If you can localize the origin of the bacteria entry, you only need to disinfect that component of the system and any remaining components down stream. The liquid can be purchased at supermarkets and is commonly known as chlorine bleach. Read the label to ensure purchase of only sodium hypochlorite. The solid HTH can be purchased from swimming pool supply dealers in either tablets or powder. Shown below are tables which provide the interior volume of water for various size cylinders.
Water also exists on the outside of the well hole in the crushed stone or rock faults.
Depending on well type and depth, this amount of water can be large. We suggest doubling the volume determined above when considering the amount of water needing disinfection. In atmospheric tanks, assume the top 10 percent of the tank is air space. In pressure tanks, assume the top 30 percent of tank volume is air space. The chlorine concentration used to disinfect water facilities can be varied based on the bacterial contaminantion level expected.