Rural Hygiene

by Henry N. Ogden

The amount of water used then, per head per day, varies from seven to sixty gallons, but only by an intimate knowledge of the habits of the household can one predict the amount of water likely to be used. Perhaps as an average in a house having a kitchen sink and a bath-room containing a wash-basin, bath-tub, and water-closet, a fair estimate of the water used would be twenty-five gallons per head per day. This amount must be multiplied by a maximum number of persons to be in the house at any time, and then this number must be increased by the amount of water used in the barn and in the yard, if these are to be supplied from the same source as the house.

Quantity used in stables.

The amount of water used in the barn is even more than that used in the house, a variant depending on the habits of the manager. The minimum quantity needed per day is determined by the number of pailfuls of water which each head actually drinks multiplied by the number of head. But besides this there are many other uses to which water may reasonably be put in connection with stock.

On a dairy farm, there is the water needed to wash cans and bottles and in some cases to furnish a running stream of cold water for the aerator. In some stables a large amount of water is used for washing harnesses and carriages; in others, but a small amount goes for such purposes. Some farmers have concrete floors in cow stables and pig pens and use a hose frequently to wash these floors clean. Other stables never see a stream of water and only see a shovel at infrequent intervals. The amount of water used outside the house is too uncertain a quantity to estimate on the average, but its influence and importance must not be overlooked.

Maximum rate of water-use.

It should now be noted that the quantity of water already referred to is the average quantity used through the twenty-four hours and does not mean the rate at which the water comes from the faucet. For example, three persons in a house use water, according to the above statement, at the rate of seventy-five gallons per day, but a whole day has 1440 minutes, and if seventy-five gallons be divided equally among the number of minutes, it means one gallon in every twenty minutes, or one quart in five minutes. It is obvious that no water-supply system for a house, designed to supply water at the average rate for the twenty-four hours would be satisfactory, since no person would care to wait all day for the amount. To wait five minutes to draw a quart of water would try the patience of any one, and while the total amount of water used in the house will be seventy-five gallons, provision must be made by which it can be drawn in small amounts at much higher rates. Practically all of the amount is used in the daylight hours or in twelve hours out of the twenty-four, so that the rate would be twice the average rate, and with this correction, two quarts of water could be drawn in five minutes.

But even this is too slow, and if one were to take a quart cup to a kitchen faucet and note the time necessary to fill the measure with the water running at a satisfactory rate, he would find that unless the cup was filled in about ten seconds it would be considered too slow a flow. Since it is possible for more than one fixture to be in use at the same time, the pipes ought to be able to deliver the total amount running from different faucets open at the same time, and if it is considered possible for three faucets to run at once, as, for instance, the kitchen faucet, bath-room faucet, and barn faucet, then the supply pipe must be able to deliver, under our assumption, three quarts in ten seconds, or at the rate of about six thousand gallons a day. It is necessary, therefore, to distinguish carefully between the total quantity of water used per day and the rate at which such water is used.

The first of these requirements governs the size of the reservoir from which the water comes or the yield of the well or spring, or the capacity of a pump from a pond to a distributing tank; the other requirement governs the size of the pipe or faucet or the capacity of a pump which supplies direct pressure. It should be noted also that with ordinary fixtures, the rate of delivery and the corresponding sizes of the fixtures are not affected by the number of persons in the house, whereas the first requirement, that is, the total quantity of water used per day, is directly affected by the number of persons.

Variation in maximum rates of water-use.

The quantity of water used, however, is not uniform throughout the day or the week. It is commonly known, for instance, that on Monday, or wash-day, when the well is the only supply, a great deal more water has to be carried on that day than on any other day in the week, and this same increased demand for water is made when the water comes in pipes into the house. Probably about half as much water again is used on Monday as on other days.