1 16 486 _}THSr A COMPARATIVE COST STUDY OF THE VARIOUS METHODS BY WHICH THE VILLAGE OF LA GRANGE, ILLINOIS, CAN MEET THE 1965 WATER DEMAND Thesis for the Door» of B. S. MICHIGAN STATE COLLEGE VV.F.Lynn ”I! THESIS M, ‘ r .. 4.“.8 I “Juana ‘ a , \hJ‘..\HL L if d . r v a u ...r ‘ .. .. - u. I \. if...\ - r”-.. LI .L j I - I .. 4... 3.9.3 . 1. . .2 . . . m G ..\. .I.~w.u~.l. ;. ... I t I I . .mgu .N u (I f 1"?) q . "In. A Comparative Cost Study of the Various Methods by which the Village of La Grange, Illinois, Cen Meet the 1965 Water Demand. A Thesis Submitted to The Faculty of KICHIGAN STATE COLLEGE of AGRICULTURE AND APPLIED SCIENCE By W. F. Lynn Candidate for the Degree of Bachelor of Science June 1948 The purpose of this study is the determination of the least expensive source from which the Village of La Grange, Illinois, can secure an adequate water supply. This supply must not only meet present requirements, but should be sufficient to adequately supply future demands for a reasonable number of years. United States Census figures and the estimates of such agencies as the Chicago Regional Planning Association indicate that the population of La Grange is appreciably increasing. Closely tied in with this pOpulation increase is the influx of heavy industry to the West Suburban Chicago area. Furthermore, reports of the falling water table in the La Grange area have been received with apprehension by many La Grange residents and they are looking hOpefully at the several prOposals advanced for obtaining Lake Michigan water. In this study, a satisfactory water supply shall be defined as a supply in which the water is free from objectionable taste, color and odor, reasonably soft, and free from harmful bacteria so as to meet the standards of the Bureau of the Public Health Service Division of the United States Treasury Department. An adequate supply shall be construed as one capable of meeting maximum demands of domestic use, industrial and commercial use, public use, loss and waste, and which has sufficient reserve for fire-fighting to meet the rate demand schedules of the National Board of Fire Underwriters. 1-928 5 i. The supply sources available may be divided into two classes; ground water sources and surface water sources. For purposes of investigation these water source classes may be further sub-divided into a shallow well supply and a deep well supply, and a stream supply and a Lake Michi- gan supply. These supply sources will be further inves- tigated, in detail,from the standpoint of the considera- tions already stated. A shallow well supply and a surface stream supply both are quickly eliminated as answers to the problem of La Grange's water supply. Ernest W. Steel, in 3333; Supply and Sewerage, defines shallow wells as being under one hundred feet in depth. Such wells are out of the question in the La Grange area where the ground water level stood one hundred and fifty feet below the surface in 1936 and was receding at about five feet each year, according to the village consulting engineers, Alvord, Burdick and Ho§$son. Furthermore, there is no stream in the La Grange area large enough to meet the required demand. The elimination of these two types of supply sources consequently leaves the deep well supply, (the type supply in present use at La Grange) and the prOposed Lake Michigan supply for closer investigation. It is felt that a brief look at the history and physical make up of the present system will aid in arriving at the most economical and sat- isfactory source for La Grange water supply. The village of La Grange is a well-to-do, strictly residential, suburban area, having only minor industries of the service type. It is located on the main line of the Chicago, Burlington, and Quincy Railroad and on primary East-West and North-South arterial highways, about fifteen miles south-west of downtown Chicago. Its first municipal water supply system was constructed in 1890 by a privately owned.water and electric company. Shortly thereafter, the village acquired both the water and electric systems and operated them until 1905. In that year, partly because of a fire which destroyed the utility buildings, the water and electric prOperties were sold to the Public Service Company of Northern Illinois. This company operated both systems for the next thirty- five years, although it is primarily an electric generat- ing and distributing concern. For a number of years, the village tried to induce the Public Service Company to install a treating plant, which would reduce the excessive hardness of the La Grange supply. Negotiations terminated in the summer of 1958, when the municipality re-purchased the water works, from the private company, for $315,000. A $425,000 water revenue bond issue was sold to meet the purchase price plus the village share of a $200,000 Public Works Administration project. This project included the present water softening and iron removal plant, elevated storage, and feeder mains. The plant was completed and put in operation during the summer of 1939. Tables I and II, following, indicate the value of the water supply and treating plant. TABLE I ESTIMATED COST OF BEPRODUCING LA GRANGE WATER WORKS Land (98% allocated to water at Stone Ave., 40% at Tilden Ave.) $22, 33 Structures (60% allocated to water at Stone Ave., 40% at Tilden Ave.) 109,620 Electric pumping equipment 48,916 Water pipes and auxiliary equipment 245,120 Consumers meters 