Low-yield Well Problems

Hello Everyone,
I recently bought a house which had well problems. The former owners had the well hydrofractured just before settlement. They were getting less than 1 GPM before hydrofracing, and I assumed that hydrofracing would provide enough additional capacity. Well, I was wrong, partly. Only when we have company over does the well pump switch trip, and doesn't recover for up to 12 hours. Although we have adequate supply for my fiance and me, she is adament that we have more water available. With a bit of water knowledge (civil engineer), I believe that I have a high static water level (well is 410' deep), with a low yield.

I currently have a goulds 3/4 HP well pump, Wellmate WM-12 pressure tank, and an ecosystems water softener. What I would like to do is add a 300 gallon poly tank with Pumptec protection on the float switch, which would collect water pumped directly from the well. I would then put a Grundfos MQ3-45 constant pressure pump on the outlet of the tank which feeds into my softener. I would like to get rid of my pressure tank, but am leary about how the constant pressure pump will work with the water softener.

I'm having a friend who has a HVAC company do the work, but as he has never put one of these systems in, we were curious as to whether this sounds like a good plan of attack. Thank you in advance for any information anyone can provide.

Thanks
Tyson

The capacity of the well is diffterent than the recovery rate (1 gpm).

If you have a 6" well you have capacity/storage of 1.47 gals/ft of water above the pump inlet. I question a 3/4 hp pump in a 410' deep well. The pump should be set at like 390-400' deep and then be more like a 1 hp and whatever gpm the total dynamic head requires.

Going to an additional storage tank and using say half of it, requires getting the same gallons of of the well as used out of the tank, all at the same time. If you don't have enough gallons, then you're back to the dry well condition where you are today. All pumps will require at least a small pressure tank, so you can't get rid of one.

A CSV (Cycle Stop Valve) for less than $150 and a small pressure tank (which you may have now) is much better than a variable speed pump and its expense.

If you go this additional tank, you should be concerned with water quality and the tank should allow for periodic cleaning and disinfection.

So how deep is the pump?

What is the static water level in the well?

Thanks for the information. I may have been in error in stating my well pump was 3/4 HP, when I went home and looked through the former owner's literature, the page in the owner's manual with the HP rating was missing. I do know that it's a 4" 60Hz Goulds. Also, when the pressure switch kicks on (when it hits 30 psi), it really takes no time at all to get back to 50 psi. That makes me think that it has plenty of capability to fill a poly tank at atmospheric pressure.

I'm not sure how low the pump is in the well or exactly where the static water level is. I've been attempting to get my hands on one of those water level indicators (my friend who works with dams uses it to measure water depth in piezometers) to find how high the water level is. Due to the historic issues with this well (I talked to a neighbor who lived there while they were buidling the house and he said that the drillers and builder were well aware of the problems) I would think that the pump is as far down as possible. But I will definitely look into this.

Gary, in regards to having the same amount of water even if I do add the tank, I'm looking to make the system pretty much like a public water reservoir. I'm not looking for it to sustain a large set amount of water over a long period of time, just to meet peak demand. If the well yield is 1 GPM (1440 GPD) or even 0.5 GPM (720 GPD), this would provide adequate water supply. It's basically like adding more length to my well shaft storage. The only time that it has run dry is when we have had company visiting. However, I'm getting married in August and will probably have a few more heads in the house in the next few years, so that's why I figured I would fix the system now.

Bob, I'm definitely going to go with keeping the existing pressure tank like you suggested and add a 0.5 HP jet pump. I was kinda lured by the Grundfos MQ3-45 due to it claiming it has a built in tank on the end of the pump assembly. I just wanted to get some opinions from experts before going through with the project. I'll let everyone know how it turns out after I install it (in the next month sometime).

Thanks again for your comments and suggestions,
Tyson

The MQ is not a variable speed pump. It is a constant speed pump with an electronic controller that turns the pump on with a drop in pressure, then turns it off with a flow switch. It has a pressure tank built into the pump that looks like a baseball. With a baseball size tank, this pump has to start every time a faucet is opened. It must start every time you rinse a toothbrush, the ice maker fills, or flush a toilet. The big problem comes when you have a dripping faucet or running toilet. This can cause the pump to cycle so rapidly that people complain about a high electric bill, just before the pump destroys itself. A regular jet pump with a small pressure tank and a CSV is a much better option for a booster.

If you have the option to lower the pump in the well, you can access the storage that is already in the well. You may need a little larger pump to deliver pressure from a lower pump setting. A CSV on the well pump will maintain a steady draw on the well, instead of the pump cycling on and off. The CSV will only allow the pressure tank to refill at 1 GPM. This will keep the pump from pumping the well dry after you have turned off the faucets, while only the pressure tank is filling with water. This has saved my pump from tripping out many times on a weak well. You could even add another pressure tank which would increase the amount of water available before the well is even accessed. Planning a little time between showers when you have company also helps.

You can also use a storage tank and booster pump as a backup for the well supply. Tying the well pump and booster pump together for the house, means your storage tank and booster pump only supply water after the well has run low.

