Sand Point

The pump burned out on my son's shallow well. We are going to replace it. We'll attempt to use the existing sand point, but before I begin, does the point have to have a second line inside of it with a foot valve, or will the new pump draw water just from the pipe that was used to pound the point? I am assuming we will use a jet pump.

Thanks for any help

The important thing is the casing diameter. If it's an 1-1/4" well use the casing as a suction line. If it's two inch or bigger, put 30 foot of 1-1/4" pipe down the well with a Foot Valve on the bottom.

bob...

speedbump said:

The important thing is the casing diameter. If it's an 1-1/4" well use the casing as a suction line. If it's two inch or bigger, put 30 foot of 1-1/4" pipe down the well with a Foot Valve on the bottom.


bob...

Click to expand...

Thanks for the prompt answer. In case we have to drive a new point, how do we know when to stop? Let's say that water appears in the new point at 20'. If we drive it down to 28', what's to say that we aren't out of the water bearing layer of sand? Also, if we go to 35' and put 30' of pipe down the well, aren't we beyond the limit of a shallow well jet pump, or is it the standing height of the water that matters?

I'm not a pro, just a long-time DIYer.
A "shallow well" pump is designed for pumping well water 25' as measured from the tip of the point to the pump. Whatever the water depth for draw down above the point, the point is where the pump is actually pulling up from. You need a check valve near the pump on the suction (well) side to hold prime, if you don't have a foot valve.
Here, we usually drive or wash down "three joints and a point', meaning three 5' X 1.25" galvanized joints and a 3'-5' point (I prefer a 5' point).
If you're driving in sand, you let the length of the pipes dictate the depth. If you're driving in sand with layers of clay, you try to end the point on top of a layer of clay (you have to drive by "feel" or resistance).
If you're driving, use a 6" X 1.25" galvanized nipple with couplings on each end tightly screwed to the point or pipe joint threads to absorb driving shock so as not to damage the threads. Remove the driving nipple, wrap about 3 flat layers of teflon tape clockwise only on the pipe threads and tighten the final connecting coupling on as tight as possible on each section. Use a backup pipe wrench to hold the pipe when tightening on the couplings.
Good Luck!
Mike
Great well-and-pump tutorials:

www.IrrigationTutorials.com (Jess Stryker)

It's the standing water level that matters not the wells depth.

The only way to know if your in water is to check every five feet with a Hand Pump

bob...

OK First attempt at driving a new point. We had about 16' of pipe in the ground when the pipe broke off at a coupling down about 9'. Pretty disheartening.
What did we do wrong? We were driving vertically, tightening the pipe by turning clockwise about every three feet of movement. We had tightened the couplings as tight as we could, but they weren't butting against each other in the coupling. (I actually don't think there were enough threads on the pipe ends to reach the middle of the coupling.) We were putting pipe coumpound on the joints. We were using 5' pipe lengths specifically marked for driving a point, likewise for the couplings, making good progress, although a lot of work using a post driver. Any suggestions? Don't particularly want to lose another point. They don't give those things away.

Were you using US-made galvanized steel pipe or that imported Chinese stuff?
There IS a difference. When drving a well, I only use US pipe.
Mike

Success (Partial)

Well, it was the weekend, when we can do this kind of work, so we forged ahead yesterday. We drove a new point - this is glacial till we're driving through, so not an easy job. Anyway, we got the point down 25', with standing water in the pipe at 15.5' below the ground surface. Problem is, we can't get any water out of it. Here's the way we have it set up - shallow well jet pump with a new back flow valve right next to the pump (because that's the way the old one was set up), only one elbow to the top of the driven 1.25" pipe. We primed the pump, but of course, that leaves the pipe going into the well empty anyway. You can't fill that because you could pour all the water you wanted into that pipe, it would just go into the ground water.

What are we doing wrong? Would it be possible to put a 3/4" flexible copper pipe 22' or 23' into the well instead of drawing water up through the driven pipe, just in case there's an air leak in one of the joints in the driven pipe? Possible to put a small galvanized pipe or copper with a foot valve into the driven pipe so we could hold prime? What say you experts?

Thank you for your help

If you have that well point in glacial till, you will not get any water out of it. If it is in fact till, the point needs to be pulled up into a more pourus media. I would then get a hand pump(pitcher pump) and try to develop the well. Ifyou are not too sure about the porosity of the media, i would set the well point so tehre is atleast 5 feet of water over your screen and try pumping it. If it pumps good then go another 5 feet and see what you have.

Sammy

If you didn't butt the joints you probably have all kinds of air leaks in the joints. I hope you put that Backflow preventer on the pressure side of the pump.

You could put 3/4" down the pipe, but you would be starving the pump and causing cavitation if you do.

You should have been checking every five feet like I suggested above, you may have gone past the vein. Just because there is water standing in the pipe doesn't mean your still in a water vein.

bob...

I'm sorry to belabor the point, but let's just say for the moment that the joints are all tight and the point is in a water-bearing layer. When starting the pump for the first time, does it somehow create enough vacuum without any water in the pipe to bring water up from the ground?

Second - If we would attempt to get water by installing a 3/4" pipe, would the cavitation damage the pump eventually - quickly? Any way of knowing?

If you fill the pump with water, leave the prime plug loose to release air, it should take off in a matter of minutes. If you have air leaks, all you will get is lots of air.

The cavitation can ruin a pump over time, but it takes a long time compared to cycling one too much. The 3/4" suction is also going to diminish the pumps ability to pump it's advertised volume of water and pressure.

If the joints weren't butted in the couplings, they are not tight. Hammering damages the threads.

bob...

Thank you, again, for all your help. We'll give 'er another shot.