need help with new well

stevehullstevehull Registered Users Posts: 20
Not exactly a solar question, but need advice on a new well and more specifically how to control it.

Background: The "old well" is not deep enough and in summer it is sucking air. It is located underneath a pump house that has good 240/120 VAC power to it, two large capacity bladder tanks, a nice manifold (with individual turn off valves) to distribute water (our house, outside frost proof faucets, my mother's house, water to the livestock barn) and the usual pressure relay to turn the old deep well submersible pump off and on. My livestock barn is about 300 feet away and the pump house supplies it with water via underground pipe. All pipes are PVC, 1" dia and can supply plenty of water (when well has water in it) to any of the locations.

All works well, but the water table is dropping and the old well is only 100 feet deep (40 years old).

New wells here are typically 200-250 feet deep and extensive water table allows pumping as much water as pump can deliver. The idea is to drill a new deeper well just adjacent to the barn (barn has good 240/120V AC power), put in a deep submersible well and connect it to the water line going to the barn. I would turn off the "old well pump" before the distribution manifold and would use the existing pressure tanks.

I really don't want to have to dig up all the water lines to replumb the property. Also, old well is underneath pump house (concrete floor) and drilling it deeper in place is impossible (according to well drillers).

Question. How to "tell" the new deep well pump to turn off? If I put a pressure switch right at the new well, controlling the new deep pump, will there be too much delay in the water transmission line? I know that I am going to be "retrograding water flow" back to the manifold from new well in pressure cycle.

Wel drillers want me to bury a control line back to the pressure tanks and control the pressure (and new pump operation) at that point (in existing well house), but they literally have never hooked up a new well like this.

Ideas? Thanks in advance.

Comments

  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: need help with new well

    Welcome to the form :)
    The well driller is right re maintaining a pressure switch at the tanks, as having it by the new well, with a long line to the tanks, will result in the switch sensing the sudden pressure drop when the pump shuts off and the water rushing down the line to the tanks still hasn't come to a stop, and instantly will turn the pump back on. Likewise when the pump starts, the pressure at the well head will shoot way up till the water in that long water line to the tanks starts to move and gets up to speed, resulting in the pump instantly turning off again. You'll end up with the pump turning on -off-on-off-on-off as the water pulses back and forth the length of pipeline from the barn where the switch would be located, to the location of the tanks. You could avoid running heavy wires from the switch at the tanks to the pump at the barn, by using the switch only to control a relay/contactor at the barn, which would then in turn, control the pump.
    Good luck.
  • stevehullstevehull Registered Users Posts: 20
    Re: need help with new well

    Wayne,

    Perhaps something in the middle of the pipe (going back to the old well) run to sense pressure? One easy thing I could do is put in a small pressure tank (2-5 gal) in the barn connected to the water pipe and put the new well pump pressure switch there. This "capacitor" will absorb much of the high spike pressure and ought to minimize the rapid cycling (which kills pumps VERY fast).

    The distance from the new well head to the barn would be about 50 feet, but I could put the well closer to the barn easily.

    Watcha think?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: need help with new well

    I may not be understanding this entirely, but I'd suggest leaving the existing PT and switch where they are and switching them from powering the old pump to powering the new one. I see no reason for new switches, tanks, or control lines since you will be using either one pump or the other but not both (and yes it can be done with both at the same time - that's when you need duplicate switches and tanks).

    I would also suggest putting check valves on the outlets of both pumps to prevent the 'pressurized' pump (the one being used) from back-feeding through the 'non-presssurized' pump (the one not being used at the moment).
  • solarvicsolarvic Solar Expert Posts: 1,053 ✭✭✭✭
    Re: need help with new well

    my mother had a similar problem to yours. They had a dug well that went low some years when it was dry but the water was good. They had a new well drilled and the water was red. So they kept thier old well system connected and had shut off valves so they could use which ever well they wanted. Still used same storage tank and pressure switch. Seemed to work ok and they only used the new well for a couple months and used the original well the rest of the time. We had an earthquake that stopped the new well but it also made the dug well have more output. So for last 17 years my brother never drilled another well. :Dsolarvic:D
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: need help with new well
    I may not be understanding this entirely, but I'd suggest leaving the existing PT and switch where they are and switching them from powering the old pump to powering the new one. I see no reason for new switches, tanks, or control lines since you will be using either one pump or the other but not both (and yes it can be done with both at the same time - that's when you need duplicate switches and tanks).

