City Water Uphill

[lemahoney08]

I have talked to numerous plumbers and engineers, all of which has non confident answers.

I am currently building a one bedroom apartment which is 75 ft in elevation higher than the city water meter and about 500 feet in distance from the meter. I have plans to build a normal size 3 bedroom house another 1200 feet further back from the road (1700 feet away from the meter) and 160 more feet of elevation (235ft higher than the tap) which would connect to the same line I am putting in now. The city water is a small community well so pressure carries. I would estimate 60lbs at the meter on a 3/4 inch meter.

I have heard everything from run 2" slip joint up the hill and bury a jet pump to push it when the pressure runs out, to run 1" HDPE to just before the apartment and let that fill a holding tank which I would then pump into the houses.
My question is, what is a good cost effective way to get water where I need it.
Is there a pump that I can bury inline which will boost the pressure in stages up the hill.
What size tank would I need in this case as I want enough that I don't run out, yet don't want it to get stagnant.
What size and type of pipe do I use. It is not flat ground, I will have to cross a creek and a driveway.
If going a tank route, is there something I can do with floats to stop it from overfilling, and stop pumping from it when empty to not burn up the pumps?
Does anyone have a system like this in place who can provide feedback on how well it works.

The picture is taken from where the apartment is located, towards the road where the meter is located to give some extra information

 

[Reach4]

Edit: I initially thought the water meter and the 60 PSI was at the lower house and the apartment was 75 feet higher. I see I mis-read. So crossed out text is not correct for your situation. I would run big enough poly up the hill. http://www.calctool.org/CALC/eng/civil/hazen-williams_p is one of several pipe calculators. The 75 ft rise will drop the static pressure by 32.5 PSI. The pipe flow resistance will drop the pressure as a function of pipe length, diameter, roughness, and flow rate. Consider bigger poly. Plug that into the calculator to see the effect.

The way I see it, the booster pump could be located at the bottom of the hill, but it could also be at the top in the apartment if the flow rate needs are normal for an apartment. If the pressure at the input of the pump is zero, you still have some margin depending on the pump. In the screen capture attached, I took the default roughness for the calculator. Poly is about as smooth as it gets. Fittings will add some drop. I used 400 ft of pipe as the length to compensate for misc, but maybe I should have left more margin.

What I would look at is a booster pump with a bypass. If the pump fails, you could still get water up top, but at a lower pressure. With a 3 valve bypass, you could remove and repair/replace the pump while keeping some water pressure in the apartment I expect the booster system would need a pressure tank too. It is possible that you could get by with no pump at all, if the apartment dwellers were tolerant of low water pressure.

I am not a pro. My calculations could be in error, so check. Do get a pressure gauge to know the actual water pressure at the bottom, but it is the minimum pressure that matters.

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[Sponsor]

 

[lemahoney08]

Can the booster pump be buried? If so would it need to be in some sort of box? Can you give some examples of what booster pumps would work. Will one booster run the pressure to both the apartment and house? A pressure reducer would be needed in the apartment if so?

 

[Valveman]

If you think you have 60 PSI from the meter, figure maybe 20 PSI when you attach a pump and start drawing from that line. Then 235' of elevation will take 100 PSI just to get water to the top. So you would want about 140 PSI to still have 40 PSI at the upper house. A jet pump will not build that kind of pressure. You will need a multistage booster pump. Vertical multistage pumps are best, but more expensive than horizontal multistage pumps. Good multistage pumps are not cheap and cheap multistage pumps are not good.

With a 130/150 pressure switch an 86 gallon pressure tank only holds 10 gallons of water. You will need at least a 44 gallon size Well-X-Trol tank, as those are the smallest you can get with 150 PSI rating. When using a CSV the 44 gallon tank will be large enough, and you can add an additional tank at either of the upper houses if you want as it would be working at a lower pressure and hold more water that way. You would not be able to add additional pressure tanks up the hill without a CSV, as they will not fill at the same time that way. A CSV set at 140 PSI would deliver constant pressure to the houses and eliminate water hammer and a lot of other problems that happen with these type systems.

You can install the pump, CSV, tank, and pressure switch in a vault at the meter, but anything underground will have high humidity and not be good for the motor, pressure switch, or other electrical components. I would install this equipment in a little, heated and vented pump house at the meter, to eliminate the moisture problem and to be able to easily access the equipment when needed.

Then you can use a pressure reducing valve like the PRV1A at the middle house to maintain the correct pressure. The size and type of pipe and the pump will depend on the GPM you require.

 

[lemahoney08]

Update, so I ran 1" HDPE line from the road 500ft. Which leaves me 100ft of pipe short of making it to the apartment with 30 more feet in elevation difference. My debate is to put in a vault and pump or a cistern tank. In testing I get 5 gallons per minute and 30psi from the line where it is now. It will be ~80ft in elevation and 1700 more feet from where the pipe is now.

