States army. The results of tillering the water are already manifest in the lessening of sickness througout the whole city. For the last fifty years the supply has been obtained from the Potomac river at Great Falls about 14 miles above the city. Recently the filtration plant was constructed and at present about 70,000,000 gal. of water per day are treated. The water flows through an aqueduct from the source of supply with a slope of gin. per mile and passes through two reservoirs before reaching the distributing or Washington city reservoir. The first reservoir is 9 miles below Great Falls and is formed by damming a natural valley. The second or Georgetown reservoir, 12 miles from Great Falls is built with embankments on hillsides, on a rectangular plan. More recently a tunnel has been constructed from the Georgetown reservoir to a central point in the city near Howard university, and a third reservoir, the Washington City reservoir, has been built at the end of the line. The capacities of the three reservoirs from their bottoms to the nominal flow lines, are approximately 150,000,000, 150,000,000 and 300,000,000 or a total of 600,000,000 gal. The main pumping station is located at Bryant and Adams streets. In this building are the pumps, which supply raw water under high pressure for washing and transporting the sand; an electric light plant; boilers and other auxiliary machinery. The main pump ing is done by three centrifugal pumps, directly connected to Harrisburg engines, all furnished by Henry R. Worthington. These pumps at the minimum lift are guaranteed to deliver 40,000.000 gal. per twenty-four hours. They have, however, actually delivered more nearly twenty-five per cent, more than the guaranty. Two pumps are used for sand-washer water, each w ith a capacity of 2,500,000 gal. per twenty-four hours with too pound pressure. The pumps are compound and are designed to stand rapid fluctuations in rate and pressure, and not with a view to give the greatest economy. The total sum appropriated for the cost ot the filters was $3,468,405. The cost of the pumping station was $183,600, The filters arc immediately adjacent to the Washington City reservoir. Water is pumped direct to the filters and passes thence through regulator houses to a pure water reservoir holding about 14,000,000 gal. The waste drainage is in general taken to the sewers of the District of Columbia; but arrangements have been made so that part of the waste, which is of good duality, can be returned to the Washington City reservoir, thereby adding to the net capacity of the aqueduct. All the masonry structures are of concrete and the general design follows closely that of the Albany filters. The floors are of inverted groined arches carrying piers with a slight batter near the bottom. The walls are concrete, built in sections not exceeding 30 ft. long, the joints being tongtted and grooved. The storage compartments are of reinforced concrete, cylindrical in form with conical bottoms. They are supported on circular concrete foundations carried well below the frost line. Each division holds 250 cu. yards as it can ordinarily be filled, which is not quite to the top. One part of sand to three or four parts of wat r is employed in the process in each of these compartments. The sand settles at the bottom, and the water rises until they are half full. It then overflows through an outlet pipe at this level until the water reaches a similar height m the adjoining compartment. The gate on the first outlet is then closed, and the process is repeated by using a second outlet almost at the top of the filter. Plans and specifications for the more important parts of the plant were completed in December, 1902, and adopted; and proposals were received in January. 1903. The prices in these proposals somewhat exceeded the preliminary estimates upon which the appropriation was based, and all the proposals were rejected. As a result, a contract for about halt the work, comprising most of the masonry, earthwork, grading, etc., was awarded to Cowardin, Bradley, Gay and company; a contract for the piping, drainage and some other parts to the Brennan Construction company and a contract for the filter, sand and gravel to L. E. Stnoot.

GENERAL, VIEW OF RESERVOIR AND FILTRATION PUMPING STATION, WASHINGTON.SHOWING ARRANGEMENT OF FILTERS WITH OPENINGS TO BEDS.

