ELECTRIFYING THE FAIRMOUNT WATER PLANT
In August, 1913, the town of Fairmount, Ind., undertook the changing of the municipal water works plant from steam to electric motordriven pumps and began tests at the plant as to the amount of water pumped, coal used, and other expenses that went to make up the cost of operation. The plant consisted of some six miles of water mains, supplying service to five hundred and sixty-six consumers; also forty-one fire hydrants, two 12 1/2×8 1/2×10 Dean Bros, duplex pumps, capacity 400 gallons each; two 50 horsepower boilers, one feed water heater and two feed pumps, six water wells, varying in depth from 40 to 300 feet, one reservoir containing approximately 26,000 gallons of water. (To be used in case of fire only.) The plant had been installed some seventeen years, being located in the business section of the town, eight squares from the railroad, situated at this point due to the abundant supply of natural gas in those days, which was used to steam the boilers. Some ten years ago the gas failed and it became necessary to use coal. During the past ten years a great deal of expense was necessary in the upkeep of the plant and, as later explained, the service was very poor. The old steam pumps were erected on the ground level and when a vacuum gauge was installed on the suction line the lift ranged from 20 to 26 feet, depending on the amount of water pumped and at times during the day not enough water could be received to supply the demand, at which times at least 15 per cent. air was pumped into the mains. This, together with a variation of from 10 to 20 pounds on the water mains, was very noticeable when taking water from the service. The operating force consisted of two engineers, working tricks of 12 hours each. The town clerk is also superintendent of the water works. Repairs and other work required on the system from time to time were made by the local plumbers and billed to the town. Coal was carted from the railroad to the plant, costing $.27 per ton for this service. There was no means of measuring the water put into the system. Installing a small 3-inch meter, capacity 350 gallons per minute, in a by-pass connection, this meter measured all the water delivered to the mains with the exception when in case of fires and when the capacity of the meter was reached, then the by-pass valve was opened and a portion of the water shunted through the meter. As the number of fires are very limited, the extra amount of water used in these cases is very small compared to the total output. This meter was later installed in a connection in the new installation in the plant. With this meter the department is able to register every gallon of water pumped into the mains and it only remains to get the amount of coal used and other operating expenses of the plant to give this data. The test was made for some two weeks, and at the end of this time the following data had been secured: Amount of coal burned in the 14-day test, 30,940 lbs.; average amount per day, 2,210 lbs.; amount of water pumped in the 14-day test, 2,892,675 gals.; average per day, 206,619 gals.; average per minute, 143 gals. Coal cost —Coal cost at mines, $1.05; freight, per ton, $1.55; cartage, $0.27. Total, $2.87. The following are the items that went to make up the operating expenses of the plant. These have all been taken on the yearly basis and allowing 365 days to the year, gives the cost per day which goes to make up this 14-day total test: Operating Expense—Engineer: Salary per month, $95.00; salary per day, $3.166; amount for 14-day test, $44,324. Repairs: Total for year, $20.00; per day, $.547; amount for 14-day test, $.7658. Oil and Waste: Total for year, $50.00; per day, $.136; amount for 14-day test, $1.904. Boiler Compound: Total for year, $26.00; per day, $.0712; amount for 14-day test, $.9968. Boiler Insurance: Total for year. $25.00; per day, $.0683; amount for 14-day test, $.9482. Coal Cost: Total for 14-days test, 30,940 lbs. at $2.87 per ton, $44.2989. Interest and Investment: The interest and investment were figured on the apparatus installed in the plant, which included boilers, feed water pumps and heater, fittings and pumps and not on the building, or $2,800.00. Total amount for year, allowing 10 per cent, depreciation, $280.00; per day, $.793; amount for 14-day test, $11,102. Interest at 6 per cent, for 1 year, $168.00; per day, $.466; amount for 14-day test, $6,524. Total, $110.86. The above $110.86 being the total amount expended during this 14-day test. Amount of water pumped, 2,892,675 gallons, or a cost per 1,000 gallons of $.0383. This gave a cost of $.0383 per thousand gallons of water delivered to the mains, and in checking the coal bills and other expenses as per vouchers paid out for the past four years, it was found the information thus obtained very conservative. Next came the proposition as to what saving as well as improvement could be made by installing motor-driven pumps. Other tests were made on the individual walls as to the amount of water that could be received by lowering the suction line 8 to 10 feet, and by so doing it was found that at least 40 per cent, more water could be taken from these wells. The following recommendations were presented: Install one 200-gallon centrifugal pump at 40 lbs. for domestic service, driven by a 10 horsepower motor; one 500-gallon centrifugal pump, at 90 lbs., for fire service, driven by a 35-horsepower motor. Place these pumps in a pit 14×20, at a depth of 10 feet, thereby decreasing the suction lift and secure more water. The pump manufacturers under this type of pump were able to guarantee an over all efficiency of 1,000 gallons of water per 1,000 watts of current, and for this class of business, namely, 24-hour load, the town could get a very low rate, which would make quite a saving over the old system. This plan met with the approval of the entire board and they immediately advertised for bids on the pumps. Plans and blue prints were made and accepted and the work was begun October 16, 1913, and the domestic pump was placed in service January 27, 1914. The 500-gallon fire pump was ready for service some weeks later. With these two pumps installed, and test made, the current per 1,000 gallons was 735 watts. The service had been very materially improved, absolutely no air in mains, steady water pressure of 40 lbs., as well as 50 per cent. additional capacity in the water system.
