'Above Ground' Equipment

I'm part way thru in getting water supply via well on our property. The well has been drilled and now we're on to the pump and associated equipment. Which brings up some questions on my part. [I don't intend to do this myself, but I'd like to be knowledgable when speaking to the contractor and I'm expected to make some informed choices and I'd like to be reasonably competent to recognize future problems.]

Some specifics on the well....

Depth: 500ft
Diameter: 6in
Static water level: ~40-50ft
Estimated flow: 4-5 gpm


-- What would anyone care to recommend wrt various above ground shutoff valves, drains, pressure gauges, relief valves, etc, etc which would provide for necessary troubleshooting, maintenance, servicing and overall monitoring of system? Not that it's been identified as a necessity, how would things change if a sediment filter was included?

-- Assuming the pump is placed towards the bottom of the well, what approach is recommended to accomodate the static water level we are seeing? Hard to say what's normal around here [SW Virginia] for static water level fluctuation between normal/dry periods...

Thanks

Mark

One thing you need to know is what the drawdown level will be, or what you or the driller assume it to be, for the purpose of selecting the pump. The drawdown level is the level of the water in the well when it is being pumped at the intended rate.

The difference between the static level and the depth of your well is so great that the drawdown level will (at least should) have a great effect on selection of the pump.

The other consideration is the use of the well. The 6" casing contains about 1.5 gallons per foot. If you are using it for household use, then the static level will control and there will be little drawdown. If you are using it for sustained irrigation, you could get serious drawdown.

The drawdown level should be the result of a pumping test, and some experience of the well driller.

If you tell us the expected use of the well and the drawdown level to be used, we can suggest a rationale for selecting a pump, and suggest a pump and accessory equipment.

If you don't have information on the expected drawdown, the well driller will probably suggest a 5 GPM pump that will pump from the full depth to the level of the pump. That may produce a lot more pressure than you need and use a lot more electricity than you need for supplying the house.

I've gotten a recommendation wrt a pump in-hand and they are calling for a Goulds 7GS15422....

hth

Mark

some question for me

There are several different pumps that would work. The main thing to keep in mind is that the pump you select can't over pump the well. In other words, if it's hung near the bottom and the well does 4 - 5 gpm. You would want the pump not able to over pump the well at that depth.

bob...

... You would want the pump not able to over pump the well at that depth.....

Click to expand...

If [BIG IF here] I'm reading the table correctly for the presently recommended pump...

At 500ft pump's rated for 7.3 gpm at 0 psi, down to 5.2 gpm at 40 psi, 3.1 gpm at 60 psi.

Pump Spec Sheet

This would be pretty close on over-pump [assuming I'm understanding the issue correctly].

Given the 500 ft is actual depth vice TDH.... should this pump be ok...???

My uninitiated thinking would be that the pump should be able to get the entire stack of water in the well just in case the static level and water supply should diminish for a sustained period for some reason.

But this is all new to me so....

Thanks

Mark

Your right, that is too much pump for your situation. Most of us agree that 1 gpm through any pump end is enough water to keep the pump and motor cool and the pump end lubricated. That pump; should you use too much water will over pump the well which will cause the pump to run dry for however long and that is what will shorten it's life. A pump that will do only 2 gpm at 500 feet for the sake of numbers, would never over pump the well and would keep running cool no matter how long the over pumped condition continued.

bob...