25,029 Meter installation 2,979 Hydrants 20,247 General equipment 561 Total Water Works Cost 54727555— Overheed: Engineering Supervision Legal Aid Organization Miscellaneous 47,251 Interest during const. (3% of all) 15,572 Total Cost $555,528 Figures from report of Alvord, Burdick, and Howson Report and based on 1956 labor costs of from $0.825 to $1.50 per hour. TABLE II COST TO LA CHANGE OF EHGD HATER SOFTENING PLANT Structures $ 60,218 Filter Equipment 28,175 Zeolite and Sand 10,394 Flocculating and Mixing Equipment 6,055 Total Plant Cost $104,820 250,000 gal. Elevated Tank (Including foundations) 25,870 C. I. Pipe and Specials 25,294 Pipe-laying 88,645 Total $192,627 The water supply is obtained from three deep wells which draw water primarily from the Mt. Simon sandstone aquifer at about the 2000' level. Diagram number I shows a cross section of the geological strata under La Grange and the various aquiferspenetrated by the wells. Well Number Five is a new test well which is not yet connected to the distribution system. Deep well turbine pumps are used to deliver water at rates of about 1000 GPM. and hav- ing a total capacity of 4.52 MGD. The average daily pump- age is approximately 850,000 GPD and the design capacity of the plant is 8 MGD. The deep well supply is excessively hard, a typical condensed analysis being: Carbonate Hardness 412 ppm Non-Carbonate Hardness £16 ppm Total Hardness 788 ppm Iron 1.16 ppm Free 002 127 Softening such a supply was considered more as an investment than an expense, as was evidenced by the large number of home softeners in La Grange before the plant was put into Operation. Comparative studies were made of construction costs and annual operating expenses of both lime-soda ash and lime-zéolite treatment methods. The lime-zeolite method GEOLOGICAL FORHRTIOKS UNDER LA GRANGE HaB%Bess Depth 1 ngl N23. 5 08 24 Drift Niagaran 1000-1200 Limestone 357' 386' Richmhnd 537 Shale Galena— Platteville Limestone 500-550 816’ 225-975 $4535 QEEI unfit "fifififiifif St. Peters — '" ”‘ 3"£: -'”Z -’%”'195 Sandstone 1040‘ Prairie du Chien Dolomite 475-550 1378' Galesville 225-275 Sandstone 1556 Eau Claire Limestone and Shale 400-450 1885 ::I I :o' W! l 3 ‘U :5: 3 2f 3 50-400 "a; u. 200 ‘”‘;1 Mt. Simon zf””§; Sandstone 20 8' ”5 I tat: _'€.- 20 5' 1917'” ::?. /. «ya-1' DIAGRAM I was selected because it was found to be cheaper in treating a water with a relatively high non-carbonate hardness. The following steps are used in the treatment plant selected: 1. - Aeration 2. - Feeding of lime Z. - Rapid mixing 4. - Slow mixing 5. - Settling in mechanically cleaned basin 6. — Recarbonation 7. - Filtration through sand 8. - Application of calgon 9. - Filtration through zeolite With the high 002 content of 127 ppm it is desirable to release as much 002 as possible without introducing an excess amount of free oxygen. This Operation is accomp- lished with a simple splash type aerator, operated on less than two feet of head and consisting of a discharge in a sheet over a vertical bell mouth onto an annular Splash plate. From the aerator, the water flows by gravity through the plant to the clear well. It has been found that trouble in the distribution system from red water can be controlled by decreasing the amount of aeration. Bagged quick lime is mixed in two paddle wheel International lime solution tanks, each having a capacity of 1200 pounds of lime per batch. The lime solution, two pounds of lime per gallon of water, flows by gravity to the inlet of the mixing compartment. The average applica- tion of lime is at the rate of 26.0 grains per gallon. The first stage of mixing is a three and one half minute rapid mix, effected by a vertical shaft propeller type agitator. The second stage is a forty-five minute slow mix by Link-Belt flocculators. The flocculating basin is eleven feet wide, fourteen feet deep, and seventy-one feet long. A single shaft with six addles extends the length of the basin. The basin is divided by wood baffles into four sections. The water next passes into a settling basin which provides ninety minutes retention. It leaves this basin with an average turbidity of 5 ppm, a Methyl-Orange alkalinity of 42 ppm, and a Phenopthalein alkalinity 421 ppm. Carbonation is provided in the next basin, where a ten minute contact period with 00 gas is provided. 2 The 002 is generated in an oil burner, passed through a scrubber, and compressed to provide the head necessary to force the gas into the carbonation basin through a re- carbonation grid. From the carbonating basin the water flows to three conventional type rapid sand filters, each with a capacity of 1 MGD when water is applied at a rate of 5 gallons per square foot per minute. The filter sand is placed on top of a five inch layer of 6 ~ 20 torpedo sand, which, in turn, rests on 24 inches of carefully graded gravel. The filter sand has an effective size of 0.50 mm. and a uniformity coefficient of from 1.25 to 1.50. The filters are equipped with hydraulic valves, recording gauges and operating tables. Hexametaphosphate is applied at a rate of about eight and one-third pounds per million gallons of water to protect the zeolite in the final filters. It is added to the effluent of the rapid sand filters by an automatic feeding machine consisting of an electrically driven chemi- cal feed pump coupled to a rate controller to vary the rate of feed in direct preportion with the filtering rate. The