Constant Pressure or Standard Submersible?

[mlblevins]

Hello all - this is my first post here, as I've never had a great deal of interest in wells, pumps, etc. But now I've got "well issues", so it's my new favorite topic!

Anyway, I live in Maryland and have a well that produces about 4.25 GPM. I've got an 8-year-old 1/2 HP Jacuzzi jet pump and a 20 Gallon pressure/holding tank. I've owned this house for about 10 months and the water has always been VERY clear, odorless and tastes fines. I've also always had at least decent water pressure as well. Recently, however, I've had issues with water pressure and sediment in the water (a LOT of sediment). I had the sensor switch replaced, but the jet pump is moving pressure up to about 45 psi once it switches on and runs and then immediately dropping to about 25 psi when it switches off (just a few psi above the "switch on" setting). The thing is also running much longer than normal, leading me to believe it's "overpumping" and stirring up the sediment.

Anyway, I've been told that there is a worn valve that's allowing pressure to escape, as it were, and that replacing the pump and plumbing is better than simply fixing the valve. I'm fine with that, because I've heard that submersible pumps are generally preferred and I'd like to upgrade from the 20 Gallon Amtrol tank (WX-202) to the 44 Gallon (WX-250).

Finally - my question...would it be recommended to simply go with a constant pressure submersible pump, or is the standard submersible/pressure tank suitable? If the constant pressure, what would the recommended HP be? I've seen 1 HP recommended, but might that be overkill for a 4.25 GPM well?

For more background - I live in a house with 3 bathrooms and also have a dishwasher. 2 people live in the house.

Any advice, answers, musings, etc. are quite welcome!

Thanks in advance,
Matt

[Bob NH]

First, help us understand what you have.

You mention a jet pump. Do you have a shallow well jet pump (one pipe to the well) or a deep well jet pump (two pipes to the well)?

What is the diameter of the casing of your well? Is it a drilled well (3' to 6" casing) or a dug well ( 2 to 3 ft casing)?

How deep is it to water in your well?

Do you have any idea how much water the well can produce (Not the size of the pump now)?

Is cost a significant consideration?

Are you planning to do it yourself or hire someone?

I would not go with the constant pressure sustem with a 4.5 GPM pump. It is barely going to make the flow you need, so you need a storage tank.

A 1 HP pump seems large for 4.5 GPM. If you get a submersible you will probably be able to use a pump with less horsepower than a jet.

The loss of pressure could be a leaking foot valve, which is a check valve at the bottom of the pipe going into the well. It is possible that you could work around that by installing a check valve at the inlet of the pump, though there are reasons not to do that.

[Bob NH]

When I was referring to a storage tank, I was thinking about the 44 gallon tank that you are considering.

You can use a pressure tank for storage by setting the precharge pressure farther below your start point.

For example, assume that you want to operate between 40 and 60 psi.

You could precharge the tank to 20 psi.

At 40 psi the tank will contain 16 gallons of water. At 60 psig it will contain 23.5 gallons, so the available drawdown is 7.5 gallons which is plenty for your 4.5 GPM pump.

But if you have a larger demand than the 4.5 gpm pump can supply, you have a reserve of 16 gallons before you are limited to the 4.5 GPM pump capacity. You can get a little more reserve if you operate between 45 and 60 psi.

If I were replacing the pump, I would consider a little larger capacity submersible if the casing is big enough. For example, the 1/2 HP Goulds 5GS05 will deliver about 6.8 GPM at more than 60 psi from a well at a depth that could be served by a shallow well jet pump.

[mlblevins]

Unfortunately, there are some details of the well that I'm not familiar with - I don't know the well depth or whether it's drilled or dug. I do know that my jet pump is a deep well pump (2 wires) and that it's 1/2 HP. We are, for the sake of moving forward, going to dig it up and find out, but are working from the assumption that it's at least 100 feet and is drilled and, further, that it is 4" or more. We'll adjust as necessary after finding these things out.

The guys I'm getting to do this work (I'm not doing it myself) are going to install a 1/2 HP Goulds 5GS05 as Bob NH has suggested - they suggested this exact pump and also let me know that the WX-250 (44 gal. tank) would be good.

