Sand/Gravel In 2" Well Pipe - Now What??

[Bob99]

Hi All,

We are new owners of a rural property with a 2" galvanized pipe shallow well that has a standing pipe extending 4' above a gravel driveway surface. It was not securely attached and someone knocked it off and sand and gravel dropped down the open 2" pipe. Shortly thereafter, our pump started producing dirty water at the tap, then lost its prime. I have been unable to re prime it. There is a subterranean 1-1/4" poly pipe running through the concrete crawlspace floor of our home back to the well pipe (6' below the surface). It is connected to a shallow well pump with check valve in our crawlspace.

Any ideas on how to correct this unfortunate incident?

Thanks,

Bob

 

[Valveman]

If it is a sand point, probably easiest to pull the point, clean out the gravel, and drive the point back in.

 

[RS]

If you can't pull the sand point, you could possibly blow it out with compressed air, if the gravel isn't too large a chunks. You would need a large air compressor, like is used to run a jackhammer, and about a 1/2 tube long enough to reach the bottom of the well. If the well isn't too deep you might get by with a shop compressor, if it has at least a 20 gallon tank. Pump it up to it's maximum pressure and the turn on the air, it should blow the silt and gravel out the top.

 

[Bob99]

If you can't pull the sand point, you could possibly blow it out with compressed air, if the gravel isn't too large a chunks. You would need a large air compressor, like is used to run a jackhammer, and about a 1/2 tube long enough to reach the bottom of the well. If the well isn't too deep you might get by with a shop compressor, if it has at least a 20 gallon tank. Pump it up to it's maximum pressure and the turn on the air, it should blow the silt and gravel out the top.

Thanks for your suggestions. With a 1-1/4" poly running inside a 2" galvanized well pipe, I'd have about 1/2" of gap down one side to push a compressed line down to the bottom. If any stones fell into the pipe, I think they'd get stuck sitting on top of the 1-1/4" poly where it enters the galvanized pipe from the side (6' under the surface) and not fall to the bottom don't you think? I'm thinking of using a flexible plastic hose attached to a shop vac to pull that stuff out and then hire a company to blow compressed air and water to the bottom to blast the stuff to the surface. Does that make sense? Can I try disconnecting the 1-1/4" poly from the pump in the crawlspace and get an industrial strength vac attached to that hose to try and suck the sand/small gravel from the well that way or is the bottom of the pickup pipe too far from the bottom of the well?

 

[RS]

I didn't realize that the poly ran down into the casing, that presents a problem, any way to get it out for cleaning? There must be a foot valve on the bottom of the poly, which would almost block off passage of an air line. A shop vac may work, but at lower depths I don't think it would .

 

[Bob99]

I didn't realize that the poly ran down into the casing, that presents a problem, any way to get it out for cleaning? There must be a foot valve on the bottom of the poly, which would almost block off passage of an air line. A shop vac may work, but at lower depths I don't think it would .

I’m told it enters the 2” well pipe about 6’ below the surface so I assume the only way to get it out is to have a back hoe excavate down to find the line and pull it out. The well drilling company told me that if there is a check valve near the pump (which there is), there wouldn’t be a foot valve at the bottom of the well on the poly tube.

 

[Valveman]

Probably has a pitless adapter. No need to dig. Just need a 6' pipe to thread onto the pitless and pull it out. With 2" casing and no deeper than it is, after removing the 1 1/4 drop pipe, you might extend a shop vac to the bottom and suck up the gravel.

 

[RS]

I have never seen a pitless adapter that would work in a 2 inch casing, but they possibly exist. Our last home had a 4 inch well, and the pitless was mounted in a saddle so that a standard 4 inch pump would clear.

 

[Bob99]

Probably has a pitless adapter. No need to dig. Just need a 6' pipe to thread onto the pitless and pull it out. With 2" casing and no deeper than it is, after removing the 1 1/4 drop pipe, you might extend a shop vac to the bottom and suck up the gravel.

Thanks for your reply. The well drilling company called me this morning after a site visit yesterday afternoon and I now understand how our well works.