addition of hexametaphosphate was found to prevent the de- position of Ca003 on the distribution piping, as well as keeping the Zeolite filters free from Calcium. Most of the effluent of the sand filters next passes upward through the zeolite filters at a rate of six gallons per square foot per minute. Each of the three zeolite filters is six by sixteen by eleven feet deep, with a cy- press floor six inches above the concrete floor of the filter box. On this slat bottom is a twelve inch layer of gravel, graded from number 20 to one inch. StaGEilized gel zeolite is placed on the gravel to a depth of six feet. This zeolite is furnished by the Elgin Water Soften- er Corporation and meets minimum Specifications Of sixty minute regeneration time, salt requirement of 0.55 pounds of salt per grain of compensated hardness per 1000 gal- lons of water softened, and an Operating exchange value between regenerations of not less than 9000 grains of hard— ness, expressed as Cacoz, removed from the water per cubic foot. These filters remove all Of the remaining carbonate and non-carbonate hardness, a total hardness averaging a- bout 450 ppm., producing an effluent Of zero hardness. The zeolite filter effluent flows to a final mixing chamber before flowing into the clear well. This effluent makes up 85% of the final plant effluent. At this final mix, unrecarbonated lime-treated water, equal to 15.25% Of the final effluent, and sand filtered raw water, equal to 1.75% Of the total effluent, are added. Here, too, soda-ash is added to make a final pH adjustment and the chlorine is added. The effluent of the final mixing cham- ber is a clear, tasteless water having a total hardness Of 85 ppm, alkalinity, and a pH value of 9.0. Diagram II, made from the village records, shows the pumping rates for the last eight years. DIAGRAM II KOOX 53% $3 «SQ SEQ hwmx NV? 3Q 84% O we \\r. I .\ \\.\ \lll. Ilmsnhxlmsml III I \ \ co 0 “32$ku N \' Kay/saw/DQ ,zo sue/MIN emu Si OEEESR x S as quSSx we Saws x m ESE? was 10 For the sake of convenience in the cost comparison of the various supply sources, the cost of furnishing a satisfactory supply from the present deep well source in 1965 will first be estimated. Comparisons will then be made with the alternative sources in order to determine the most economical supply source. In estimating the cost to La Grange of furnishing an adequate water supply in 1965 from a deep well source, the quantity Of water required and the cost of supplying this quantity must be estimated. In predicting the 1965 demand, four types of demand will be considered; domestic, industrial and commercial, public use, and loss plus waste. La Grange, being a strictly residential community and zoned accordingly, the industrial, commercial, and public water demands depend directly on the domestic demand. Further- more, since 1940, the maximum quantity of unaccounted for water was 10.85% of the total pumpage in 1944. This amount varied from the minimum in 1942 by 2.56%. In this same period, 1940-1947, the maximum total pumpage was 12.9% over the minimum. From these figures, the percentage of loss and waste in 1965 will be estimated as 10% of the total pumpage and therefore will be a function Of domestic demand. Consideration of the above facts leads to the con- clusion that for a residential community like La Grange, the total predicted demand will prOportionally follow the domestic demand. To obtain the domestic water demand in La Grange for 1965, both a population prediction and an estimated rate of use are reguired. Since a population prediction is basic in a study of this kind, separate predictions from various viewpoints will be made and weighed in arriv- on ing at the final estimate. These results are shownwcurves of diagrams III, IV, and V. The arithmetic method of predicting population is particularly suited to old and non-manufacturing cities which are prevented from further expansion by surrounding communities. In this method, the increment of growth is assumed as the difference between the last two census figures. This increment for La Grange is, 10,479 minus 10,105 or 376, and gives a predicted 1965 p0pu1ation of 11,419. Since La Grange is at present expanding consider- ably and this predicted result is not supported by the other results, this value will be given minimum weight. If a mean value for the percent increase in popu- lation over a nimber of census periods is obtained and applied to the 1940 census figure, another value for the predicted 1965 population is arrived at. By this method, the estimated 1965 population is 19,529. Still a third method for predicting pOpulation used was to plot values of all available census figures so as to get a curve showing the population growth for La Grange. To obtain a more accurate curve, the population of inter- mediate years was determined prOportionally, using school census figures, water pumpage, and records of telephone subscribers. From the curve obtained, a pOpulation trend was arrived at, and, when extended from the year 1940, when the population was 10,479, this trend indicated a 1965 population of 16,750. DIAGMiM III \BNX ka\ 0©m< $.93 QVm,\ OMmV 0N3 me.\ _ V _ _ \ _ \ _ u _ \. ski mkxfibg \ llrlll I... ll .ll. lllllll\lulll. Ill. IIII— .||.I. \\ 9V§ \\\ Nx _ \\ _ \ m omko‘ \\ bimlk x6 torts to\o\c\ v? xi 8 V \\ w wsNK.v§\ \N KO mx b% R rtkokkxb _ nNQ ON NGETQG (VQOK WNBVEFN WM >\O\K (#30504 Spa/097041 u/ Ala/,1 p/na’ac/ DIAGRAM IV ORGY btmkk bwbthKN “3.