If my calculations are correct, I will have about 12psi when I reach the appartment through 100 more feet of 1" HDPE line. So I would need to boost 40psi to have a fair amount of pressure there.

At the end of the run at the main house, I would have lost 40psi in elevation and 10 psi in friction loss, so I would have negative -20psi when I got there. So it would need to boost the pressure to around 80psi when it left the pump house

So can anyone recommend a pump which could take 30psi input and turn it into 105psi output?

 

[lemahoney08]

Would something like this work?
https://www.freshwatersystems.com/p...230v-1-hp-pressure-booster-pump-96860207.aspx

 

[Valveman]

Would something like this work?
https://www.freshwatersystems.com/p-4439-grundfos-mq3-45-230v-1-hp-pressure-booster-pump-96860207.aspx

That is the perfect pump to use if you want something expensive that needs to be replaced every 2 or 3 years.

When you attach a pump to that line it is going to suck the pressure way down. If you put the pump house further down so you have 30 to 40 PSI at the pump, the pump might not suck the pressure below zero. At a point where you only have 12 PSI, a cistern tank before the booster would be best.

Either way I would go with something mechanical that will last a long time instead of any pump with electronics in it. Something like this would be best.

 

[lemahoney08]

Where the line ends now (500ft from the meter) i have 30psi and 5gal/min flow rate. So would a pump not work well pulling from that line? Can you provide model/brand/link to the pump shown?

 

[Valveman]

Where the line ends now (500ft from the meter) i have 30psi and 5gal/min flow rate. So would a pump not work well pulling from that line? Can you provide model/brand/link to the pump shown?

That is a long and small line to be sucking water out of. I would be afraid if you draw more than 5 GPM the line pressure will go below zero. You need a larger line to suck from than if pushing water. With a 2" line and a large meter at the bottom you might just boost the pressure. But with the small line and small meter a pump will suck all the pressure out of the line. I think a cistern tank would be best.

That is a Sta-Rite pump in the picture and Goulds work fine as well. The model and size will depend on how many GPM's you want to push and at what pressure is needed.

 

[lemahoney08]

So if i go a cistern route... it will fill at 5gal/minute at the end of the 1" line. So then I need 72psi leaving to go to the apartment and 105psi leaving to go to the house. What is the best way to do this and can you provide some pumps/models of I would assume deep well pumps, pressure tanks size, and cistern size?

Also what types of valves/switches/floats would I need to plumb this all together? I want to make sure to shut the pump down if the tank runs dry.

 

[Valveman]

With one house and one apartment I am assuming about 10 GPM. I would use about a 1HP, 10 GPM submersible in the cistern. Set the CSV at 105 PSI with a 95/115 pressure switch, and use a pressure reducing valve set at about 50 PSI on the line going into the apartment. A Cycle Sensor will shut the pump off if the cistern runs dry. I would use something like this except that you have city water filling the cistern instead of a well pump. You will also need about a 44 gallon size pressure tank with the CSV because of the 105 PSI required.

If you are filling the cistern at 5 GPM while taking out 10 GPM, a 500 gallon cistern tank will let you run for almost 2 hours before the cistern runs dry. And I doubt that you will ever run wide open for 2 hours straight.

Use the float switch in the cistern to run a 24V solenoid valve from the city line.

 

[lemahoney08]

Can the pressure tank and CSV be inside the apartment on the 50psi side? If not, do I need a vault to bury the CSV and tank? Would I need another pressure tank in the apartment and house?

 

[Valveman]

You could put the CSV and tank at the apartment. But you will need to set the pressure switch high enough to get water to the house. So you would set the CSV and pressure switch like at 80/100 and then tee off to the house and apartment. The line teed into the apartment would probably still need a pressure reducing valve set at 50 PSI or so. A little drawing of elevations and distances to the house and apartment would help.

 

[lemahoney08]

Here is a areal with overlays

 

[Valveman]

Looks like I was guessing pretty close. You could put the cistern and booster pump at the apartment and set it at 80/100 so you would see 45/65 at the upper house 80' higher in elevation. Then you just need to put a pressure reducing valve on the line that feeds the apartment so you can set it at 50 PSI or so.

 

[lemahoney08]

Better to do that and have 100+psi in your house than to bury a pressure tank in a vault?

 

[lemahoney08]

Sorry for all the questions, but will a deep well pump be able to adequately push the water 80 feet in elevation AND through ~2000 feet of pipe? I know it can do either by itself, but not sure about the elevation and distance.

 

[Reach4]

You can use a pipe calculator to find the pressure loss due to flow. http://www.calctool.org/CALC/eng/civil/hazen-williams_p is one example. Add some pressure for fittings. Add the pressure at the end of the line. Convert the sum to head. Add to elevation head. Select a pump with the desired head and flow characteristics.

 

[Valveman]

A deep well jet pump is not what you want. Submersible or not, you will need a multi-stage pump to work at 80/100 PSI.

 

[lemahoney08]

Could you provide a model of multistage pump you would recommend?