Spring Water Pump/Piping

[mattly1]

Hello everyone, I'm new here and hoping to gain a little insight from you all. We are building a new home and have a spring and creek on our property, the spring we'd like to use for water is down a STEEP and rocky bluff, about 300-400' of total run from the house. I've had a well guy out and he said using the spring would be no problem, that he could install a "lake water system" in which the pump (housed in a basin sunk into the spring area) would fill up the pressure tank then drain the remaining water back out of the supply pipe so it wouldn't require trenching down the bluff to avoid freezing- SW Missouri for climate reference.

This sounds great, but I have some concerns which he didn't seem too concerned about so I thought I'd get more opinions here.
The volume of a 1" supply pipe traveling 400' is roughly 16gal, correct? With a standard well pump wouldn't we be looking at around a minute of pumping just to get the water back up to the pressure tank each time the switch activated? Would a larger than normal pressure tank alleviate this issue? How much energy would we be wasting to pump back up the water through an empty pipe every time?

I'd much rather use the spring water than a well, it's a cheaper option and also a better quality water. We have a high sulfur content in most well water from our neighbors. I also know we'll need an extensive filter system which as already been priced in. Any input is welcome, thank you!

 

[Valveman]

With a drain back system, yes it will take a minute or two for the water to fill the lines when the pump is started. You will need a large enough pressure tank to supply the house for a minute or two until the water gets there. Most houses use about 5 GPM max, so a 44 gallon size tank (10 gallon draw) would be minimum. An 86 gallon tank would be better with 20 gallons of draw. This is because the tank needs to deliver 10 gallons after the pump is started. So, using a 40/60 pressure switch and only putting 28 PSI air in the tank, will allow another 10 gallons as the tank drains from 40 to 30 after the pump is started. With the proper air vent/vac valve up top, all the air will be released before the check valve at the tank opens.

 

[mattly1]

With a drain back system, yes it will take a minute or two for the water to fill the lines when the pump is started. You will need a large enough pressure tank to supply the house for a minute or two until the water gets there. Most houses use about 5 GPM max, so a 44 gallon size tank (10 gallon draw) would be minimum. An 86 gallon tank would be better with 20 gallons of draw. This is because the tank needs to deliver 10 gallons after the pump is started. So, using a 40/60 pressure switch and only putting 28 PSI air in the tank, will allow another 10 gallons as the tank drains from 40 to 30 after the pump is started. With the proper air vent/vac valve up top, all the air will be released before the check valve at the tank opens.

Thanks for the quick reply! Would it be beneficial to avoid big PSI swings to look into a re-press pump?

 

[Valveman]

If you have room for a small cistern and re-pressurization pump, it would work much better for draining back. All you need to do it drill a hole in the check valve on the pump. When the pump is off, the entire line from the cistern to the pump drains back with no special vent/vac/check valves up top. You also will not have to wait for water in the house when the re-pressure pump comes on, so a little 4.5 gallon size pressure tank is all that is needed with a CSV system, as in the PK1A kit.

 

[mattly1]

@Valveman That is very similar to the system we put in at work, just with a 1500gal storage tank for water cooled CNC machines. We also have a Variable frequency pump, is that similar to the CSV you are talking about?

What size storage tank would be needed in this setup, I imagine something like 120gal would do the trick?

 

[Valveman]

The cistern needs to be large enough that the spring pump runs several minutes to top it off. You only want the level to drop a foot or two in the cistern before the spring pump comes on to refill it. I would guess a 200-300 gallon cistern would work best.

With a CSV controlling the pump a 4.5 gallon size pressure tank is all the re-pressure pump will need.

The CSV was designed to replace expensive and problematic Variable Frequency Drives or VFD's like the one cooling your CNC machines. We have been replacing VFD's with CSV's now for over 30 years. When your VFD starts giving problems, as many do all too soon, you can replace it with a simple, inexpensive, long lasting Cycle Stop Valve.

Many people incorrectly think a VFD is needed to reduce the amps and save energy on a pump system. This is absolutely untrue. The amps of a centrifugal pump will decrease almost exactly the same when running full speed and restricted with a valve as when the RPM is slowed with a VFD. Not only does a simple valve reduce amperage the same as a VFD, but reducing the amperage with a VFD actually increase energy cost. Kilowatts used per gallon produced greatly increases with a decrease in motor amps from the VFD.

In other words, a VFD can decrease the amps needed to spin the pump/motor, but increases the energy used to pump a gallon of water. Hard to understand, which is why so many people incorrectly think a VFD saves energy.

 

[mattly1]

The cistern needs to be large enough that the spring pump runs several minutes to top it off. You only want the level to drop a foot or two in the cistern before the spring pump comes on to refill it. I would guess a 200-300 gallon cistern would work best.

With a CSV controlling the pump a 4.5 gallon size pressure tank is all the re-pressure pump will need.

The CSV was designed to replace expensive and problematic Variable Frequency Drives or VFD's like the one cooling your CNC machines. We have been replacing VFD's with CSV's now for over 30 years. When your VFD starts giving problems, as many do all too soon, you can replace it with a simple, inexpensive, long lasting Cycle Stop Valve.

