Long pipe run uphill from well to home

[water_bender]

I am designing a water system for a single family home, and I have some questions. Here is the situation:

The well will be located way down a hill from the home. Pipe run from well head to home will be about 1100 feet long. The elevation difference is 150 feet. The well might end up being about 200 feet deep.

I have heard that this situation could cause a lot of water hammer, so I'm trying to design it to prevent that. I got an estimate from a well driller who said to install check valves every 100 feet but I've read on this site that extra check valves will actually cause more water hammer. I calculated that the weight of the water in the pipe (assuming 1 inch) will be about 442 lbs when it's stationary, so I don't think one check valve will be able to handle that.

Does anyone have any advice about how to prevent water hammer in terms of check valves, pipe diameter, pipe material, etc? I am already considering a CSV.

Thanks!

New Mexico

 

[LLigetfa]

I calculated that the weight of the water in the pipe (assuming 1 inch) will be about 442 lbs when it's stationary, so I don't think one check valve will be able to handle that.

The check valve will not see that weight as PSI. The PSI is based only on vertical height of .43 PSI per foot. Deep well pumps have check valves designed for depth.

Water hammer should not be an issue as there are no fast closing valves downstream. If you do deploy a CSV, then the flow rate will be down to 1 GPM when the pump shuts off.

 

[Sponsor]

 

[Reach4]

The well will be located way down a hill from the home. Pipe run from well head to home will be about 1100 feet long. The elevation difference is 150 feet. The well might end up being about 200 feet deep.

I think you would choose a pump as if it were a 350 or 375 ft deep well.

I would use 200 PSI poly pipe with barbed fittings. Don't pull the pipe tight in the trench. Poly is cheaper than PEX and it is larger ID than PEX. https://terrylove.com/forums/index.php?threads/tips-for-400-ft-pipe-run.74073/ has some discussion including selecting pipe size.

For size, it depends on GPM you are designing for. 10 GPM is usually enough for a house IMO, but others think more.

It is usually best to put the pressure switch and tank at the house. It is not mandatory. If you decide to have a separate meter at the well, I would upsize the long pipe. 1100 ft is a long way, so after study, I might go for the separate meter. The cost of a separate meter varies by location. You are probably talking about running #4 AWG wire for that distance with a 3-wire pump. Not cheap.

You want your well at least 5 inches ID. You want a sand and clay free well, and that may mean casing all of the way. Check locally in the area you will be drilling for the neighbor's well experiences.

I agree with only having a check valve in the pump, plus one more just above the pump.

Is the motivation for the location the expectation that the well will have to be 150 ft deeper if drilled closer to the house?

 

[Valveman]

Just need a well pump the same as if the well was 350' deep and needs to deliver 50 PSI up top. That would be a pump that can produce 10 GPM from 465' of head total. Use one good check valve on the pump and reduce the flow rate, like when using a CSV, before the pump shuts off. That is how to eliminate water hammer on pump stop. Then using a CSV to greatly reduce the number of cycles, also reduces the number of possible water hammer events.

Power and a small well house at the bottom of the hill would keep you from having to install large wire for a long distance. You would need a pressure switch setting of 105/125 and a 86 gallon size tank with a pressure rating of 150 PSI, like a WX302. A regular CSV1A set at 115 PSI would deliver a constant 51 PSI to the house on top of the hill.

 

[Reach4]

http://www.pressure-drop.com/Online-Calculator/

I would use 0.03 mm for roughness. Add some length to compensate for fittings.

I would want less than 5 PSI pressure drop at 10 gpm with the pressure switch and tank at the bottom of the hill. If those were at the top of the hill, I expect 10 or 15 psi would be OK.

So I am thinking maybe use 1.5 to 2 inch ASTM D2239 poly for pressure stuff at bottom, and you could go to 1 or 1.25 if up top.

 

[Reach4]

An additional option would be to supply power at the well, but to have a smaller wire with a control signal running to the pressure switch at the house.

 

[Valveman]

Nothing but trouble with an 1100' control or power wire. Impedance among other things, becomes a big issue with these long lines.

 

[water_bender]

Why the well is so far away -- The area is already kind of hit or miss for groundwater but from the well logs it looks like a well would have a better shot down the hill near the river

Check valves -- Ok, so you still recommend just one check valve. What kind of check valve should I use - the built-in pump one or another one?

I have considered getting a separate electric meter to go to the well site, especially since the power lines are much closer to the well than the house, but I was talking to an electrician and he recommended against that since it would cost $30 a month just to have that meter there, plus the cost to get it installed, might as well just have a long wire. I don't know if it would be possible to "splice" off the current power line going to the house or something.. to avoid the extra meter.

The electrician I talked to recommended that I put the controller down by the well, and have the pressure switch and tank up by the house. He said the 1100 foot wire could be a little smaller that way. I didn't necessarily understand that.. since it would still need the same power, right?

So it looks like I have a few options with the electrical and I'm trying to figure out which would be best value (capital cost plus power bill).

1. Pressure switch, tank, and controller at house
2. Pressure switch and tank at house, controller at well
3. Pressure switch, tank, and controller at well

 

[Valveman]

If you are using a good brand pump like a Grundfos or Goulds, the built in check should be fine. Any other brand pump and I would add a good check valve like a Simmons to the pump.

