Uphill Cistern

[Crafty42]

Building a new home. Will be supplied by a spring that's about 8-10' lower than the home. I'd like to have a ~100 gallon cistern in the house to pull from. I currently live in a home on the property and was fortunate enough to have a basement that is gravity fed to a tank that the pump pulls from, but the new home I'm building won't have that luxury. Any simple ideas to pull water from the spring to a cistern that the jet pump will then use to feed the pressure tank?

My current idea is a two pump system, one that kicks on/off by the tank level, but I'm not exactly sure how I would set this up, what size the pump should be, etc. In case of some high demand time and low spring flow, I don't want to risk the 1st pump sucking the small spring reservoir down to a point it's sucking air. I know this could happen no matter how I set it up, but looking to prevent it as best I can. So the slower the pump pulls from the spring to fill the reservoir, the better, since it's just topping off the tank.

Thanks for any input.

 

[Valveman]

Depends on how much room you have in the spring as to which pump is best. A sump pump maybe all you need. But a regular submersible well pump can be laid on its side and controlled with a float switch. A Cycle Sensor can protect the pump from running dry, and you can restrict the flow to as little as 1 GPM to keep from sucking the spring dry.

 

[Crafty42]

Depends on how much room you have in the spring as to which pump is best. A sump pump maybe all you need. But a regular submersible well pump can be laid on its side and controlled with a float switch. A Cycle Sensor can protect the pump from running dry, and you can restrict the flow to as little as 1 GPM to keep from sucking the spring dry.

Thanks for the reply.

Unfortunately, the spring house is small. Maybe 3'x3'x3' on the interior with only a ~2' diameter hole that's only about a foot deep. I had considered a sump, but thought it best to just keep all the mechanicals in the house. And I won't need to run power to the spring (not that it's far). I'm guessing I'll just need to throttle the flow to get a desired flow rate or just deal with any issues if/when they arise. could also maybe damn up the front of the spring to provide a larger reservoir there.

 

[Valveman]

I don't think that is enough room for even a sump pump. You need enough room and volume the pump can run for a few minutes instead of seconds when it comes on. Even restricted to like 1 GPM the sump would need to hold like 5 gallons of water. A sump pump with a built in float switch would shut the pump off when the sump is dry. Adding an additional pump up float switch at the cistern would control the level in the cistern. The sump pump can then be throttled with a valve to make it run a few minutes or even continuously if it matches the amount coming into the sump.

 

[Crafty42]

I don't think that is enough room for even a sump pump. You need enough room and volume the pump can run for a few minutes instead of seconds when it comes on. Even restricted to like 1 GPM the sump would need to hold like 5 gallons of water. A sump pump with a built in float switch would shut the pump off when the sump is dry. Adding an additional pump up float switch at the cistern would control the level in the cistern. The sump pump can then be throttled with a valve to make it run a few minutes or even continuously if it matches the amount coming into the sump.

I believe I could place a sump on a platform to keep from the bottom with a lot of sediment and be fine. But again, not looking to go this route unless it makes sense to.

2' diameter by just 6 inches would hold 11 gallons. 1^2*pi*0.5 is 1.57cf. 7.48 gallons per cf. Counting inflow, which fluctuates and I haven't measured, I think things are fine.

Maybe I should go with a smaller cistern. Say 65-70 gallons. If I can get my first pump to kick on when the cistern tank drops ~20 gallons and my pressure tank draw is around 8.5 gallons, then the cistern pump will only kick on every 3 cycles of the main pressure tank pump. I would believe I have enough inflow to cover that in time and estimate the cistern pump (assumed 3/4hp jet pump) puts out 7 gpm @ 10' of head, so would take 3 min.

I could just go back to the way things were and eliminate a cistern all together, but I liked having one as a slight sediment tank and resrvoir in case some short periods of high demand arise.

 

[Valveman]

The larger the cistern the more cushion you have. With a small cistern you are always working on a razors edge, not having enough water to work with.

 

[Crafty42]

That kinda goes without saying. The reason I wanted an indoor cistern was more for a sediment tank and the ability to add and treatment I may want. having it indoors helps in the winter, but I'm starting to consider that maybe an outdoor tank wouldn't be better, especially if gravity can feed that tank.

So what are thoughts there if any? I could see myself going this route. Maybe a partially buried tank (they need cleaned every so often, I think).

 

[Valveman]

A buried tank has to be bedded and backfilled properly or it will always be a problem. You can get away with a lot of things using a tank sitting on the ground. A submersible well pump makes a good cistern booster no matter is the tank is buried or not. Really need to be able to get in them to clean them well no matter where they are either.

 

[Crafty42]

A buried tank has to be bedded and backfilled properly or it will always be a problem. You can get away with a lot of things using a tank sitting on the ground. A submersible well pump makes a good cistern booster no matter is the tank is buried or not. Really need to be able to get in them to clean them well no matter where they are either.

I live in the NE, and with only going for a maybe 250 gallon tank at most, I'd worry about an above ground tank freezing. I've got to consider my options, but if I bury a tank, I can gravity feed it and won't have to use a pump at all to feed the tank. I clean my current tank regularly enough that I know what to expect. I'd need to every once in awhile shut off the supply, pump the tank out and clean it and a smaller tank I can do much easier. Mainly I'm just getting the sediment out of the tank. House filters and UV filter takes care of any other issues like any bacteria concerns.

Way I see it, I can gravity feed a buried or partially buried tank with one pump, or I can put the tank inside the house and use two jet pumps, one to feed the cistern, one to feed the house.

 

[Valveman]

As long as there are no problems burring the tank, it is a good solution to the gravity issue. One other option is to use a submersible well pump in the cistern as shown above. There are benefits to using a submersible, especially with an underground cistern. Besides that 1HP, 33 GPM, 230V pump you can search for on the Internet only cost about 170 bucks.