This past week has been a water well learning curve for me. A couple of weeks ago our well started pumping some air along with the water. This past weekend we ran out of water. The well has been in operation since last August with no troubles whatsoever until now. Total drilled depth is 330 feet; (4 inch pvc shaft), with the 2 hp pump located about 100 feet down. We have not had much rain and the rice farmers have been pumping non-stop for weeks, so evidently the water table dropped enough to not allow the water to come up as far in the well shaft, so the pump started getting air. The pump also overheated enough to come off the end of the 1 ¼ inch plastic pvc supply pipe along with the 4 inch shaft slightly collapsing at that point.
The well guy came out and got the pump out and will replace it with another 2 hp pump, but slightly smaller in diameter so it will fit into the shaft without restrictions. He was also going to install some type of gizmo to prevent the well shaft itself from being drawn down again. The new pump will be at 250 foot depth to ensure an adequate water supply.
The nice thing is that he is doing all this at no cost, although I said I would pay him for the additional piping needed to increase the depth. He said that he should have had the pump lower in the first place, but at the time, the 100 foot depth was more than adequate.
Anyway, after being without water for several days, I've really been thinking of how to have an additional water storage tank (say 500 gal) in case the pump ever fails again.
What I want to do is have a tank that would be plumbed into the house water supply line so that the water to the house would go through the spare tank first to ensure that it had a constant fresh supply. The piping routing would be: pump to pressure tank to spare tank to house. I would also have a small auxiliary electric pump that could be fed by either house or generator power so that I could maintain water pressure in the house plumbing. Some bypass plumbing and valving would also be needed to avoid pumping water backwards to the pressure tank, and also to isolate the extra pump during normal operation. I assume that the spare tank will need to sealed to withstand the normal water operating pressure.
The main routing would look like this (spare pump/valves not shown):
Well Pump ---->Press. Tank----->Spare Tank---->House
Sorry for the very long post, but you are my best source for info. Does this idea look feasible?
Your idea is certainly feasible. all you're really doing is putting in another pressure tank in line but, as you said, it will have to withstand 50-60 psi which rules out the normal poly tanks. Guess it comes down to how often you expect this to be a problem? You could also consider a two pump system which would add a little to your operating costs. Have either a cistern or poly tank in the basement, feed that from the well pump using a level switch instead of a pressure switch. Use that as the reservoir to draw from useing a shallow jet pump to the pressure tank to the house. Accomplished what you wanted without having to pressurize the big tank. Also gives you a back up pump and a 500 gal reservoir in case of deep well pump failure. That said I don't understand the rational for drilling a well 330 feet deep but only putting the pump down 100??????????????????? True you want a little settling space and don't want the pump sitting on the bottom sucking mud but that extra 230 feet is useless if the [pump isn't able to access it!! I'd put the pump down to maybe 20-30 feet of the bottom. Gives you a larger reservoir and may put you below the water table so you don't run dry again from the rice farmers!!
Thanks Gerard. I also did not understand the initial rational of drilling so deep, then putting the pump way up higher. I do know that there is a 20 foot long well screen at the very bottom, but still, I was very surprised at the pump level. It's one of those (frequent) times when I did not know how the system was set up - it was hard to know what to ask/check [img]/forums/images/icons/crazy.gif[/img]
I do know that the water table here is very high, especially in the winter months, but did not know what the variation may be over the course of a full year. Guess I know now.
To be honest, I hope that this will be a very infrequent occurrence, but since the cost of the materials/tank/pump is not really too bad plus my "free" labor, I like the idea of the back-up system. Especially after having to take a few cold water sponge baths out of an Igloo ice chest! [img]/forums/images/icons/tongue.gif[/img]
We have a problem with our well once in a while. The well never goes dry but it will go through a period of refreshing slowly. This causes a problem with gardens and lawn watering.
The solution was to add a 500 gal. poly tank to the system. The well pump fills the tank on a timer and then the house draws from the storage tank which has its own pump that supplies the pressure tank. If we have a problem with the well pump the system works independently and we have 500 gallons to run the house until repairs can be made. That way the tank is drawing water in short fifty gallon gulps instead of the pump just drawing the well down. The buffering effect of the tank has solved our problems. In the future I will add another outside tank for just summer use for watering the gardens. All the wells in our area have the same problem and going deeper is not a solution.
Our tank is just a poly tank. If you wanted it to hold the pressure of the pump that is much more expensive. I am very pleased with our system and watered trees all morning without a problem. The tank is recovery nicely and we will draw water for the lawn tonight.
