WATER TANK STERILIZATION

Water storage tanks and delivery pipes must be sterilized prior to use in holding disinfected water for household use. This requires the addition of considerably more chlorine compound than mere disinfection (50 parts per million of available chlorine). The tank and all delivery pipes are then flushed after a period of hours at the least, followed by refilling with water to be used for household use. There is often sufficient chlorine compound left in small tanks to disinfect the clean water used to refill the tank, but larger tanks should have the refilled water disinfected at half the normal 1% rate.

If water must be hauled or pumped via hose or pipe to the tank, and pipes or hoses used to deliver the water to the home, all the auxiliary pipe line from the source to the point of distribution should be sterilized prior to use. If galvanized pipe is used, do not leave it filled with a strong chlorine compound for more than several hours, or the galvanizing (tin) may be adversely affected by the chlorine, as tin is an active metal. First, thoroughly flush the pipe line, and determine the capacity (volume) of the pipe line.

 

Amount of Chlorine Compound Required For Tank Disinfection

Gallons	5.25% Bleach	25% Chloride of lime
100	2 cups	3 ounces
250	5 cups	7.5 ounces
500	2.5 quarts	1 pound
1,000	5 quarts	2 pounds
2,500	2.5 gallons	4.5 pounds
5,000	4 gallons	9 pounds

Volumes of Pipe Lines

Diameter	Gallons/100 ft.
2"	16
4"	65
6"	150
8"	260
10"	410
12"	590
16"	1050
20"	1650
24"	2350
30"	3672

Capacity of Circular Wells:

Diameter	Gallons/foot
4"	0.65
6"	1.5
8"	2.6
12"	6
2 ft.	24
3 ft.	53
4 ft.	94
5 ft.	147
6 ft.	212

Multiply the gallons per foot figure by the depth of water in the well to get the total gallonage.

 

Capacity of Rectangular Wells or Tanks

The capacity of a rectangular well or spring box is found by multiplying the length by the width by the height, all in feet, then multiplying by 7.5. This will give the total gallonage. After determining the total gallonage in the well or spring, add the proper amount of chlorine compound, mix thoroughly, and allow it to stand for at least 4 hours and preferably longer. In all cases pump the chlorinated water through the entire system (pipes, tanks, etc), running the water through the various faucets until the odor of chlorine is discernible.

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