City Water Works

Underdatt of July 5 Prof. C'. E. Gieene, cliosei) as engineer !iy tlie special comralttee on city water wtuks selected by the Mayor, subinittetl to the committce li s report of incthods for flirntabbig tlie city of Aun Arbor witli an abundan! supply of water, traiismiltiug thefewlth a plan lbowing the location of tlie various points reterred to, and tlie system of plptöjf and hydrants proposcd tor the city. The followlng is r gtimmary of the report : Iiecognizing that in any estímate liberal provisión for future needs shouUi be made, Professor G reene calis the present populatiou of the city 0,000, and estimates that pumps, pipes, etc., should be calculated on a prospective increase of (63 % , or for a populatiou of 15,000, and maximum daily consumption of 66% gallons per inhabitant, making a maximum daily supply of 1,000,000 gallons. If a smaller quantity is thought stifürient, some reductions in the estimates can be made. The source of water supply beiug the lirst question, the feasibility of Keuring the water from Whitmore Lake, nine miles away, and from Base Lafce, about twelve miles distant, is refeired to. Both lakes are about 100 feet above the court house square, Whitmore wlth litlle orn visible outlet, and Base Lnke witli a con stant streain flowing through it. A con duit for eonveying water from either o these lakes would be very expensive and the head would not be suffleient at Am Arbor without the use of pumps. I pumps are to be used, it is better am more economical to get the supply, i possible, nearer at hand. A nine mile 16 inch pipe would oost, Iaid, from f l0, 000 to $125,000. The water must then be taken first dircctly from the river, through a prope filtering medium, or second, indirectly from a well or from tubes sunk inlo tht ¦and and gravel near the river, or ihird by nteicepting springs and some drain age área naturally tributary to the river through a wall drain if thonght neces sary. If a reservoir, stand-pipe, or tank is used, it should be placed 011 the highes ground, wfiich is just outside the city limits, on the northwest, near Chubb street This is 155 feet above the court house square, and 112 feet above the University campus. It is 220 feet above the surfaee of the water in the the river at the nearest point, Cascade filen, wliich Í9 2,7(0fee distant. From this reservoir site to tlie corner of Main and Huron streets,mostly by the public streets, is about 7,100 feet. If the water is to be taken from the river, either directly or through an adjacent filter well, and pumped by steam to this reservoir, the pumps should be at or mar Cascade Glen. If to be pumped by vvater-power, the dam maybe in the same location, or at the upper railroad bridge (the old McMahon power), or at the lower raiiroad bridge, near the Whitmore Lake road. Either of these locations wonld require from 1,800 feet to 2,000 feet more of rising main, at a cost of Trom $3,700 to $5,400 iccording to size, and not including additional cost of pump power. If dependence is to be placed upon grouud water solely, Prof. Greeue doubts whether Cascade Glen would be a desiradrained'tlícfe ís"smafi, "the suppiy would be Umitod in amount, therefore, and the water is probably morethan usually hard The quanlity of water thrown into the stream on the est side of the city, from the country southwest of jhe Chubb road, would probalily not be suffleient. A pumping engine 1 ere, too, must be supplied with coal hauled by wagons. Lower down, the streams and springa from the vvestward are charged with i ron. At the upper railroad bridge quite a flow of water comes iti from the west and the quantity could doubtless be increased by ditching and tile-draining Neither tlie season uor time of year are favorable for determining the minimum flow. Water in greater abunJance apparently thau at either of the other places and ol excellent quallty, can be obtaineci on the uorth side of the river, west of and near to the Whitmore Lake road. This water enn be pumped by steam or water power, as it can be collected and led in a pipe to the rirer and pumped there. The river must be crossed in this case, but the jiroblem presents no practical diflicultiej. If direct service is planned, the site for the pttmpug house, if power is to be used, would probably be the lower railroad bridge. If steam-power is to be used, Cascade Glen will be far enough ibove the city to be free from all undesirable drainage, and a. well sunk iiHo tlie sand and gravel, with a pipe to the rivcr for emergencies, will serve for supply. The supply main will theu run directly toword the city. For pumps at the lower railroad bridge and direct supply, about 1,500 ft. more of main would be needed. The piping for the city is shown in detail on Professor Greene's drawing. The water from the proposed reservoir site strikes the niain at Miller avenue near ts junction with Manu street, and runling east on the avenue reaches Main street, from which point it is distributed hrougliout the city. The mains range from 16 inches to 4 nches in diameter. The hydiHnts are 80 in number. On tlie plan circles of JOO feet radius give an idea of the amount of territory easily reached by them. The distribution is so ananged as to give a ciiculation in most of tlie pipes and to ermitofa fiow of water from twodirecïons to most of the hydrants. The pipes are computed at $.'