“.th .m. \V EQKK «£5.6me Omfi< ONm< && OWQV QMQV QVmV QVQV _ V n _ d n ,w _ Q w. _ I_ w. 1 1_I .. IwNwmx IIIIIII m “ Mx w _ v m _ \ -l l I l - _ __ . \ ®\ wmhxux *\ \\ 11\ \\§.\>\OU \<«\QW~§Q\~W QQVUxtU «(TQ\>\\W \Kk\\< >\QW\~\(Q>\OU \«Q WWETWQ TV QOK Q>\.N&K >\O\k¢\.w\vo\9§ Q\m.\ O V3» 00 5300050041 0/ 4104 0/00/06/ '4‘ w\ Another quite reliable method of obtaining a trend curve for La Grange is by comparison with similar residential communities in the vicinity. These communities should all have passed through the last available census population of La Grange and be as near like La Grange as possible. communities, of this type,selected were Elmhurst, Highland Park, Elmwood Park, and Park Ridge. They have all exceeded the 1940 population of La Grange and all are well-to-do residential suburbs of Chicago. The population growth of each of these communities was plotted and a composite trend curve was obtained from the population curves. Since all four of these communities followed the same distinct growth trend, it is logical to assume that La Grange will also follow this trend in its future population growth. sing this method, the pre- dicted 1965 pOpulation of La Grange is 17,500. By combining the several results obtained and wuight- ing them according to their apparent accuracy, a population figure is obtained for La Grange in 1965 of 17,000. The Chicago Regional Planning Association has made a prediction for La Grange of 16000-18000 in 1960, thus checking closely with the results of this study. DIAGM ‘ v QKQV 0W0< Obo< Oxym< Omd< «\wa 0Na.\ \ \ \1llllll \ QQD\\ NQETQQ TV K0 xxkaqu >\Q\k_\ VDQGQ. QNK U\Q.VG\Q\ O\m.\ V N\ ®\ ON spa/0577041 u/ (10.1.; 0/00/00! 14 The next basic consideration in predicting the water supply necessary to meet future demand is a determination of the probable per capita rate of use. In such a deter- mination, such things as population characteristics, clim- ate, water rates and the quality of the water must be taken into consideration. The present p0pulation of La Grange is made up mainly of home owners, since by ordinance the great majori- ty of the buildings are single—family residences with mul- tiple-family residences next in number. Practically all of these dwellings have large yards and are connected to the village sewerage system. Both of these factors tend to increase the quantities of water used. Although ex- pansion is limited to the South by the surrounding com— munities, rather extensive expansion is already in progress. This eXpansion is controlled by the village zoning ordi- nance as outlined on the zoning map in the appendix. It is also expected that any expansion beyond the village limits will be in areas soon to be annexed to the village. Such annexation will be mutually beneficial as it will permit use control of the new area by the village and will give the residents the benefits of public utilities. With the future pOpulation so controlled as to ap— proximate the present pOpuletion in character and the quali- ty of the water unchanged it is reasonably assumed that the 1965 rate of use will approximate rather closely the present rate. Present pumpage rates are about 320 million gallons per year as obtained from pumping records. From this rate, the average daily per capita consumption is ar- rived at as 75 gallons per capita per day. With both the population for 1965 and the per capi- ta demand predicted, the estimated total demand rate can be determined. To meet the estimated demand 75 times 17000 or 1.275 MGD will be required. This is the average annual demand rate. The maéimum hourly demand rate will occur on the day of maximum consumption and equal 1.275 MGD times 1.5 times 1.75 or 5.547 MED. The maximum daily demand rate equals 1.75 times the average annual demand rate or 2.2 MGD. Moreover, to this demand rate, the fire demand must be added, as it is common practice to add the fire demand to the maximum daily demand rate on the basis that most fires overlap the period of maximum daily consump— tion. The importance of meeting the National anrd of Fire Underwriters' Standard in planning a water supply can not be overlooked as the ability to meet these standards is directly reflected in the local fire insurance rates. In their grading schedule, the Fire Underwriters give the water supply a relative weight of 34%, higher than any other single item in determining adequacy of fire protection. In determining fire demand, the National Board of Fire Underwriters uses the formula, G = 1020 P (l - .01 P). G is the required flow, in gallons per minute, and P is the pOpulation, in thousands. Substituting the predicted p0pulation value for La Grange of 17,000 in the above for- mula, 4000 GPM is arrived at as the fire demand rate which must be supplied for a ten hour period during the four day period of maximum consumption. The rate of 4000 GPM equals a fire demand rate of 5.76 MED and added to the domestic demand rate, on the day of maximum demand, the total maximum estimated demand rate for La Grange becomes 8.035 MUD or 5525 GEM. The Board of Fire Underwriters further states that pressures must be high enough to insure system pressures of at least 20 PSI in areas adjacent to heavy fire demand zones. The present system in La Grange maintains pressures of between 50 and 54 psi., thus permitting use of automatic sprinkler systems and providing against large pressure fluctuations due to meeting