760' deep well with 9' static head, 1 gpm, 40 ft of casing

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LuckyDog

New Member
So the subject is my new well at my NH house I am building.

According to NH DES, I need (they recommend?) a minimum of 600 gallons of water within a two hour
period once each day. According to their table, I can achieve this by setting a pump at 360'.
http://des.nh.gov/organization/commissioner/pip/factsheets/dwgb/documents/dwgb-1-8.pdf
My math says 290 is fine.

I have been looking at the Gould GS series. The impeller is listed as some polymer (plastic) but the tech brochure states it is floating stack.

I am thinking something like the 07GS07 or 05GS05 with a CSV and 20gallon pressure tank.(Flotec FP7110T). I don't foresee ever drawing 500 gallons in 4 hours, but it will be nice to know it is there.

Am I off base? Can I use 200 psi Poly pipe or do I need to go to sched 80 PVC?

It is a three bedroom house and the septic is rated at 450 gallons per day. It will only be me and my wife and we are ultra conservative when it comes to using resources.

//Paul

Reach4

Well-Known Member
According to NH DES, I need (they recommend?) a minimum of 600 gallons of water within a two hour
period once each day. According to their table, I can achieve this by setting a pump at 360'.
http://des.nh.gov/organization/commissioner/pip/factsheets/dwgb/documents/dwgb-1-8.pdf
My math says 290 is fine.
600 gallons in 2 hours is 5 GPM.

Your static level is 9 ft. So it could be that you could have your pump down 50 ft and have plenty of water. You may be able to pump your well at 10 GPM all day without the water dropping much. Did you get a GPM measure from your well digger?

In determining the pump you need, it is the water level that counts -- not the pump level. So you would want a pump that would work fine with water 9 ft down and at whatever level the well might pump down to. You could get that measured, or you could guess.

I suspect that a 1/2 HP 10 GPM pump would work for you just fine. I would not go to a 5 GPM pump unless there were very unusual circumstances. 7 is OK.
Am I off base? Can I use 200 psi Poly pipe or do I need to go to sched 80 PVC?
The people with the rigs prefer the rigid schedule 80 pipe with threaded couplers. Yet poly would more than do the job. That would be preferred for people without the hoist truck.

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Valveman

Cary Austin
Staff member
If you set the pump at 290' you would need the 7GSo7. It would still deliver 4 GPM at 50 PSI from 290'. Using a CSV1A with that pump and a static of 9', you will have 173 PSI of back pressure. So you would need 200# poly or sch 80 PVC pipe. You really only need a 4.5 gallon size tank like comes with the Pside-Kick kit, but a 20 gallon tank won't hurt anything.

Reach4

Well-Known Member
1/2 HP 7 GPM could let you work at 40/60 PSI if the static water level fell to 140 ft. Below that, it would need a different pump.

No GPM report from the driller?

LuckyDog

New Member
When we hit 760 feet, he showed me that it was flowing 1 GPM. (using the air from the drill rig to pump)

There were a couple of spots where the drill dropped liked it had hit a cavity or sand pocket, but no joy for water. I am pretty sure that I have a lot more water available than 1.5 gal/ft but it has not been measured.

Reach4

Well-Known Member
When we hit 760 feet, he showed me that it was flowing 1 GPM. (using the air from the drill rig to pump)

In that case, I agree that the deeper set make sense. For the drop pipe, use what the pump installer prefers, as long as that is not galvanized.

http://www.geotechenv.com/Reference_Pages/water_measure_tables.pdf has gallons per foot table in the top center. About 1 gallon per foot with a 5 inch ID casing.

http://www.hydro-terra.com/well-volume-calculator/ You could put the proposed pump location as the well depth into the calculator.

Craigpump

I'd use a Psidekick with a Grundfos 3/4-7 on sch 80 PVC along with a cycle sensor so you wouldn't run the pump dry if you happen to leave an outdoor spigot running by mistake.

Poly pipe is NOT designed for downhole use, it's way too flexible and has a permanent curl in it due to the way it's manufactured and then rolled up. It may sound easy to install and pull out, but I can assure you it isn't, that's why they make Up Z Dazy's and other pump pullers and why old time pump guys have bad backs.....

A 6" well has a nominal 1.5 gallons per foot.