They tell me the 1-1/4” black poly pipe that is attached to our pump in the crawlspace is connected to the SIDE of the 2” galvanized casing (we believe 6’ below the surface) with an AIR SEALED fitting. It doesn’t go down the well to the bottom to pick up water like I assumed. This setup relies on a SEALED WELL TOP to allow suction to be created when the pump is turned on, drawing water up the 2" casing from the water table and into the 1-1/4” black poly pipe attached to the side of the 2" galvanized well casing and to the pump. Without a sealed standing pipe at the top (ours was knocked off), priming is not possible.

They say the initial step is to have our plumber re thread the well pipe top (it sits about 8” below the driveway surface), replace the standing pipe, make sure all of the threads are sealed and then prime the pump. If it doesn’t pick up sand/stones then we are all good. If it does, they will have to come out and clean out the well either using their rig to go down the centre of the 2” casing, or in the alternative, if the well is producing enough water, they can use a gas powered vacuum to suck the sand/stones up (carried up by the well water - if there is enough water to do so).

It is possible that once we re thread and seal the well, it will prime without a problem and we’ll just have to run the water for a time to flush out the dirt. The only thing I didn't understand was, if our well is drilled to 100' (common in the area) and the water is sitting in the pipe within 25' of the surface (it must not sit lower than that or a shallow well pump wouldn't work), how can any gravel dropping down from the surface get picked up from the bottom of the hole? Maybe if the water production is low, the pump is strong enough to create turbulence, stir the sand up and carry it along with the water? I guess we'll see what happens tomorrow when the plumber comes to rethread the standing pipe connection.

Thanks again for your reply.

B

 

[Valveman]

Working like a sand point you are correct the gravel at the bottom should not be sucked up the 2" casing. Just clean out the gravel from the pipe, seal all the connection and you should be good.

 

[Bob99]

Working like a sand point you are correct the gravel at the bottom should not be sucked up the 2" casing. Just clean out the gravel from the pipe, seal all the connection and you should be good.

Thanks, the plumber will rethread the 2" cast iron pipe at the ground level and attach a new standing pipe using a new coupler tomorrow. Then we'll see whether we can prime the pump and what quality of water we get. Hoping for the best.

 

[Bob99]

Probably has a pitless adapter. No need to dig. Just need a 6' pipe to thread onto the pitless and pull it out. With 2" casing and no deeper than it is, after removing the 1 1/4 drop pipe, you might extend a shop vac to the bottom and suck up the gravel.

@ Valveman, after doing some reading , I now understand what a "pitless adapter" is. I suspect that is what is being used to connect the 1-1/4" poly hose to the 2" galvanized well casing. It's fun figuring out how things work. Thanks for you post.

 

[Valveman]

@ Valveman, after doing some reading , I now understand what a "pitless adapter" is. I suspect that is what is being used to connect the 1-1/4" poly hose to the 2" galvanized well casing. It's fun figuring out how things work. Thanks for you post.

May not be a pitless. Being used like a Sandpoint the 1 1/4 poly can just be attached to a tee or elbow to the 2" casing.

 

[Bob99]

May not be a pitless. Being used like a Sandpoint the 1 1/4 poly can just be attached to a tee or elbow to the 2" casing.

The way I understood it from the guy at the well drilling company, there is no poly pipe running downward towards the water table at the bottom from the attachment fitting. There is just the poly pipe attached at the connection point running from the 2" casing hortzontally back to the pump in the house. The well standing pipe is sealed at the top and when you prime the pump and run it, the pump creates a vacuum and sucks the water up the 2" casing and through the adapter, into the horizontal buried poly pipe and to the pump. It sounds strange to me, but either way, if there is a pitless adapter with poly running downward into the water, it can be removed from the topside if need be and they can get tools to the bottom to clean out any sand/gravel. The pitless explains (to me) how cleanup tools and 1-1/4" poly can occupy the same space (albeit not at the same time).

 

[Valveman]

A pitless is made to hang drop pipe inside the casing. If there is no drop pipe, there is nothing for the pitless to connect to. Probably going to just be a tee out the side of the 2" casing that is necked down to 1 1/4 to attach the poly pipe going underground.