Thanks for the information Bob. I can get a 300 (35" x 84") gallon poly tank for around 200 dollars (from a local manufacturer), or a tall 200 gallon tank for about 350 dollars (due to shipping). I had reservations about needing 300 gallons, but if I get more for less, I think I'll go with the 300 gallon tank. I also have a specified area in my basement, which has no use, which could fit both of these tanks. I've heard from a friend who has a 250 gallon Well Manager system that all he has to do is shock the tank with chlorine about once a year to keep it "nasty" free. Has anyone had bacterial issues with allowing water in an exposed tank like this? 300 gallons will be used in no more than two days (average use per the water softener - 190 GPD), since all water will go through the storage tank. I will use the Goulds J5SH to pump the water from the storage tank to the water softener and distribution system. I was also planning on putting the Pumptec on a 120 minute reset. Thanks again for all of the information, it is really appreciated.

Thanks
Tyson

The 300 gallon tank is fine and 2 days of residence time will keep it from growing much. Rather than wait a year I would add about 1 oz of plain unscented chlorine bleach when you think about it; maybe once a week. If you just put it in the top of the tank it will diffuse and dilute before it gets to the outlet so you will probably never notice it, but it will take care of anything that gets into the tank.

You will need a check valve somewhere in the jet pump line. If it is after the pump then you need to be sure the pressure switch is measuring the pressure. Most of those pumps come with a pressure switch on the pump, with the wiring going through the pressure switch. You probably want to use the switch that you are now using with your submersible.

The two float switches in the tank must either be able to handle the load of the motors or you will need relays. The one at the bottom of the tank will control in series with the pressure switch and will be open on low such as a sump-pump switch. The one controlling the well will be close on low (normally closed).

You can get float switches with weights so you don't have to attach them to anything in the tank. I usually cut the the plug off (if it has one) and run the cord through a 3/8" hole in the flange at the manhole. A knot on the outside adjusts the height. The range is adjusted by adjusting the length of the cord beyond the weight.

Tanks like you will have tend to collect sediment from the well that you never knew you had so don't be surprised. They also collect insects that get in through the vent. A bit of chlorine keeps it all safe.

The Well Manager your neighbor has will have a Cycle Stop Valve or two as important parts of how that system works. It is probably one of their systems that switches back and for from the well pump to the booster pump as I suggested earlier. This is how they can supply so much extra water from so small a storage tank. Stay with the Well Manager design and you will be better off.

Tyson, constant chlorine into your softener will ruin the resin in a short time. And chlorine disinfection by products are a possibility if you don't filter them and the chlorine out of the water.

I suggest my inline pellet chlorinator and special mixing tank followed by an automatically backwashed special carbon filter; then the softener.

You can't get more water out of the well than you are now unless the pump can be lowered from where it is now; or you time the outflow from the well as you are talking about doing now. With timed withdraw, you still can only get a limited volume of water which may or may not be sufficient for your peak demand times. So this 300 gals or whatever volume out of the new tank will have to be taken from the well whenever this tank calls for water from the well.

So my point was for you to get into the well and find the depth and the static water level and the pumping level before you go into this new tank and pump etc. because you may not need them. And you will be much better off without the tank etc. if you can do without them. The well driller can tell you that information or, if he filed it, the state well drilling report will but may not have a pumping test on it. If you have one done and then set the pump 10' of the bottom, you get all the water out of the well plus some recovery gpm volume. You may need a larger pump to do that but it is much less expense and hassle than a storage tank etc. and you could sell your 3/4 hp or use it for the storage tank if it were still needed.

I am in water treatment and can tell you any/all atmospheric water storage tanks will need cleaning and sanitizing at some point or your water quality will deteriorate and that can be very quickly depending on where you live.

That is especially true of a well that is constantly drawn down substantially like yours. And if you go with the extra tank, you should go with what Valveman suggested. It is the best way to do it and IIRC it will cost much less than the Well Manager.

Low Volume Wells

Over the years I have drilled in areas of the world where water wells provide dependable but very low yields. A well that only supplies ¼ gallon per minute can supply 360 gallons of water in 24 hours. Today in the United States the average person uses approximately 75 gallons of water per day. Meaning a household of 4 people would use about 300 gallons per day while still having 60 gallons left over. Depending on the size of the storage tank, when it is full there’s enough reserve left over to use for other things.
Depending on the climate and regulations in your area, the non pressurized tank can be buried or just hidden. It can be made of plastic and almost any size from about 200 gallons to 3000 gallons depending on the amount of money that you want to spend; the space allowed and the amount of storage you desire. Keep in mind that the larger the tank the more storage you have in case of a fire.
The second pump can be a submersible inside the non pressurized tank or a shallow well jet pump outside or in the garage or storage area. The hydropneumatic (pressure tank) can be very small if you use a Cycle Stop Valve in the secondary system. The Cycle Stop Valve will supply a constant pressure while providing a variable flow depending on the demand. With a small tank the pump will run until there is no water drawn. The amperage drawn will be in relation to the gpm demand.
A "Cycle Sensor" will turn the pump off when the well runs low on water and restarts automatically when the timer is set to come on again. The Cycle Sensor can be adjusted to restart again anytime from 0 hours up to 5 hours. These controllers must be adjusted to coincide with the time it takes the well to replenish itself.
Depending on whether using a submersible or a jet pump for the second pump you must have a check valve in the respective location before the Cycle Stop Valve and the pressure switch should be mounted near the hydropneumatic tank. For more detailed information I suggest you contact Cycle Stop Valves http://www.cyclestopvalves.com/ they can walk you through a proper design for your needs.

Can anyone recommend an online place to get the proper floats for this tank? I will need four controls: one to the jet pump for low level in the storage tank, one to kick my submersible on, one to turn it off, and a backup for this one in case it fails. Any recommendations on setup and places to order them online will be appreciated. Thanks.
-Tyson