Under subsequent proposals, contracts for pumping machinery were awarded to Henry R. Worthinglon; for boilers, to Babcock and Wilcox company; for valves, to the Coffin Valve company; for Venturi meters, to the Builders Iron Foundry: for special castings, to the Wilkinson Manufacturing company; for sand washers, to the Norwood Engineering company; and for sand bins to Rudolph S. Blome anil company. The late Col. A. M. Miller was in charge of the work from its inception until his death on September 18, 1904; Captain W. P. Wooten was in direct charge of the work under Col. Miller’s direction and succeeded him temporarily. Col, Smith S. Leech took charge of the work in November, 1904, Capt. Wooten remaining in direct charge of the filter plant. On August I, 1905, Lieut. Col. R. L. Hoxie succeeded Col. Leech in charge of the work. Lieut. E. J. Dent was assigned to the work and succeeded Capt. Wooten in direct charge of the filters May 10, 1905. Capt. Spencer Cosby succeeded Col. Hoxie in December, 1905, and is now in charge. Allen Hazen, C. E., who superintended the operations, and 1C. D. Hardy, C. E„ have been connected with the work up to the present time. Since the completion of the filtration system the relative turbidity of the water has been cut down from 36 as received at its source at Great Falls to 1 3-10, and the bacterial efficiency is ninety-nine per cent, per cubic centimetre. The plant is of the English type, and each filterbed occupies an acre. Each one resembles a lofty vaulted stone room built underground, as shown in the illustration, the roof being sup ported by numerous arches, with glazed openings, resembling manholes, that admit light. Their coverings can he lifted off, so as to admit of fresh sand being passed through them into the beds when they are cleaned. The walls and roof arc of concrete, and the pillars, which are of the same material, are built at intervals of about 10 ft. The height from floor to floor is also 10 ft Over the concrete floor, before filtration begins, are laid 6 in. of crushed rock and 3 ft. of sharp white sand, and through this the water perco lates when the filter is filled. Between this rock and sand and the roof about 5 ft. of water rests At night the beds are lit up by electricity, and outside the thick concrete walls are embankments of earth. The filters mav be cleansed, when necessary, without much difficulty. The surface of the bed accumulates mud, and a film of a gelatinous nature settles upon it. This is -the residuum of clay and mud left behind on the sand, after the water has percolated through, and so long as it is not allowed to get too thick it serves as a filtering agent and helps to reduce the bacteria and other foreign material that might otherwise pass through. It is in reality a blanket on the top of the sand, and is known to the Germans by the words “schmntz decke.” In time it becomes too compact and stops the filtration process. The water is then drawn off, and workmen scrape off the scum with ordinary shovels. The men, standing on broad, fiat “mud shoes” of leather, carefully scrape off the top of the white sandbed overlain by the “sclunutz decke,” the fine edge of the shovel being inserted about a quarter or half an inch at most into the sand. The whole surface having been scraped in this way to the depth of about half an inch, and every particle of mud having been removed in the wheelbarrows, the filter is ready for use once more. The whole process occupies only a few hours, and the work can be accomplished by unskilled labor. This scraping is necessary about once in every thirty days, and at that rate it takes something like two years before the 3 ft; of sand is so reduced to 2 ft. in thickness as to require renewal. The sand thus removed can be used again, and is collected on the roof of the filterbed to be washed by an automatic cleaning device attached to each bed. With it will be connected a means of ejecting hydraulically the sand scraped from the filters to this washing device, which is an iron chamber through which the sand, in passing, is thoroughly cleansed by being sprayed with filtered water. The mud runs off into the sewers, and the sand is removed to storage for future use. Before the Potomac was filtered it contained from 740 to 230 bacteria to the cubic centimetre; after filtration only from 117 to 60. In the fall the average turbidity of the water, as received at Great Falls, is thirty-six parts of suspended matter in 1,000,000: after filtration, 1.3 per month. Each of the filters clarifies on an average 3,000.000 gal. a day, and, as Washington’s daily consumption averages 68,000,000 gal., twenty-three filters onlyneed be used, leaving six for reserve purposes and to be operated while others are being cleaned. The filters are built alongside of the city reservoir, whose capacity is 70,000.000 gal. It is the last of three reservoirs that bring the water down from the Great Falls—a distance of sixteen miles. The capacity of the first at Dalecarlia, ten miles below the falls, is 82,521,500 gal. It is used both as a storage and sedimentation basin. Two miles above Washington, on the heights above Georgetown, and connected with the first reservoir by a continuation of the conduit, is the second, or Georgetown reservoir, from which the water comes to the city distributing reservoir at the filter plant through a 4-ft. conduit. The combined capacity of these three reservoirs is 300,000,000 gal. Although the quality of the water has improved considerably before it reaches the city reservoir, and is still further improved by settlement there, it is still very undesirable for domestic use. It is, therefore, pumped from that reservoir through 72-in. and 52-in. rising mains, with 20-in. branches, on to the filterbeds, where it filters slowly through the 3 ft. of sand at the rate of about 3 vertical inches an hour. An underdrainage system collects it, and it is carried by piper to the regulator house, in which are the valves for regulating the rates and operating the filter. From that house it is conveyed to the reservoir for filtered water, the capacity of which is 15,000,000 gal., and distributed throughout the city. The accompanying illustrations show the interior of one of the filtration beds, over whose concrete floor is a layer of 6 in. of crushed rock and 3 ft. of sharp sand, through which the water percolates, and the top of a filterbed before it is covered with soil and sodded, showing the moulded concrete manholes already described.

INTERIOR OF FILTER BEFORE SAND COVERING WASHINGTON.SHOWING ROOF OF FILTER BED WITH CONCRETE MANHOLES AND WOODEN MOULD USED IN MAKING THEM, WASHINGTON.

DISTRICT PUMPING STATION.

