Shallow well drilling-jetting

[Chipper]

I need to jet drill a shallow well for irrigation. I've never done this but I saw some old-timers do it when I was a kid.My questions:
Can you use PVC or should I stick with Galv.
Will I be able to remove the pipe after I hit water and install a well point or is it easier to drive the point down vs jetting.
Anyone know of any links to how-to sites.

 

[DaveO]

Wow, I have no clue. But I look forward to reading the responses you get. This could be a skill that will come in handy very soon in the Raleigh area.
Dave

 

[Threejs]

I guess I could tell you what I have read in the foxfire books, but it won't do you any good. :nah:

 

[Gofor]

My experience was watching the guy do it for me in FL. [Shallow (33') well for lawn irrigation] However, being he was very good and talkative, I picked up some tips. (I ended up with a 55 gpm @ 40 psi volume where two neighbors who went with the lowest bidder ended up with 12 gpm at 20 psi).
First: steel pipe will be more ridgid and less tendency to bend off on its own as it hits obstructions (hard clay, tree toot, etc). PVC is too flexible.
Second, If the water stops coming up out of the hole bring your "drill" back up immediately. Otherwise, the silt will pack in along your "drill" and make it almost impossible to remove.
Third, put a sleeve on the forward tip of your "drill" at least as large as the well casing (pipe, screen and any PVC connectors that hold it together). Ex: If your well pipe is going to be 1 1/2" PVC, use a 1 1/2" steel pipe to drill and put a sleeve on the end to increase the diameter of the hole large enough so the connectors on the pvc will drop down in it. You may be able to use a 1" steel pipe to get more velocity at the drill, but you still will need almost a 2" diameter tip to blast a big enough hole for the 1 1/2" pipe and connectors.
If your drill does get seized up, you may be able to run another smaller pipe down alongside it to free it up. (That happened also and they used 3/4" schedule 80 for that).

Down there, the "soil" was mostly sand, and the guy knew when to stop when we started seeing crushed shells coming up for about 12" of depth. The porous shell layer let the water flow enough to replenish the well point as fast as it was pumped out. The "lo-bid" guy stopped at a 2" layer that wasn't as deep, and it did not provide enough water to the well point. I don't know what guage you would use to determine a good water flow unless you have some neighbors that have wells that can give you a depth estimation.

The only other well I watched being drilled (I was about 6 yrs old) was when my dad, uncles and grandpa dug one using an auger-type post-hole digger (12"d) that was made to use 3/4" pipe. They constructed an A-frame and went down almost 100' (twist down with pipe wrenches about 6" and pull up and dump and then back at it. After 10', it meant disassembling/reassembling pipe at joints every 10' up and down. Took several weeks and a whole bunch of cussin' when they went too far and had to get the car and a block & tackle to pull it up, not to mention a wagon load of beer. My dad inherited the post hole digger, and my older brother inherited it when Dad died. I can probably get it for you if thats the way you want to go. (By the way, they drilled where a guy using a willow witching stick told them as 2 previous attempts came up dry. Where they drilled it came up as an artesian well with water coming up to about 6' of the surface level).
Haven't used a well point hammered in, so can't comment on that. Those that tried it in FL ended up with smashed well points when they hit a layer of hard pan.

Hope this helps

Go

 

[Chipper]

Thanks Gofer, Your comment about watching the silt for flow is the important piece of info I was missing. I should have water at 15 or 20 ft. as we are only at 20ft above sealevel. I found this article on the net but I think it it lacks some of the import stuff such as the part about getting the pipe stuck and why. View attachment wellinstallation.pdf

 

[Joe Scharle]

I'm from Va Beach and drove a couple there, but never tried it here. It will work if the water table is high enough (<20') where you live. Basically, you keep dropping a weight onto a strike collar that's first screwed to a wellpoint pipe and then onto each 4' section thereafter. Hosing in some water helps too. Pump it with a shallow well jet pump.
Joe

 

[sapwood]

:eusa_thin That's a much better technique than the one I learned. We started with a 3 foot diameter bore until hitting rock at 12 feet. A few sticks of dynamite later, my dad and his friend put me in a windlass bucket, lowered it, and told me to dig. After a while we hit water. He sent me back. So we would scoop a bucket or two of water, then a bucket of dirt and repeat until I couldn't keep up with the rising water. The finished well was 3ft diameter, 21 ft deep, with 10 ft of water. I gained great insight regarding the term "colder than a well-digger's arse" :lol:

That was 1957 and AFAIK the well is still in use. :icon_thum:icon_thum

Roger

 

[RandyJ]

That was 1957 and AFAIK the well is still in use. :icon_thum:icon_thum

Wow Roger, 1957 was before you were born.:icon_scra:roll::eusa_naug

 

[Threejs]

:eusa_thin That's a much better technique than the one I learned. We started with a 3 foot diameter bore until hitting rock at 12 feet. A few sticks of dynamite later, my dad and his friend put me in a windlass bucket, lowered it, and told me to dig. After a while we hit water. He sent me back. So we would scoop a bucket or two of water, then a bucket of dirt and repeat until I couldn't keep up with the rising water. The finished well was 3ft diameter, 21 ft deep, with 10 ft of water. I gained great insight regarding the term "colder than a well-digger's arse" :lol:

That was 1957 and AFAIK the well is still in use. :icon_thum:icon_thum

Roger

That is how they described it in the foxfire books. Dangerous stuff.

 

[Ken Massingale]

:eusa_thin That's a much better technique than the one I learned. We started with a 3 foot diameter bore until hitting rock at 12 feet. A few sticks of dynamite later, my dad and his friend put me in a windlass bucket, lowered it, and told me to dig. After a while we hit water. He sent me back. So we would scoop a bucket or two of water, then a bucket of dirt and repeat until I couldn't keep up with the rising water. The finished well was 3ft diameter, 21 ft deep, with 10 ft of water. I gained great insight regarding the term "colder than a well-digger's arse" :lol:

That was 1957 and AFAIK the well is still in use. :icon_thum:icon_thum

Roger

I have also 'enjoyed' that experience, Roger. Once and that was 1 too many. Mine was to 'clean-out' the well.

 

[NCPete]

when I was a kid, we had a rock lined 6' deep shallow well, almost 10 feet from a stream that ran through our property. We had the pleasure of cleaning it out every other year or so, no concern about it caving in, but gosh it was some cold water! My boots are probably still wet!

 

[Gofor]

... I should have water at 15 or 20 ft. as we are only at 20ft above sealevel. ... View attachment 4800

Sea level has little to do with it. My house in FL was 11' above sea level and we were only 200 yds from the water (gulf fed bay with tides, etc). You will need to find a water bearing porous layer of sediment that will allow as much volume of water to flow into the well as you are pumping out of it. (Called an aquifer) During the wet season there, I could hit standing water with posthole diggers (did so when I put in my mail box). Even tho the soil was sand, it was not porous enough to supply a lawn irrigation pump.
Ground water level will have an effect on the well once it is in place, tho, because it will allow the water to come up in the well casing to the ground water level. A suction pump can practically lift water only about 20'. (theoretically it is 33' in a total vacuum). For this reason, you will want a foot valve either at the bottom of the casing or at the top, so that it will keep the casing full of water up to the pump regardless of ground water level. Otherwise you will have to prime the well every time you use it.

Hope this helps.

Go