Sand in well water

[Big Archery Nut]

I recently bought some land with an existing well. It has a 2" well casing and a 1" drop pipe with a jet pump. Total depth is 55' with the drop pipe down 40'. It had sat unused for about six years and I'm not sure how old the well is. I replaced the pump and drop point and the ejector two years ago. This spring my flow went from five gallons a minute down to one gpm. We pulled the drop pipe and then the 2" check that was above the point. All looked good. We filled the pipe and it held water showing us that the point was plugged. With some effort we pulled the 1-1/4" point. It was plugged with sand and corrosion. We replaced the point with a new 60 gauge point and sealing check valve. We then put down the drop pipe and installed the pump. We got it running and now I seem to continually pump some sand. If I let it run for about 3 hours the sand quits coming. Once it sits for a few hours I pump sand again. Is this normal? Does it need to run for a while to clear this up? We think the new point is as fine of screen as the old plastic screen point. Should I have used an 80 gauge point instead of the 60? Is there a way to determine the proper screen guage? Is it normal to pump some sand after replacing the point? Never noticed sand before. Any ideas?

Thanks

 

[Speedbump]

Yes it is normal to get sand for a while. But once it clears, it should be done pumping sand.

My big question is how did you get the old point out and the new one back in? I have only done maybe 3000 + screen changes in my lifetime. We use a rig set up to do this and we use water jetted through the rods to wash the sand and gravel out of the end of the pipe after we pull the screen and Bremer check. If you just pulled the screen and put one back, you didn't pull a heave which is very unusual. Once you heave sand into the casing, you can't put a new screen in until you clean it out.

As for what screen should be used, without looking at the material down there, there is no way of telling what screen to use. Your only seeing the fines which don't mean anything.

bob...

 

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[Big Archery Nut]

The guy that helped me has done quit a few wells so I believe that he has done this before. He had a tool called a carrot which works like an easy out. That is attached to the end of a length of 3/4" rigid pipe. We drop that down and add lengths of pipe until we got to what you called the Bremer check valve. It threads into the end of that and then he used 2 large jacks to pull it loose. For the old point he uses a home made rig which is an 1-1/4" tap welded onto a coupling which is reduced down to a 3/4" pipe. We drop that pipe down and threaded that into the coupling on the drop point. This took a lot of effort to break it loose. As we pulled up the point we poured water down the 2" casing to keep sand from being drawn up as we lifted the pipe and point up. Once done with that he has another homemade fitting that has a spade type end with a hole and a check valve in it. He lowers that down into the casing adding lengths of pipe till we get down to the bottom of the casing. We then keep pouring water into the casing as he pumps the spade up and down drawing the sand that is in the casing into the 3/4" pipe which is attached to this spade and check assembly. We did this three times to remove the sand from the casing and it also goes past the end of the casing into the sand/gravel bed. Once cleaned out we dropped the new point down the 2" casing. He threads a cap onto the 3/4" pipe drops it down until it hits the coupling on the end of the drop point and hammers it down until it seats in the foot valve on the 2" casing. We then drop in the new Bremer check and he seats it the same way.

Sorry this is a little winded but I hope you understand. Do you feel we just need to run the pump enough to clear out the sand that was still in the casing? Will this hurt my pump? We are only at our land every other weekend and so the well does not get used a lot.

 

[Speedbump]

There is no foot valve in the bottom of the casing. You have that confused with something else. The Bremer Checks I am familiar with have a bail on the top that can be caught with a tool called a check grab. I enclosed an attachment of a Bremer Check. If you only filled the 3/4" pipe three times, you didn't get much sand out. If you didn't get out all the crud that was around the screen, it will just plug up faster next time.

Pouring water down is an old trick used by lazy drillers who wanted to save one step. Washing the well out. Not adding water is what gets all the crud that was on the screen and some additional sand up into the casing when the screen is pulled. Then you go back with circulated water and wash all the sand and crud out. This is when you add the water so you don't heave it again while pulling out the rods. Then you drop the screen, beat it out the end of the pipe, drop the bremer, smack it real good with a plunger on the end of the rods and go to pumping with the plunger. This is what develops the well and gets the fine sand out.

You can use your pump to clear the well, it shouldn't hurt the pump to pump a little sand. Hours of sand pumping shouldn't even be noticable.

bob...

 

[Big Archery Nut]

I was wrong with the foot valve. I meant to say drive shoe. The Bremer valve is what we used. It also has a check in it.

So if I have this right on the end of the 2" casing there is a drive shoe that the drop point seats into and the screened point sticks out into the sand and gravel bed. When you replace that point you need to clean that area below the casing or the fine sand that was there will just plug up my new point? Are you saying that over years of use that pocket of sand and gravel fills up with fine sand plugging up the point? Did we do all of this for nothing?

