Is my well filling up with granite dust causing my pump to suck large amounts at a time?

[DanGa]

Here are the specs of my well:

5-year-old 500' drilled well. Static water level is 40'.
11 GPM production.
1.5 HP Franklin 3-wire pump set to 450'.
Your standard Well-X-Trol pressure tank and Tee setup.
No filters before pressure switch.

Here is what it is doing:

We have always had some granite dust in our well water. Seemingly a bit more the past few years. But nothing a sediment filter can't take care of. But for the third time in the past year, and it has only happened when using the unfiltered 3/4" spigot at the well house on full blast, after a few minutes of running the water wide open, I get a huge amount of granite dust and the flow of water stops because the pressure switch is dead/open. And when I say a huge amount, I mean enough to turn the water black.

The first time it happened, I removed the pressure switch and riser and cleaned it as best as I could. It didn't look terrible at all. The second time I just replaced the pressure switch entirely. This third time was last night and I did not take apart the switch. I did flip over the manual lever on the pressure switch probably 3 dozen times and I could hear the control box click on and I would get a tiny pulse of water but the pump wouldn't kick on. Eventually I got the pump to kick on and stay on long enough for me to not have to manually engage the pressure switch.

I'm not sure if I have multiple issues at the same time. The pump taking three dozen attempts over the course of an hour before it finally cut on last night is concerning. My fear is the well has built up 50' of granite dust over the last 5 years and when I turn on the highest flowing faucet in the system, I'm sucking a giant slug of granite dust up from right beneath the pump.

Any ideas?

Thank you.



edit: Added static water level.

 

[WorthFlorida]

It seems the granite dust level is right at the pump intake causing it to jamb up. I'm no plumber and how to fix it? I would call the well company since others may have had the problem. One possible solution is raise the pump to 400'. Any nearby neighbors with a well?

 

[Sponsor]

 

[Valveman]

Could water be running backwards through the filter from the tank to the spigot? Might be back flushing the filter. If not, then opening a large spigot may be the only time velocity in the well pipe is fast enough to bring up and solids. They maybe just settling to the bottom when the flow is low. Cycling the pump on and off also surges the well up and down, which can stir up sediment. Also, have you ever just pumped the well hard for hours or days. It could be the well was never developed and you could pump out the granite and be done with it.

 

[DanGa]

It seems the granite dust level is right at the pump intake causing it to jamb up. I'm no plumber and how to fix it? I would call the well company since others may have had the problem. One possible solution is raise the pump to 400'. Any nearby neighbors with a well?

Two month ago my neighbor drilled a 400' well about 500 yards from mine. They had enough sediment that the well driller suggested a sediment sleeve for it.

 

[DanGa]

Could water be running backwards through the filter from the tank to the spigot? Might be back flushing the filter. If not, then opening a large spigot may be the only time velocity in the well pipe is fast enough to bring up and solids. They maybe just settling to the bottom when the flow is low. Cycling the pump on and off also surges the well up and down, which can stir up sediment. Also, have you ever just pumped the well hard for hours or days. It could be the well was never developed and you could pump out the granite and be done with it.

The well house is about 100' from the main house. The only thing in the well house is the well, pressure tank and an exterior spigot about 6' from the pressure tank. The sediment and carbon filters are in a utility room in the garage. So there's no way it is running backwards back to the well house, past the spigot tee and into the pressure tank tee.

I pumped the well hard for a good day when we first installed the pump as the well had sat for a year unused while we were building. But that was 5 years ago. I do have a low pressure cutoff pressure switch. And a cycle stop valve.

The overwhelming sediment surge has only ever happened when using the well house spigot that is 6' from the pressure tank. Even though that 3/4" hose spigot flows a bunch of water, does it even matter when comparing to the amount of water the pump itself is pumping into the pressure tank? I mean, 15 GPM into the pressure tank during a normal pump cycle is no different than 15 GPM into the pressure tank when using the larger spigot, right?

What I am unsure of is whether the pump itself is getting clogged causing my low pressure cutoff pressure switch to trip or whether the huge amount of sediment hitting the pressure tank tee/switch causes it. I believe it is the latter because I always notice the sediment in the hose right as pressure is dwindling and I go into the well house to see no pressure on the tank.

 

[DanGa]

I do believe the short term fix is to raise the pump if it is, in fact, sitting on top of a built-up bed of granite dust. My only concern is this last occurrence took quite a few tries to get the pump to kick on more than a short 1/2 second burst. Was the pump clogged? Is the start capacitor in the controller going out? Combination of both?

One other thing too. When this does happen, it clears up right away once the pump starts running again. So it's not like there is 400' of granite dust coming up the line. It really seems like a slug of sediment hitting all at once.