I am fairly ignorant when it comes to wells, so please bare with me. I have two wells on my property. One deep well in my yard that I currently use, which is very iron rich. The other I recently discovered because I never knew what it was. Underneath a concrete slab in my basement is what my neighbor told me, an artesian well. It is approximately 3 feet in diameter, concrete, and travels an unknown depth from my basement floor. I was told it could provide plenty of water that is not iron rich and quite tasty. When I uncovered it, it had about 6 inches of what looked to be stagnant water, and under that, sand. The sand seemed to sink quite easily as pressure is put on it. Is it normal for the sand to be there? Does this sound like a usable well? If so, what would be my course of action to utilize this well? Thank you for your help.

 

It sounds like an abandoned well, possibly an old hand dug one. It was probably filled with dirt, rocks, sand and whatever else they could find when the modern deep well was drilled. Usually the old hand dug wells are taping into water that is close to the surface which is more easily contaminated and I don't know if modern codes allow the use of them. An old well be be grandfathered in if has been in continuous use but I am almost certain they would not allow reconnecting to an abandoned well.

 

Im with pilot dane. I would say it may just be the water table. You may be able to pump it with a point of some sort and see if it recovers any. Artesian wells are under pressure and not subjet to the movement like ground water. It all depends on the source.

I would pump it and see how it recovers. I would only use for irrigation if anything, but have it tested anyway. If its contaminated you may indeed contaminate another source of drinking water somewhere.

Alot of times also old sump pits were dug. At least the house I grew up in had one. All the houses had them. Same thing, move the lid and water was there. As a kid we were amazed by this. It was ground water at the water table and my father pumped it to water his lawn.

Mike NJ

 

Artesian wells are under pressure and not subject to the movement like ground water.


All wells ARE under pressure and all wells ARE subject to movement be it hand dug or drilled.

Well 'A' is 100 feet deep and the water table is 50 feet. =21 psi at the bottom pushing water up to the 50 foot mark.

Well 'B' is 100 feet deep and water table is 100 feet 1 inch. =43.5psi at the bottom pushing the water out the top. (Artesian well) The term was used to describe a well that flows. When in all actuality all wells can be called artesian wells, some just have more pressure than others.

Both wells are under pressure, one just has enough pressure to flow out the top of the well casing where the other does not.

Both wells have water in them that came from somewhere else. All wells are subject to moving ground water. Some just move faster than others.



As far as using the water under your house?

Lawrosa, just about summed it up.
I would only use for irrigation if anything, but have it tested anyway. If its contaminated you may indeed contaminate another source of drinking water somewhere.

 

i agree w/ the dude.. ive almost gave up trying to explain this.

around here there is artesian, and flowing artesian.



i can drive 15 minutes down the road and this same well might have a 30' water level due to elevation. both are are artesian wells, both are drilled into the same "floridan aquifer" with the same water quality, one just happens to "flow" or "free-flow". i was always told that any well with a water level that rises above the confining layer is technically considered "artesian".

i have no idea what could be under the house.

 

Movement as confined versus unconfined aquafiers.

Artesian aquafiers are confined.

Some water in artisian basins is said to be 1 million years old because they are so large. The one in Austraila is the size of Texas.

Other aquafiers are unconfined and move ground water freely from surface to the soil pores and fractures and back. The watertable (upper layer of saturation) is where saturation starts, but below that is complete saturation.

This does not make sense. How could the water table be lower then the well? How does a 100ft well push water up to the watertable?

I am just trying to understand that.

Hopefully the OP will learn from the pics that he just has ground water in his basement.









Mike NJ

 

I see what your saying about the confine vs unconfined

What the bottom does not show is the sand that the well is in may only be 10ft thick.
The pressure on the water sand may be enough to push the water in the well as high as 10 ft from the top of the well.
That is the problem with online pictures, they dont tell the whole story.

I don't think a 100 ft well is pushing water up 50 ft to the water table. That does not make sense to me.

As you have said as the aquifer is recharged the pressure in it goes up. Hence the 50ft water level.
We have wells here on the gulf coast that are 90 feet with a water table of 7.
Now if you have a well in a rock that is 100ft and there is only 20ft of casing, the water may be coming in to the well at say 100ft and 80ft but the water at 100ft has a higher pressure than the 80ft water, the 100ft water will go into the 80ft water and water level may never get over 80ft.
Wells in sand don't act this way. They are cased all the way down to the sand and a screen at the bottom, and grouted or cemented from the bottom up and sealed at the top.
The only water that can get in is the water that is at 100ft, and depending on the pressure on the water, the water level could be anywhere from the top of the water bearing sand to a flowing well.


