Cleaning silt from a bored well
 

The well is 30 years old, 24 inch casing, supposedly 70 feet deep with water about 35 feet below the surface. We are in Georgia dead clay and the well is getting to the point where any amount of rain turns the water red.

I watched a few tube videos on building an airlift pump. Not much info on how high the device will lift above the water table. They aren't expensive to build but I really don't want to waste time on something that won't work.

One thought I had was to buy the head of a trash pump and fit it with a 2HP electric motor. Lower it down the well so that lift isn't a problem and let it work.

Another thought was to sacrifice a jet pump in the hope it would last long enough to remove the silt.

Still another option is to pay a well company some ridiculous sum of money for doing a lousy job of it.

Any suggestions?

Doug

You could rent a large compressor and blow out the well from the bottom. This is sometimes done by drillers as "well development".
More here: Section 10: Well Development

You could sacrifice a $100 submersible pump to get the silt out. The well guys usually use old worn out pumps to get gunk out of wells.

As to your red is it clay or is is rust? Also how is the well sealed. 24" is a big hole and not as easy to purchase well seals for as you would have to weld one together.

The well is lined with concrete cylinders and cannot be sealed. The red is definitely red clay. It got substantially worse in 2016 after the wife burned up two pumps. I was out of town and she had to pay to have them replaced. The well service guy didn't want to deal with her again so he dropped the foot valve another 10-15 feet to reduce the chance of pumping it dry again. The foot is now sitting just above the silt build-up and picks it up after a heavy rain.

24" bored wells were popular here for decades. After eight years of low rainfall well companies stopped servicing them and started pushing deep wells which are more drought tolerant and don't fill with silt.

I agree that pumping out the silt is the only practical solution. I found an old jet pump that should last long enough for the job. It will have to wait until fall when cool weather arrives.

Gotcha. Have seen a few of those in Misissippi where my relatives have land they grow trees on.

Funny coincidence... I just got done pulling the pipe out of our well. 100' of pipe and a jet at the bottom. I thought the foot valve was leaking but it turned out to be the supposed stainless nipple rusted out over 6 years...

Before pulling it out I blew as much water out with the air hose that I could. Then after pulling about 40' out and taking a break I blew it out again. This time I blew a hole in the fitting and it was much lighter as the water was gushing out as I pulled it out.

Headed to pick up a piece of pipe to extend the well casing and drop in a submersible pump. Not playing with inefficient, noisy and maintenance hog jet pumps anymore.

Oh and my water has allot of rust in it from the casing and there is some from the iron oxide in the soil. However the iron oxide is in sand instead of clay here. Looking at local drill records we have sand down to around 150'. Once I run the pump for a while every spring it clears up and it's crystal clear unless I don't pump water for a few months or so. Looking forward to watering the trees and grass again...

I am on my third foot valve in 20 years. The only part that is stainless is the screen. The body is cast iron. The first one blew a hole in the side, as much from silt abrasion as from rust. The second one was less than three years old but looked terrible. The pump installer refused to use it.

I considered a submersible. But they are more expensive than a jet pump and my wife won't bother to turn off the pump when she runs it dry. The permanent solution is going to be a timer on the well pump.

If time permits I am going to pick up two IBC's and use them as a buffer between the well pump and a separate house pump. The house pump will be below the IBC's. I can put a level switch in one to shut the house pump off automatically if the tanks get too low.

The well is fine - the problem is a "loose nut" at the garden hose.

What went on mine was the 1" drive pipe nipple on the jet.

My well is just for irrigation and I will see what the output is with the new pump before I redo the watering system. With the jet pump I was planning to get several ibc totes and let the pump fill them and then use another pump to water with. With no back pressure on the well pump it produces more water.

The current water level is 34' and the lowest after a really bad summer was 45'. That was a bad summer where we had over 100 days at or above 100* and much of it was 105*+ with a week at 117* every day with lows of 85*. So the lakes were low etc...

I'm going submersible as the pump cost is pretty much the same and they move allot more water and less hassle and my well is 100' which a jet pump is not very efficient for deeper wells.

Instead of timers and ICB's you might look at:

Pumptec Family | Residential/Light Commercial | Drives & Protection | North America Water | Franklin Electric

Somebody kick me!