of large sudden drafts and offsetting losses from partial clogging, leakage, or ex- cessive pipe lengths. The total demand rate in 1965 has been predicted at 5525 GPM., which must be maintained for ten hours at such a head as to prevent system pressures from dropping below twenty PSI. The present pumping capacity of the plant is 8000 GPM., which can handle the ten hour plant output at 2080 GPM plus 920 GPM from storage. In ten hours, at 920 GPM, 552,000 gallons will have been drawn from the storage capacity of 763,250 gallons. This capacity includes a 482,000 gallon reservoir, a 250,000 gallon elevated tank and the top twenty-five percent of a 125,000 gallon standppipe. This leaves 211,250 gallons of storage which could be used as a supplementary supply by installing another pump operating at 552 GPM. The present system would therefore fall short of meeting the maximum demand rate by 2525 GPM. Since the plant capacity of three MGD would still be considerably over the maximum daily domestic demand, the additional peak: and fire demand could be met by construction of an additional reservoir. The reservoir would permit storage of water treated during slack demand periods and should be so connected to the system that turnover would be con- stant. Additional pumpage would be required to meet the maximum demand rate. Water from the reservoir should be pumped into the system mains at some distance from the Ster Avenue plant to prevent excessive pipevfriction losses due to high water velocities. This would also add to the safety of the system by decreasing losses due to leakage or breaks. The following figures itemize the various factors involved in determining required additional storage; Required maximum demand rate 5525 GPM Available from treating plant 2080 GEM Available from present storage 920 5000 GPM 5525 cm 5000 Required additional storage 2525 GFM All above rates are based on a ten hour pumping period as required by the Board of Fire Underwriters. The rate available from the plant is based on a capacity of 5 MGD and the rate available from storage is based on the agailable pumping capacity of 3000 GPM. The additional supply required is equivalent to a- bout one and one-half million gallons available in ten hours, or at a rate of 2525 GPM. A reservoir 10' x 100'x 200' would have a volumn of 200,000 cubic feet and there- fore the required capacity of one and one—half million gallons of water. It shall be assumed that this reservoir shall be constructed of reinforded concrete and at such an elevation as to permit gravity flow from the treating plant. In estimating the cost to La Grange of supplying increased water demands by the use of a new reservoir, the 19 cost of the reservoir and of required pumps will be included. It is assumed that that the reservoir will be constructed on land already belonging to the village, and that addi- tional treating costs will not affect the present water rates as they will be met by the additional consumers supplied. Since the design and an itemized cost estimate for the new-reservoir are beyond the scOpe of this study, an approximate estimate will be made by comparison with costs of other reservoirs recently constructed or under con- struction, such as the 10 MG Lansing, Michigan reservoir. By this method, the reservoir's estimated cost will be $70,000. To this value must be added the cost of pumps capable of pumping 2525 GEM and maintaining a head of 54 PSI. Three electrically driven centrifugal pumps, two operating at 1000 GPM and costing $10,000 each, and the other Operating at 500 GPM and costing $5000, would bring the figst to $95,000. The installation of the pumps and necessary pipe would bring the total cost to an estimated $100,000. If this project were financed by a 20 year serial bond issue at 5% interest, the gist should be reflected to the consumer by not more than a 5¢ per 1000 gallon in- crease in water rates. It is to be expected that this in- crease would be considerably less as the bonds should be 20 obtained at less than 5% and part of the cost could be met by any surplus of the present Water Works. 21 Another solution pr0p0sed in meeting the predicted 1965 water supply deficit is by the use of stand-by wells. The supply from these additional wells could by-pass the treating plant and be pumped by electrically driven cen- trifugal pumps into the supply system at points so select- ed as to give dispersion of supply. Once again the supply required from these wells to gheet maximum demand would be 2525 GEM. In addition to Well #5, as yet not connect— ed to the system, two new wells would be required, since the wells in this vicinity average 1000 GEM. These new wells would be kept as integral parts of the La Grange water supply system in—parts—ef—the—Ba—Grangesfiater—supply system.in the event that growth beyond 1965 made necessary the expansion or refurbishing of the three million gallon per day treating plant. The problem of selecting the aquifer from which these wells would draw there supply will not be undertaken in this study as it would involve extensive studies of the lithology of the geological formations underlying La Grange, thv qualities of the waters from the various aqui- fers, and the varying costs in drilling to different levels. However, well #5, the new test well, was drilled to 557 feet and obtains a sufficient flow from the highly fissured Niagasag limestone at that level. Therefore, this