Sand point clogging and unusable.

[irrigator]

Hey guys, looking for some advice on driving a well point.
My location is at sea level. I live in a beach town in NJ. Soil is 100% sand, and water is found EASILY near 2 feet below adjacent grade. I'm not off grid, we have city water and sewer but I would like to pull ground water just for kicks. Strictly non potable.
I "washed" down a 1-1/4" PVC sand point and pipe to about 13' depth. Plenty of water! Level has never been below 5 feet. It is somewhat affected by the tide, but normally 2-5'.
I hooked up a transfer pump that I used to use for rain barrel. I fished a hose down the well and it pulled up good usable albeit brackish water, but continuous flow was not possible as the well was running dry. If I gave it a few minutes it would slowly refill. Turns out the well point is clogging with sand. The sand is pretty fine. If I poured water into the pipe, it is slow to drain also.
Next, I setup the well pipe for what will hopefully be normal operation. I fished hose down to the bottom and flushed everything thoroughly with city water until it ran clear. Pulled that back up and glued a threaded adapter on top of the pipe and affixed my transfer pump. Made sure to prime it well, but the pump was actually stalling out/overloaded. Hmm. Flushed everything again, lots of sand. Tried a traditional pitcher pump, same thing. Plenty of suction! But unable to draw continuous water.
Seems to me that the sand is so fine that its flowing into well point and jam packing it. So What are my options? Tempted to redrive a steel point and pipe with 80 mesh from Home Depot, but I am wondering if that would clog as well.

 

[Valveman]

You need to use a fine enough screen or point to keep the sand out of the well. Too small a screen and you restrict the water. Too large a screen and the sand gets in.

 

[Sponsor]

 

[irrigator]

You need to use a fine enough screen or point to keep the sand out of the well. Too small a screen and you restrict the water. Too large a screen and the sand gets in.

I used a PVC well point which has slots. Guessing the slots are too big to keep the sand from getting in. do you have any experience driving a steel well point? I see they sell a 60 and 80 mesh I don't know if that would be better

 

[Greenmonster123]

I would try digging by hand down 6’ or so, just below the lowest static you have seen if you can dewater your hole while digging. Lay your new stainless point horizontal surrounded in gravel. Fresh water will float on top of the salt and the gravel will help keep the sand out. That’s how they used to be done near the beach here.

 

[Reach4]

I would try digging by hand down 6’ or so

Dang, you are energetic!

If I were digging a well, I would not put a point in it, but rather put a lining and use a submersible.

 

[Greenmonster123]

Dang, you are energetic!

If I were digging a well, I would not put a point in it, but rather put a lining and use a submersible.

I wouldn’t dig it by hand, I would use my mini excavator lol. OP seemed like he was looking for weekend projects

 

[irrigator]

Update, I drove a new steel well point with 80 mesh. It was any easier, but I am down to 15 feet with it. Still the same problem. I am unable to pull up water. The point and pipe are just clogged with sand slurry

 

[1984]

I think greenmonster123's idea could work, but maybe try digging a much wider hole than you think necessary. I have no idea how wide, but probably at least several feet across. Then fill in that hole with a well-mixed mixture of fine and medium gravel plus coarse sand.

Don't use gravel that's evenly sized. If you do, that will leave gaps or "air pockets" that will allow the fine sand to flow through. (The worst kind of gravel to use will be gravel that's about evenly sized and rounded/polished.) Hopefully the addition of coarse sand will fill in the gaps that are in-between the gravel fragments, but there needs to be enough coarse sand for this to work.

Hopefully this "buffer" of several feet of gravel mixed with coarse sand will help limit the flow of the surrounding fine sand into your pipe. I've never tried this and have no idea if it'll work, but it's a suggestion.

 

[Valveman]

Update, I drove a new steel well point with 80 mesh. It was any easier, but I am down to 15 feet with it. Still the same problem. I am unable to pull up water. The point and pipe are just clogged with sand slurry

Probably not clogged by the formation is just too tight to let water flow. Is there water standing in the pipe? Will the pipe take water if you pour some down? A well that can't take water easily also cannot make water easily.

 

[irrigator]

Probably not clogged by the formation is just too tight to let water flow. Is there water standing in the pipe? Will the pipe take water if you pour some down? A well that can't take water easily also cannot make water easily.

I stopped the project at 17-ft depth. I'm exhausted! I have flushed the pipe from top to bottom with a 20 ft stick of pipe and garden hose. Flusting good amount of fine sand sludge. Still not able to bring water up despite a large amount of suction by the pump. Flushing again does not produce much debris. And fishing the pipe down the galvanized does not feel like there is any obstruction or sand.
Could it be that only the screen is clogged?
By manipulating the PVC pipe up and down using my hand and creating suction I can draw water up the bottom.
It is not a situation where I can pump water into the well pipe and it will not spill over. So water is not flowing freely through.the.screen. what do I do now?

 

[Valveman]

Are there any other sand point wells in your area? Might not be possible in that area. Got to have a water bearing sand formation at less than 25' for a sand point to work.

 

[irrigator]

Are there any other sand point wells in your area? Might not be possible in that area. Got to have a water bearing sand formation at less than 25' for a sand point to work.

I know of a few at roughly 15' depth which produce usable water

 

[WorthFlorida]

I know of a few at roughly 15' depth which produce usable water

Are they closer or further from the shore line? From your trials it seems that this water, mostly rain water is sitting on top of a salt water. This fresh water is not underground feed, no rock formation or springs. It'd be interesting to figure out how some can get enough water. You can look up your local co-operative extension in your county and ask for a geologist that may know if the area can provide fresh water.

 

[irrigator]

Are they closer or further from the shore line? From your trials it seems that this water, mostly rain water is sitting on top of a salt water. This fresh water is not underground feed, no rock formation or springs. It'd be interesting to figure out how some can get enough water. You can look up your local co-operative extension in your county and ask for a geologist that may know if the area can provide fresh water.

Really equal in distance to the shoreline. All, including me are on a barrier island

 

[irrigator]

So since I am Able to raise and lower the inner pipe and draw water using my hand as a check valve, now I am thinking why not just add a check valve in line. I should be able to draw water up from that simply by raising and lowering the pipe. If I do some plumbing above the check valve I can have the water aimed at a container on the ground. I'll try it

 

[Valveman]

That is called a bailer. If you can bail water out you should be able to pump water out?

 

[irrigator]

That is called a bailer. If you can bail water out you should be able to pump water out?

Oh ok. Well I wasn't able to pump with my pitcher pump. Maybe a more powerful pump could do it. Really not sure. My pitcher pump makes great suction but seems limited by the shortness of the stroke.

 

[Valveman]

I am kind of that way myself. Lol! You can at least get an idea of the GPM with a bailer.

 

[Etbrown4]

Irrigator,
Did you get the well working?

I have nearly the identical setup and depth in fine sugar sand on the nc coast. Like yours my water is about 3' below grade.

My sandpoint is at 18' and connected to a 1 1/4 pvc well pipe. Above grade i have a 3/4 hp centrifugal well pump and it flows about 9 gpm.

I have seen the well point fill with 3' of sand and like you, have once flushed the well point with a water hose, operated from ground level. Have been able to run lawn irrigation for a year between cleaning.

 

[Valveman]

Sounds like you need a finer screen on the sand point.