New Sand point

Discussion in 'Pumps and Tanks Well Forum & Blog' started by Bigland, Jul 5, 2011.

  1. Bigland

    Bigland New Member

    Messages:
    5
    Location:
    Ontario
    Hi Everyone ,
    So glad i stumbled across this website ,so much great info.

    I recently decided to drive a sand point for irrigation of my back lawn. We are in a very sandy area and our lawn requires lots of watering. I started by driving a 36 (80 Guaze) point conected to 1 1/4 galvanized steel . My first attempt hit water at 12 feet so i continued to drive the pipe to 19 feet. It was here i noticed the first problem . When washing out the pipe my water hose continued down into the sand about 25 feet and i washed up buckets of very fine silty sand. I realized that my well head must of broke so l pulled up my pipe (for the record i would rather drive 10 wells down then to pull one up) Unfortunately i was right it had broke at the coupling.
    After looking at the fine silt i purchased a 100 guaze point and drove it down . Now im at 19 feet with seven feet of water in pipe. The well will take my whole water hose without filling the pipe but only produces about 1 gal a minute( which it will do all night if i leave it) My concern i that no sand came up when i was developing the well making me think my new screen is to fine and plugging up? Any ideas

    I am running a 1/2 power shallow well pump with a one inch discharge line.

    Cheers
    Bigland
  2. gritres

    gritres New Member

    Messages:
    56
    Location:
    nw florida
    the goal of the screen isn't to keep all the particles out, you want it to allow the finer stuff through during the development of the well so you can actually get some decent flow after you're drawing water between larger particles. if the price of the pipe isn't too much of a concern keep that one in the ground and drive another one with a larger screen and connect them together with a T and then draw from them both. you'll never get a whole lot of water from a 3 foot metal screen, 5 GPM if you're lucky and hit great sand in my experience. and remember deeper isn't always better when it comes to GPM, it can be much worse if you drive past sand and hit some muddy clay, but it just provides more insurance against droughts when the surface water will lower
  3. Bigland

    Bigland New Member

    Messages:
    5
    Location:
    Ontario
    Thanks I will try that . Should I go with a longer screen . They seem to only sell 36 in the area i live

    Cheers
  4. gritres

    gritres New Member

    Messages:
    56
    Location:
    nw florida
    the more screen you have under water (as long as it's all under water and remains that way when the pump is running) the better, but 3 foot is the most common size for bangable points. you just may need a lot of them to actually water your lawn when you consider an average hose bib puts out 5 gallons a minute and you'd have to get really lucky to get 5 gallons a minute out of the points. Your average 1/2 hp shallow well pump should have no problem pulling up 10+ GPM if your water table is at 12 feet, you're definitely being limited by your well screens here.
  5. Bigland

    Bigland New Member

    Messages:
    5
    Location:
    Ontario
    hi Again
    Update drove down 4 foot well point 80 gauze . Static water level 12 feet and 20 feet of pipe in ground including well point. Sucked out a little more sand but still only pulling 1 gpm. Maybe im not developing these wells correctly. Thoughts?
  6. gritres

    gritres New Member

    Messages:
    56
    Location:
    nw florida
    a thorough pumping with a pitcher pump provides a lot of back and forth water flow which is generally enough to develop a small shallow well. if you want to get more advanced you can use a surge block in between pumping sessions where you take, in your case, about a 16 foot pole with something on the end of it slightly smaller than the diameter of the well and force it up and down over and over to surge water in and out of your screen. you want to remove the finer stuff around the screen and pump it out and surging water in is what loosens them. you can also take a garden hose and hook it up and force water down for a bit, but you only ever want to force clean water down.

    1gpm isn't much, can you get more than that when you use a manual cistern pump or not?
  7. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,080
    Location:
    NW Ontario, Canada
    By my math 20 feet minus the 4 foot sand point is 16 feet minus the 12 foot static level, only gives you 4 feet of table to draw down. Is the pump sucking in air?
  8. Bigland

    Bigland New Member

    Messages:
    5
    Location:
    Ontario
    Theres roughly 8 feet of water in the pipe. I pumped some water down from the garden hose for a half hour as suggested by Grites which helped and i am now a two gallons a minute. Should I drive deeper. Dont seem to be sucking air.I may by a hand pump amd work on developing it more.

    Also is it a good idea when i join my two points to use a one inch pvc drop pie inside my 1 1/4 casing?

    Cheers
    Rich
  9. Bigland

    Bigland New Member

    Messages:
    5
    Location:
    Ontario
    HI Gritres

    Not sure what i would get with a hand pump i dont have one. Should i invest in one

    Cheers
    Rich
  10. gritres

    gritres New Member

    Messages:
    56
    Location:
    nw florida
    in my experience you can't expect to get much more than double the starting GPM by developing so you're probably at your limit. going deeper will only increase the flow rate if you hit better sand beneath it but there's simply no way to tell without trial and error. it's sounding like you're going to need 3 of them to get a normal hose bib worth of pressure and power 1 sprinkler. the drop pipe will definitely not increase your flow rate and there's not really any reason for it unless you have breaks in your pipe and are sucking air because of it.
  11. gritres

    gritres New Member

    Messages:
    56
    Location:
    nw florida
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