The district pumping station is located on Bryant street, near Second street Northwest, immediately south of the new city reservoir and filtration works. It is used for pumping to such parts of the district as are too high to be supplied directly by gravity from the clear basins of the filtration plant. 1’his section includes all territory having an elevation of 70 ft. above mean tide. The station building, which is built of brick and Vermont blue marble, is 256×148 ft. in plan, and in addition to the pumping plant proper it contains machine, carpenter, pipe-fitting and paint shops, meter-testing room, store rooms and a number of office rooms. The pumping equipment consists of two 20,000,000 gal. vertical triple-expansion engines, with double-acting outside-packed plunger pumps operating against a net head of 75 ft.; one 7,000,000 cal. horizontal tripleexpansion engine with double-acting outsidepacked plunger operating against 170 ft. head, and one 2,500,000 gal. vertical triple-expansion engine with single-acting plungers operating against 375 ft. head. There are also a 12,000,000 gal. vertical engine for 175-ft. head and a 30,000,000 gal. vertical engine for 75-ft. head. These engines werde manufactured by the Norberg Manufacturing company of Milwaukee, Wis.; the Barr Pumping Engine company, of Philadelphia; the Allis-Chalmers company, of Milwaukee, and the Holly Manufacturing company, of Buffalo, N. Y. The first engines were installed in 1903 and others were placed in service as occasion demanded. As previously stated, the first high-service pumps directly into the water mains supplying Capitol Hill and that portion of the city lying between L street and Florida avenue, Northwest. The second high service pumps into the Brightwood reservoir, which has a capacity of 35,000,000 gal., and the third high service pumps into the Reno reservoir, Tenlcytown, which has a capacity of 4.500,000 gal. fhe pumping station described is the only one in the District.

SEVAGE PUMPING STATION.

The sewage pumping station is located at Second and N streets, Southeast. The building is of concrete foundation and brick superstructure, and is 275×125 ft. fhe construction, which was commenced in 1902, was completed in 1906 under the direction of the architects Giddett & Vogt, of Washington, D. C. The engines installed in the building are triple-expansion with centrifugal pumps, comprising eight storm-weather pumping engines, with a capacity of 65,000,000 gal. a day; three sewage-pumping engines of 65,000,000 gal. a day, and two sewage-pumping engines, each having a capacity of 20,000 gal. daily. The engines were manufactured by the Allis-Chalmers company and cost $253,000. The engines pump 150,000,000 gal. a day, all of which is discharged into the Potomac river, thus handling the entire sewage of the city.

HIGHPRESSURE SYSTEM.

The high pressure system for fire protection in the principal part of Washington was tested recently with a considerable degree of success. Chief Engineer William T. Belt of the lire department furnishes the following particulars of the test to FIRE AND WATER ENGINEERING, It shows very good results. He says: The proposed high pressure, gravity fire system for Washington is designed to utilise the water from the Mort Reno reservoir, which is 415 ft. above mean tide-level. There is a fall of seven miles front this reservoir to the area which it is proposed to protect. The idea is to lay four large trunk mains, the main feed to IK36 in., with laterals of 24 in., and 12 in. The hydrants for this system are to be located not more tnan two hundred ft. apart. They were made by the A. P. Smith Manufacturing company. The area which it is proposed to protect is eighteen city blocks long and eight blocks wide. As an auxiliary, the 26-in. main feedpipe will be connected to the large pumps in the city pumping station. At the present time there is one high-pressure fire-hydrant, with one 4 1/2-in. and two 2 1/2-in. outlets, connected to a 12-in. maint which is fed from this reservoir. This hydrant is located eleven squares north or higher than the highest point of the area which it is proposed to protect with the high pressure system. At recent tests held from this fire hydrant the following results were obtained. The water pressure on this hydrant was taken before the test and found to be 165 pounds. First test, two single lines of hose, connected to a monitor pipe on hose wagon, with 1 1/2-in. nozzle. Stream thrown 256 ft. The same lines connected to the same pipe with 1 3/4-in. nozzle, threw a stream 240 ft. The same lines connected to the same pipe, with 2-in. nozzle, threw a stream 200 ft. Second test, two lines of 2 1/2-in. hose, siamesed into one 2 1/2-in. hose leading to a water tower on a sevc-nty-five-ft. ladder, with 1 1/2-in. nozzle. The stream was thrown a distance of 198 ft. Third test, eight single lines of 2 1/2-in. hose, with i-in. nozzles. These eight streams were thrown a distance of 182 ft. Fourth test, three lines of 2 1/2in. hose, siamesed into a three-way deluge set, with 2-in. nozzle. The stream was thrown a distance of 255 ft. Fifth test, three lines of 2 1/2-in. hose, siamesed into two three-way deluge sets, with 2-in. nozzles, making three streams. These streams were thrown a distance of 195 feet. Sixth test, four lines of 2j4-in. hose, siamesed into two two-way deluge sets with 2-in. tips. Water thrown a distance of 252 ft. Seventh test, six lines of 2 1/2-in. hose, siamesed into three two-way deluge sets with 1 1/2-in. tips. Water thrown a distance of 198 ft. Eighth test, six lines of 2 1/2-in. hose, siamesed into two three-way deluge sets, with 2-in. nozzles, making three streams. Water thrown a distance of 195 ft. During the tests mentioned the pressure 011 the hydrant was used from 60 to 117 1/2 pounds.

INTERIOR OF FILTER SHOWING CONCRETE FLOOR, WASHINGTONHIGH PRESSURE FIRE SERVICE AT WASHINGTON. TEST OF ONE SMITH HYDRANT THROWING EIGHT STREAMS.

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