New service line to hilltop at distance.

[stevepag]

Hey guys,

I’ve read a lot of posts on the forum, but I think I’ve got a situation different enough to warrant a separate post.

I want to run a water line to a new house site on my land from county water at the street. I understand that a well is an option, but let’s please keep that out of consideration for now.

Length of run – 2600 Feet
Water at meter is 92lbs pressure from a 3/4” line. I have no idea what the flow rate might be.
Change in elevation +163 feet

From what I understand, I’ll lose about 70lbs of pressure just from elevation alone (163x.43) which would put me at around 22lbs.

I realize that I could have a booster pump at the base of the rise, but given power access and other factors, I think a better option for me would be to have the city water (at whatever low-pressure its at) fill a tank in the home’s basement and pump from that. There is also a possibility that I’ll use this supply for one or two other structures which would have their own “trickle tanks.” I’m planning on using rolled HDPE pipe.

Questions:

• What diameter pipe should I use, and does it matter much given that I’m planning to store water at the top of the hill?
• Assuming my county could/would increase my meter to 1” (or bigger) is it worth the effort? What better performance would I get?
• If my plan (low-flow to a hilltop tank) isn’t a good one, and I just do the booster pump at the bottom of the hill, what size pipe should I run then?
• Is HDPE a good choice? Would you recommend a different pipe material?

Thank you in advance for your advice and suggestions.

SP

 

[Reach4]

What is the minimum pressure at the meter. If you lose 70 psi due to altitude change, you would have to have a minimum be higher than 70. A bigger water meter would not help significantly. So if 90 psi is the minimum pressure, then things should work.

SIDR poly is a good choice. Two inch would be good, but would not be a minimum. Depending, it could be considered overkill.

I am wondering about using a suction booster pump at the house with 2 inch pipe. A multi-stage centrifugal pump may be good. I am not a pro.


https://www.menards.com/main/plumbi...pe/13550/p-1444431555879-c-8570.htm?exp=false is one instance of 2-inch.

https://www.menards.com/main/search.html?search=sidr searches for more.

 

[Sponsor]

 

[wwhitney]

Length of run – 2600 Feet
Water at meter is 92lbs pressure from a 3/4” line. I have no idea what the flow rate might be.
Change in elevation +163 feet

In order to properly design this, you need to know the minimum static (no flow) water pressure you will ever get at the meter, and also the minimum residual pressure at the meter with some given flow rate (specified at maybe 10 or 20 gpm). E.g. you'd like a statement from the water company of the form "never less than 85 psi static; and at least 80 psi when flowing 10 gpm at the meter."

As you observe, you'll lose 71 psi just from the elevation rise. So if the static pressure ever drops below 71 psi you won't get any water at the top of the hill (barring the use of a pump that would put the line under partial vacuum; not sure if that is allowed).

If you make it over that hurdle, if you want to commit to using sufficient storage at the top, 2 gpm of flow would give you 2880 gallons of water per day. If that's enough, you could get away with a fairly small pipe for the 2600 ft of run; in a 1" true inner diameter plastic pipe, 2 gpm over 2600' would only drop 4 psi.

However, it may not be prudent to size the pipe that small, as the material portion of the installation cost is likely a small factor, and a 2" (true inner diameter, adjust for the actual pipe diameter) could give you 12.3 gpm at that same low drop of only 4 psi.

Upsizing the meter or the water lateral upstream of the meter is likely of no value, as the system performance is going to be dominated by the 2600' water lateral you install. Although if for some reason the water company will give you a significantly higher minimum static pressure or residual pressure with a larger meter, that could be worth it.

If it's easier to get electricity for a pump say 500' from the house than all the way at the meter, and if the elevation rise is uneven so that point at 500' from the house is significantly more than 20% lower in elevation, it could be worth installing a booster pump inline.

Cheers, Wayne

 

[stevepag]

What is the minimum pressure at the meter. If you lose 70 psi due to altitude change, you would have to have a minimum be higher than 70. A bigger water meter would not help significantly. So if 90 psi is the minimum pressure, then things should work.

SIDR poly is a good choice. Two inch would be good, but would not be a minimum. Depending, it could be considered overkill.

I am wondering about using a suction booster pump at the house with 2 inch pipe. A multi-stage centrifugal pump may be good. I am not a pro.


https://www.menards.com/main/plumbi...pe/13550/p-1444431555879-c-8570.htm?exp=false is one instance of 2-inch.

https://www.menards.com/main/search.html?search=sidr searches for more.

Thank you for the advice Reach4!

Pressure at the meter is 92lbs...so i think I'm good. For argument's sake, if i went as small as 3/4", would the line friction keep it from getting to the top?

Right now, I'm thinking 1 1/4" is a good balance and, if for some reason my service becomes inadequate I could put in a booster at that time.

SP

 

[stevepag]

In order to properly design this, you need to know the minimum static (no flow) water pressure you will ever get at the meter, and also the minimum residual pressure at the meter with some given flow rate (specified at maybe 10 or 20 gpm). E.g. you'd like a statement from the water company of the form "never less than 85 psi static; and at least 80 psi when flowing 10 gpm at the meter."

As you observe, you'll lose 71 psi just from the elevation rise. So if the static pressure ever drops below 71 psi you won't get any water at the top of the hill (barring the use of a pump that would put the line under partial vacuum; not sure if that is allowed).

If you make it over that hurdle, if you want to commit to using sufficient storage at the top, 2 gpm of flow would give you 2880 gallons of water per day. If that's enough, you could get away with a fairly small pipe for the 2600 ft of run; in a 1" true inner diameter plastic pipe, 2 gpm over 2600' would only drop 4 psi.

However, it may not be prudent to size the pipe that small, as the material portion of the installation cost is likely a small factor, and a 2" (true inner diameter, adjust for the actual pipe diameter) could give you 12.3 gpm at that same low drop of only 4 psi.

Upsizing the meter or the water lateral upstream of the meter is likely of no value, as the system performance is going to be dominated by the 2600' water lateral you install. Although if for some reason the water company will give you a significantly higher minimum static pressure or residual pressure with a larger meter, that could be worth it.

If it's easier to get electricity for a pump say 500' from the house than all the way at the meter, and if the elevation rise is uneven so that point at 500' from the house is significantly more than 20% lower in elevation, it could be worth installing a booster pump inline.

Cheers, Wayne

Thank you Wayne - you're insights about pressure loss and pipe diameter are particularly helpful, along with your suggestion of an inline pump.

SP

 

[Valveman]

With a 3/4 line you will never get anything but a trickle flow, but it might work. I would use the 1 1/4" but still set it up for trickle flow to more than one cistern. A float valve in each cistern will work fine with the 10-20 PSI is should be getting. Just need a little jet pump or submersible in each cistern to supply as many as 4-5 houses or just one.

 

[Valveman]

You could also use a multi-stage booster at the top of the hill. Figuring a loss of about 80 PSI to the top of the hill, it would need to run with a 120/140 pressure switch setting to have 40 to 60 for one or multiple houses at the top of the hill. Of course you can get a constant 50 PSI at the top by having a constant 130 PSI from a Cycle Stop Valve at the bottom. There are many advantages for using a CSV on any system, but especially a system like this.

 

[stevepag]

With a 3/4 line you will never get anything but a trickle flow, but it might work. I would use the 1 1/4" but still set it up for trickle flow to more than one cistern. A float valve in each cistern will work fine with the 10-20 PSI is should be getting. Just need a little jet pump or submersible in each cistern to supply as many as 4-5 houses or just one.

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Thank you very much for your reply and insight Valveman. These are things that I haven't thought far enough ahead on!.
SP