study will presuppose that additional wells will be drilled to this same level and cost estimates for wells will be based 22 on this assumption. It will also be assumed that 2500 feet of cast iron pipe, 12 inches in dgameter, will be required to connect each new well to the system. The following table shows a detailed estimate of the cost of a new well, cogpletg with pump, pump house, and connecting main. The cost of meeting the increased demand by the use of stand-by wells is estimated at $80,000, about $20,000 less than by using a new reservoir. TABLE III ESTIMATED COST OF NEW WELL, 350' DEEP 0'-40' 28" Drive Pipe 40' at 12.00/Ft. 0'-80' 20" Liner 80' at 8.00/Ft. 1-28" Shoe, at 200.00 1—20" Shoe, at 150.00 0'-80' Drilling 80' at 15.00/Ft. 80'-850' Drilling 270' at 15.00/Ft. One Cementing at 700.00 One 1200 GPM Test at 700.00 Total Cost of Well 2500'-12"C. I. Pipe 2500 at 6.00/Ft. a 480.00 640.00 200.00 150.00 1200.00 3510.00 700.00 700.00 $7580.00 15,000.00 One 1000 GPM D. w. Centrifugal Pump at 10,000.00 10,000.00 One Pump House at 5,000.00 Setting Cne Pump at 600.00 Engineering and Miscellaneous, 3,000.00 600.00 3,600.00 (10%) Total $ 39,780.00 The subject of a suburban Lake Kichigan Water Supply is currently under consideration by the City of Chicago and a number of west and south suburban communities. In fact, Certificates of Convenience and Necessity have been granted by the Illinois Commerce Commission to the Greater Chicago Lake Water Company in June of 19;? and to the Illinois— Indiana Water Company in July of 1947. Since records of investigations of ground water supplies by the Illinois State Water Survey Division, at Urbana, have shown no need for concern over the adequacy of well water supplies, the only basis for comparison between lake and well supplies is one of economy. The report to the Village of La Grange by Alvord, Burdick, and Howson in 1956 concluded that, since at that time Chicago water was still unfiltered, treatment at La Grange should be included to remove turbidity and objection- able tastes and odors. To maintain necessary pressures, pumpage at La Grange as well as at the Chicago city limits was considered necessary. At that time, the consulting engineers estimated the cost to La Grange, of such a pro- ject, in excess of $450,000. Oscar Hewitt, Commissioner of Public Works in Chi— cago, is advocating a new Chicago water supply district to supply the west and south suburbs for a radius of about thirty miles. This district would require large mains, new pumping stations, and booster pumps. Due to the dis— tances the water would have to be pumped, very large re- servoirs would be required to meet fire demands and to smooth out fluctuations in demand: The cost of such a vast program has been estimated at twenty-six million dollars. Although this is a very large figure, if enough communities were involved, La Grange's share could be small enough to make this type supply economical. The main argument to this supply is the fact that so many communi- ties are involved and unanimity of need is not coincident that it is doubtful if the plan can gain the popular sup- port needed for fulfillment. Cf the various proposals for obtaining Lake Michigan water, that deemed most practical is one in which La Grange would pump water, bought from Chicago, through its own pipe line. This is the preposal which was investigated in 1936 by the village consulting engineers, with certain factors changed. By state statute, it is possible for La Grange to lay such a pipe line and buy water from Chicago at that citggh rate of about 7.36 cents per thousand gallons. The need for treatment at La Grange, formerly deemed necessary. could be eliminated by obtaining water from the new south side filter plant in Chicago. Water obtained in this man- ner would compare favorably with the present supply with the possible exception of noticeable chlorination. 25 In considering a Lake Michigan water supply, it might be well to consider the supply of the Village of La Grange Park, which adjoins La Grange on the north. This .community obtains its water from Chicago through a sixteen inch main, connecting to the Chicago system at Austin Boule- vard and Garfield Street. Theconnection is to a twenty- four inch main which feeds a few blocks from a thirty- six inch main. The pressure of the water supplied by chicago averages about twenty-five PSI. A booster pump- ing station was required since, during peak city demand periods, the supplied pressure drops as low as five PSI. The low pressure also makes storage necessary, and this is taken care of by an 100,000 gallon elevated tank and a 500,000 gallon underground concrete reservoir. No treat- ment other than chlorination is given this supply. Total pumpage for the year ending June so, 1947 was 675,295,208 gallons. The reservoir was constructed in 1928 at a cost of $25,125.16, and the booster station in 1945 for $28,000.00 (including cost of land). Thebooster station contains two 1500 GEM pumps. The water is bought from Chicago for $0756 per thousand gallons. To permit a lake supply, La Grange would require about ten miles of main, booster pumpage, and a storage reservoir. The reservoir and booster pumps are made neces- sary by the fluctuations in supply pressure. As before, the supply must meet a maximum demand rate of 5525 GPM for 26 a period of ten hours, and an average annual daily demand of 1.275 MGD. To obtain the maximum economy