Other info - Initial GPM during the yield test was actually 6.6 GPM right away, then 5.45 after 15 minutes and fell to a fairly constant 4.28 shortly after that.

Anyway, I wasn't second guessing the guys who are doing the work...they seem quite knowledgeable. However, they did mention that a constant pressure pump was an option, albeit more expensive. I told them I'd think about it, but wanted other input besides theirs on this issue.

From what we know thus far, does the Goulds 1/2 HP 5GS05 and WX-250 seem like a good option? Though I'm sure it would work quite well, it doesn't seem to me that a booster pump/storage tank/pressure tank setup is necessary...keep in mind that I was entirely satisfied with water quality and pressure with the jet pump and 20 gallon tank setup (until recently when things broke down) and now I'm just replacing it with a presumably better pump and larger tank.

I guess I have another question or two on top of that - I currently have no filtration in place, other than on my refrigerator water/ice dispenser. Wondering if anyone recommends a spin-down filtration system to keep sediment out of the water?

Additionally, potability tests showed good water, and the only other issue I may have with the water is that it could be slightly acidic. So if the spin-down would be a good option, is there some addition/attachment to the spin-down that also takes care of pH levels?

Thanks again!
Matt

[Bob NH]

If you have solids in well water, you often have a range of solids. A spin-down will remove coarse sand. It will not remove finer material. I would not install one.

The reduced flow was probably caused by the lowering of the water in the well. That reduces the capability of the jet pump. What you need to determine is the level of water before and during pumping.

The 5GS05 should give you 5 GPM to 60 psi with water level down to 100 feet below the surface. It will probably do more than that. Whatever the water level, it should do better than the deep well jet for the same conditions.

You should be sure that the well is pumped until the water clear with a work pump (not your new pump) down near the bottom of the hole. If there is sand and sediment in the well, you want it cleared out so it doesn't damage your new pump.

[mlblevins]

Bob NH - thanks again for your reply. I'll make sure the guys that are doing the work do just that, i.e. - pump the well with a work pump until the water is demonstrably clear.

Again, thanks for helping out a newbie on the subject. I'll let y'all know how things go!

~Matt

[speedbump]

The sediment is probably just scale build up from the old plumbing which came loose from the recent lowered pressure. If it is really SAND, you have a more severe problem and I wouldn't go happily forward installing all new equipment into a sandy well. Sand eats pumps among other problems. So if your well started pumping sand, you may need a new well too.

bob...

[mlblevins]

Thanks for your input speedbump...I'm getting "dirt" more than sand, i.e. - I can see sediment in a glass of water, the tanks in my toilet actually have a kind of muddy deposit on them that wipe away easily and my sink faucet screens are gunked up, but I wouldn't characterize the sediment as sand.

Interestingly, I think what you've suggested about the low pressure causing the sediment buildup to be "flushed" is probably correct. I think the pump was overpumping too, which I presume could have caused or exacerbated this problem.

On another note, my water seems now to be more clear, but the pressure is still lower than normal, so perhaps the sediment that was there has been totally flushed out.

That actually leads me to yet another question, for anyone who may know or have suggestions - I'd like some assurance that whatever sediment is coming through isn't going to get caught in faucet screens, the heating element of my hot water heater and dishwasher, the icemaker in my fridge, etc.

If the spin-down isn't a good option, is there some simple filtration system that is? Or, alternately, is the spin-down at least a good option in the event that some sand does end up getting through (to protect appliances and such)? Maryland has sandy soil in general, but where I am (further inland from the Chesapeake than I've previously lived), the soil is better.

Thanks again!
~Matt

[speedbump]

First of all, don't think of the above ground soil as having anything to do with where your well water comes from. Most drilled wells have many different layers of sand, clay, rock, hardpan, phosphate, shale and other types of material before actually reaching an aquifer.

Jet pumps don't just go bad out of the blue. Jet's plug up, and so can impellers. Your scale may be preventing the flow you are used to at a bushing or other fitting in the plumbing. If the pump still pumps up and shuts off at the top pressure, the pumps fine.

bob...

