Getting Water During Power Outages?

[Anthony W]

We have a private well with a submersible pump and an 80 gallon pressure tank. If our power goes out when the pressure tank is full, it can supply enough water to flush our toilets many times or have running water to cook or wash up. Unfortunately, it always seems like the pressure tank is near it's minimum level when our power goes out, leaving us only enough water for one or two flushes.

So, I'm investigating options for having at least enough water to get us through a day with minimal usage (no laundry, showers, etc.) during power outages. Most of our power outages last less than 12 hours, so I don't really need a long term supply of water. We have a wood stove for heat and backup battery supplies for lighting/entertainment.

Right now I keep a couple of 5 gallon containers full of water in our pump house with a couple drops of bleach in each. I filled them up mostly to have water for flushing toilets, but we're getting older and carrying 5 gallons of water down to the house and pouring it in the toilet tank isn't very user friendly. Especially if it's icy and dark during a power outage in the winter. I also wouldn't feel comfortable drinking stored water that may be a few years old. I filled them up a few years ago and so far it hasn't been worth the trouble to haul them in when the power has gone out. We don't really have any place in the house to keep the 5 gallon containers.

I could get a generator for the pump, but again it's not very user friendly on a cold winter night in the dark. Not to mention having to store the generator, fighting to get it started, or worring about fuel going bad.

A battery backup system would be nice, but finding a system large enough to support our 1/2 HP 240V pump for a day would be cost prohibitive.

I thought about adding a second pressure tank, but unless I'm missing something, we could still end up in the situation where both tanks could be near empty when the power goes out. I would need a way to ensure one tank is always full, and I'm not sure that is possible.

Another option is to add a storage tank in the pump house, and add a second booster pump. Unfortunately, that would add a lot of cost and complexity to an otherwise simple system.

I also thought about adding a storage tank in our attic space above our bathroom, and plumb it in just to feed the toilet from gravity. But, I would be limited to a tank that could fit through the attic opening, would need to redo some plumbing in the house, and would have to add a pan and drain in case the tank leaked. It's simpler mechanically, but a lot more work to install.

Is there a simple way to supply our well water during short term power outages?

Thanks!

 

[Bannerman]

An 80-gallon pressure tank will hold only about 20 gallons of water. At the pump cut-in pressure at say 40 psi, the pressure tank will contain almost 0 water and will contain 20-gallons @ the 60 psi cut-out.

For a pressure tank to operate as it should, ~3/4 of the tank volume will contain compressed air when the tank is full. The compressed air will push the 20-gallons from the tank to the faucets until the pump is activated when the pressure lowers to 40 psi.

A pressure tank is not intended for water storage but only to reduce cycling by the well pump.

There are 12-volt DC pumps normally used in RVs that could be powered by a battery. Since RVs are also typically equipped with closed plastic water tanks, perhaps one of those would be suitable to keep a supply of water. As it seems you are most concerned with flushing toilets, perhaps the 12-volt pump could transfer water to a portable jug which is then poured manually into each toilet as that would eliminate the need for plumbing modifications.

 

[Sponsor]

 

[VAWellDriller]

If you leave your tank pre-charge the same, and reduce the delta on the pressure switch, you will always leave some in the tank. Adding another tank would then double that minimum amount you would have. Using above example with an 80 gallon tank, 38 psi precharge and 40/60 switch you would have somewhere between 0 and 20 gallons of water in the tank at any given time. If you change pressure switch to 50/60 then you will have between 10 and 20 gallons in the tank at any given time.

You mentioned you have a 1/2 HP pump and not wanting the hassle of a gas powered generator. FYI - You can run a Grundfos 115 volt 1/2 HP pump with an inexpensive inverter and car battery. IF you wanted to change the pump, you could make a relatively inexpensive 12 volt battery based backup system for the well pump.

 

[LLigetfa]

If you leave your tank pre-charge the same, and reduce the delta on the pressure switch, you will always leave some in the tank.

Do you have a particular brand and model in mind? Every Square-D I've ever had the displeasure to use did not have the option to reduce the delta that far. I switched over to the EPS15/99 with does allow for the small delta but Cary discontinued them.

A hydro-pneumatic tank without an airmaker is one way to have a reserve of water on hand that is constantly being refreshed. If/when there is a power failure, a battery powered air compressor can be used to push the water out of the HP tank.

