OT: Water Well Upgrade Questions Concerns

My water well is a dug well that is about 45 feet deep, with a drilled well in the center. My guess is that the dug well was the original well on the property, and at some point in the past they upgraded by installing the drilled well in the center of the dug well.

Had some well guys out to fix a minor problem with a yard hydrant, and got to talking with them about the well. They recommended I upgrade the well to current state code. The plan would be to fill in the dug well with Ag Lime, and install a new Campbell Adapter and well cap.
Makes sense to me, I figure I’d rather just go ahead and get it done so that it’s up to code, and more importantly so that its able to be worked on in case of problems. As it stands right now, the well guys aren't able to work on the pump or anything becasue they won't go down into the dug well.

Anyone ever had this done before? Any pitfalls or problems? I’m always hesitant to mess with old stuff that has been working OK. I’m afraid it will end up bringing on all sorts of other problems.

That dug well is an accident waiting to happen. The sooner you get it filled in the better.

The dug well has a pretty heavy concrete cap on it.

Explain the accident waiting to happen.

are you sure its not a 30" bored well with a 6" drilled well in the middle if it is the well should be lined with a concrete caseing down to the bottom

I'm a little concerned about lime, as it might leach into watersupply, and you'll get lime in the water. Wonder if sand or gravel would be a better bet.

Yeah, I'm not sure about the Ag Lime part. I don't think I've ever even seen Ag Lime, or really know what it is. I asked the well guy about it, and he said its just like pea gravel, just smaller sized pebbles. Said it was a bit cheaper than gravel, and that's why they liked it. Said it would take 1 semi-truck load to fill in the hole.

The dug well is lined with big stones. It's maybe 4 feet in diameter.

It's old-school, I've had two different well companies look at it, and both said they hadn't seen one like that in awhile.

Well, just off the top of my head...
Walls lined with big stones: how solid?? how can you tell how solid after obviously many years? moisture softening soil in back of rocks? surface water (rain) pressure building/built up behind rocks? minor temblors loosened rocks? weight of rocks settling unevenly over years built up pressure points that could push out/eject rocks? Etc...
Then vibration effects: when the well dug and rocked, probably very little powered equipment; now, all kinds wheeled/tracked vehicles, power eqpmt giving off vibrations, even from nearby roads if formations right, not to mention vibrations/harmonics from pump.
So you've been down 100 times...so maybe your luck is running out. And how's the air down there? I wouldn't go down without an air circulator going...no, on second thought, like the well guys, I wouldn't go down.

The main thing is that the hole needs to be filled with something that won't bridge the hole, leaving the potential for a later cave-in.

It's good that the well is capped, but there's always a potential for a side to cave in.

Most hand dug wells were dug down to the water level then had wooden pilings dug in to the mud, rocks sit on top of the wood pilings. Typically what happens is the wood rots out, then the rocks slide down, sometimes gradually, sometimes all at once. Sometimes they collapse into the well, sometimes they stay more or less in place. Look at the top 4-6' of rocks, rocks that are a different size, shape or color could indicate slippage that has been repaired. No rocks in this area could indicate unrepaired slippage. If there is no water in the bottom of the old well, plug it with a 2' layer of fresh concrete, then fill with sand to the frost line. You'll have to keep adding sand till it all settles down, but this will stabilize your situation. Take pictures of what you do as you do it, may protect you from the law.

I asked a local well driller about putting a 6" well in the center of an existing 70' hand-dug well. He said he could not do that. So how is your smaller well casing supported in the larger well at the top?

Bringing things up to current code is not always an improvement. Much depends on exactly what you're doing.

I've in New York and I'm sure wells vary by regions. But, at least here - I've got some experience since I've worked with a few well drillers over the past 40 years. Also have several properties with dug wells, pit-wells, and upgraded drilled wells.

Here, dug wells are - just dug wells. Pretty self-explanatory. The first drilled wells were done two ways.

One way - the casing top got buried below the frost line - 5-6 feet down. So, if the pump went bad - you had to dig it up to repair.

The other way - was to built a well-pit with a top on it - again - with the well-top below the frost line. This way, if repairs were needed, you could take the top off, go down into the pit, and work on it. Problem is - this pit can act like a funnel when the roof leaks and pollute the well.

This is the reason why modern code requires a "pitless adapter" and a buried well casing. The name "pitless" comes from its ability to eliminate the need for a pit. It enables a well to be drilled with casing installed, and a pump istalled and removed - from below the frost line - but accessed from above. It's just a brass, take-apart 90 degree valve held together by gravity.

With your well - as you describe it. If the water is still good, I have no idea why anyone wants to throw lime in there. Sounds crazy to me. If you have existing well casing down in the bottom, all you need to do is add more and extend the casing a few feet above ground. Steel or PVC. Make sure you have a pitless adapter installed, and then fill in the hole. I've done many, it's a one-day job.