Why would they set pump at 520' when static water at 180'?

[stevenshager]

Only getting 2gpm from unrestricted spigot (no pressure tank or softener). Grundfos 5S10-22 is pulling the 9.8 amps as listed in specs.

The pump is hanging on 1" Schedule 80 PVC at 520'. Well is cased the entire 790' with 4.5" PVC. When the pump was set the TEST DATA shows Static Level 180', Time 30 Minutes, Rate 7 GPM, Pumping Level 195'. That was 20 years ago.

Something has happened to cause the reduced water flow. My guess is that my downhole pipe has a crack in it, causing all but 2 GPM to leak out.

My question is "Why set the pump so low in the well?" At 350' I could probably get a 50/70 setting at my pressure tank, which would be great for showers. But since they were professionals, I'm thinking there has to be a reason that they set the pump at the 520'.

Does the test data I've shown mean that the well was producing 7 GPM, or does it mean that they were pumping 7 GPM, and that the static level dropped 15' during that 30 minute test?

I'm going to pull the pump to look for that "crack". When reinstalling I would prefer to raise the pump by 8 sticks, to say 352'.

 

[Jeff H Young]

I think you may have double posted? the pump being deeper is better 20 year old spec may not be the same today

 

[Sponsor]

 

[Reach4]

"Only getting 2gpm from unrestricted spigot (no pressure tank or softener). Grundfos 5S10-22 is pulling the 9.8 amps as listed in specs.

The pump is hanging on 1" Schedule 80 PVC at 520'. Well is cased the entire 790' with 4.5" PVC. When the pump was set the TEST DATA shows Static Level 180', Time 30 Minutes, Rate 7 GPM, Pumping Level 195'. That was 20 years ago."

When did you measure the 9.8 amps? If recently, ... wait....

Do you have an above-ground check valve? Do you notice air in your water?

"My question is "Why set the pump so low in the well?" At 350' I could probably get a 50/70 setting at my pressure tank, which would be great for showers. But since they were professionals, I'm thinking there has to be a reason that they set the pump at the 520'."

If you could get 70 psi with the pump set at 350 ft, you could get 70 psi with the pump set at 520. It is not the depth of the pump that determines how much pressure you can develop; it is the depth to the surface of the water.

A reason to set a pump deeper than is initially necessary is that if the water table drops, the pump could continue to deliver water. 2 gpm but 2 gpm is better than sucking air.