Even an HP tank with airmaker can provide additional reserve as most are not empty at the pressure switch cut-in so the remaining water can be drawn out at lower pressure.

 

[Anthony W]

If you leave your tank pre-charge the same, and reduce the delta on the pressure switch, you will always leave some in the tank. Adding another tank would then double that minimum amount you would have. Using above example with an 80 gallon tank, 38 psi precharge and 40/60 switch you would have somewhere between 0 and 20 gallons of water in the tank at any given time. If you change pressure switch to 50/60 then you will have between 10 and 20 gallons in the tank at any given time.

Interesting. I installed the pump and pressure tank 30 years ago so I'm not sure what the switch is set at now. It might be a good exercise to check the tank charge and switch settings again. At least I would know what I'm starting with.

You mentioned you have a 1/2 HP pump and not wanting the hassle of a gas powered generator. FYI - You can run a Grundfos 115 volt 1/2 HP pump with an inexpensive inverter and car battery. IF you wanted to change the pump, you could make a relatively inexpensive 12 volt battery based backup system for the well pump.

I've actually been planning to install a 120V pump when it comes time to replace it, just to make it easier to power from alternative power sources. Any idea how long a submersible well pump typically lasts? I installed our Grundfos 5S05-13 stainless steel pump back in 1991. I knew nothing about pumps at the time, it was just what someone recommended. We've had no issues with it, but the clock is ticking... It's one of those things we've thought about replacing before we retire in a couple years.

It has been a while since I've researched pumps. Do the new 120V pumps still require the external control box?

We have a 98ft well, with a static level of 35ft. If I remember correctly, I put the pump around 60ft down.

 

[Reach4]

Do you have a particular brand and model in mind?

https://www.supplyhouse.com/Amtrol-146-832-Guardian-CP-Control

 

[LLigetfa]

At that price I could buy four of Cary's discontinued units and have three spares.

 

[LLigetfa]

My first EPS lasted 8 years and I bought two replacements so I have one spare.
https://terrylove.com/forums/index.php?threads/frugality-at-its-finest.82903/

 

[Fitter30]

Lp gas generator fuel never goes bad. Have a 6k gen 7k peak runs my well pump can heat my water, fridge ,runs some lights, a 5k btu window ac for a bed room and lp gas fireplace for heat. Can't run everything at once but can pick and choose be warm or cool ,have water, showers , toilets.

 

[VAWellDriller]

Interesting. I installed the pump and pressure tank 30 years ago so I'm not sure what the switch is set at now. It might be a good exercise to check the tank charge and switch settings again. At least I would know what I'm starting with.



I've actually been planning to install a 120V pump when it comes time to replace it, just to make it easier to power from alternative power sources. Any idea how long a submersible well pump typically lasts? I installed our Grundfos 5S05-13 stainless steel pump back in 1991. I knew nothing about pumps at the time, it was just what someone recommended. We've had no issues with it, but the clock is ticking... It's one of those things we've thought about replacing before we retire in a couple years.

It has been a while since I've researched pumps. Do the new 120V pumps still require the external control box?

We have a 98ft well, with a static level of 35ft. If I remember correctly, I put the pump around 60ft down.

4" motors can be bought either 2 wire (internal capacitor, no control box) or 3 wire with a control box with external capacitors.

I should have clarified that what I was referring to was a Grundfos 3" SQ 1/2 hp pump that will run on a cheap and dirty inverter or a very small generator. I see lots of pumps last as long as yours, you must have pretty good water and a good setup system. You are certainly nearing the end of it's life at 30+ years old. I have installed lots of the grundfos 3" pumps and have never had one fail...not even one. I have one that's about 15 years old that I use as a test pump pretty regularly ...a 1/2 HP 115 volt that I run with a Honda 1000 inverter generator. I have several of the small Honda generators and though they are pricey, you get what you pay for....

 

[Anthony W]

Lp gas generator fuel never goes bad. Have a 6k gen 7k peak runs my well pump can heat my water, fridge ,runs some lights, a 5k btu window ac for a bed room and lp gas fireplace for heat. Can't run everything at once but can pick and choose be warm or cool ,have water, showers , toilets.

We have a separate electrical service at each building (pump house, garage, and house - about 100' apart) which also complicates a generator backup.