I was going to post some additional info to correct some of my previous statements and saw your post. I like the system that you have described - looks very feasible. So the 500 gal poly tank is between the well pump and the pressure tank if I understand correctly. I do know that the 500 gal poly tank is much less than a steel pressurized tank, so I can see the economics of your setup.
I spoke to the owner of the well company and I was initially given incorrect info on the pump depth from the guy who first came out. The well is drilled to 330 ft, but the original 4 inch diameter 2hp pump was initially placed at 220 ft, not 100 ft. The water table for our area was at 140 ft, so the pump placed at 220 ft should have been OK. The original pump was rated at 20gpm at 65 psi. The replacement 3 inch diameter 1.5hp pump is rated at 12.5 gpm at 50 psi. Unless we re-drill the well (which we don't want to do), we have to use the smaller 3 inch diameter pump to fit into the shaft which is now narrower than 4 inch due to the original pump overheating. The new pump will be placed to 280 ft, which should provide adequate water.
It also looks like I'm going to get popped for the cost of the new pump. The well company sez they will provide the labor to get this up again, but since they cannot control the water level (hence the original pump failure) the new pump is my cost. By the time this is all done, we'll be about $1100 lighter in the pocketbook. What a mess [img]/forums/images/icons/mad.gif[/img] Looks like I'd better check well pump pricing.
Just some more information, I used about 300 gallons of water this morning and checked the tank after lunch. It is topped off again so I am ready to water again.
The depth of our well is only 85 feet and that is the reason that we have a small reserve in the casing. In our area if you go beyond 100 feet you will hit sulfur in the water. We opted for the shallow well with better water and have to suffer with five to six gallons per minute replacement. The tank system solves our problem and it is wonderful not having to worry about over drawing the well. The bonus is that if the pump in the well needs to be serviced, we still have 500 gallons in the tank for emergency household use.
Can you please explain how your timer is set up? Would using a float valve also be a reliable way to maintain adequate water level in the tank?
Are you using a timer to avoid a frequent stop/start situation with the well pump?
Thank you.
<font color="blue"> Can you please explain how your timer is set up? Would using a float valve also be a reliable way to maintain adequate water level in the tank?
Are you using a timer to avoid a frequent stop/start situation with the well pump?
Thank you.
Nick
</font color>
There is a float valve in the tank and a wall mounted timer. Every fifteen minutes the the timer tries to turn on the pump in the well for a set time. If the float in the tank is tripped the pump delivers water to the tank. If the float shows the tank as full then the circuit is not completed and the pump does not turn on.
This system really has the pump in the well turning on far less than a conventional system. The pump in the tank provides the pressure and does the constant on/off that normally would be done by the pump in the well.
The system cost me about six hundred more than a conventional system but I did go for a submersible pump rather than a shallow well pump at the tank. I hope this helps. I had this all installed by a sub but it really is not rocket science. I can buy all the parts from the local supplier and add to an existing system.
Nick,
It sounds like you have a good plan to avoid future shortages, at least for 500 gallons. The system Tenebrous describes is pretty common in areas that have slow flowing wells. I believe the term used for the pump at the storage tank is a Jet pump. In our area Lowes and Home Depot both sell them as well as the submersible deep well pumps.
I could be wrong but I am thinking that when our well was done the well company added some kind of device that shut down our pump if it started sucking air. Given your situation it may be worth asking about such a device so you don't lose another pump in the future. One more melt down and you will not have enough casing left to replace the pump. It has be a cheaper alternative to redrilling.
Tenebrous - thanks for the info. I think that the extra $$ are well worth it. I had asked some questions about irrigation in an earlier post and this info helps to resolve not only the reserve questions but also to supplement the info I got about irrigation. My plan is to go ahead with a similar setup.
Mark, I will head over to the local Lowes/Home Depot and see what they've got. The 4in pump that was removed is still working fine and I know that it will probably wind up in someone else's well. I told the well guy that I either want half cost credit for the pump or I want the pump back. It's not even a year old. The problem is that we can't re-use it because it won't go down further past the part of the casing that is drawn in, so we have to go with the 3 in pump. I wanted a 1.5 hp pump rather than the 1hp they had in stock, so it's Monday before they get back out here.
God bless our neighbors - I have a few hundred feet of garden hose attached to their well, connected to our hose bib (with backflow preventer), so we have water in the house. They don't know it yet, but I'm heading over there to do some mowing and tractor work as a thank-you.
It's not the end of the world, but this has certainly been enlightening .... and frustrating. Thanks again for the help here at CBN. [img]/forums/images/icons/wink.gif[/img]
PS - the original pump did get hot enough to hit the internal thermal cut-off, but was evidently not damaged.
Reply With Quote
