About To Drill Well - Have Some Questions

[Pettrix]

About to drill a well in Northern Arizona. Well depth is around 360 feet with around 30-40GPM of water at that level. Here is what they priced out:

Drilling = 6.5" Bore Hole - 380 @ $10 per foot = $3,800
Casing = 7" Steel = $500
Casing 4.5" PVC Solid = $1,120
Casing Perforated 4.5" PVC = $500
Permit Fee and Mode/Demobe = $550

TOTAL = $6,470

PUMP SYSTEM = Grundfos SQE Constant Pressure 1.5HP - 10GPM - Motor Set @ 360 = $3,720
Pump Model = 10SQE15-330
Pump Controls = Grundfos Constant Pressure CU301 w/ 2 Gallon Pressure Tank

TOTAL Pump system = $3,900 w tax

TOTAL WELL COSTS = $10,370


Questions:
1 - How does the above look? Decent pricing? Anything out of line?
2 - Is that Grundfos pump good? I was thinking about a higher output (more than 10GPM - maybe 30GPM)
3 - Should anything be modified to the above proposal?
4 - Is it possible to run that well pump on a gas powered generator for a while until I start building my home? I need the water for site work (compaction, concrete)
5 - What's a good gas or diesel generator to run that well pump during construction?

 

[oosik]

When I put a "well" on my property- my well is an enclosed spring- the excavator recommended Grundfos. i questioned the very small pressure tank but he said it worked fantastic and it would never have a problem with "over cycling". The Grundfos system was designed around the small pressure tank.

I didn't go with the Grundfos system - mainly because it was quite a bit more $$$ than what I currently have.

I ran my well on a generator for a week or so - until I got electricity down to the pump house. Just be sure the generator is big enough.

What a hoot - until we got electricity down to the well. We did everything necessary twice a day. Run down, start the generator - come back, do dishes, wash clothes, flush toilets etc etc. The spring is 175 feet away from the house.

 

[PILOON]

Well digging prices sound OK, in fact quite good. To convert to Cdn $$ a steal.
Pump brand and equipment also good except I find prices on the high side but then maybe full retail? or retail +(I buy wholesale from distributor)
Last year (in Canada) I did a well for client and pump, tank. controls and all hardware was in the $1K range, true we were only 100 ft deep but pump was 3/4 12 GPM w/o any fancy constant flow controls. They estimated well produced 20-25GPMs.
At 30/40 GPM I really don't think any complex controls are needed unless you have very high consumption needs that could run the well dry.
Just my opinion but I am not a well engineer.

 

[crackerjack222]

Questions:
1 - How does the above look? Decent pricing? Anything out of line?
Pricing looks reasonable to me.
2 - Is that Grundfos pump good? I was thinking about a higher output (more than 10GPM - maybe 30GPM)
Grundfos is top of the line pump for this application. You could save a few $$ by going with a cheaper pump, but if you want quality, stay with Grundfos. To get higher output you would need higher hp. Not worth it unless you plan to do a lot of yard/garden/field irrigation. 10gpm is ok for a residence and typical yard/garden. In my experience a few years ago the largest pump I could put in a 4" well was 5hp without going to three phase, then max hp was 7.5. Things may be different now tho.
3 - Should anything be modified to the above proposal?
See above.
4 - Is it possible to run that well pump on a gas powered generator for a while until I start building my home? I need the water for site work (compaction, concrete)
I have run a 1.5 hp submersible with my 5500 watt gasoline generator. It handled it ok with only a slight pull-down during startup.

I am not familiar with the setup they are quoting, but it is probably a variable speed pump given that the pressure tank is so small.


5 - What's a good gas or diesel generator to run that well pump during construction?
No recommendation from me.

 

[Jimbrown]

The well price is very good. You could not get it done for that around here, Cochise county.

The pump is a good one. It is 220 volt so you need a generator capable of that.

I don't like those type of pump setups for Az because there is no reserve of water. The power goes out you got 1 1/2 gallons. I pump into a 1800 gallon storage tank. And pressurize from there.
Might want to think about that.

