Any well experts here?

[Cord]

Have a older well that does not have a screen, but instead was gravel packed. We're having a problem with silt getting past the gravel pack and can't seem to find a solution. Bailing couldn't penetrate the gravel pack. Drillers don't want to touch it because the casing is a 7". The whole house filter is working great, but it'll clog quickly once we start watering the lawn this spring. Originally I was hoping to remove the existing gravel pack and then repack the well, but I can't find anybody to take on a old school technique like this. I sifted out some sand and small stone chips last year, but I'm nervous about dumping it down the well for fear I'll choke it off.

 

[SandburRanch]

Have a older well that does not have a screen, but instead was gravel packed. We're having a problem with silt getting past the gravel pack and can't seem to find a solution. Bailing couldn't penetrate the gravel pack. Drillers don't want to touch it because the casing is a 7". The whole house filter is working great, but it'll clog quickly once we start watering the lawn this spring. Originally I was hoping to remove the existing gravel pack and then repack the well, but I can't find anybody to take on a old school technique like this. I sifted out some sand and small stone chips last year, but I'm nervous about dumping it down the well for fear I'll choke it off.

I know very little about wells and zero about packed wells but our well pumps a small amount of sand so early on I had to do something because the washing machine fill valve stuck in the fill position because of a sand particle but we caught it before any damage was done to the house.

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.

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.

Pictured is a soil sample that shows some information about the weight of certain soil particles compared to water weight. A similar test of your water may indicate whether a sediment tank would benefit.

 

[adventure bob]

I have a similar problem only mine is starting to reduce production of the well. If gone form 8GPM down to just under 6 in 7 years. Pump has been out and works great. Silt is simply clogging the bottom. My well guy says its easier to just drop a new well than repair one of these older ones.

 

[Ford850]

I have a similar problem only mine is starting to reduce production of the well. If gone form 8GPM down to just under 6 in 7 years. Pump has been out and works great. Silt is simply clogging the bottom. My well guy says its easier to just drop a new well than repair one of these older ones.

When I had mine drilled years ago, it took less than 2 hours from the time they showed up until the left. That was drilling, sealing the casing, and capping a new 107' well. The guys came to run the line to the house on another day.

 

[Egon]

Might be able to run a small pipe down the casing and use water or air to flush it out.

 

[Cord]

I have a similar problem only mine is starting to reduce production of the well. If gone form 8GPM down to just under 6 in 7 years. Pump has been out and works great. Silt is simply clogging the bottom. My well guy says its easier to just drop a new well than repair one of these older ones.

That's what they've been saying. I was thinking that it was just a money grab, but it's now sounding like it's not possible to rehab our well. Just to let you know, we flowed ours off the top of the casing at an estimated 35gpm for several days and only saw a foot of level drop.

 

[Cord]

Might be able to run a small pipe down the casing and use water or air to flush it out.

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.

 

[Cord]

I know very little about wells and zero about packed wells but our well pumps a small amount of sand so early on I had to do something because the washing machine fill valve stuck in the fill position because of a sand particle but we caught it before any damage was done to the house.

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.

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.

Pictured is a soil sample that shows some information about the weight of certain soil particles compared to water weight. A similar test of your water may indicate whether a sediment tank would benefit.

I installed a screen filter several years ago because we were getting some scale. That has cleared up and now it's the fines. Takes a good 20 minutes to settle out of a glass of water. I installed a tandem whole house filter and that has really cleaned up the water. However, I know that when we start watering the lawn, those filters will clog up pretty quickly. Plus I'm filling up my pressure tank with sediment. It's a time consuming PIA to get the pressure tank clean.

 

[PILOON]

This could just work for you.

I draw lake water and there is always some silty material that clogs any normal filter thus clogging it, also wanted very frequent changes. (and costly)
I resorted to using a swimming pool filter* with a mesh insert that was just fine enough to catch the silty material.
Needed to adapt down size to 3/4 pipe thread as pool filters are 2 inches but that was do able.
I now only need to flush a few times per year and that can actually be rigged for back flushing.
My water is always clear and porcelain bows stay white. (and clothes)

The filter is in a clear bowl that is screwed into the mounting. I installed ball valves before and after the filter so that removal for cleaning is easy with very minimal leakage.
Have been running this rig for close to 20 years with excellent success.
My indicator for cleaning is when water flow diminishes noticeably.
I use a 2" bottle brush to clean that filter and usually do that over the toilet bowl so as not to soil anything.

My silty material is a reddish brown very fine material.

*my understanding is these are basically 'sand filters' and my supplier had them in a variety of mesh sizes.

 

[alligatorob]

You might try some redevelopment tricks before replacing it. Basically just pumping harder than you normally would and doing something to agitate while you are doing it. As Egon suggested injecting air or water at the same time can help. I've seen it done with a big air compressor injecting a lot of air at high pressure in the bottom of the well, turning the well into a geyser for a while. Whatever water you get out you'll want to waste, it should be pretty silt laden. The idea is to get that silt out using aggressive pumping/agitation so that when you go back to your normal pumping its clear.

Doesn't always work and kind of depends on how much water your well will yield and how deep it is, but if it does work it should be cheaper than a new well.

 

[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.