deep well casing leaks

Hi Donzi

This may be normal shale common in the well bore especially after heavy rains. Also if the well area is under heavy use the water table may be quite low. You can lower a string and weight down in jerk motions and using a cheap stethoscope listen for splash and know the water level. Then run it hard and test again very quick.

I use a spin down filter with strainer to spin out shale and further trap it with a 250 mesh or even 500 mesh strainer (cleanable) prior to entering the second stage paper 'whole house' filter. The ugly black shale water is sparking clean and I do not need to change the house filter but once a month under heavy use as I keep the spin down filter drained off each 2-3 days and clean the strainer each week.

Sleeving is typically done with PVC. Is the 2" a typing mistake? Even new casing is PVC these days.

Good luck !

Petro Power

Thanks for the input--We had just discussed putting a pre-strainer on the system to avoid changing the relatively expensive carbon filter so often--guess I'll have to visit my local plumbing supply to see what they have can be readily removed, cleaned and reinstalled.

Wasn't typo error --this area, FL- has a lot of 2" casings-wish it were 4"--would be relatively easy to install sleeve and save it without redrilling.

But since it is just small shale particles and the water is clear I think I'll try the prefilter first.

Imagine the pumps impeller will need to be replaced soon--this shale is like sandblasting material--can't be good for it.

Thanks again--Donzi

I agree, 25 years for galvanized steel in this service is a long life. Quite frankly, I am surprised you have achieved this service life. If the water is good, I would re-drill and install a 4" casing of PVC.

fab1818:

Agree 2" ain't much, but the recovery rate (15GPM) is satisfactory for residential use.

Your right , a 4" casing would be a breeze to "sleeve" (even drop in a 3.5" PVC sleeve), but the 2" does present a problem since the sleeve would have to be "thinwall", making it quite flexible and difficult to install without kinking or distorting it.

Here in florida one doesn't ususally have to go far for water since the lakes sit only a few feet down from the front door.

May have to drill if pre filter don't do the job--Hate to see couple grand go down the hole, if ya know what I mean.

Thanks--Donzi

Only in Florida would a well of 80 - 120 feet depth be considered a "deep" well, and probably only in Florida would a 2" casing be considered sufficient. That's the diameter we used to use for monitoring wells (when I was doing that). And I've seen water wells go 4 -5 times that deep. I concur with redrilling at 4", even though it will be more expensive than a pre-filter alone. Oh, and install that, too...

EnvioreMan:

You're right "only in florida" , but we're sitting on water.

The 2" casing wouldn't be adequate in other areas because they're not sitting on an underground body of water (can't spell aquafer)--the 2" casing exceeds 15 GPM which is quite sufficient for residential use.

Looks like not many suppliers of continuous "thinwall" tubing are available anyway but let me ask you a question since you were in the business.

Lets assume the casing itself is not ruptured (rust or structural) but in fact the original seal at the base of the casing has been compromized--could an additional section of galvanized pipe (say 8-10') be dropped inside the casing, hoping to seal the base on inpact, as long as the section dropped does not extend up to the debth of the pumps foot valve. (I'm assuming it's several feet off bottom until I actuall pull it and check the actual debth).

Of course if the casing has water 40' up in the casing I guess I could shorten the pumps "down" pipes to get the foot valve away from the bottom--may not even need a prefilter--what do you think?

Donzi

I think I'd have to know some details that quite likely are no longer available to make more than a SWAG here. At what depth was water encountered during initial drilling? At what depth/intervals on the installed casing are the perforations/slots that admit water into it? With a 15 gpm recharge, at what depth is the pump valve, and how likely/often does the drawdown strand it? (That last one is the most likely to be known/knowable.)

Actually, the end of the casing is seldom sealed, it is usually bedded in pea gravel that acts as a filter to keep out the kind of sediment you seem to have in your house filter. The pea gravel extends up the slotted portion of the casing, and the upper portion is grouted in to keep out surface contamination. Water enters the casing through the slots, fills the casing, and the pump delivers it to your house. As water is pumped out, more flows into the casing.

EnviroMan:

You're right - No one seems to remember who even installed the system--The original owner doesn't even remember how deep it really is (thinks it's 80'--100').