With the closing down of the old steam plant the problem of giving the alarm in case of fire must be solved, as in most small towns a volunteer fire department exists and some means must be provided to notify them when a fire occurs; this problem being met in the following manner: Installed a motor-driven air compressor. Size of motor, 7 1/2 horsepower, compressor, 4 1/2X4 1/2 inches, delivering 25 cu. ft. of air per minute. Compressing air into a tank 4×10 ft. to 200 lbs. pressure. Placing a reducing valve on the discharge of this tank and connecting the old steam wild cat whistle to this outfit. This making a much better alarm than the old system and costing complete $510. The current used to operate this compressor is approximately 6,900 watt hours per day, requiring about one hour’s run in 24 to keep the tank compressed to 200 lbs. pressure. Besides using the outfit for fire alarms, time blasts are given of 12 to 10 seconds duration at 5 and 7 a. m., 12 noon, 1, 6 and 8 p. m.
Cost of Operation.
The plant now being completely electrically operated and the time required from the attendants to look after same was so limited that the board decided to remodel the old building into a residence and turn the job over to one man. The cost of making this building into an up-to-date cottage was $2,367.80. The change is now complete and the operating man has so much time to spare that he is given the entire system of water works to care for, making all taps, cutting on and off services, reading and setting meters and other duties that previously had to be taken care of by outside men. So simple is the plant to operate that the attendant’s wife has charge of the plant while he is out doing such duties. All the pumps are equipped with electrical alarms, arranged so as to sound in case of trouble or should the pressure fail. The switchboard is placed in easy reach of the attendant, whether in the residence or pump room, and should a fire occur in the wee hours of the morning when the attendant is in bed, the time required to have the fire pump in full operation is only a minute and one-half. The plant now having been in operation over one year without one cent of expense for repairs, the following data has been secured covering every item of expense in the amount of water pumped over this period: For the year ending February 1, 1915—Amount of water pumped, 76,196,230 gals.; average amount per day, 208,756 gals.; average per minute, 149 gals.; amount of current used, 570,466 K. W. H.; average per thousand gallons, 754 K. W. H. Operating Expense: Salary of attendant ($60.00 per month), $720.00; oil waste and packing, $1.75; incidentals (fuses, electric), $.75; total, $722.50. The above amount does not cover the charges of interest on the investment and depreciation. Amount expended in making all of the above changes on the plant: Pumps, $1,250; small primer pump, $125; pipe and fittings, $310; compressor and tank, $510; foundations and pit, $275; labor, $325; total, $2,795.00. Cottage (7 rooms), $2,367.80; walks and incidental expense, $125.00; total, $2,492.80. Lowering wells and suction line: Pipe and fittings, $375; concrete, manhole over wells (6), $150; miscellaneous material, $200; labor, $1,554.27; total, $2,279.27. Grand total, $7,567.07. Note: The labor charge on the lowering of the wells and suction lines also covers the charge of removing the old suctions and some other expenses in leveling up the grounds around the plant.