Pump Sizing on deep well

Discussion in 'Pumps and Tanks Well Forum & Blog' started by clackamas, Jan 14, 2009.

  1. clackamas

    clackamas New Member

    Messages:
    6
    BTW - thanks in advance!

    Our driller just completed our well yesterday. Its 740' with a flow of 90GPM @ 740', 80 GPM @400', 60 GPM @ 300' with a static water line @ 82'.

    We are building a house for a family of four that uses quite a bit of water, I also want to run a line around 300' (probably 3") to irrigate an orchard. I also want the flexibility to help a large pond out in the summer, its 9800 sq/ft in surface and I figure I may have to add a couple of ft over the summer.

    From what I gather from physics since my static water line is so high, a very deep pump won't hurt too much.

    Right now the well is 8" steel cased down to 740'. I think I probably want a liner of some sort to keep the casing from putting rust in my water. the water is hard with a hardness of 8 (what ever that means).

    What sized pumps should I start looking at? What liner should I use and what size?

    BTW - I live in Western Oregon so don't pease don't bash me for wasting water.
  2. valveman

    valveman Moderator Staff Member

    Messages:
    4,391
    Location:
    Lubbock, Texas
    You apparently have up to 90 GPM available. Your house use is minimal. You probably only need 10 to 12 GPM for the house. We would need to know how you would like to irrigate the orchard and fill the pond. Do you need all 90 GPM, or can you run less than that to irrigate the orchard?
  3. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    Unless you have corrsive water (low PH)I wouldn't worry about the casing rusting. Is that hardness 8 grains per gallon or 8 ppm? If its 8 ppm it's not hard at all but at 8 grains per gallon i would install a water softener. You should have a water quality report from the driller.

    sammy

    www.tylerwellandpump.com
  4. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    I'm not sure what a liner would do for you. If the casing is black iron, it will rust a little, but you will never know it in the house. If it's galvanized casing, don't worry about it at all.

    If you truly wanted to get the full 90 gpm from 740 feet, you would be talking in the neighborhood of 30 horsepower. Do you really want a pump that big? Do you have three phase power?

    bob...
  5. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    How about feeding the pond and then having a pump system from the pond to feed the orchard? It would keep things simple at the well for the house and if there is a problem with the pump it would be a small enough to setup to access it without a pump hoist. You could probably set a pump at 400 and be okay but it really depends on how much water you are looking for.

    sammy

    www.tylerwellandpump.com
  6. valveman

    valveman Moderator Staff Member

    Messages:
    4,391
    Location:
    Lubbock, Texas
    Irrigating from the pond is a good idea. You have to filter out the fish, frogs, and leaves but, it will allow you to use a lot of water for irrigation, while still having a small pump in the well for the house and for refilling the pond.
  7. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    Just curious, why didn't they stop at 400 when they hit 60 gpm at 300? Little strange unless you were looking for over 60 GPM.

    sammy

    www.tylerwellandpump.com
  8. clackamas

    clackamas New Member

    Messages:
    6

    We did not hit rock until 640 and did not hit any significant water until the last 5 ft. apprently in that last few feet we hit all that water. Does that make sense?
  9. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    No it doesn't make any sense because you said they had 60 gallons per minute at 300'. When a rock bored well is drilled you case off the well into rock, continue drilling and most guys well test every 40' or so. So if they cased off beyond 640' how on earth did they come up with 60 GPM at 300' without the well being cased before 300'.

    sammy

    www.tylerwellandpump.com
  10. clackamas

    clackamas New Member

    Messages:
    6
    You got me, I am just the owner. I would imagine that the pressure, like an artesian well is what I have, I am just speculating but that makes sense to me. It pushes the colum up, thats why the static is @ 82'. I probably only get a few gallons a min @85ft.

    All I am relaying is what I was told. I am a total newb as far as wells are concerned. I grew up with a community well but I never had to deal with it.
    Last edited: Jan 15, 2009
  11. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    Here in New England the depth to bedrock is usually withing 100' so there is not much unconsolidated material (overburden). I don't know what state you are in but that is a lot of overburden. If for some strange reason they were able to calculate 60 GPM in unconsolidated material, using a rotary method, i would have loved to save a lot of money by screening that material and calling it a well.

    It's also a little strange that you have a water analysis already(you siad you know the hardness). A pump test is done after the well is drilled and the water sample is taken. It should be sent to a lab and most labs take about a week to get results back(testing and paperwork). Unless they had a test kit on site but why they would be doing on site tests would be a little strange.

    sammy

    www.tylerwellandpump.com
  12. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
  13. valveman

    valveman Moderator Staff Member

    Messages:
    4,391
    Location:
    Lubbock, Texas
    It is not uncommon for some areas to have wells like this. You can drill in dry dirt for hundreds of feet, then when you punch through a certain layer or rock, the water comes up almost to surface. Your pump test would then be to see, at what levels the water comes up to, at different flow rates.
  14. clackamas

    clackamas New Member

    Messages:
    6
    Have not rcvd the bill yet. My property is in the Willamette valley in Northern Oregon. The valley, one of the richest farming valleys in the country, has hundreds and hundreds of feet of aluvial deposits, mostly clay that were deposited during the myriads of Ice age floods (Missoula floods).

    A bit of interest to folks, we hit wood and various levels all the way down past 400'. The valley had some bad days in the last 100K years. Anyway, yes we have 640' of overburden, mostly clay. The practice here is to drill to the rock, even if you hit seems of water in the clay. Apparently this is not done in all places.
  15. sammyhydro11

    sammyhydro11 Previous member

    Messages:
    709
    Location:
    Massachusetts
    Wow, that's cool stuff. When i was working for a geo drilling company in Boston, the deepest we hit rock was 190' but i'm sure that's not the deepest in New England.

    sammy

    www.tylerwellandpump.com
  16. clackamas

    clackamas New Member

    Messages:
    6
    My well guys told me that they have hit places in the valley with 1600+' of overburden.
  17. clackamas

    clackamas New Member

    Messages:
    6
    It would be sprinkler irrigation during summer months, about 1 ac's worth of blueberries and various fruit trees. For the pond I would just run a hose to it, a rather large one I imagine since I may have to fill say 1' over 1/4 of an acre.
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