The real problem with the jet pump is that once it pumps dry it must be primed again. Even a timer cannot completely prevent this. It also doesn't prevent a dry pump from restarting over and over until it burns up.

Looking at the Franklin Electric website I finally realized that a submersible pump combined with the Franklin monitor (or home brew equivalent) completely eliminates this problem.

So now I need to look at submersibles.

EDIT: I still need at least one IBC for gardening and fire protection.

Since we are on the subject of pumps, has anyone tried the cheap submersibles on ebay? They are half the price of those in the box stores (which are also made in China).

The ebay jet pumps are considerably less expensive as well, even for identical brands. Home Depot knows when someone comes in for a well pump it is because that person is out of water.

There is a 1/2HP pump for $32.99 with free shipping. If it lasted one day I could probably get most of the silt out of my well. Then I could install a better pump.

I ended up going with a hallmark pump. Its an import like all the others but at least it has some backing here in the US. Since I needed a 3.5" pump my choices were severely limited to it or pumps starting at $400. Will see how it lasts. My water ace jet pump did just fine till the fitting at the jet sprung a leak and had been in service for 4 years or so.

I should have mine running in a week or so. Gotta collect a few more bits and pieces before I drop it in the well. Hopefully I can get 15gpm or so but will see. Measured the static level and its 33'...

Oh and try to get a pump that has 100' of wire on it already. The wire is pricey. Locally its about .80 a foot but online its cheaper at aquascience.com.

I finally got my pump in and running. I had to pull it twice though... Not fun in 108* heat.

It would not pump. Come to find out the plastic valve in the outlet was made wrong and didnt allow enough water around it. Its basically there to limit pump output so the pump never free flows and always dead heads. This reduces amp draw and increases pump life.
So what I had to do was to drill 4 1/4" holes in the plastic piece in the pump outlet. After that it pumped water like a fountain. I have my outlet valve about half way open and i'm getting just over 10 gallons per minute at close to 60 PSI. That will be pretty nice for supplying the sprinkler system. Now to finish getting it plumbed in etc.


Oh and to add. The static water level has dropped to about 40' as we haven't had rain in over 3 months and its been 100*+ since the end of may and 115*+ for about a week. 108* is pretty well the normal summer temp here now.

Bulldog;

Perfect timing. I tried to use the jet pump to flush some of the silt from the bottom. As soon as I stirred up the silt the orifice in the foot plugged. That was a week ago. We've been getting our water from 350 feet of garden hose connected to my neighbor's well.

I pulled the jet pump and tried to install the submersible. It's been so hot the pvc couplings kept failing. I finally cleaned out the foot valve and reinstalled the jet pump today.

The instructions that came with the submersible said I needed a convection sleeve on the pump or it would overheat in a 24 inch bore. So we made a nice sleeve with a long filter screen to prevent large stuff from entering and clogging the pump.

After the problems with couplings I gave up and called the well company. They wanted $1850 to install a new pump, switch, and tank. That seemed high but I was out of energy and didn't care about the price. But when I asked them about the cooling sleeve he said it wasn't necessary. They would install the pump 2 feet off the bottom and said I would never have a problem.

Having the foot valve 2 feet from the bottom is what gave us muddy water and finally plugged the jet. I also started having second thoughts about a well company telling me I didn't need a cooling sleeve on a submersible when every other source of information (including data on the pumps they install) contradicted this claim. Seemed like more shoddy work to me.

So for now I'm back to the jet pump. The foot is now 5 feet above the silt which gives me 15 feet of standing water above it. I am still looking at ways to remove the silt. Using the jet or submersible pump is not going to work. The clearances in the pump are calculated for efficiency, not sludge.

There are some air operated diaphragm pumps on ebay under $200. These generally tolerate quite a bit of solids and can be lowered into the well on a rope to get right into the silt. That may be my next approach.

I thought of buying a trash pump head and mounting an IP67 rated electric motor on it so I could lower it into the well. That's a lot of work but may be the best way to remove the silt.

Yesterday I measured water at 32 feet and bottom at 52 feet, giving me a 20 foot water column. The person I bought the place from in 1996 said the well was originally 65-70 feet deep. So we have around 15 feet of silt.

It's too hot to work out there so I'm going to procrastinate and hope the wife doesn't burn up another pump before I get the 330 gallon IBC's set up for garden water. In the mean time I may put a PLC and contactor in the electric line to limit run time.