sand coming in well and crust at 150 feet

[K Paterson]

I have a drilled well that is 172 feet. The casing ends at 150ft. The bottom of my pump has been sitting at 150 feet for 15 yrs. Just last week I started pumping a lot of sand. Putting a camera down the well we found a hole in the side of the casing at about 144ft. Also, at 149ft 11" approx, there is a crust build up. This crust build up has built up to a point were the hole in the casing is now only 3.5" round, just enough opening for my pump to go through. I think the sand is coming in through the hole in the casing and then sitting on that crust and then my pump is pumping it into the house. I also have alot of Iron in the water. Why would that crust build up just at the bottom of the pump? Is it possible, the magnetic field from the pump motor is attracting the iron over time and it is sticking to the bottom of the casing? Over time this has built up to a point where we cannot even use high pressure water or air to break it up. Should my pump sit below the casing?

Thanks

 

[Valveman]

It is not usually a good idea to set a pump below the casing. If you have enough water in the well, you may be able to raise the pump above the hole at 144'. This might stop the sand problem.

I don't think the magnetic field of the motor has anything to do with the crust. These type things usually tend to accumulate in areas of high velocity. Where the water enters the casing and passes by the pump, the vleocity increases.

 

[Sponsor]

 

[Gary Slusser]

Most if not all rock bore wells up'n down the east coast and west into the mid west have the pump set below the end of the casing; without problems.

Many rock bore wells have maybe 50'-100'+ of casing but the well is 200' to 500'+ deep. Setting a sub pump so far off the bottom of the well leaves a large volume of water that can not be used. And IMO it's not a good idea.

Water hardness scale and bacteria encrustations form where the velocity of a flow of water is higher than the flow rate in the rest of the pipe etc..

Sulfates and chlorides may also form encrustations there. All those things usually have an off white/gray color. If it is a rusty color, then the water contains ferrous iron that comes out of solution there causing ferric iron/rust staining. That high velocity can also cause erosion holes in copper tubing, usually just past an elbow or Tee where the end of the tubing wasn't reamed properly.