[mlblevins]

Hi Bob - and thanks again. Yes, the pump definitely works. I'm certain of that because I've still got water in my house and I can watch it start and run until it gets to the pre-set pressure and then switch off. Afterwards, however, the pressure drops about 20 - 22 psi (immediately), so the theory is that there is a fitting or valve that's worn and is allowing pressure to escape.

Since this has to be fixed, and digging is involved to fix it, I figured I'd replace the jet with a submersible. The jet is 8 years old anyway, so I'm comfortable with that.

I guess I should be certain that the well isn't pumping sand though. Is there a particular way to do this?

Just wondering so that that I can ask the guys working on it to do so. Bob NH noted that I should make sure any sand/sediment are cleared out with a work pump prior to the install of the new Goulds. I'll have them do that, but is there anything else that you think I should be aware of, especially regarding the well itself and whether there are any problems with it? Any filtration you recommend to further protect appliances and such?

Thanks!
Matt

[speedbump]

Your immediate drop of 20/22 lbs sounds like a nearly waterlogged tank to me. How long does the pump run after it starts with no water running?

To check the well for sand, just run the pump open discharge full blast and see what's in the bucket after catching water in it for a few minutes.

bob...

[mlblevins]

Hi Bob,

When the pump starts running, it runs for about 5-7 minutes before switching off (with no water running). It's not always the exact amount of time, but that's a good estimate, and it's never less than 5 minutes.

Prior to the problems I'm having now, it ran for a much shorter period of time...probably about a minute or so, but it also ran often (almost every time the toilet was flushed). Does any of that mean anything to you? And would such a problem with the tank lead to increased sediment?

~Matt

[Bob NH]

It seems like it could be some restriction between the pressure switch and the tank, or between the gauge and the tank. That would cause the pressure to go up and the switch to go off without having the tank up to pressure. The flow through the restriction would cause the pressure to be higher, but would go away when the flow (pump) stops.

An immediate drop of 20 psi and then stopping is not characteristic of a leak. It takes a while for the tank to lose the water through the leak.

If the pump runs for 5 minutes, that doesn't sound like a waterlogged tank.

Are there any valves between the pressure switch and the tank? Five minutes is a long time to pressurize a 20 gallon tank that has only about 6 gallons drawdown. That is also consistent with a restriction in the line to the tank.

[mlblevins]

Hi Bob NH - I actually had the pump checked for restrictions between the pump and the switch and there was sediment buildup that has now been removed. The problem is still there, of course, but I imagine it's possible that there is still restriction where the pump is attached to the gauge - that wasn't checked.

There is one valve between the pressure switch and the tank. When I run water to force the pump to cycle on, and then close that valve, the pump races to the shut-off psi and then falls right back down that same 20-22 psi, barely above the shut-on point.

I guess by now I'm kind of belaboring the point, but I'm actually enjoying learning about this despite the fact that it's in response to a problem. Any light you can shed regarding what I've noted above would be great.

Also, you noted that you wouldn't recommend a spin-down filter because it will only trap coarse sand and sediment. Is there some filtration system/setup that you do recommend to protect appliances (fridge, dishwasher, etc.) from damage due to sediment, and to keep the sediment out of my sink screens? I cleaned those out today as well, and there were some large particles in them and my refrigerator filter is jammed full of sediment. Note that I don't expect to have a lot of sediment in the water in the future, but something was happening for a few days that was creating sediment in the water.

Now, of course, the sediment in the water is much, much less pronounced, but I can't help but thinking that a simple filtration system would offer good insurance against damage to appliances, or even the fridge filters, which cost $35 each. What do you think?

Thanks!
Matt

[Bob NH]

There are large cartridge filters that will do what you want, and there are backwashable granular filters that are contained in a housing/tank that looks a lot like the tank of a water softener.

I am an advocate of the cartridge filters, but they must be large enough to handle the flow and the dirt. They can remove particles down to the range of 1 to 5 microns depending on the cartridge you choose. That is similar to what your refrigerator cartridge removes but the filter is sized to treat all of the water used in the house. You can't see 5 microns.

Others advocate the backwashable filters. I believe they remove particles down to about 50 microns. I will let others tell you the advantages of those.