CONSUMPTION OF WATER IN SMALL TOWNS

CONSUMPTION OF WATER IN SMALL TOWNS

The author has on three occasions within the past year been called upon to prepare plans and specifications for the enlargement and improvement of the pumping stations and other parts of the waterworks plant in towns with a population of from three to four thousand inhabitants. In one instance these improvements involved the construction of a filtration plant. In each instance the only available data regarding consumption were based on the plunger displacement of the pumps, from which the per-capita consumption could be estimated from the best obtainable data regarding the population supplied. No attempt was made in any case to subdivide the consumption into the several purposes for which water was used. The following data regarding the consumption were derived from estimates based on plunger displacement and the number of strokes made by the pumps, as shown by the station records:

Before attempting, however, to specify the size of pumping engines to be installed, or filter capacity to be provided, the author decided to make some investigations to determine the true consumption of water and the purposes for which it was used. Before proceeding to detail the results of these investigations it may be well to state that in town (1) the water company supplied water to a bleachery, presumably for fire protection, at a flat rate of about $160.00 per year. This bleachery had a 6-in. connection directly from the to-in. force main. In town (2) the water company supplied a lace mill at a flat rate of $150.00 per year, a railroad watering station on a meter and a lumber mill at a flat rate. The results of the investigations are as follows:

I believe the above serves as an apt illustration of the errors which may result from conclusions drawn from inaccurate or insufficient data. It proves the fallacy of estimates of consumption based on plunger displacement, modified by a conventional correction of five per cent, or ten per cent, for slip. In fact the author has, in many instances, found a large amount of slip to exist in pumos apparently well cared for. Improper conclusions are misleading and may involve a useless and unnecessary expenditure of money for larger pumping units than required, and for filters and mains of greater capacity than actually called for, as well as in a useless endeavor to correct evils which do not exist rather than to attack the root of the trouble. In town (2), as a result of these investigations, the flat rate for water at the bleachery has been abolished and a meter installed. When the owners of the bleachery realised they were to pay for all water, used or wasted, they commenced an investigation which disclosed numerous leaks in their svstem of pipes. These leaks being repaired, their daily consumption rapidly fell to a few thousand gallons per day. As a result of the change the saving in coal at the pumping station has amounted to about $76.00 per month since the installation of the meter, or $900.00 per year. In addition, in the past two quarters the bleachery has paid water hills amounting to $220.00, or at the rate of $440 per year; therefore, adding these amounts and deducting the $160 per year previously paid tor water, we have

900.00 + 440.00 — 160.00 = $ 1,180.00 per year as the saving effected. As the gross rev enue of the company amounts to but a little over $14,000 per year, this saving amounts to over eight per cent, of the gross income. In addition, a saving of about $3,000 was effected in the reduced cost of the pumps and filters required, due to reduced pumpage. In town (2) requisite time has not elapsed since the completion of the investigation to install meters; but it is safe to assume that results equally as gratifying will be realised

NICHOLAS S. HILL, Jr. C. E.

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