I need some advice, as I am not 100% sure my well guy is figuring things correctly. They drilled a new 6" well and hit a large vein at 385 ft. The well guy drilling estimated a conservative 80-90 gpm.......he was unsure but said it may be as high as 100 gpm......he said the well will never go dry regardless how much I use!!! They did not know for sure the water level in the well and they were already quoting a pump I needed. After discussion I figured out that they needed to know the water level to figure out the right pump and tank. So the guy told me to drop a marble size rock in the well and time it until I hear the splash. I did it twice with a stop watch app and it times at 2.8 seconds.......he said 25 ft. per sec. which comes out to 70 ft. for the water level.
This is what they are proposing to me for a system, a Goulds 10GS10 pump (10 gpm, 1 HP, 1 1/4" discharge, set at 300 ft.), a Goulds 44 gal tank (w/15 gal. draw down), I presume 1 1/4" pipe between the two which is approx. 100 ft. to the basement, pressure sw., etc. etc.
The house is new 2900 sq. ft., 4 bedroom, 3.5 bath........and I may possibly want to be able to run sprinklers or maybe even install a sprinkler system if needed later.
The Gould charts for this pump says at 80 ft. water level with a 40/60 sw. settings, that this 10GS10 pumps out 15.5gpm to 13.7 gpm. It also list a shutoff pressure of 132 lbs.
My concerns are mostly having a proper sizing so that the pump cycles are at least 2 mins., .......also the guy says the pump at 300 ft. can handle this load all day long, as the 300 ft. level doesn't affect the pump.... he said it is only pumping the water the 70 ft., the remainder of the pipe coloum is just the draw down available for the pump should I ever need it. I mentioned do we need a larger tank since this pump can basically supply that 15 gal. draw down in 1 min. I also asked if we needed a CSV valve.......he knew what they were, but apparently they only use them to correct water hammer, etc. they apparently don't use them to control pump cycles.....plus he mentioned a couple hundred to install one. He seemed to be getting aggravated with my questioning his pump wisdom so I let it go.......thinking I can add the CSV if needed later on. If so, which CSV do I need, I want to install it in the basement and maybe have one that is adjustable......but I've read some leak a little.....please advise...
Also he is quoting me $1985 for the Goulds pump, wire, piping, etc. to install it at the well head, and set a temp tank setup to use during construction. Then after construction he's quoting another $1135 to install to the house, approx. 100ft. set tank and system up.........this is located in NC......do these prices sound in line or HIGH ? .............this did not include the drilling cost which was $8 a foot @ 385 ft = $3080.
Any help/advice the experts can give will be greatly appreciated!!