Many people incorrectly think a VFD is needed to reduce the amps and save energy on a pump system. This is absolutely untrue. The amps of a centrifugal pump will decrease almost exactly the same when running full speed and restricted with a valve as when the RPM is slowed with a VFD. Not only does a simple valve reduce amperage the same as a VFD, but reducing the amperage with a VFD actually increase energy cost. Kilowatts used per gallon produced greatly increases with a decrease in motor amps from the VFD.

In other words, a VFD can decrease the amps needed to spin the pump/motor, but increases the energy used to pump a gallon of water. Hard to understand, which is why so many people incorrectly think a VFD saves energy.

I did some reading on Cycle Stop Valves, Inc pretty interesting stuff, and seems like a long lasting solution. I understand what you're saying about VFD pumps, and while the one in our shop works well currently I would rather have something a bit more simple (and cheaper) in my home. Do you have a recommendation for a home re-pressure pump? Elevating the cistern a foot or so may be possible, to allow an outlet toward the bottom if necessary.

 

[Valveman]

Any shallow well jet pump that can build at least 70 PSI max will work with a 40/60 pressure switch. Something like this 1HP would work.
https://www.tractorsupply.com/tsc/product/countyline-shallow-well-cast-iron-jet-pump-1-hp
But if all you want is 30/50 pressure a 1/2HP shallow well jet pump is all that is needed. Like this.
https://www.tractorsupply.com/tsc/product/countyline-shallow-well-cast-iron-jet-pump-1-2-hp
You can also use a submersible well pump in the cistern. This way it would be silent, self priming, and pump more pressure for the HP. There is a 1HP pump that a lot of people are using mainly because it is just over 100 bucks. Here. Submersible Pump, 3.5" Deep Well, 1 HP/220V, 33 GPM/207', all S.S. Hallmark Ind | eBay

 

[mattly1]

Any shallow well jet pump that can build at least 70 PSI max will work with a 40/60 pressure switch. Something like this 1HP would work.
https://www.tractorsupply.com/tsc/product/countyline-shallow-well-cast-iron-jet-pump-1-hp
But if all you want is 30/50 pressure a 1/2HP shallow well jet pump is all that is needed. Like this.
https://www.tractorsupply.com/tsc/product/countyline-shallow-well-cast-iron-jet-pump-1-2-hp
You can also use a submersible well pump in the cistern. This way it would be silent, self priming, and pump more pressure for the HP. There is a 1HP pump that a lot of people are using mainly because it is just over 100 bucks. Here. Submersible Pump, 3.5" Deep Well, 1 HP/220V, 33 GPM/207', all S.S. Hallmark Ind | eBay

Thanks for the recommendations! I like the submersible pump, if I can get a 300gal tank tall enough to accommodate it. I assume the entire pump assembly needs to be submerged at all times for cooling?

 

[Valveman]

Thanks for the recommendations! I like the submersible pump, if I can get a 300gal tank tall enough to accommodate it. I assume the entire pump assembly needs to be submerged at all times for cooling?

Glad you ask. At least the bottom 2/3rds of the pump/motor needs to be submerged, as the intake is in the middle. But you can lay it on it's side, requiring a wider, but not as tall storage or cistern tank. You can make a cradle to hold it just off the bottom. You also need a flow inducer sleeve, made from a short piece of 4" thin wall PVC drain pipe, a 4.5" hose clamp, and a little electric tape. I will post pictures.

 

[mattly1]

Glad you ask. At least the bottom 2/3rds of the pump/motor needs to be submerged, as the intake is in the middle. But you can lay it on it's side, requiring a wider, but not as tall storage or cistern tank. You can make a cradle to hold it just off the bottom. You also need a flow inducer sleeve, made from a short piece of 4" thin wall PVC drain pipe, a 4.5" hose clamp, and a little electric tape. I will post pictures.

The flow inducer is just to make sure it intakes from the bottom of the cistern? So it would need to be slightly elevated off the bottom if it were installed vertically with that sleeve? If so would the PVC output pipe be enough to hold it in place?

 

[Valveman]

The flow inducer is to force water past the motor before it goes into the pump intake for motor cooling purposes. In a lake, cistern, dug well, or any large body of water the pump can actually be pumping cool water while boiling water at the bottom of the motor. There has to be a flow past the motor and the flow inducer makes sure of that.

Installing vertically it is best to just hang the pump from the tee/elbow on top of the drop pipe. Another tip is to use a short piece of poly pipe or strong hose to hang the pump from, which insulates the motor/pump vibrations from the tank and plumbing to make it even more quiet.

 

[mattly1]

The flow inducer is to force water past the motor before it goes into the pump intake for motor cooling purposes. In a lake, cistern, dug well, or any large body of water the pump can actually be pumping cool water while boiling water at the bottom of the motor. There has to be a flow past the motor and the flow inducer makes sure of that.

Installing vertically it is best to just hang the pump from the tee/elbow on top of the drop pipe. Another tip is to use a short piece of poly pipe or strong hose to hang the pump from, which insulates the motor/pump vibrations from the tank and plumbing to make it even more quiet.

Makes sense. Thanks for all your info, I appreciate it! Might end up doing this thing by myself instead of hiring the well guy, if I do I may have a few more questions before it's all said and done.

 

[Valveman]

Let me know if I can help with anything.