Shop Products
Houzz Logo Print
novice_grower

Artesian well pump selection

novice_grower
17 years ago

I am in the process of selecting a contractor for a new deep well. Contractors are telling me I will most likely get an artesian well. But their quote includes submersible pump. I should be able to put a pump above ground. Is there an advantage to put the pump immersed in water? They said the pump would be at about 40' depth. Thanks.

Comments (9)

  • mchristensen
    17 years ago
    last modified: 9 years ago

    As you know, an Artesian well by definition means when you bore to the depth of the water it will, from internal pressure, flow spontaneously.

    Most likely get... ? Is the submersible quoted as an option should well drilling hit an aquifer rather than an artesian well?

    If you do have an artesian well I can come up with NO reason to install a submersible pump.

    What is the contractors reason???

    boosterpumptech

  • novice_grower
    Original Author
    17 years ago
    last modified: 9 years ago

    I called a local irrigation supplier and asked the question. He said an artesian well typically does not have a good flow rate (a few gpm), and a pump is necessary to get a decent flow rate for irrigation. That's all I learned.

  • mchristensen
    17 years ago
    last modified: 9 years ago

    Having deficiencies in flow or pressure or both may be a very good reason to include a submersible pump.

    Insufficient flow would require a larger water storage tank ( above ground or buried ) filled by the artesian well in order to use an above ground "booster" pump system.

    Of course, the tank ( smaller version )is required even if the flow rate were adequate ( you would likely need to increase the pressure ).

    My previous statement was based on 'a preference' to an above groung pump system versus a submerged pump.

    A submersible pump may very well be the least expensive to install ( not necessarily the most efficient nor the least expensive to operate ).

    My problem with installing a submersible pump to provide the 'service' is that it has to be sized to meet ALL of you water demands,ie. landscape irrigation, household water supply, livestock, etc.

    With or without an artesian well, if the demand is high enough, a water storage tank with at least 1 booster pump would be the correct installation.

    I never specify one pump to meet ALL water demands ( in this specific type of application ). It may cost more to install a duplex or even a triplex pump system, however properly designed it will ALWAYS be more efficient, last much longer ( 15, 20, 30 + years ) and cost less to maintain and operate.
    [ I'm probably going to stir it up now ]

    [ =Note= Do not fall for the MBS ( merchandising bull shi? )of VFD ( veriable frequency drive ) pump systems. Has no application in residential, farm or most commercial projects. Here I go stirring it up again.]

    I've gotta go, I may continue this later. By all means ask questions if you wish

    boosterpumptech

  • novice_grower
    Original Author
    17 years ago
    last modified: 9 years ago

    Okay, the picture is clearer now. I have been able to talk to a contractor who put in several wells in my area. According to him, 4" well with 1 hp above ground pump will give no "draw down". (Is this the right term? Water level does not go down because of the native water pressure. This is a free flowing well.) My neighbor is against submersible turbine pump because lightning can easily kill the pump.

    Now I have a choice to make, to go with PVC casing or galvanized steel casing. PVC is definitely cheaper. I live in Florida and freezing is not a concern. Is there a reason to avoid PVC?

  • mchristensen
    17 years ago
    last modified: 9 years ago

    If PVC is handled and installed "expertly" there should not be a problem.

    Consederations are vibration and heat ( to name two ). Vibration may be caused by seismic activity, nearby heavily traveled highway or even nearby manufacturing. The higher the ambient and/or water temperature the lower the working pressure of the PVC ( likely not a consideration in your case ).

    Here in California, with many earth quakes a month, PCV drop pipe is still widely used.

    Galvanized drop pipe will have a shorter life due to corrosion and will of course add "metals" to the water.

    We have yet to discuss the purpose of the well. Will it supply household water? Will it supply landscape irrigation?

    What pressure (feet of head) at what flow rate will the 1 hp pump provide?

    Sorry, don't mean to be asking you so many questions. You on the other, hand may ask away.

    boosterpumptech

  • novice_grower
    Original Author
    17 years ago
    last modified: 9 years ago

    Thanks for the reply.
    1) Purpose: Immediately, irrigation. Long term, household + irrigation. I will be growing plants in pots. Irrigation need is about 15 gpm, 2-3 times a day. Irrigation needs 35 psi at the sprinkler head, or 40 psi pump discharge pressure. 1 hp centrifugal pump will do the job, I think.
    2) Most likely, I will have an artesian well. Will I still need a drop pipe? Or pump directly from the well casing?
    3) thanks for the explanation. I will go with PVC.