 

[Bob99]

Makes sense. I’ll have a better idea when I meet with the plumber tomorrow morning.

 

[Bob99]

Update...

The plumber showed up this morning with a plan to re-thread the 2" galvanized male pipe end coming out of the ground (the well casing) and re-fit a shorter standing pipe to not come above the surface of the gravel driveway (I know, not exactly code). It turns out his pipe thread tool had a 30" arm on it which would have required us to excavate 10" down and 3' out side so he could cut the well pipe shorter and re thread it. Instead, he cleaned off the threads with a wire brush, added teflon tape and pipe dope and refitted a shorter section of 2" galvanized with a cap.

While the plumber was getting the piece ready, I took a powerful flashlight and laid flat on the ground to see what I could see in the 2" well pipe. It turns out a collection of 3/4" stones from the driveway were packed in and blocking the well pipe about 6' from the surface (not good). After some discussion the plumber went back to the shop to get a large shop van with a 1-1/2" hose and he was able to vacuum the stones out. What we observed after was a thin metal rod crossing the inside of the pipe (horizontally) at the point where the stones had accumulated. I observed standing water about 2' below that level. So, the stones must have fallen into the well casing from the driveway and gotten jammed in there.

The shorter standing pipe was fitted and sealed. Afterwards the plumber primed the pump and had me turn on the water to a utility sink in the mud room of the house (mistake). Water started coming out (with some air) and then ran steady, but with a greyish colour. I say "mistake" because the home has a water softener with no bypass piping installed. So, everything coming out of the well went through it first. I had already shut off the sumply to the hot water tank, so no gray water in there. We should have just tested the water at the outdoor hose bib before turning water on in the house. Oh well - next time.

I ran the water for about 10 -15 minutes and it was slowly getting clearer. I'll run it for a couple of hours when I'm back at the cabin this weekend. Hopefully it will clear up and that will be the end of the story.


This standing pipe will have to be shortened at least 4". It is just high enough to catch the oilman of a sports car!@


Center is bottled water, right is from kitchen tap, left is from the main bathroom.

 

[Bob99]

So I came back to the lake on Friday, turned the pump power back on at the breaker box and it immediately started running. That isn't good news because it means the pressure has somehow dropped in the well system. The pump ran for a bit re-primed itself but air mixed with water was coming out of the tap along with a fair bit of turbid water. I found that if I left the garden hose running for an hour, I had perfectly clear water but after I shut it off and didn't use water in the house for several hours, I would get the same sputtering (air/water) along with dirt.

I'm thinking air is getting into the system, but from where? Either the well standing pipe the plumber attached is not sealing, or the check valve at the pump is leaking from sand stick in the seat and allowing water to run back into the well, replaced with some air? Does that make sense? And then, when the pump has to re prime itself, it stirs up what has fallen to the bottom of the well and that is what is coming out of the tap?

 

[Valveman]

It is hard to make a steel threaded fitting to seal air tight. I don't even like a priming port on the suction side of any pump for that reason. It is also not good to have a high spot in any suction line like that stub up with the cap. Air accumulates in the high spot. I would prefer an elbow instead of a tee underground.

If you don't see a leak on the floor, the water went back through the leaking check valve. That and an air leak at the well head would cause the problems you mention.

 

[Bob99]

It is hard to make a steel threaded fitting to seal air tight. I don't even like a priming port on the suction side of any pump for that reason. It is also not good to have a high spot in any suction line like that stub up with the cap. Air accumulates in the high spot. I would prefer an elbow instead of a tee underground.

If you don't see a leak on the floor, the water went back through the leaking check valve. That and an air leak at the well head would cause the problems you mention.

Thanks. That is what I suspected as well. The plumber will be out in the next day or so. He should have cut new threads on the standing pipe coming out of the ground but cleaned them up instead and used pipe dope and tape. We'll have another look at that. Check valve is going to be removed and cleaned out as well. Hopefully that fixes it.