THE MULTIPLE MINIMUM 79 



the cost per 1000 gallons net that is paid by a taker who uses 

 twice as much. 



On the other hand, with the same assumptions, if a third 

 taker uses only one-half of the quantity of water that is permitted 

 under the minimum rate, that is to say $4 worth, he will pay the 

 same amount for this as one drawing the maximum quantity 

 permitted under the minimum, and the works will realize twice 

 as much per 1000 gallons from the sale of the smaller quantity as 

 from the sale of the whole amount permitted under the minimum. 



Such irregularities under meter rates now in force are very 

 common and they represent a substantial injustice between 

 different classes of small takers. 



The Multiple Minimum. When a minimum is used for small 

 meters, the same amount may also be used for larger meters, 

 but it is common and advisable to use larger amounts for the 

 larger-sized meters. Amounts larger by 50 per cent then those 

 suggested for service charges in the following chapter may be 

 considered. 



Another variation is to have a series of minimums graded 

 according to the number of families or the size of the house, or 

 or according to the number of fixtures. Such scales fortunately 

 are not common. They represent a combination of flat rate 

 schedules and meter rates and are sometimes useful to steady 

 and insure revenue during the trying period of transition from 

 flat rates to meter rates. 



The minimum rate as now commonly used represents impor- 

 tant ideas that cannot be ignored, but in the form in which it is 

 commonly used it brings about inequalities and injustices in 

 the charges. 



Method of Ascertaining the Proper Minimum Rate. From 

 the standpoint of sanitary conditions, the minimum rate is that 

 amount which at the rates otherwise adopted will pay for the 

 quantity of water that it is desired from a sanitary standpoint 

 that each taker shall use. 



From the standpoint of furnishing adequate revenue, the mini- 

 num rate is ordinarily a matter rather of experience than of 

 calculation. 