in a system of this type, the size of main, size of reservoirs, and head pumped against must be so balanced as to give the minimum annual cost. In determining this minimum cost, such items as costs of right-of-way and replacing pave— ment may be considered either as constants or as functions of the main size. For the solution of the most economical design of this pipe line, a graphic determination is shown on the accompanying diagram. Crdinates are annual cost and ab- scissas are pipe diameters. The curve starting at the origin of the axes represents the annual cost of the pipe line, including interest and depreciation, as a function of pipe diameter. The intersecting curves represent an- nual pumpage costs, at the rates shown, as functions of pipe diameters. Graphical addition of the intersecting curves gives the upper series of curves. The abscissas of the minimum points of these curves indicate the most economical pipe diameters for the corresponding pumping rates, under the imposed conditions. In obtaining points for plotting the curve for an- nual cost of pipe, items considered included; cost of pipe, cost of constructing pipe line, interest of five per cent, and two per cent depreciation (fifty year pipe 27 life assumed). For example: 52800' - 12" C. I. Pipe @ $4.55lfoot $229,680 10 miles - 12" pipe line construction @ $5.95/foot 814,160 Interest on bonds (5%) ‘ 27,192 Depreciation (2%) 11 420 Total Cost $582,452‘ Annual Cost of 12" Main, $11,649/year = 582,452 “—517- Other points on the curve were obtained similarly for other pipe diameters. Unit prices used are from pro- posals recently accepted by the Michigan State Highway Department. In plotting annual cost of pumping curves, pumping rates used were such that, when added to supply from a pro— posed reservoir, the maximum demand rate could be met. As an example, the curve shown for the 820 GEM pumping rate presupposes a two million gallon reservoir equipped with pumps capable of supplying water at a rate of 464 GEM at a pressure of fifty PSI for ten hours. This supply would meet demand requirements of the Board of Fire Under- writers. Heads pumped against were obgééned by use of the Hagen—Williams formula with a C value of 100. Pumping costs were computed on a basis of $0.10 per million gallons per footof head pumped against. DIAGRAM VI 0M, .33th SE wt was mad qxokééoow knot moguS ax \Nx NEQQ «\xo. VN m\ N\ m 0 , 0 A/ / , // \ 9 V 0 \\ on m; M \fi? am a 1r \ .0“ WW. \ ado 0N3 u I. \\u/ too can W r e. m E m hwhw\ / 2 W t o awed. \1 / / / 0h. [\7 (D In selecting the pipe to be used, the most economi- cal diameter for this system was graphically determined as fourteen inches. However, an eighteen inch pipe was selected although its cost is about tentpercent above the smaller pipe. The eighteen inch pipe was selected because it is adaptable to efficient, economical supply of the higher demands which will be imposed on the system by ex- pansion of La Grange after 1965, or by annexation by the village of any neighboring built-up areas. With the eighteen inch main, it is prOposed to add a two million gallon underground concrete reservoir to the present storage of about 750,000 gallons. The com- bined storage will permit economical pumpage at the aver- age demand rate by smoothing out pressure and demand varia- tions. The reservoir will also provide an adequate emer— géncy supply in event of failure of any part of the system east of La Grange, thus insuring fire protection. Two 1000 GEM single stage, electrically driven centrifugal pumps will be required at the Chicago City Limits pumping station. Ordinarily one of these pumps will meet the demand and the other will act as a standby for use in case of failure of the first pump or to meet de- mands above 1000 GEM. It will also be used in case of heavy fire demand and to ennable maintenance on the first pump. The present pump at the La Grange water works, rated at 5000 GEM, can be used at the reservoir. To secure ade- quate turnover of stored water, pumpage would normally be coincidentally into the reservoir and from the reservoir iate—tae—reeerveir—ané—frem—the—reserveir—into the system, with present elevated storage balancing demand and pressure variations. Without the costs of securing right-of-way and re- placing pavement, the total estimated cost of a system of this type to supply La Grange with Chicago water is $1,227,500.00. This figure includes ten miles of cast iron pipe at $7.35 per foot, construction cost of the main at $10.50 per foot, a two million gallon underground con- crete reservoir for $95,000.00 and a booster pump station at $35,000. All of these figures were obtained, compara- tively, from costs of the Lansing, Michigan, ten million gallon reservoir and from the costs of Lake Michigan water supply systems to several villages gear La Grange, includ- ing La Grange Park, Brookfield, and North Riverside. In determining the cost to the La Grange consumer, it is well to note that the three communities mentioned above charge $0.56, $0.36, and $0.53 per thousand gallons. Variations are believed due mainly to the length of main involved and the head pumped againSt. Using these consid- erations it is inconceivable to predict that La Grange could supply Chicago water for less than $0.60 per thousand gallOnS o so In arriving at the most economical course for La Grange to follow in meeting her present and future water supply requirements, it is felt that the minimum amount of construction possible should be undertaken. This is in view of the unbalanced conditions existing in the con- struction fields, as in others, in the present post-war period. Any large construction work would be paid for during the next twenty or thirty years by the expediency of a water works bond issue. Any large construction pro— ject, such as a pipe line to Chicago, contracted under pre- sent elevated labor and material costs, might well prove a mill-stone threatening the financial security of La Grange. The Village has a very high financial standing and this justly high standing must be protected. 