Welcome to TheWellGuy. I think your 138psi was meant to be 138' of head, and for the pump option that started this discussion (Goulds 7GS15), the 10gpm max flow limit is exceeded below 380'...so the 60psi doesn't help much. I had hoped a VFD would alleviate this... but it appears it will not...
Helpful thoughts, thanks again to Artisi and BigInch. I modeled well drawdown last night with excel and I included a cistern with pump as well as a small cistern-level-controlled pump in the well. I plotted drawdown vs time, with different demand scenarios. I tried different flow rates from...
Thanks to all for the insights. Yes, the well is a frustrating one. Deep, low yield wells seem to be very common here in Placer County, CA (think Sierra foothills). We have 1.5 GPM with a test pump at 500ft, and the 560ft hole was solid granite. It was just drilled and tested, and I measured...
A new well delivers its water at 500ft, but recovers overnight to 10ft. A VFD-controlled 7GPM/1.5hp submersible looks great to cover the range of depths and flows to supply the house at a constant 50psi. The pump is rated for 10gpm max, but at first use of water in the morning, it will face...