Developing a spring into a water source - pumping

[Tickridgescott]

We found a spring on our property today - very nice flow. We will be watching it this summer but seems to put out about 1/2 gal per minute.

Here is my question.... The spring is about 1350 feet away from the cisterns (near the house). Elevation is about 70 feet below the cisterns. Would 1 1/4" pipe be sufficient to run this ditance? Can I use 1" pipe? Basically it will be emptying into the cisterns so there is no pressure it is pumping against other than the 70 feet of head in the pipe going up. I am not sure yet on the elevation but 70 feet is a guess.

 

[Bob NH]

You could put it through 3/4" poly pipe. You could use a shallow well jet with a tank. Let the pump maintain pressure and let it run to the cistern.

But is it worth it? Pump, wire, pipe, and controls could be $500 to $1000.

 

[Sponsor]

 

[Jadnashua]

I'm guessing here, but you'd probably need to build a catch basin so there would be enough water to pump. A pump that can handle the 70 height will want to pump 5 or more gallons per minute. You'd want to have enough so you could run the pump for a few minutes prior to having a level switch turn it off and wait for it to fill up again. Lots of opportunities to have a pump run dry. Now, if it was above your cistern, it would be a different story.

 

[Tickridgescott]

my plan is to install a catch basin which then goes through a small chamber to get out any sand/silt and then drop into a 150 to 200 gallon holding tank. When the tank fills it will operate a float switch and pump (when the upper cistern calls for it) up to the cistern. Then shut off on low float switch. Probably will pump several times per day.

I am not sure what you are trying to say in your post Bob. 3/4" poly?

I am wondering what is the minimum size I should run for a 1350 foot run.
3/4 sounds very small, but then maybe it doesn't matter because volume is not an issue at all.

 

[Bob NH]

3/4 poly will work because the total flow is only about 1/2 gallon per minute.

Use a shallow well jet pump with a small pressure tank. The pump will work on and off, running about 10% of the time, and the flow will run to the cistern as required.

If you want to run the full flow of the pump with no tank, then you should use a pipe that will handle the total flow rate of the pump, which would probably be in the range of 1" for a small pump.

 

[Valveman]

Valveman

My email to you was returned unread. I must have the wrong address. Following is a link to the radio telemetry you ask about. Isaaca & Associates.
http://www.isaacstech.com/radio_products/index.htm If you are
pumping from the spring, we can do this with out telemetry. Just put a
2 GPM Dole valve on the pump, small pressure tank, and pressure switch at the pump. Use the float switch to simply open or close a sprinkler type solenoid valve at the contact tank. When the solenoid valve opens, it drains the little tank way over by the pump, pressure switch starts the pump, pump fills contact tank, solenoid valve closes, pressure tank at the pump fills up, pressure switch shuts off pump. All without wires or telemetry. With 200 gallons in the catch basin and with it refilling at 1/2 GPM, the 2 GPM Dole valve would allow the pump to run a couple of hours at a time. With a 2 GPM fill rate for the cistern, pipe as small as 3/4" could be used for the 1350'. Otherwise you would need larger pipe and the pump will cycle on and off at least every 40 minutes.

 

[Tickridgescott]

developing a spring into a water source

I got a topography map today on the GIS system and found out that the location of the spring is 200 foot below the cistern. I prefer a submersible pump in the lower tank (low flow) because if i used a jet pump and pressure tank how would I keep it warm in the freezing winter. I don't want to have to build a pump house and heat it.

Are there very low flow submersible pumps on the market?