There is no such thing as a confined aquifer.
If there is no way to recharge it, its called a hole, not a aquifer.
If water cant get out, and also cant get in, its called a void.
If water can get in and then is pump out, its called an aquifer.

And yes water will seek its level.
If the (confined aquifer) is 100 feet under ground, and the are no wells or cracks for the water to get out. The water level in it would be at the top of the ground or 0 feet.
Then someone puts a well in it, and starts pumping the water level will fall until it is refilled from the recharge zone. Then its not confined anymore.
If it never gets a well or crack in it, its just a big hole nothing more nothing less.


Some water in artesian basins is said to be 1 million years old.

Very true.
I have a solid rock about the size of a baseball that has a small amount of water in it.
Even so, it sill called a void or hole if it has no recharge zone.

 

I think well dude meant that the well is 100 ft, the water level is all the way at the top plus one inch, or free flowing out the casing. In other words, there would have to be about 43 psi of pressure at the bottom of the well to push the water up 100 foot.

WWD also I think geologists use the term confined vs. unconfined to describe the layers of material on top and bottom. Water can still get through the "impermeable rock", albeit at a very slow rate. The unconfined water is what me and Justin call "ditch water" LOL. It's the stuff everybody makes the home-made wells down to.

 

Yes and you can get water at the 7 ft. But How reliable would it be. That water table does not stay at 7 ft. It fluctuates with climate. Deep wells are more stable with the supply of water. The pressure is the water above it pushing down on the lower level of water.

If the 100 ft has higher presure then the 80 ft the the 100 ft is a artesian aquifier (confined) and the 80 ft is unconfined. They may be both confined aquafiers at different pressures. It would be two artisian aquafiers on top of each other, with different water table levels.

Did you see my pics???? I was editing my post a few times. I notice while editing, people can view the original.

Ground water feeds both types but there is a difference. Do a search of aquafers vs artisian aqufiers and you will understand what I am saying.

Mike NJ

 

Thank you all for the responses and explanations. It is my understanding, based on the responses, that I have nothing more than a ground water well that has been filled with sand... perhaps when the water was tainted or did not provide enough supply for the house. Ground water has just come to the surface of the sand as the water table has risen... thanks to the non-stop rain. I suppose I should have included these with my initial post... a couple of pics of the well.

 

IMG_20110520_010157 | Flickr - Photo Sharing!

IMG_20110520_010218 | Flickr - Photo Sharing!

 

i agree on the unconfined and confined. unconfined in this area is like TW said.. "ditchwater"

tons of wells made into the "first rock" around here are within 100' and have water levels as shallow as 6". the water table has changed little to none in 25 years. i've drilled some 2" wells that produced over 100gpm. drive 15 miles and the well might be 120' and have a 65' water level. its different everywhere, those charts are only good for the area it was made in.... and unless a seasoned driller drew it up, i wouldnt even trust it.

a million years old... LOL heck why not 10 million? they know that about as much as they know the weather.

wow, those pics are wild Nick.

 

Cutti those pics are gross.....LOL


You talking drawdown of only 2" or 6"? Probably a artesian aquifer was tapped. Your not scratching 2" below the surface and pumping 100 gpm.......


Probably a unconfined aquafier and when you pump the water, the level drops alot from 65'. (draw down)

I think you guys are just toying with me. You are just water and the other guy is well water dude.....You should know all this stuff.

Water

Mike NJ

 

i think u read me wrong lawrosa, i meant 2" diameter casing... the well might be 100' deep with 80' of casing set on rock and the rock drilled out open bore, but water level can rise (from that rock) to within feet of the top of casing when finished, and water level fluctuate very little to none over time. and drawdown very little when pumping. subs are usually set 20-30' below the water level in my area. usually plenty of water around here... u just have to be able to get to it, thats the real challenge here.

lol, i'm not toying with u.. just informing u that wells are different everywhere and they can change fast from location to location, which is why they call this a unique business. lol, i only claim to really "know this stuff" in my area.

i dont drill ditchwater, i case it out and get real water. all the wells i drill are from confined zones. in that 120' well with the 65' water level, it will have around 100' of grouted casing.... and i can drop a 25gpm sub at 75-85' and run it full flow for as long as you desire.

fyi, the well in that pic is about 500' (i have some over 700 that flow, some 700 that dont). there are usually 3 different confined water zones to make a well around here.