 

[Anthony W]

I should have clarified that what I was referring to was a Grundfos 3" SQ 1/2 hp pump that will run on a cheap and dirty inverter or a very small generator. I see lots of pumps last as long as yours, you must have pretty good water and a good setup system. You are certainly nearing the end of it's life at 30+ years old. I have installed lots of the grundfos 3" pumps and have never had one fail...not even one. I have one that's about 15 years old that I use as a test pump pretty regularly ...a 1/2 HP 115 volt that I run with a Honda 1000 inverter generator. I have several of the small Honda generators and though they are pricey, you get what you pay for....

I was looking at the 5SQ05-90. Would that be adequate for 5gpm, with our pump placed 60' down in our well? Or would it be smarter to go with the 5SQ05-140? Nothing urgent, but I would like to figure out what we need BEFORE we need it.

 

[Reach4]

I was looking at the 5SQ05-90. Would that be adequate for 5gpm, with our pump placed 60' down in our well? Or would it be smarter to go with the 5SQ05-140? Nothing urgent, but I would like to figure out what we need BEFORE we need it.

You want to drive this into a setup for 40/60 psi? Or would some lower pressure work. For 60 psi, that is about 140 ft head equiv. Then add the depth to the water surface, which is what -- 30 ft lower than the pressure switch?
So would be thinking maybe 5SQ05-180 to be able to run 40/60.

 

[Valveman]

A generator is a good idea for times when the power is off for longer periods of time. You can also just reduce the air charge in the pressure tank to like 20 PSI. When using a 40/60 switch this will give you an extra 10 gallons or so below 40 PSI.

My favorite is to use a hydro or retention tank with an air vent/vac valve on the top. Placed in line before the pressure tank water is always flowing through this tank and stays fresh. Between the hydro tank and the pressure tank install a tee, check valve, and another tee. Install a little 12V RV pump to draw from the first tee and pump into the second tee after the check valve. These pumps work at pressures lower than the 40/60 switch on the well pump. So, when the power goes off and the pressure drops, this pump automatically comes on and fill the pressure tank.

 

[LLigetfa]

You can also just reduce the air charge in the pressure tank to like 20 PSI. When using a 40/60 switch this will give you an extra 10 gallons or so below 40 PSI.

YMMV. Some tanks have an internal dome limiter and at the reduced pressure, the diaphragm might hit up against this limiter. The classic symptom is that as the pump is refilling the tank, the pressure will climb slower before the diaphragm touches the limiter but shoot up faster when it does touch.

 

[Fitter30]

One electric meter for all buildings?

 

[Anthony W]

One electric meter for all buildings?

Yeah, we had power brought to the property before we had any structures on it. There's a meter out at the road and a buried line that comes down to an in ground junction box. When we built our pump house we connected the new breaker panel to the junction box. When we built our garage, we ran a line from the first junction box down to a second junction box. Then the garage breaker panel connects to the second box. When we built our house, that panel also connected to the second box. It's a bit complicated, but it all works.

 

[Anthony W]

My favorite is to use a hydro or retention tank with an air vent/vac valve on the top. Placed in line before the pressure tank water is always flowing through this tank and stays fresh. Between the hydro tank and the pressure tank install a tee, check valve, and another tee. Install a little 12V RV pump to draw from the first tee and pump into the second tee after the check valve. These pumps work at pressures lower than the 40/60 switch on the well pump. So, when the power goes off and the pressure drops, this pump automatically comes on and fill the pressure tank.

This sounds interesting, but I'm not sure I understand the setup. Can you supply any more details about how it works?

 

[LLigetfa]

Can you supply any more details about how it works?

A retention tank has the inlet on the bottom and the outlet at the top. Place a Tee on the inlet with a 12V RV pump inlet connected there.

Place a Tee on the outlet with a foot valve hanging off the side. The foot valve serves as a vacuum release to let in air when the RV pump runs. Put a check valve further down the line. Place another Tee past the check valve on the outlet with the 12V RV pump outlet connected there.

When the power fails, run the RV pump to move water from the retention tank forward to feed the house.

Do note that having a check valve now means you will need to use an expansion tank for your water heater.

 

[Fitter30]

There should be a main breaker should be a main breaker / disconnect just below the meter could hook a generator there with a manual transfer switch.