 

[MacLawn]

Seems decent to me, but I don't know about that tiny pressure tank. I think mine is a WellXTrol, or some such, about 25 gallons (?) with the vinyl bladder inside. My last one lasted over 30 years! My Funk & Wagner 3/4 hp pump lasted over 33 years! My well is 500', casing is 100', the rest through Georgia blue granite, pump is about 350' down. Your quote seems good, but again, I'd want to know more about the pressure tank size. If my power goes out, we still have enough water in our tank for quite a lot of use.

I've researched generators too for my well pump, neighbor has one, but all I can find is it MUST be big enough.

 

[Valveman]

Grundfos makes good pumps. But you want to stay with their standard 4" pumps that spin normal 3450 RPM, not the SQ or SQE that spins 10,700 RPM. The 2 gallon size tank only holds about 1/2 gallon of water. But your water comes from the pump, not the tank. You just have to make sure you have a pump large enough to supply the demand. The constant pressure systems like with the variable speeds (VFD's) or a Cycle Stop Valve (CSV) will allow you to use as large a pump as you think you want, and still be able to use it like a small pump without hurting anything. The constant pressure systems do not need a large tank, because the pump does not cycle on and off like the old style pressure tank only systems, that require a much larger tank to limit the number of cycles.

Pressure tanks of any size are not reliable for storing water for power outages. They fill up when the pressure gets to 60 and they drain out completely when the pressure drops to 40. And you have no way of making sure they are at 60 PSI when the power goes off. If the pressure happen to be at 41 when the power goes off, even a large tank will only have 1 gallon of water left in it. And Murphy will make sure that anytime the power goes off, the pressure will be at 41 or so. Store a few 5 gallon jugs in a closet or have a generator ready for power outages if you really want water during this time.

I think the 1.5 HP is the largest of the SQE type pumps. If you want more water you will need to go with a standard pump with higher horsepower. A CSV will make a constant pressure system out of any size standard pump. The CSV will be much less expensive than the VFD type systems, and will make the pump system last longer.

Variable speed or VFD type constant pressure systems are a good idea. They solve lots of problems that are common to the old pressure tank only systems. But you can get the same performance without all the computerized complications of a VFD by using a CSV instead. Then you can have a large a pump as you want, and use it anyway you need.

 

[flusher]

Price looks OK.
In May 2005 I paid $5500 for a well with 6" bore to 154 ft depth. It blew out at over 100 gpm.
My pressure tank was larger (28 gallon).
Franklin pump 220 volts, 1.5 hp. Produced about 30 gpm.


Good luck

 

[CobyRupert]

Pressure tanks of any size are not reliable for storing water for power outages. They fill up when the pressure gets to 60 and they drain out completely when the pressure drops to 40. And you have no way of making sure they are at 60 PSI when the power goes off. If the pressure happen to be at 41 when the power goes off, even a large tank will only have 1 gallon of water left in it.

I don't understand this. Are you saying you'll have 41 psi of air in the tank but no water?
Up here we have pressure tanks (ballast tanks) that have an air bladder in them (so the air doesn't diffuse into the water). When the power goes out this will push the water out until the pressure is near zero.
Some say that a 30 gallon tank might hold 20 gallons of water and 10 gallons of air when it's pressurized ( say 50 psi cut-out (off)) and you can draw off about 10 gallons before it cuts-in (on) at 30 psi.
But if the power is out it will still push water at 30 psi and lower to almost zero psi (but at a flow rate that slows with the pressure drop)
There's good information on the charts at the bottom of this webpage: Water Tank Size - how much water is in the water pressure tank? How much water volume do we need to avoid short cycling the water pump?

 

[Egon]

The pipe costs seem low but I'm not familiar with your costs.

Just for information on a fixed pump the diameter of the stages will influence the volume. The number of stages the pressure. Your pump rate should not exceed the inflow or drawdown rate.