Bottom of Pump / Bottom of Well

Discussion in 'Pumps and Tanks Well Forum & Blog' started by GPM, Apr 30, 2007.

  1. GPM

    GPM New Member

    Messages:
    5
    How much room should there be between the bottom of a pump and the bottom of the well? In 97 we measured the bottom of the well at 384' and the pump was sitting at the end of 17pcs of 2" galvanized = 357', with water at 240'.

    Now, using a very sophisticated $9.95 fishing line counter, the bottom of the well measures 360' and the water at 180'. which if this were true, would seem to indicate that the pump motor was essentially sitting in the silt as the pump / motor combo measures just over 4'. Water has always been clear.
  2. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    How far you set that pump in the well really depends on what it produces for water and the amount of draw down they measured during the pump test. Every well is different especially rock wells. A rock well has different draw down patterns than screened wells because of the different aquifer characteristics. I always leave at least 25' between the pump and the bottom of the well. Every well produces a certain amount of silt and sediment that will collect on the bottom. Setting the pump far enough off the bottom keeps the pump away from that material. If your measurements are correct i would raise that pump 30' feet and expect the same problem 10 years down the road. The material will eventually come up to where ever the material is coming from and stop but who knows where that is. It could be where its at now or it might be coming from where the casing sits in the rock. You have to keep in mind the more you raise that pump the more storage capacity you are losing from the well. I would monitor it and if it gets to the point where your water volume starts slowing down you will want to look into drilling the well out or find out where the material is coming from and get it resolved.I would measure the well with a 500' tape with something heavy on the end of it to confirm your measurements.

    SAM
  3. valveman

    valveman Moderator Staff Member

    Messages:
    4,426
    Location:
    Lubbock, Texas
    In many areas the well will always fill up with silt or cuttings to the bottom of the pump/motor. I like to set my pump just a couple of feet off the bottom and use a flow inducer shroud. This keeps the sediment from filling up the well. You may have to filter it out at the top of the well but, it is better than having to pull the pump and clean out 100' of well every few years.

    This way always keeps the pump at the deepest point, so you can use the full draw down of the well. You can either filter out the sediment a little at a time, or pull the pump and clean out the well ever so often.

    If the pump was sitting in the mud, you should have been able to see a mud line on old the motor. Thrust bearings don't last very long in this condition.
  4. GPM

    GPM New Member

    Messages:
    5
    What, pray tell, is a flow inducer shroud, and where do I get one? I would much rather filter out the sediment at the top than have to clean out the casing unless this approach were to cause pump problems.

    I could not see a mud line on the motor, and that was my fear that the motor would overheat if it was surrounded by mud instead of water.

    Thanks all.
  5. Rancher

    Rancher Guest

    Last edited by a moderator: Apr 30, 2007
  6. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    I agree with valveman and that is another option and i would also lean towards the idea that maybe your well collapsed at one point and thats what caused your well to fill with all that muck. If the well is going to keep producing silt and sand you should see traces of it as you pump the well. if you dont see the traces of it after you reinstall the pump I'll bet the well collapsed and thats the end of your problem.

    SAM
  7. valveman

    valveman Moderator Staff Member

    Messages:
    4,426
    Location:
    Lubbock, Texas
    You must have 5" or larger casing to be able to use a shroud. A shroud can be made from a piece of 4" thin wall sewer pipe. Cut a piece 2/3rds as long as the pump and motor. Cut three pie shape wedges from one end. Slip it over the motor and pump until the bottom is flush with the bottom of the motor. Use a 4.5" hose clamp over the pie shape wedges and tighten to the pump. Use pipe wrap or electric tape and tape over the hose clamp and pie shape wedges to seal off the upper end of the shroud. Water must now enter from the bottom between the shroud and the motor. This keeps your well cleaned out to that point and keeps mud from building up around the motor, which will burn up the motor.

    You really need to get that well bailed out and the pump back to the bottom. A good bailing job will get out most of the fill, so the pump does not have to pump that stuff. If you have a hole or a break in the casing, I would not set the pump below that point.
Similar Threads: Bottom Pump
Forum Title Date
Pumps and Tanks Well Forum & Blog broken pump at bottom of well shaft May 5, 2009
Pumps and Tanks Well Forum & Blog fiberglass sump pump pit has a crack/hole in the bottom Oct 9, 2006
Pumps and Tanks Well Forum & Blog How close to bottom of well can place a sub? Apr 19, 2014
Pumps and Tanks Well Forum & Blog Bottomless Sump Pit Mar 24, 2006
Pumps and Tanks Well Forum & Blog Need backup battery pump recommendations in overhead sewer system Aug 20, 2014

Share This Page