0n the other hand, no community can afford to put up with an unsatisfactory water supply, as both health and safety from fire must be protected. Therefore, this study concludes that, from both economical and practical standpoints, the present well system should be eXpanded. The method of empansion prOposed is by adding one more well, (in addition to well #5 which is, as yet, not connected to the system). The new well will tap the same shallow limestone aquifer as well number five. Both wells will be equipped with electrically-driven centrifugal pumps and be separately connected to the supply system for stand- by emergency use. In addition, a one-and-one-half million gallon underground reservoir shall be constructed at such time between the present and 1965 as the village deems consistent with financial interests. At the time of con- struction of this reservoir, the supply from the two new wells will be routed through the treating plant. This so- lution will mean a percentage of the water in the mains will be unsoftened during emergencies and peaks demands until the reservoir is completed. At that time all water in the distribution system will have been softened. The cost to La Grange of securing an adequate water supply by this procedure is estimated at $45,000 when the new well is drilled and connected to the mains and $75,000 more when the reservoir is built. The total cost would thus be $120,000, which could be more equitably distributed than if it were all completed together. By meeting water demands by this method, this study concludes that La Grange will have the most economical supply consistent with requirements of the Illinois De- partment of Public Health and the National Board of Fire Underwriters. Furthermore, this supply will be a softened supply free from any objectionable taste, color or odor and independent of any outside political group or organization. OUTLINE OF STUDY OF COMPAHATIVE COSTS OF MEETING I. II. III. IV. FUTURE WATER DEMAND CF LA GRANGE, ILL. Purpose of study Present La Grange supply A. B. History of supply Description of present plant Prediction of 1965 water demand A. B. C. D. 1965 population prediction 1. Arithmetic method 2. Uniform p rate of increase method 5. Extension of trend method 4. Method of comparison with similar communities Prediction of per capita rate of use Water demand 1. Domestic use 2. Industrial use and commercial use 5. Public use 4. Waste and loss Fire demand Methods of meeting 1965 water demand A. Construction of new reservoir 1. Reservoir's estimated capacity 2. Design of reservoir 5. Estimated cost of reservoir Use of additional wells as standby supply 1. Estimate of required well capacity 2. Well design 5. Cost of new wells C. Lake Kichigan water supply proposals 1. Southwest suburban water district 2. Supply through village-owned pipe line a) La Grange Park village supply b) Lake supply for La Grange 1) Pipe line design and cost estimate 2) Reservoir design and cost estimate 2) Estimate of cost and amount of pump- age required v. Conclusion A. Selection of most economical method of meeting 1965 water demand of La Grange B. Reasons for choice Appendix Zoning map for La Grange Water supply map for La Grange Outline of study Bibliography k . .' -.' ms is $53.5 - . . ‘ 3.; - “ J,“ g: :l f‘ '1'- ' 9‘ .~ 2: ".3?“ f: -- BIBLIOGPMAPHY *1)! ‘41,"; skin's. .M y; The World Almanac, 1946, p. 459. TheD Daily_ News Almanac Year Book, 1911,1912,19Z4. Water Suppl tSewerage, Ernest ‘N. Steel, p. 8-27, p. 57- 85 .I%O- 255. Hydraulics, George E. Russel, p. 180-266. A1vord,Burdick, and Horvson Report on La Grange Water Supply Systemo of FeE. I0, I93 6. Water ‘Norks Eng. Journal, April 10,1940, "A mime-Zeolite Softening PIant", by Louis E. Howson, p. 424. Pittsburgh-Empire Water Journal, May-June, 1946, p. 6, "Hard WatEr Goes Soft", by J. W. Krause. The La Grange Citizen, 4 Sept., 1947, "Ill. Has Ample Water Supplies Says l’cEflldxney". Ibid., July 31,1947, "New Well for La Grange Has Strong Flow". La Grange Pl. Citizen, Sept. 11,1947, "Contract in Awarded on NEW WeII Project". Ibid., Sept. 11, 1947, "Water Supply Adequate". Enrollment Enrollment Data and Estimates for 1950 of Board of Ed., DistrictIUE, Cock 00., IIlInoIs. Emping Records, Softening éost Records, Village of La Grange, WatEr Dept. The Zoning Ordinance 2f the Village gf'Lg Grange, March 30, 1944. Standard Schedule for Grading Cities and Towns of the U. S., with Refer rence to Their? Fire Defenses and—P H sical I942 ed. Conditions, NatI_ Board of Fire Undem riters, Well Records of Electro-Motive Division of General Motors at La Grange. State of Illinois, Water Survey Division Lab. Analyses 111,274; 94,269. Report on Village Wells at £2 Grange,by State of 111. Water Survey DiviEIon. 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