Water well prob, need ideas....

[MotorSeven]

2 years ago I put in a well. I have a small creek running thru the place, so an excavator dug a big hole & I had 11 tons of sand dumped in the hole. I used a 1 & 1/4 sand point driven type wll head that I drove down about 4' into the sand. The pump is about 30' away & has 6' of elevation. I used a new 3/4 horse motor & new pressure tank. There is a check valve at the well point and pump.
The system worked fine for about a year, then I noticed that the pump was running 2-3 min before shutting off & I can hear air in it. Thinking that I had a broken line, I dug the entire line up, pulled the well point, cleaned the screen & holes with a pressure washer, installed a new check valve & new pipe. It still did the same thing, so I just pulled the pump & checked the impeller...it looks fine. The pressure in the tank is set around 28lbs. It is now taking over 3 min to hit the shut off pressure.
Now here is the puzzling part, in the well house I have a 325 gal storage tank. If I switch the pump from the creek line to the storage tank, it shuts off after 40 seconds, and I hear no air..........

This thing is driving me nuts, not to mention spinning the meter on the pole like a gyro....$$$$.

Suggestions???

RD

 

[chh]

It sure sounds like an air leak. What kind of pipe did you use on the suction line? I used 2' O ring pipe once on a farm project on the advice of the plumber helping me. Even after is was covered and backfilled the high volume pump would pull air past the O rings. The system would work for several days and then airlock. Like to have driven me nuts. Finally laid wire and put in a submersible pump and the system never had a problem after that. I was on a 500' run with a gravity feed though so I had a lot more room for problems than you.
Do you have a way to pressureize the supply side? Maybe use water from the storage tank? I'd bet it would show you the leak if you could get the line up to 30 or 40 psi.

 

[Western]

I have a couple of "possibilities" but I'm not a well guy, only worked on mine when I have to.

1st thought , maybe cavitation, or basically stuck air pocket. Might try priming the whole system with water and giving it a go. Can be several cause for cavitation.

2nd thought, I had a similar problem and found the bladder in the pressure tank had ruptured, so basically the pump had to run longer to achieve the desired psi. changed to new tank.

Had an pressure tank on the ranch once that was "bladderless", so I had to use an air compressor every couple of months to keep enough air in it to help build pressure.

Probably not much help just a couple of ideas.

 

[charlz]

Now here is the puzzling part, in the well house I have a 325 gal storage tank. If I switch the pump from the creek line to the storage tank, it shuts off after 40 seconds, and I hear no air..........

Can you clarify here? When you "switch the pump from the creek line to the storage tank" are you pumping FROM the storage tank or TO the storage tank?

I'm pretty sure you mean FROM but I could be reading it wrong. If so it sounds like you either have an air leak or insufficient supply of water on the creek line side. Where is the check valve on the creek/well point line? Could be the water is draining out of part of the line and your pump is sucking air from a few feet of empty pipe? I had a foot valve on my pond pump go bad and caused this problem.

 

[Egon]

If so it sounds like you either have an air leak or insufficient supply of water on the creek line side.

When you dug the well point out was there lots of water?

The sand you have had dumped in can act as a filter and get plugged.

 

[tommu56]

Is the well pipe in a "caseing" if so check water level before turning the pump on and while its running my guess the stone filter to the creek is getting plugged and level is dropping at the well point for every foot it has to " suck" water it will reduce the flow by a given amount.

tom

 

[PILOON]

I gather your pump can draw from either creek or large storage tank and that the pump has its own small pressure tank attached.

Since air problem is only when using small tank it sure sounds like a tank bladder leak to me.
Those bladders are located inside of (generally) steel tanks and condensation makes rust causing abrasion to the bladders which in turn causes leaks.

Another maintainance item is the air valve on the tank (typical innertube valve) that often leak due to bits of dirt etc.
Start by replacing that valve stem and repressurise the tank with air using the recommended PSI setting. (I seem to recall it being 2PSI less than cut-out setting).
Incorrect PSI will cause those symptoms.
The owners manual will provide correct PSI setting.