    I would also suggest putting check valves on the outlets of both pumps to prevent the 'pressurized' pump (the one being used) from back-feeding through the 'non-presssurized' pump (the one not being used at the moment).
    Agree! This would definitely work best. And since (if I understand right) the old well and the new one by the barn are only 50 feet apart, running wires that far is no big deal. I had thought that perhaps they were 4 or 5 hundred feet apart, but 50 feet is really nothing.
  • stevehullstevehull Registered Users Posts: 20
    Re: need help with new well
    Agree! This would definitely work best. And since (if I understand right) the old well and the new one by the barn are only 50 feet apart, running wires that far is no big deal. I had thought that perhaps they were 4 or 5 hundred feet apart, but 50 feet is really nothing.

    No, the old well and new well location are about 300-350 feet apart - a LOT of digging/trenching! There are already check values (water diodes!) on all the lines to prevent a back feed from any one circuit into another (and one on the pump)
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: need help with new well
    stevehull wrote: »
    No, the old well and new well location are about 300-350 feet apart - a LOT of digging/trenching! There are already check values (water diodes!) on all the lines to prevent a back feed from any one circuit into another (and one on the pump)

    Yes but, you have to run the wire to the pump anyway right? Or was this new pump going to be powered from a different, closer source?
  • stevehullstevehull Registered Users Posts: 20
    Re: need help with new well

    Let me summarize my first post. I have an existing well that is located beneath a concrete poured slab in a pump house. This pump house contains two pressure tanks, the well pump controller and a manifold that has feeds to four water circuits. This 40 year old well is not deep enough and is sucking air in the summer. I need a new (and deeper) well). Access to this well pump area (to drill another well) is tough due to topography, trees, etc.

    About 300 feet away is a large livestock barn with 240/120V AV and a good water line (1 inch) from the existing pump house. This would be an ideal place to add another well due to ease of access, the existing piping and high amp AC power supply.

    The plan is to dig a well there (near the livestock barn) and turn off the other well pump.

    However, putting a pressure switch right at the top of the new pump casing, and monitoring the pressure at that point to controll the new well pump, has the potential to create lots of on-off cycling as the water must retrograde go back 300 feet to the existing pressure tanks before distributiion to houses, irrigation, other barn etc.

    Is it feasible to put a small pressure tank insider the livestock barn with a pressure switch there and only trench the necessary 30 - 40 feet out to the new adjacent well?

    Would this cut down on the water flowing back/forth and the resultant pressure switch turning off and on?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: need help with new well

    Okay so this is more like a "dual well" system rather than an "either well" system. Not a problem, just a slightly different configuration.

    You're on the right track: build an entirely new well system at the second location complete with its own PT and switch.

    If you could run the pipe from the new well & small PT all the way to the old pressure tanks first it would not be so troublesome. Here you're trying to use the existing pressure tanks for capacity and the long pipe run with adjacent taps for feeds is going to cause exactly the trouble you suspect; too much cycling on the new pump and water pressure surges. Ideally you'd have PT of equal size at each location. Would it be possible to add equal tank capacity at the new well or move one existing tank?

    Exactly how it will behave if done "as is" will depend on which taps are opened, how much water they flow, and where they are in relation to the different wells. Closer to the new well will make it cycle more as the far tank will have to push water along the whole pipe length before it can contribute pressure to the opened tap.

    This is why large houses have their plumbing done in loops: each tap taking off along the way and a return line back to the beginning. It doesn't keep the pressure up, but it keeps it even at all taps regardless of which ones are opened.
  • Texas WellmanTexas Wellman Solar Expert Posts: 153 ✭✭
    Re: need help with new well

    I have done what you are referencing many, many times. The answer is to put the switch as close to the tank as possible. This may involve adding another, smaller tank near the new well. This tank can be from a few gallons to as large as you think you need. They even make tanks now that can be put down inside the well, inside the casing that hold several gallons of capacity.

    The other option is to use bigger pipe and a smaller pump so that when the pump first kicks on it doesn't swing the pressure where the switch is. In the business we call it "chattering" the switch, and if you've ever seen it in person you will know how destructive it can be. It may be as simple as using 1.25" pipe instead of 1" pipe. There is also a device, called a "snubber", that goes just before the pressure switch that is supposed to suppress the pressure waves and keep the switch from chattering. I've seen them work, but they can easily clog with minerals or such.

    Good luck.
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