Comparison Between Operating Conditions Under the Two Methods of Charging for Water Consumed—Flat Rate System Unjust to Consumer—Meterage Provides Best Method of Checking Operations—Saving Effected by Meters

THERE has always been some controversy as to the relative merits of conducting water works systems on a flat-rate basis and all-meter basis, with conditions otherwise the same and as to whether the benefits to be derived warrant the installation of the all-meter system. The owners and operators are practically unanimously in support of the meter system, while the consumers uniformly contend for the flat-rate basis; and this fact alone tends to show upon whose side the benefits of the meter system lie.

Of course, no criterion can be established for the entire country from statistics gathered in any one locality and, furthermore, it would be foolish for any one man to undertake from his own experience to prescribe the best operating methods for localities other than his own and operating under conditions with which he is not familiar. I have been manager of the Water Works System at Tuscaloosa, Ala., for about eight years. During this time the plant there has been operated first upon a flat-rate basis and later upon a practically all-meter basis, and I am therefore in position to give facts and figures by a comparison of which the many advantages of the meter system can be easily seen. However, I certainly do not wish to be regarded in the light of trying to tell other managers and superintendents how to run their business, or to insinuate that I know it all, or any more than any one else; but, having operated my plant under both systems and had opportunity to observe carefully the results of both operations, it has occurred to me that probably the figures covering these operations might be of interest to other operators who perhaps at this time find themselves under similar conditions as we were when we contemplated the change from the flat-rate basis to the meter basis.

Flat-Rate System Unjust to Consumer

There are many advantages of the meter system over the flat-rate system that need no comparison to establish their validity. One of the foremost of these is the great injustice to the consumers themselves in the flat-rate system. Upon this slack basis one consumer may pay a stipulated amount for his water—based probably upon the number of openings—and probably use 5,000 cubic feet of water within a given time; while another consumer, with the same number of openings and paying the same basic amount for his water, could use 10,000 cubic feet of water within the same time and with no additional cost.

However, being a manager of a plant, of course, I am concerned chiefly with the operator’s side of the matter, and it is the benefits and advantages to be derived by the operator himself that 1 propose to show in making a comparison of the statistics set out herewith, representing the operation of our plant first upon a flat-rate basis and later upon a meter basis. Of course, the points of greatest concern to the operator are: Increasing the general efficiency of his plant, cutting down the amount of water to be pumped, cutting down the amount of fuel consumed—with the consequent decrease in operating expense—and increasing the revenue.

*Excerpts from a paper read before the annual convention of the American Water Works Association at Buffalo, June 9 to 13.

In 1911 the plant of which I am manager was operating upon a flat-rate basis. We commenced installing meters in the fall of 1913, with the idea of metering the entire system, which was practically completed in 1915. Beginning with the year 1916 the plant was operating upon practically an all-meter basis. Therefore, by a comparison of the statistics covering the operation during these two years the effect of the installation of the meter system can be shown; and by this comparison I propose to show how the amount of water pumped per day in 1911 under the flat-rate basis was decreased in 1916 under the meter basis by about 27 per cent, notwithstanding the fact that there was an increase in the number of consumers in 1916 of about 65 per cent, and how the amount of coal consumed in 1911 was decreased by about 170 per cent in 1916, and the operating cost decreased proportionately.

General Operating Conditions and Equipment in 1911

The general conditions under which the plant was operated in 1911, and the equipment, were as follows:

The power plant is situated upon the banks of the Warrior River, about three miles above the city of Tuscaloosa, Ala. The plant is situated upon an incline—the settling basin being above the plant and the water flowing by gravity through slow sand filters to the dearwater basin below the plant. The water was pumped from this clear-water basin to a stand-pipe in the city— the tank having a capacity of 125,000 gallons and an elevation of 100 feet. The pumps were operated twentyfour hours a day, working against a pressure of 165 pounds at the plant. The actual equipment consisted of three 72-inch by 16-foot return tubular boilers; two horizontal compound, non – condensing Worthington pumps—alternating in operation weekly. The cylinders being, high pressure, 16 inches; low pressure, 25 inches; water plungers, 11 inches; stroke, 15 inches; rated capacity, 24 gallons per stroke; the water pumped in 1911 is figured on the delivery of these pumps, allowing 10 per cent for slippage.

The figures covering the operations during the year 1911 are as follows:

General Conditions in 1916

The general conditions under which the plant was operated in 1916, and the equipment, were as follows:

The operating conditions in 1916 were the same as in 1911, with the exception that a new reservoir had been built within one-half mile of the power plant, it is 62 feet high and 75 feet in diameter; constructed of reinforced concrete. This reservoir was planned and built by Morris Knowles of Pittsburgh, Pa., and is a magnificent piece of engineering work. Also a new high-service pumping engine was added—Type Myer; gear flywheel; high pressure cylinder, 14 inches; low pressure cylinder, 30 inches; water plunger, 10 1/4 inches; stroke, 24 inches; condensing; rated capacity, 30 gallons per stroke; manufactured by Laidlaw Dunn Gordon Company. The amount of water pumped in 1916 is figured on the delivery of this pump, allowing 5 per cent for slippage. The number of pumping hours was reduced in 1916 to an average of 10 hours per day.

The figures covering the operations during the year 1916 are as follows:

Comparisons of the Statistics for the Two Years 1911 and 1916

All the above figures are taken from the records of the City Commission of Tuscaloosa, Ala., and can be verified upon inquiry.

Provides Best Method of Checking Operations

From a standpoint of efficiency, and in order to check the operations of the plant, it is essential that the operator account for, so far as is possible, all the water that is pumped; and it is unquestionable that the meter system provides the best method for this. However, notwithstanding all the benefits derived from the employment of meters, even where the meter system is employed certain conditions arise in which it is not practicable to use meters. It will be noted that while employing the meter system almost entirely, we still have 190 consumers receiving water on a flat rate. This condition arises from the fact that these 190 consumers live outside the sewer zone and have each only one opening on the premises, and twenty meters placed on consumers under identically the same conditions show that 50 per cent of the minimum allowed under the flat rate is never reached.

With the meter system in operation during the year 1916 we were enabled to account for 85.8 per cent of all the water pumped during the year. These figures would be higher but for the fact that we had no way of accounting for the water used in fighting fires, and the amount used in street flushing, sprinkling, etc., is purely an estimate based upon the capacity of the tank, and the estimate is in fact considerably below the amount of water actually used for these purposes. The figures in substantiation of this are as follows:

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