  • novice_grower
    Original Author
    17 years ago
    last modified: 9 years ago

    I just read your reply to my eariler post, which was for irrigation only. Current thread is for different application at a different location. You said not to mix irrigation and household. I wish I had read your post earlier.

    Can I put 2 pumps on the same well? One shallow well jet pump with 40-60 psi pressure switch on 80 gallon tank (household water), and the other with sprinkler pump, directly connection to sprinkler heads with no tank on a timer? Thanks.

  • mchristensen
    17 years ago
    last modified: 9 years ago

    I'm confused now.

    1]As to the irrigation now and water supply in the future;
    a) 35 psi at the head for potted plants??
    b) I believe you should re-calculate your irrigation system losses. You are not going to get 35psi at the heads with 40psi pump discharge ( assuming required piping AND fittings are installed ). What pressure can you live with in the house?
    c) I believe you can pump from the well casing ( artesian well ) however, even though it was said that draw down is not a consideration, be sure that flow demand does not bring draw down back into the calculations ( however momentary the draw down / recovery may be. Cavitation must be avoided ).

    2] Your question = can I put 2 pumps on the same well?
    a) The question you should ask ( of your well company )is can the well ( and the piping )provide for 2 pumps, when and if there is a demand for both pumps at the same time. You can install as many pumps as the well AND the piping can handle.

    3] Duplex or Simplex pump system?
    Without getting into an engineering white paper, here is the reasoning for a 2 pump ( duplex ) rather than one pump ( simplex ) system when providing for landscape irrigation and household water supply.

    a) when you are connected to city water with good pressure and good flow capabilities, you can pretty much do what you want with the irrigation system ( low flow, high flow, drip, etc. ). This is NOT true the moment it is known that a pump is required ( assuming that a VERY large hydropneumatic tank or more accurately a series of hydro-tanks is not intalled ). With a pump you may have to ( most likely 'you must' ) redesign your irrigation demands to the operating parameters of the pump. You should not operate your pump below 1/2 of the design point .
    a1)This is not "carved in stone" as all pump performance curves are not the same at the same conditions, but it is a very good "rule of thumb" ( the exception to the rule is if replacing and/or repairing the pump(s) yearly or every 2 to 4yrs etc. is acceptable ). An example = a pump is called out for 15 gpm at 100 feet of boost. If the pump is correctly chosen ( this is not done more often then you may think, even by long time "pump dealers" ) you should not have any valve stations that demand LESS than 6 to 7 gpm ( refer to a1) above ). Pump "charts" tell you very little, pump curves are required to choose the right pump. The requirements of an irrigation pump are not the same as for water supply.
    b) Water supply pumps are typically abused because they are cycled to often ( the reason for the tank )(a larger tank will help ). I need to condence my response, to much to cover, to little time. You may have a high demand of 15gpm at 100 feet of boost for the house, however your pump design point will only be 10gpm at 100'..., chosen further to the right of the curve allowing the pump to operate further to left of the curve = lower flow, say 3 to 4 gpm and you will accept the pressure drop when and if the demand is to high.

    Now add the 15gpm irrigation need to the 10gpm water supply need. 25 gpm with actual pressure boost for highest need ( the irrigation typically ). Lets stay with 100' of boost for conversation purposes. Now where does 1/2 of design point put you? 10 to 12.5 gpm. You may want to re-read 1]c) . Of course there is always the assumption that there will be no household water consumtion at the same time as there is landscape irrigation consumption. Another post needed here?

    Yes an acceptable pump system can be engineered around this problem, but not at the same level of pump efficiency.

    One pump or two, per the above example, well and piping would need to supply 30 gpm.

    I hope this is of some help and not the opposite. There is so much more to this but I've got to go

    booster pump tech

  • carlamcphrsn494_gmail_com
    12 years ago
    last modified: 9 years ago

    have an artesian well. had 1/2 hsp pump connected summer 2010. this spring or during winter (freeze?) pump burst. landscaper adv due to pressure of well. installed new pump (1/2 hsp) and bladder tank this week. advises artesian well has much stronger force than other wells. is this true? should the water not fill bladder and hold until used and then fill again while in use. would this affect the pump or the well? why cut off electricity or water source to pump when not in use? use for irragation and fill inground pool. 16 1/2x32 ft pool, 3ft to 5ft deep. not drained. just top off.