New install pressure tank on temporary mobile home -need advice please

[MTGreen]

Hello all,
Hoping to get some advice on a pressure tank setup.
Well is 160' deep with an in-well 3/4hp 5gpm pump and pitless adapter installed 6' beneath grade with electric and poly stubouts.
Pad is located downhill of the well about 270 horizontal feet away.
Initially need to plumb in a small mobile home (400 sqft) which will transition to a house with a full foundation/crawlspace later on. Trench/line comes up under the mobile location and in the middle of the future crawlspace.
Frost line is about 48" here.

I'm looking at a 6' trench and the electric and poly stubouts from the well.
I've got 1" 250psi poly tubing, 10/3 NM-B wire, and 1 1/4 schedule 40 conduit.

I need to plumb in a pressure tank that will work with the mobile. I will buy a real tank later to install in the crawl space.

Internet shows small pressure tank under mobile with heavy insulation and some kind of heating device (tape or heat lamp setup) -I have concerns about the heating device failing/freezing.
I'm also seeing tanks designed for burying which seem to be a bit more expensive.

I need some advice on a simple setup with the knowledge that it needs to be reliable but only needs to last 2 winters at most
-how big?
-where to install?
-if I do a buried tank do I install at house or at well if well is uphill of tank?
-what kind of insulation/heater/etc.?
-do I need a check valve outside of the well itself?

Thanks much for any feedback

 

[oldnslo]

When I purchased my current home the pressure tank was buried next to the well since the house was just sitting on slab and previous owner was cheap.. this lasted around 9 years since there was no way to check air pressure in the tank.

Do you have the option or funds to build a small well pit to put the tank in? Two or three junk tractor tires stacked up should work and be rot resistant for a few years.

 

[3Ts]

Personally, I try to avoid a temporary solution. It means I have to do it at least twice and have to pay twice. I like the idea of a well pit. You're running electricity to the well and down the bore hole, so no reason you can't run it into the well pit and then to the pump. That way you can use it to provide some heat in the well pit if you need some. The risk is that if there is a leak the well pit could fill with water and your electrical box. However, since you're downhill, I'd install a "drain to daylight" which would prevent any flooding concerns. While I'm building it, I'd also insulate it so very little heat is needed to keep it from freezing.

Note: I'm in the south and have an above ground pump house. It is insulated and I don't need to heat it very often. We do get below freezing temps here, but unless it gets into the low 20's I won't need to heat it. I use one of those 120v electric room heaters from a big box store.

 

[MTGreen]

Thanks to you both. I did some more research and talked to a few more folks and I think the pit with the pressure tank next to the pump is the way to go. I just need to expand the trench to fit concrete rings for the pit. I didn't think about the drain to daylight for flooding that's an excellent idea

 

[steve tym]

Make sure the pit is big enough to get in and work. A 4' well tile would work nicely.
Screen the end of the drain to keep out the rodents.
While it may seem convienent to have the well in the pit, it makes it more difficult to service.

 

[Carl_NH]

Dig below the pitless adapter then install the drain pipe then 8-10" crushed stone for drainage to daylight downhill. You can add an heat tape around the tank tee and tank too that turns on at 34*.

 

[MattB4]

You can not use NM-B wire for burial. You will have to either use UF (Underground feeder) or conduit with THHW rated wire.

 

[MTGreen]

The pit will be located about 6-10ft from the well and is either 5' or 6' outside diameter my excavator couldn't remember which. I'm using NM-B in conduit. The direct burial types of wire do not survive the rodents here.

 

[ponytug]

The pit will be located about 6-10ft from the well and is either 5' or 6' outside diameter my excavator couldn't remember which. I'm using NM-B in conduit. The direct burial types of wire do not survive the rodents here.

That sounds great. 5-6' will give you the elbow room you need for service.

If you drain to daylight with rock, I would suggest lining the trench with geotextile and then folding it over on top of the rocks. It will help keep soil out of your drain rock.

All the best,

Peter

 

[LouNY]

The bigger the better for the pit, with a daylight drain and #10 wire going to the pit I'd put a small lighting panel in, say 60 amp rated with 8 spaces plus a 30 amp 2 pole main breaker. Then my pump controls and starter are there also along with an outlet or two for power and some lighting for when not if you need to access ot some night to work on something.
A nice large pressure tank to reduce the number of pump starts and your ready for a mobile or the house or even a couple of outside hydrants.
Also I would not go with a crawl space it may save a bit of money but not much. A full height basement with a good vapor barrier under gravel would be much nicer working in then a crawl space, wiring plumbing, duct work, any kind of maintenance were you can stand and walk. My home has a half basement and half crawl space, the "crawl" space is over 4 ft tall but it's not enough to walk around in now for me. When I was younger it was no problem to crawl or duck walk or even just bend over and crouch and move around, now I have an extremely difficult time getting or out of there and end up having to hire someone to do the simplest things in there, such as just stringing a cat 5 cable in there.