I'll have to pull the pumps plumbing to see what the approx. debth is-

Do you thing shortening the "down" pipe (2--3') ,to get it away from the sediment it's picking up, would solve the problem as long as the foot valve doesn't come out of the water in the casing?

Can some of the sediment be removed with a "drill" bit type device assuming this has just acculumated over the years?

Donzi

Questions better asked of a water well driller more familiar with the conditions in your area, I'm afraid. But most drillers will share info like that readily, so it won't hurt to ask. Hard to tell which part of the aquifer the sediment is coming from - could be top 2-3 feet as easily as bottom 2-3 feet, could be somewhere in the middle. Could be from the whole thing. Local drillers should have some experience with this kind of problem and the solution. Plus, the sediment is infiltrating from without, so removing anything from inside the casing will only help temporarily. One thought, though, this sediment doesn't resemble corroded pipe material does it? I'm outta here now, but will look for any replies come Monday...

If you just have accumulated silt in the bottom of the casing, perhaps you could remove it by removing the pump from the casing and inserting an air hose down the well and using a compressor to buoyantly flush the silt from the casing.

aqua doc:

Good thought--finding a 2" bit with a 100' + flex shaft (and something to turn it with) isn't available at the local hardware.

I've replaced the filter 2 days ago (again) -think i'll just see how long it takes to plug it up--I wonder if the compressed air would raise the water and (more importantly the silt) which is fine rock, in the casing (could be 30-40' down) from the top to get "flushing" action.-

I've got a old jet pump (vertical style) --maybe I could add 4-5' of pipe to my exixting plumbing and use it to "vacuum" the silt out of the casing below the existing pumps plumbed debth ? Don't want to use the new pump since this stuff has got to be murder on the pumps impeller.

As another has noted-this "silt" might be iron pipe fragments--Gonna have to dump the next filter into a container, get a magnet and see if the sediment is rock or iron.

With my luck it will be rock with a heavy iron content--back to the drawing board.

Should be intresting--Thanks --Donzi

A friend of mine in Covington, GA had a similar problem with iron and sand sediment. He replaced filter after filter and still had red water and plugged filters. A deep well professional was called in after suffering through this for a about a year and the problem was a ruptured supply line just out of the pump. This caused a continuous circulation at the bottom of the well that stirred up the sediment. A symtom of this was that the pump ran more than you would expect. Once the line was replaced ($500) the water cleared immediately. Have you pulled the pump and ruled out this possibility?

Keith:

Appreciate the input--but the down line is ok--pump holds pressure (60lb) all day without leakdown as long as no water is used.--I really think now that the rock sediment has just built up in the casing over the years to the point it real close to the foot valve and the pump is suckin it up.--still have to check at the next filter change to make sure it's rock and not iron sediment from the casing. It's beeen 4 days now since the last change (daughter may not be using much water) so when she hollers again that she's got no water, I guess we'll find out.

Thanks--Donzi

Just how "fine" are these particles? They'd have to fit through the screened part of the casing to come from outside. Also, rust may not be magnetic...

Envioreman:

They're real fine--just a bit bigger than sand--I've been dumping them out of the filter without really looking close except I'm nearly shure their just real fine shale or whatever kind of rock you'd expect to find in northeast Florida , 60mi inland from the cost.--When she tells me it's blocked again, I'll investigate the material a little closer before I dump it and check it for iron content. Whatever it is, it blocks a large carbon "whole house" filter in a short time leaving the larger pieces (still very small) setteled to the bottom of the plastic filter casing. I guess I should disect the old filter and see what kind of material is blocking it--she say the water just stops all of a sudden which I find a little hard to beleive (I lived in that place 3 yrs and never had a problem except for the heavy mineral content which I solved with the filter).

Who knows --Maybe it just decided to start doing that the day we moved out.

Thanks --Donzi

In the oil business they can preform what is known as a squeeze cement job, this entails pluging above and below the fracture point and squeezing cement in the area then redrilling the area. It might be cheaper than drilling a new well. In todays markets with respect to water well drilling in the south west Texas area, you would be waiting a while on a permits and such. Better to spend the money on getting the well fixed rather than try to drill a new one. You might check with some of the reputable contractors in the area and see if they can do one for you. If you have lost the casing and its not usable anymore you might get someone out to see how much of it (if any) they could pull. The point being that there are other options available, yet they will depend on what a new well would cost.