Any well experts here?

[Egon]

There has been talk about trying to redevelop the well (the process you suggest), but there is a concern this could actually choke the well off and destroy it. I guess they'll blow the packing out and then start drawing in natural material. If they pull too many fines, the formation will pack solid.

This would only be loosening up the sediments in the casing.
With air it puts everything into suspension to be carried out by water.
With water you use outside water to wash out the casing. It would require a volume of water great enough to carry the sediments.

If the water bearing formation around the well bore has been packed with fines that restrict permuability and porosity it's probably best to move over a distance and go new.

You might be able to drop a weight down the well to check on sediment depth but this would require pulling the tubing.

Note that these are thoughts and your local drillers know your conditions.

 

[alligatorob]

Note that these are thoughts and your local drillers know your conditions.

Yep, an experience local driller would know best. He should know all about redevelopment and what works best in your geology with your well construction. We are all just speculating from a poorly informed distance.

 

[TemporaryKubotaOwnerMark]

Knowing a little about specific gravity, in the well house I installed a recycled hot water heater as a sediment tank and that took care of that sand problem reaching plumbing components. That was bout 30 years ago but since then I've installed a filter just down stream of the sediment tank to remove anything with a specific gravity less than water.

I did exactly the same thing, with good results. Now I blow down the 'sediment tank' every now and then, and my whole house filter gets whatever it misses.

One other item during construction, I separated house water from outdoor water and that modification should help the filter change frequency in your situation for outdoor use.

Agreed. No way would I have my outside water going through my whole house filter. That's just crazy. That's what Tees and valves were invented for.

 

[Valveman]

Gravel for a gravel packed well should not be inside the casing. Casing with small perforations is installed to the bottom of the hole. Then gravel is poured on the outside of the casing. The perforation are small enough to keep the gravel from getting into the casing. Then the gravel acts like a screen or a media filter to keep sand out of the casing. The fines will collect in the gravel and form an even smaller screen as it does.

If you do not need to deepen the well I would not try to get the gravel out. With 7" casing you can go back in with 4" or 5" casing and gravel pack between the 4" and 7". You will need to cap the bottom of the 4" liner and use centralizers to keep it centered. Using .020 perforations and a silica gravel that is just large enough not to go through the .020 slots, it will make a good filter and keep the sand out.

It is not usually possible to deepen or recase and existing well. But if a liner will fit you have a chance of saving the well and making it sand free.

 

[smokinmad]

My daughters well did this....they ended up with a new well......the driller suggested they buy a large water tank to fill from the well, then draw their house water from the tank....NO SETTLEMENT in their house water, it's in the tank.....

Ever thought about talking to your local Volunteer Fire Dept...most depts. are Starved for money...for a Donation to the Firefighters, they might be willing to feed a 1 3/4" hose down the pipe and WASH the gravel out of the well. At 100 pounds of nozzle pressure, you would have "Ole Faithful" gushing out of your well......doesn't hurt to ask...

 

[Valveman]

High pressure will drill the well deeper. But you need more volume and some heavy mud to get the stuff to float out the top of the well.

If you drilled a new well and you are still needing a cistern tank to settle out the sediment, the well driller didn't do his job right.

 

[muddstopper]

-When my well was drilled, it was 200ft deep and had 20gpm of flow. Static level was 35ft from the top of well. Over the years, the water level got lower until static level was 75ft from top. Lot of wells been drilled in my area over the years and the water table is lower than it used to be. I started having mud and silt filling my well, so much so that the pump was actually encased in mud and burnt out. after raising the pump level a few times, I started running out of water. My fix was I brought in a well driller and he setup on my old well. He dropped in his drilling rods and blowed the well clean using air. I decided since he was already set up, to drill the well another 100ft deeper, so now I have a 300ft well. I dropped the pump to 200ft, which leaves 100ft of well for any sediment. They disinfected my well to kill off any bacteria and I havent ran out of water since. Total cost was $500. I already had a whole house filter and I have noticed I havent had to replace the filter as often as before.

As a side note, the county I live in charges $500 for a well permit and $250 for a repair permit. I did a end around with the well company and didnt pay those stupid fee's. Just be aware that not all well drillers will work with you when it comes to county permits and not all counties charge ridiculous fees. How things work in your area could be very different than my area.

 

[buickanddeere]

Is this well into a gravel aquifer , in sand or drilled into the bed rock?

 

[muddstopper]

Is this well into a gravel aquifer , in sand or drilled into the bed rock?

Dont know if your asking me or the OP. My well is in rock.

 

[buickanddeere]

Dont know if your asking me or the OP. My well is in rock.

Sorry, the OP.
We are lucky here the previous owner was cheap on the well. Drilled through 80ft of impervious blue clay, hit 19ft of gravel aquifer underground river which is under pressure and they stopped drilling at the bedrock. We have spring water that pushes up to 22ft from the surface. We have pumped 10-11gpm over 14hours straight. Well water level only dropped 6 inches.
Neighbour had their well drilled over 300ft total, 200ft into the bedrock. Their water rusts everything, scales up the tea kettle and smells like fresh peeled boiled eggs.