 

[Valveman]

Valveman

You can get a 5 GPM submersible. I would still put a 2 GPM Dole valve on the discharge of the pump. If the 200 gallon catch basin will freeze solid, so will the submersible. (not good) If the catch basin will not freeze solid, you can take the check valve out of the pump, install a 2 GPM dole valve, and pipe up the hill to the top of the cistern. Use the telemetry switch to start the pump when the cistern is low and off when the cistern is full. Without a check valve the entire line will drain back into the catch basin each time the pump shuts off. (line won't freeze) Use as small a line as possible or the catch basin will be emptied just refilling the line. A larger catch basin would also help. The 2 GPM Dole valve will put some back pressure on the pump so when it comes on with the empty line the pump will not go into upthrust condition. Also need a low amperage device that will shut off the pump if the catch basis runs dry, then times out for long enough to recharge the catch basin, and restarts the pump as long as the cistern is calling for water. Pump Tec or other similar product will not work because of the low amperage caused by the 2 GPM Dole valve. The Cycle Sensor will work for dry run protection because it is designed with adjustable underload to be used with Cycle Stop Valves which causes similar amp draw to the Dole valve.

 

[Bob NH]

The wireless and all of the other controls are a lot more than necessary.
Telemetry transmitter with level switch in cistern
Telemetry receiver/contactor
Dole Valve
Low current control

OR a Keep It Simple System - 2 level switches

First, are you going to bury the line to keep it from freezing? I assume that you are.

A 1" pipe will hold about 60 gallons of water. That is 30 minutes of pumping on the valveman proposed flowback system. You could use a smaller pipe (say 3/4 poly) and probably get it down to 35 gallons or so, but you would still be using 35 minutes of every pump cycle (fill up, drain back) producing no water.

The only controls you need are:
1. Float switch or whatever you choose in the cistern to turn on power to the pump. This is the same one that is used for any of the other sources. Only need one to call for water. Might need a relay to direct power to more than one source.

2. Level switch in the spring to keep the pump from pumping down too much. But this one should be a submerged pressure actuated switch so it will always be below the ice.

I don't know why a Dole Valve is needed. What is the problem with letting the smallest available pump (about 5 GPM) pump to capacity?

I would develop the spring by putting a large crock in the spring with provision for admitting the ground water from below. That way you will get some earth warming and can cover it up and get some protection against freezing. If you use that crock, your float switch can be a standard control.

 

[Valveman]

Valveman

Bob NH I like Keep It Simple. Always more than one way to skin a cat. I was using the Dole to keep from upthrusting when the pipe is empty and to reduce the number of cycles. I agree with 3/4 pipe and I like the earth warming of the spring idea. I like the float switches too, but I was trying to not have to run wire all the way. Either have to run wire all the way or have additional power source at spring though. Are you thinking a two wire pump, running the wire through it at the cistern and again at the spring? tickridgescott had ask about the radio switch is why I went that way. I had rather run wire than use radio but with the price of wire these days???? If the pipe is on top of ground, have to remove check valve to keep from freezing but pipe underground would solve that. And you would have to go underground if there was wire with the pipe. Where I live it is so flat you could see your dog running away for three days, and a spring is a coil of steel wire. You can't take a step without stepping on a water well though so I have done numerous subs in wells and lakes. Always good to hear how other pump guys do things as the only school for pump people is the school of hard knox.

 

[Bob NH]

If there is another source of power at the spring, then it could be controlled by radio control. But another way would be to put a small bladder tank at the well (even inside the covered crock where it won't freeze) and put a float valve in the cistern. When the tank is low, the valve opens, causing the pressure switch to actuate and start the pump. Float valves are quite inexpensive and are very reliable.

I have seen overhead wire in rural areas, even on trees. With the price of copper, and considering the size needed to overcome voltage drop, the lowest cost might be overhead aluminum triplex.

 

[Tickridgescott]

Thanks for the ideas. No power at the spring. I am thinking of putting a float switch in the cistern (high/low - call for water on low, turn off circuit when high) - that wire will then run from the cistern down to the spring and into a 150 gallon catchment (no worries about freezing as it will be under earth and flowing), wire will go to float switch (again high/low - only turn ON pump on high, shut off pump on low).....