ThirdGenPump

7gpm 3/4hp is fine if you only plan on using it for household use. A 5gpm pump will eave you rather unhappy if someone flushes a toilet while you're in the shower, 5gpm pumps just don't get used very much anymore for modern households.

If you have any plans to use that well for outside watering you need to reevaluate. Even just washing your car blows through water way faster than your well can keep up with. Running from a hose anything over 20 minutes you'll see a serious drop off. I'd seriously consider hydro-fracking it, it could give you a lot different numbers to work with.

FloTec tanks are garbage. I prefer Well-x-Trol. There are a number of in between brands if you're trying to be budget conscious.

As mentioned you could run a really small tank with a CSV. I still like using 22 gallon tanks even with a CSV, WX-202's are pretty cheap and it makes for a little less cycling with low use applications like washing your hands.

LuckyDog

New Member
7gpm 3/4hp is fine if you only plan on using it for household use. A 5gpm pump will eave you rather unhappy if someone flushes a toilet while you're in the shower, 5gpm pumps just don't get used very much anymore for modern households.

I figure with a CSV-1A, I will be running 10GPM for the first 150 gallons. That is a pretty long shower.

FloTec tanks are garbage. I prefer Well-x-Trol. There are a number of in between brands if you're trying to be budget conscious.

lol, I was given two tanks because previous owners upgraded to larger tanks.
The Flotec still holds air fine. (and the bladder is replaceable)
The Well-X-Trol has a small leak and can't be repaired.
So, free trumps for the time being. If the Flotec doesn't last, I will look at Well-x-Trol and the others. Just my experience as of now.

As mentioned you could run a really small tank with a CSV. I still like using 22 gallon tanks even with a CSV, WX-202's are pretty cheap and it makes for a little less cycling with low use applications like washing your hands.

That is why I plan on staying with a 20 / 22 gallon tank. (5 gallon drawdown). Washing hands, brushing teeth, watering the dog, hell, even washing the dog. I don't wash my car.

Valveman

Cary Austin
Staff member
With the CSV1A you will only be running as much as the shower head uses, and only for as long as the shower is on. So if the shower head delivers 2.5 GPM, then the CSV will make the pump produce 2.5 GPM and hold the pressure at a constant 50 PSI, no matter if the shower is on for 10 minutes or 10 days. It does the same thing when you are washing hands, brushing teeth, or washing the dog. The pump comes on and stays on for as long as you are using water. The CSV controls the flow from the pump and it goes right past the tank, straight to the faucet(s). It doesn't matter if it is a 1 gallon tank or a million gallon tank. This reduces the cycles so much for uses of water that last longer than a couple of minutes, that it doesn't hurt for the pump to cycle for 30 individual toilet flushes throughout the day. Even though 30 toilet flushes probably won't cause an extra 30 cycles per day, because the pump will already be running for the kitchen sink, washing machine, or something else in the house when you flush the toilet. Only when you use more than 1 gallon of water or flush a toilet, wait 2 minutes and use water again, will you cause an extra cycle. If you flush a toilet 100 times in a row, the pump just stays on continually until after the last flush.

I also use to think 5 gallons of draw down was good with a CSV, but after so many years I realized it isn't of much benefit.

Oh and the reduced cycling caused by the CSV will make even cheap tanks last longer, as there bladders are also cycled much less. And any tank with a replaceable bladder is replaceable for a reason, usually because it isn't that good to start with.

LuckyDog

New Member
With the CSV1A you will only be running as much as the shower head uses, and only for as long as the shower is on. ...

Probably should have said, I CAN run 10GPM until the well level goes below 100 FT. I know the flow is dependent on the outlet device / fixture.

... Only when you use more than 1 gallon of water or flush a toilet, wait 2 minutes and use water again, will you cause an extra cycle. ...

My wife is an RN and washes her hands A LOT. Less than a gallon each time, but so frequently.

... And any tank with a replaceable bladder is replaceable for a reason, usually because it isn't that good to start with.

lol, That is why I am putting a union coupler on the tank fitting. Just planning on the inevitable.

Craigpump

Have you looked into replacing a bladder? Are they even available?

Sta Rite used to sell a Signature 2000 series with a so called replaceable bladder, most of them were replaced under warranty within a few years because the bladder could not be removed without making an ungodly mess.

LuckyDog

New Member
Haven't looked. Not worried about it at this time. I won't move in for another 4 years. It is mainly a primitive camp / place for me to go do real work for now.

