FARM WATER SUPPLY AND SEWAGE DISPOSAL 353 



height it is desired to elevate the water, and reduce the result 

 by one-third to take care of friction and losses in the pipes. 

 The remainder will be the quantity of water delivered. For 

 example, if the flow is 4 gallons per minute, the fall is 9 feet 

 and the water is to be elevated 24 feet, we have four times 9 

 equals 36; 36 divided by 24 equals 1-1/2; reduce this by 1/3, 

 and we have 1 gallon per minute delivered, or 1,440 gallons 

 per 24 hours. 



323. Selecting a System. In selecting a water system, 

 many make the mistake of installing one that does not furnish 

 sufficient water. It is much better to have a cistern or tank 

 with greater capacity than actually needed than to have one 

 too small. The same is true in selecting a pressure tank for 

 the hydro-pneumatic system or an air tank for the fresh- water 

 system. The first cost will be a little greater, but the expense 

 will be less in the end. As a basis for estimate, one must re- 

 member that after a modern water system is installed, much 

 more water will be used than before. For each person, one 

 should estimate at least 25 or 30 gallons per day ; for each cow, 

 15 gallons; for horses, 10 gallons, and hogs and sheep, 3 gal- 

 lons per day, allowing for an additional supply to care for 

 chickens, for watering the garden, washing the car or buggy, 

 sprinkling the lawn, etc. 



324. The Septic Tank. No modern water system is 

 complete without proper disposal of the waste water and sew- 

 age. Oftentimes the sewer is simply tile that leads down to 

 the field or into a ditch or small stream. This method of 

 sewage disposal is not sanitary, nor is it safe from a stand- 

 point of health. If a large stream is at hand, into which to 

 discharge the sewage, it can be used with safety; a small 

 creek, however, would soon become contaminated. 