3/4" line is okay? and issues with it being too much resistance against pump? it is 200 foot elevation upwards, 1350 foot by way of the buried line.

how about check valves along the way? do i need to install multiple check valves along that 1350 foot path? or the one on the pump is okay by itself?

thanks again for all the ideas.

scott

 

[Valveman]

Valveman

At 5 GPM you will loose a little over 1 PSI per 100'. 1350' count on about 15 PSI loss plus the 200' lift. 5 GPM 1/2 HP will get you 5 GPM at 231' total head, should do it. Multiple check valves can cause water hammer problems. Don't see any problem with just the one check that should come with the pump. With a 240 volt motor you are gong to need #8-3 conductor copper wire for that distance. Maybe Bob NH will chime in with help on which float switch is best and how to set up catch basin, and maybe he will double check my figures as well. Best of luck.

 

[Tickridgescott]

thanks valveman - i have done the research and know how to do catch basins - so that is not a prob.

I do have one quick question - off topic - this is in relation to the statement you made about multiple check valves. I just got my pump installed this week in my cistern and hooked up to water yesterday. I did put a check valve in as soon as the water enters the house. What is water hammer prob's? Just curious if my check valve will mess things up? Everything seems to be working really great - great water flow, pressure, etc.

 

[Valveman]

Valveman

Multiple check valves are no problem as long as they are both working like new. The problem happens when the bottom check leaks back a little bit, (even a couple of thimbles of water) and the top check is holding perfectly. This is like putting your finger on top of a straw full of water. The water will not drop out of the bottom but it is at a negative pressure between the two checks. Still have positive pressure above the top check. So when the pump starts, the pressure between the two checks changes from negative to positve instantly and you hear a thump. That thump is water hammer and it puts 10 times the normal pressure on you pipe and system. So if your pump delivers 100 PSI (231' of head), when you hear the thump, the pipe leaving the pump sees a 1000 PSI pressure for an instant. If you only have a check at the bottom, the pipe is always under positive pressure when the pump starts and no water hammer. In a water well situation the pipe and pump actually try to jump out of the well when this happens. In your case it will probably just burst the pipe right at the discharge of the pump.

 

[Tickridgescott]

if it were you, would you remove the check valve in the house? I have it first thing in the line as the water enters the house. I hate to cut into the line and have to do it, but i will if it is 'better' to not have it there.

 

[Valveman]

Valveman

"I just got my pump installed this week in my cistern and hooked up to water yesterday. I did put a check valve in as soon as the water enters the house."

I am a little confused about this statement. You must have a check valve on the pump in the catch basin, and you must have another check on the booster pump before the pressure tank. I do not think you need another check on the line from the catch basin pump before the cistern.

 

[Tickridgescott]

sorry, i will clarify.....

I have a 5000 gallon cistern which the rainwater goes into from the outbuilding. It gets filtered before entering the cistern. The cistern is right in front of the house (at about a 10 foot elevation difference - -- the cistern is underground).

I have a 1/2 hp submersible pump in the cistern which has a check valve in it of course. I have 1 1/4" pipe going underground out of the cistern up into the house in the mechanicals room. It goes into the pressure tank. But, before it does, i have installed a check valve in line (between where the pipe enters into the house and the pressure tank). WOndering if this is going to cause me issues in the future. (I am in the construction process right now and am not moved in or anything). If it is going to cause problems I can do the necessary work to remove it.

The reason i had put it in is that a neighbor friend of mine showed me his water system setup (he pumps out of a well into his house). His system has been up and running for 8 years. He has a check valve in the location which i mentioned above (right before it enters pressure tank).

 

[Valveman]

Valveman

Second check valve probably will not cause a problem although it is not needed. The check valve on the pump would also be more reliable if it had full system pressure on it when the pump is off. As it is, the check on the pump is only being held closed by the small amount of pressure between the two check valves. I probably would not go to the trouble of taking out the second check cause I am basically lazy. But if I started hearing or feeling a thumb in the system when the pump starts, then I would remove it. If it is going to be a major pain for you to remove it later, then I would do it now. If the check on the pump ever fails, it has to be replaced anyway, regardless of whether or not you have the second check in place. If the check on the pump fails the second check will cause a thumb (water hammer). Without the second check, failing of the check on the pump will cause cycling on and off while you are not using water.