Bore development is a very important part of constructing a water bore. There are all different types of screens that can be used. But they will not keep the fine sand from entering the hole. By developing the bore it flushes the fine sand from the aquifer surrounding the screen.
Fractured basalt aquifers usually have little sand in them and clean up quite quickly.
We use compressed air to develop a bore. If it is a sandy aquifer we lower a 4 way Tee piece into the bore on poly pipe and air is injected through the screen flushing sand and any remaining sediment from the surrounding aquifer.
Depending on the aquifer this can take anything form half an hour to several hours. It is continued until there is no sign of any sand comi8ng from the bore.
If a bore is developed properly it will increase the life of the pump, because if fine sand enters the hole it will eventually fill the hole to the pump level and damage will result.
photos taken while developing a bore
©Sam Hensen 2009