I am mainly doing the well so I can have the floor poured for the radiant heat.

It all has to get done eventually. I just look at cutting corners when it makes sense. I know some things I will have to replace / fix later; or worst case, do it completely again. That is why I am looking at putting in the correct /best pump set-up now and use the old tank that is holding air.

I plan to also put a shroud on the pump when I put it down. Any long draw of water is going to be all top fed.

ThirdGenPump mentioned outside water use. That has me thinking again. We plan on some chickens, my wife wants a nanny goat or two. Maybe a raised garden bed? The soil is all sand. I don't expect to be building up a large plot for a garden. Too much work and money; I can think of better ways to spend those resources.

LuckyDog

New Member
Trying to decide if I should start a new thread or continue here.....

The question: Should I or can I use a Dole valve with a CSV?

Reading the IOM manual for the 7GS07412 submersible pump. The manual states, "Any well with a high static water level may allow the pump to operate off the curve to the right or outside the "Recommended Range" shown on the pump curve. We recommend using a "Dole" flow restrictor or throttling with a ball valve to prevent upthrust damage to the pump and motor. ..."

That is my situation here. The pump is being set at 300 feet, the static head is 9 - 18 feet. (I just measured it last week and NH is in a bit of a drought)

I have ordered a CSV125-50 and will mount this at the pitless adapter. There is maybe 5 or 10 feet of head from the pitless to the tank.

Is a 10 gpm Dole valve a waste of money with the CSV installed? Or because of such a high static water level, it is a good idea?

ThirdGenPump

I find dole valves to be unessesary on the smaller pumps with or without a CSV. In my area almost all the static levels are very high allowing pumps to start with flows well above thier recommended curve. I've never had issues with pumps failing prematurely for that reason.

You can use a dole valve in your situation to prevent the pump from out pumping the well, but you have the depth so it's simpler to set the pump deeper.

Valveman

Cary Austin
Staff member
According to the curve, a 7GS07 needs a minimum of 200' or 86 PSI to keep from being in upthrust position. With a 10' static level and starting the pump at 40 PSI, you will only have 102' of head when the pump starts. As long as this only happens on startup you should be OK. I just wouldn't run it for long periods of time with a wide open hose or pipe at really low pressure (less than 50 PSI). With a CSV, as long as you limit the output of the hoses to less than 10 GPM, the CSV will keep enough backpressure on the pump to keep it happy. Basically just don't use more than 1o GPM for any length of time and you will be OK. Like ThirdGen says, on small pumps like this upthrust is not usually much of a problem as on larger pumps.

PumpMd

Kevin
I find dole valves to be unessesary on the smaller pumps with or without a CSV. In my area almost all the static levels are very high allowing pumps to start with flows well above thier recommended curve. I've never had issues with pumps failing prematurely for that reason.

You can use a dole valve in your situation to prevent the pump from out pumping the well, but you have the depth so it's simpler to set the pump deeper.

Valveman will try telling you that is not good putting them in the upthrust condition...but notice how you and I get very long pump life by doing this. I can do this up to a 5hp. I don't struggle my pumps when the water level drops around here. Easy way for a pumptec to finish the job when it pumps off.
The thing about a Dole Valve is that they restrict you close to the gpm they say but why do that when you can have full flow from the pump where the dole valve can cause problems when the user wants more water then what the dole valve will give you. Cycle sensor or a pumptec would do the rest when you pump it off.

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MI Well Drilling

Oh well !
You may want to just bite the bullet and plumb in a good tank now. I've seen many many cases where Flotec tanks may still hold air but make your water stink. You've done research on a good pump and valves match all that with a good new tank. If you plan on having a softener salt tank nearby put in a flexcon fiber wound FL 7 (22 gal)

Craigpump

My experience tells me you won't get the life out of a Flexcon fiber would tank, use a Well X Trol and be done with it. I've seen Well X Trols last 20+ years with a softener sitting right next to it.

LuckyDog

New Member
Thank you all for your guidance.
Parts are on order.

Luckily I am only using the system for a hose bib right now. I will be installing filters and approptiate softener before I feed the house. That is a year or two off yet.

I'll watch for Flotec smell. I can assume it'll smell like moldy vinyl?

Hey, wait a minute.

This is awkward, but...

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