The wire will be the same size no matter if the controller is at the well or at the house. But with the controller at the house you will need 4 wires going down hill. With the controller down at the bottom you only need 3 wires from top to bottom.

I am seeing about 4 bucks a foot for #4 wire with 3 or 4 conductors. Maybe add another dollar per foot if you put it in conduit, which I recommend. So $5500 worth of wire would be the same as 15 years of meter charges. But it would eventually get paid off and the meter would not.

 

[LLigetfa]

Where is the transformer (can) for the service to the house? Normally on such a long run they run the high voltage line closer to the house and put the can on a nearby pole. To share one meter with both locations, the can would need to be near the meter. Around here they call it central metering with the meter usually on the same pole as the can and then branching off after the meter.

If the well location is near the road access to the house, there may be other uses for power there, such as a yard light, security cameras, motorized gate, etc.

 

[Reach4]

The electrician I talked to recommended that I put the controller down by the well, and have the pressure switch and tank up by the house. He said the 1100 foot wire could be a little smaller that way. I didn't necessarily understand that.. since it would still need the same power, right?

I am in agreement with that, especially given the $30 per month.

With the controller down the hill, you will have fewer wires. It would be better to get a 3-wire pump controller that has not only a start cap but also a run cap. I am not sure if that would translate to smaller wires, but everybody would definitely want the controller at the well.

If he suggests to run less than 4 AWG, let's discuss. I am thinking 2 HP pump.

 

[Sid Post]

My advice living at a farmhouse I bought, is to skip the "two meter" approach for electrical power. I'm in the process of going from two to one meter as a $5~$6 electric bill plus $28 meter service cost is aggravating to say the least.

Move the house meter to the "road" service pole and branch off to the well house from there.

 

[LLigetfa]

Move the house meter to the "road" service pole and branch off to the well house from there.

I would not run a low voltage (240V) house service that far. There will be too much voltage loss and ground potential voltage issues on the neutral.

 

[water_bender]

Thank you all for your helpful responses.

Looks like this is a weird scenario where the service meter is on the neighbors property a few hundred feet away. But the house has a 200 amp breaker panel and an available 30 amp breaker that we can put the pump on. So I'm now thinking, controller at bottom of hill, pressure switch and tank at top of hill -- I think this will be the best option financially.

I do actually have a question about the CSV. I'm trying to figure out how it works and it looks like it basically keeps the pump on all the time. It seems like this would be bad for the pump to just stay running and also bad for energy costs. I'm not really concerned with "city water pressure", small pressure tanks, or over-cycling the pump. The only reason I'd be interested in it is to reduce the water hammer. Am I mistaken about the device? Are there other methods/products to reduce water hammer?

 

[Reach4]

But the house has a 200 amp breaker panel and an available 30 amp breaker that we can put the pump on.

Is "the house" the neighbor's house or your house?

 

[Valveman]

I do actually have a question about the CSV. I'm trying to figure out how it works and it looks like it basically keeps the pump on all the time. It seems like this would be bad for the pump to just stay running and also bad for energy costs. I'm not really concerned with "city water pressure", small pressure tanks, or over-cycling the pump. The only reason I'd be interested in it is to reduce the water hammer. Am I mistaken about the device? Are there other methods/products to reduce water hammer?

Pumps are made to run 24/7/365. I have one in a stock water well than hasn't turned off in over 16 years now. And it will last longer this way than if it were cycling on and off even small numbers of times. With a good pump the amps are reduced when using small amounts of water, so the electric bill should show very little difference if any. The CSV only keeps the pump running when water is being used. And keeping the pump running while water is being used is HOW the CSV gives you "city like constant pressure", allows you to use a smaller tank without "over-cycling" the pump, prevents water hammer, and makes the pump last longer.

 

[water_bender]

Is "the house" the neighbor's house or your house?

It is my house.

 

[water_bender]

The CSV only keeps the pump running when water is being used.

So just to be clear, the pump keeps running while water is being used but will shut off after the faucets are turned off?

 

[Valveman]

So just to be clear, the pump keeps running while water is being used but will shut off after the faucets are turned off?

Exactly!

 

[Juniper Jane]

If you are using a good brand pump like a Grundfos or Goulds, the built in check should be fine. Any other brand pump and I would add a good check valve like a Simmons to the pump.

The wire will be the same size no matter if the controller is at the well or at the house. But with the controller at the house you will need 4 wires going down hill. With the controller down at the bottom you only need 3 wires from top to bottom.

I am seeing about 4 bucks a foot for #4 wire with 3 or 4 conductors. Maybe add another dollar per foot if you put it in conduit, which I recommend. So $5500 worth of wire would be the same as 15 years of meter charges. But it would eventually get paid off and the meter would not.

I really don't know much about any of this but my neighbor works in the construction field and said in many projects he has worked on he sees long runs being done with aluminum wire, direct burial or in conduit. An electrician told him it was a lot cheaper and does the same thing??? said he has seen this as a common practice over his 40 years of experience.

Our local utility company uses aluminum on the poles to the house.

Just curious about the aluminum wire since no one mentioned it, what is your take?

Thank you, sorry for butting in on your thread - just curious .............

Jane