 

[Speedbump]

The drive shoe is just a heavy duty coupling used to keep the end of the pipe from getting buggered up.

The screen is simply knocked into the sand below the drive shoe. Usually a 1' piece of pipe is on top of the screen, this is left in the casing for the Bremer to sit on.

The sand isn't what plugs the screen, mineral build up over the years plugs the slots. The fine sand is pumped clear, then the pump is hooked back up.

Whether or not you did this for nothing depends on if the sand stops or not and if you get the amount of water you were looking for.

bob...

 

[Big Archery Nut]

What they use up here is a 3' drop point. Looks like a point you would drive without the large tip. The tip is flush to the case of the point. The 1-1/4" coupling on the end on the point stops inside the drive shoe. You need to pull that up the casing when you change it out and drop the new one down it.

Sounds like I may just have to run the pump a little longer to clean out the sand.

 

[steven-sr]

I have been following your discussion on the construction of a 2" cassing. I have a 2" well that I think the screen is pluged. The volume of water that I can pull from the well is low. The pump is new and is a 1 HP deep well with the jet in the bottom of the well on the end of a 1-1/4" drop pipe.

What I am not undering from your thread is what keeps the screen from dropping out of the bottom of the cassing? If I understand right, once you get the Bremer check and screen out and flush the debree from the bottom of the cassing, you drop the new screen down the cassing. If the screen will drop down the cassing, what stops it at the bottom of the pipe.

While jetting out the cassing, wouldn't it be possible to dig below the end of the cassing?

When I drop a weighed line in the cassing it measures about 80 feet. The drop pipe measures abour 42 feet.

Steve

 

[Speedbump]

Steve,

Its hard to keep the hole open below the casing (practically impossible) actually. If you aren't careful after jetting out the casing and keeping the hole full of water, the sand will heave back into the casing as much as 15 feet. They you go back in and do it all over again. So when you throw the screen in, it will stop at the bottom of the casing and you must hammer it back in place.

As for the 1' of pipe (called a Blank) it was to keep the Coupling and Bremer in the 2" casing. I knew one guy who welded a ring around the inside of his Drive Show and one around the Coupling on the top of the Screen so it couldn't go out the end. Seemed like a lot of wasted time to save a couple of dollars worth of pipe.

bob...

 

[steven-sr]

Bob

Is there any way to determine just how deep the cassing is? Or do you just drive the point bach to the spot that you pulled it from?

So reading your replies to Big Archery Nut, It looks like once you retreve the check and screen, you pump water down a pipe that you insert into the bottom on the casing to flush the sand from the cassisn. I once dug a 2" well through 50 foot of solid clay using a water jet. I drove the casing as far as I could then pumped water wthough a 3/4" pipe with a spade on the bottom of it with two 1/4" holes drilled in it as jets. I would work it up and down digging the clay from the bottom of the cassing. as the water flowed out of the top of the 2" cassing, it would bring up the clay with it. I am assuming that this same method could be used to clear the sand from the bottom of the cassing.

Then I should continue continue pumping water into the top of the cassing while I retract the flushing pipe so it wont heave. then drop the point with about a foot of 1-1/4" pipe attached to the top to garentee that the point stays in the cassing, ddrive it tto the point where it originaly was and drop the check in and seat it by rapping it with the same plunger that I will pump with.

Then I can pump with the plunger and let the water flow out of the top of the cassing untill the water runs clear.

Then connect my pump back up.

Does this all sound correct? I think I am understanding all that you said correctly.

Can I purchase the point and check from you?

It looks like I can make a tool to retreive the check, but should the point have a 1-1/4" NPT female thread on it? Even if they used the 1 foot extension on top of the point?

Thanks for time,
Steve

 

[Speedbump]

It sounds like you have done this before. Your description is right on. The only thing I did different was use 1" pipe for jetting. We also used a 55 gallon barrel cut in half and a flow head on top of the well made of 3" pipe that made it possible to catch the cuttings and recirculate the same water. Once you get to the end of the pipe after pullling the screen and while washing out the heave, the well will start drinking the water out of the barrel letting you know you are out into the vein. There are lots of little tricks that we used. We also marked the 1" pipe after we screwed into the screen to know where to put it back to.

To pull the screen is harder than it would seem. We used a set of jars which would slide in and out of them selves for about 3.5'. The jars and a walking beam on the rig made it possible to hammer the screen up and down to get it loose and out of the vein and up through the casing. It is the build up of mineral on the screen that made it so hard to pull. Stainless Steel Screens (which practically everyone but me used) would pull right out of the encrustation and leave it in place. This is not conducive to a long lasting new screen.

bob...