 

[MTGreen]

The bigger the better for the pit, with a daylight drain and #10 wire going to the pit I'd put a small lighting panel in, say 60 amp rated with 8 spaces plus a 30 amp 2 pole main breaker. Then my pump controls and starter are there also along with an outlet or two for power and some lighting for when not if you need to access ot some night to work on something.
A nice large pressure tank to reduce the number of pump starts and your ready for a mobile or the house or even a couple of outside hydrants.
Also I would not go with a crawl space it may save a bit of money but not much. A full height basement with a good vapor barrier under gravel would be much nicer working in then a crawl space, wiring plumbing, duct work, any kind of maintenance were you can stand and walk. My home has a half basement and half crawl space, the "crawl" space is over 4 ft tall but it's not enough to walk around in now for me. When I was younger it was no problem to crawl or duck walk or even just bend over and crouch and move around, now I have an extremely difficult time getting or out of there and end up having to hire someone to do the simplest things in there, such as just stringing a cat 5 cable in there.

I agree I would like to go with the full basement if I can. It's going to depend on what's under my house site. The property and the surrounding area have spots of underground concrete-like areas that range from 2 to 10+ feet below the surface that makes excavation difficult

 

[Uncle_Charlie]

I'm watching this thread as I will need to drill a well at my property at some point, and would like to know as much as possible ahead of time.

 

[steve tym]

Something to keep in mind with a pit.
The pit could be considered a confined space. As a licensed pump installer, at some point these confined spaces are going to be a problem.
I like where the pit is heading, sounds like it will be good enough to keep even when the house is done, with or without a basement.
I agree with an above poster, pull some #10's out there and put in a 30 amp service. Pump, heat (you probably won't need it below ground), light, curtousy outlet, ect.

 

[MTGreen]

Pump and pitless have been installed since this pic and cap was rotated to drop down into trench

 

[Valveman]

Large pressure tanks are an old way of controlling a pump and require lots of space and heat. With more modern ways of controlling a pump like a Cycle Stop Valve large pressure tanks are no longer needed. With something that solves the cycling problem like a CSV controlling the pump, a tank as small as 4.5 gallon size is all that is needed. With a tank that small it could be installed above the water heater or someplace inside the house where freezing won't be an issue.

 

[MTGreen]

I have a 2 wire pump so no control box.
I bought a 26gal 30/50psi pressure tank which is sized for my pump. Since the pressure tank is uphill by the well I think the downhill gradient will further improve the output pressure.

After further discussion with my excavator today, I'm going to use a 500gal septic tank as a well pit. He will set on gravel and poke holes in the bottom for drainage and I'll hammer drill holes in the sides for water/electric in/out. I can also still place the drain to daylight pipe as well. I like this idea much better as it will give me more room inside and the screw on manhole riser is more child/weather resistant than an open stacked concrete ring pit with a flip up lid. He says the price is about same and it will come on the same truck as my 4 bedroom house septic tank. Definitely a confined space here!

 

[ponytug]

I have a 2 wire pump so no control box.
I bought a 26gal 30/50psi pressure tank which is sized for my pump. Since the pressure tank is uphill by the well I think the downhill gradient will further improve the output pressure.

After further discussion with my excavator today, I'm going to use a 500gal septic tank as a well pit. He will set on gravel and poke holes in the bottom for drainage and I'll hammer drill holes in the sides for water/electric in/out. I can also still place the drain to daylight pipe as well. I like this idea much better as it will give me more room inside and the screw on manhole riser is more child/weather resistant than an open stacked concrete ring pit with a flip up lid. He says the price is about same and it will come on the same truck as my 4 bedroom house septic tank. Definitely a confined space here!

Don't forget to ventilate it well! A confined space like that can accumulate lethal amounts of CO2.

All the best,

Peter

 

[jyoutz]

Make sure the pit is big enough to get in and work. A 4' well tile would work nicely.
Screen the end of the drain to keep out the rodents.
While it may seem convienent to have the well in the pit, it makes it more difficult to service.

I have a pit made of cinder blocks for the pressure tank and well controller. The well shaft is located outside the pit several feet away. The pit is about 6’ deep and I’ve never had anything freeze. Once when we had -30F for a few nights, I did put a heat lamp in the pit, but don’t bother with that unless it’s -10F or below.

 

[Valveman]

Any kind of pit is a pain. Confined space to work in and causes humidity that rust out the pressure tank, and turns all electrical components like the pressure switch green. You nearly need to keep a fan blowing air through the pit to keep the humidity down. A pitless adapter with the tank and controls in the house is much better.

A 26 gallon tank only holds 7 gallons of water. Even if you only have a 7 GPM pump the tank is minimally sized. The pump will still cycle on and off for every 7 gallons used. This is not good for the pump and will cause the pressure in the house to vary from 30 to 50 over and over.

A 26 gallon size tank is way bigger than needed with a Cycle Stop Valve, but will work fine. It is just much larger than the minimum required 4.5 gallon tank that could be used with the CSV and not need a pit at all, as seen above.

But adding a CSV1A to the 26 gallon tank will still solve all the problems except for space.

 

[LouNY]

I like the idea of your cycle stop valve, but I'm still old fashioned enough that I like large pressure tanks.
I also like pits next to wells if the ground conditions can accommodate it and it sounds like the OP's does very well.
The OSHA definition of confined spaces that many people are concerned with is a gross over regulated and pushed issue.
A normal water well with no entrained methane or H2S will not have issues with a pit type tank and control setup.
I actually like your drawing in the previous post (#19) but with all the components located in a pit next to the well and with a much larger pressure tank.
One advantage of a pit or pump house next to the well is the ease of adding yard or barn hydrants in the future. As well as having the ability to have power at that location. Nothing like have 30 amps of 240 volt power to use for the well and power outlets.