 

[MotorSeven]

Y'all are quick. Let me answer these questions...

-I used 1 & 1/4 pvc schedule 40 pipe(remember I replaced all of it when the symptoms first showed up, and cleaned & re-inserted the sand point.
-I have primed the snot out of it, it does not sound like it cavitates when switched to the storage tank.
- I am drawing out of the storage tank when I close the line to the creek/sand point.
-The water in the creek is currently standing 10 inches over the sand on the bottom, sand point is about 4' below the sand.
-Pipe is not in a casing, runs 30' out from the well house, then drops 6' into the creek(all new pipe). No "O" rings anywhere.

Western, Piloon- you may be onto something, the water has alot of sand/grit in it. I installed a real big filter after the smaller ones were getting clogged & blowing thru. I had to stop using the charcoal filters because they clogged the fastest. There is no filter before the pressure tank & the pressure tank is in play when drawing from the creek or storage tank. This is what confuses me, if the pressure tank was comprimised, wouldn't it show the same symptom when drawing from the storage tank?
From creek- pump runs over 3 min, then tank is pressurized & shuts off.
From storage tank- pump runs 40 seconds, " " " ".

The way I see it I have these options(feel free to add to the list) to find the problem:

1-cut the pipe at the pump, lay a new one on the ground, put a foot valve on it and lay it in the creek.
2-install a new pressure tank.
3-install a 1 horse(new) pump.
4-give up and call a well digger to put in a "real" well....$$$$.
4-yank all my hair out and start drinking Rebel Yell straight from the bottle.

Before ya'll ask, no we do not drink this water, we have a spring at another location on the property(it would ne a logistical nightmare to get a line to the spring because there is a 40' wide creek in the way & it's 2000' away.)

Keep the ideas comming..........

RD

 

[tommu56]

MotorSeven

The sand might be sand blasting the impeller the head on the tank might be helping it.

The pipe might be filling with the sand or sediment if its getting past the well point.

on the dry fire hydrants have helped put in have a check valve on the end to back flush the sediments out of the line before you draft from them maybe you could do some thing like that and back flush it periodically.

or rig a sand trap before the pump

http://www.kunst.cz/doc/lpv_en.pdf

or reduce the size of the line this will increase the velocity and keep sediment in suspension.

tom

 

[MotorSeven]

When I pulled the pump last week there was very little sediment in the impeller area. How does reducing the size of the line help? It seems that the increased velocity of the water going to the pump would cause more damage from the sand blasting thru the impeller. I have thought about building a large(5' tall 8-10" in diameter) filter using charcoal, coarse sand & pebbles. Kind of like an aquarum filter on a much bigger scale.

RD

 

[studor]

You can get a shraeder valve arrangement that will screw into either a 1/8" or 1/2" port in the pump (I just bought one at Home Despot here in Canada) -- inflate to 30psi or so with a compressor and see if the line to the creek leaks down which would mean you have a leak somewhere in the suction line --this would cause the line to partially lose its prime and take a lot longer to come up to pressure. If the line does hold pressure then it is either partially blocked line or the jet venturi has been "sandblasted" enough that it is not as effective as it should be. The storage tank may be above the pump enough that the jet isn't really required and that would cause it to come up to pressure much quicker -- just some guesses based on going through some interesting pumping problems of my own Unfortunately I need the water to mix with the Rebel Yell (weak stomach)

 

[tommu56]

if you reduce the diameter it will increase the velocity

the pump is spinning and it throws out the sand with the water

Just in front of the pump in the present set up if you went to a 6" piece of pipe Vertically looking like a T with a shot vertical baffle would let the sand settle


Ill try and draw up what I am talking about
tom

 

[tommu56]

Here is my sketch


tom

 

[MotorSeven]

Thanks Tom, I can build that no prob. Stu, I am going to do a pressure check. Since I have a check valve at each end of the line, I need to tap into it between those valves. I think I'll drill & tap into one of the collars. I have a gage, just need to rig an air valve. I'll try it tomorrow......