(2 50 per ton for cast ron, to be luid 5J to 0 feet in the rTround. Approximate estimates of the cost are s followg: 60,500 feet, U}4 miles, of liping, $63,001 ; eighty hydrants, $4,000; valves and special apparatus, $1,395. Total cost of distribution, $09,056. It will probably not be necessary to lay all f tliis pipe at once; the more important points can be reached lirst, and the sysem extended later. Belter prices can irobablj be obtained for winter manuleture, and delivery then and In the prlag. If reservoir pressure is mea, the weight of pipe, all large, made in abov omputatioi), can be reduced somewhat. If a reservoir is used in the location lieady retened to, it may be built of uch a capacity as to contain from four to en days' supply, depending on the deïand; continuous pumping will then be nnecessary, the pumps being run only y day on days required. Uut one set of unips will In this case be needed, and a ngle enginepr. A reservoir of 4,000,000 gallons eapacity, giving fourduys' supply for ló.OOO inhabitants, or ten or more days' supply for the present population, will cost, as por Mr. Greene's estimule, $-i,400 this indudes tli pinchase ol' i ruëcrvoir site ot' four acres. A vnlve connection muy be mail between inlet and outlet pipes wliicli will perinit of Increased pressure on the main, if such preasure is at. any time deeniud necessary. If, in place of a reservoir, a stand-pipe or tank is thought more deslrable togive gieater pressure, one 35 ft. in diameter and 00 ft. high, giving an elevation of over 210 feet above the court house square, and bolding 430,000 gallons, oi:e day's supply or more, under present needs, and a supply over night and for fiies at any time, can probably be built forfrom $10,000 to $12,000, to whlcb should he addeil cost of protection agaiust freeziog. The following are the estimates of cost of water supply under the different plans : Water power with reservoir, $111,000; water power, direct supply, $111,100; steam power, wlth reservoir, $97,350; steam posver, direct supply, $90,400. The Professor thinkstliatwilhcloserestimates, etc, these ligares muy be reduced enough to cover the usual 5 added for engineering and oontingencles. The supply computed for is 1,000,000 gallons per day with reservoir, or 100,000 gallons per hour, direct supply. The amount of power required to raise 1,000,000 gallons 225 feet per day is 3!iJ norse power, if running contiiiuously.aiid 5 horse power if running ten Iiours per day. " Not one-half of this amount will be needed for the supply of this city for several years," adds Mr. Greene. For direct service, 100,000 gallons per hour, will require 126 norse power. The pumping expenses by steam to reservoir are placed at $2,900 per aninim. For direet supply bv steam the pumping account is estimated at $5,Ï5O per year. For pumping by water power to reservoir, with one engineer and supplies.etc ,$1, 280. For direct service, with two engineers and supplies, $2,510. Expense of clerk, or executive offleer, inspector and repairers, office rent and sundry expenses, are placed at $3,000 per annum. Of five illustrations of the expense of water works operated In as many cities we cite that of McKeesport, Pa., population 8,212 in 1880, where the system, built in 1882, resembles the one suggested here. They have a well 28 feet in diameter, 32 feet deep, with 30 cast-iron perforated 4-inch pipes driven ten feetdeeper; two Worthington dúplex, high-pressure pumps, each of 1,500,000 gallons capaciiy force through 1550 feet of lü-iucli pipe to a reservior 22C feet square and 20 feet deep, 310 feet above the river; 9 miles of cast-iron pipe, 12 ft. 4 in. in diameter; 70 hydrants, 76 gates, and 210 taps; cost, $98,304; running expense, $2,100 per annum. Professor Greene says, " For the city of Ann Arbor, I would recommend the reservoir system, with motive power by water, f it can be obtained at figures which seem reasonable, and with water taken from a well in the gravel near the river, with a pipe connectiou to the river lor emergencies. If water power can not be used, then steam power pumping to reservoir is recommeuded. The cost of annual maintainance will, in ray opinión, more than offset tin; greater tirst ei s:." If, as has been suggested, an arrangement can be made with the present ownwiniutfeftia'üamgiy-n.. tlie necessary pumping at an igreed annual rate, to be regulated by the quantity of water used, the estimated cost of the works would be very materially reduced. What may be expected frotn the reservoir service? The 16 inch main, delivering 75,000 gallons per hour, with calculated pressure of 64 pounds on the square inch, will .throw, at the court house square, through 100 feet of hose, and a one inch smooth nozzle, a stream 90 feet vertically or 120 feet horlzontally, discharging 168 gallons per minute, and permitting of seven streams at ouce. With 300 feet of hose and one inch nozzle, we can play 67 feet vertically or 9G feet horlzontally, with elght streams. Allowing the same rate of tlow, etc, in the 12-inch pipe, at the Universlty campus the pressure will be 43 pounds on ihe square inch, and this will give, through 100 feet of hose, live streams, 64 feet vertically or 90 feet horizontally ; or through 300 feet of hose, 43 feet vertically or 70 feet horizontally, with six streams. A great advantage of a constant head of pressure on the pipes is the Immunity from shocks, which tend to cause breaks j and leaks ; ligbter pipe can be safely i used, and all house littings are less expentive.