RD

Oh, and the water level in the storage tank is about halfway up on the pressure tank........hmmmmm.

 

[tommu56]

MotorSeven

The longer you make the sand trap the better it will give you more time between emptying it.
and if you have some thing bigger in diameter ( 8, 10 0r12") even better it slows down the water and will let sand drop out

the positive head from the tank is helping with the pump head the suction from thhe creek will reduce the total head the pump Will develop

if your foot valve leaks when doing your test double up on them make sure they have a soft disk (Teflon or rubber) to seal with some sand stuck between faces brass to brass will definitely leak if any dirt is in there
or try a Hayward PVC ball check that might be better but it will have a bigger diameter.

tom

 

[Egon]

Have you considered burying a caisson and pumping from that. It would give you a water reservoir to pump out of.

You may also want to consider a lower volume pump?

 

[PILOON]

When you draw from the reservoir tank there is no problem because the level is higher than the pump eg; positive pressure.
When drawing from the well the slightest air leak will cause a lot of those symptoms.
One grain of sand in a checkvalve will allow leakdown and your pump then needs to evacuate the air before it can draw water.
Since you are not drawing very high, in theory you should not even need check valves as that pump should be able to 'self prime' itself.
All joints need 'pipe dope' to assure tight joints.(I even slightly heat PVC before clamping to assure tight seal)
The black 200PSI PVC pipe lines have a white tracer imbedded in the PVC body. That white strip when exposed to sunlight actually breaks down and becomes pourous allowing air leakage at times.
The slightest nick in a barbed pipe elbow or rust will allow air to enter the line.

The cheap 'box store PVC' (rated at 60PSI) will develop air leaks for sure if it was kinked at any time as when in use, under pressure fluctuations, the 'kink' will develop into the slighest crack and allow air to infiltrate and then cause all sorts of symptoms.

Any lakeside installation that I have done uses only brass fittings, heat on PVC b4 clamping and only blue 200PSI line and pipe dope on all threads.
When caught short I have often resorted to Flextra brand caulking as a thread sealant.

Have some that have 300 ft runs with 60 ft elevations.
One system uses 1 hp pump, 100 gal bladder tank and a manifold to supply 5 chalets.
Even the challet that sits 80 ft higher up enjoys 35PSI at the tap.

I'm not a plumber, but sure learned a lot 'on the job'.

Good luck.

 

[studor]

Like Piloon, my wild guess is that you have an air leak between the check valve nearest the pump and the end of the line in the creek. The pump maintains prime because the first check valve keeps water in it, but because the line itself leaks the pump has to resuction the line each time, then it pumps and builds pressure. the tank being nearer and high enough reprimes immediately. Frustrating ain't it

 

[tommu56]

RD
I didn't think of it till now can you use a submersible pump that might be your best solution every thing would be positive pressure.

Do you have any pictures maybe we could shed more light on it.

tom

 

[MotorSeven]

I pressurized the system today to 30psi. I did have a small leak at the priming plug above the pump. I watched the sand hole in the creek & had zero bubbles. In an hour it dropped to 10psi. Should this hold longer, or indefinatly?
Now as for the pump having to re-prime every time that is not the case. I can pump from the reservoir(40 seconds), immediatly switch to the creek, open a faucet & let the water pressure drop until the pump kicks on. It then will run over 3 min.
So can I assume that it is either the pump pr pressure tank? I am leaning towards the pump, since when looking at the impeller I have no clue as to what it should look like.

Piloon, all my fittings are hard pvc, either screwed or glued. No flex pipe or clamps at all. Egon, yes I have thought of the cassion, but this creek can rock & roll during a flood & I was worried that it would wash out. Tom, if I do replace this pump you can bet your %#@ that it will be a submersible.
Stu, frustration??? Miller High Life is taking care of that right now........

RD