RickB
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Still the best answer.
Good vs Poor Wells - What makes a well a good well?
- Thread starter Pettrix
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Still the best answer.
cat fever
Elite Member
I agree with this post as well as Egon's.
My well is 180' deep with the pump at 156'. The drill truck was pumping over 100 GPM with no draw down on the well. My area sits on a giant aquifer so geology plays a big part.
CurlyDave
Elite Member
Whenever the discussion turns to wells, I always like to start an analysis from the back of the water supply issue.
We have a 4 bedroom house and the county required a 350 gallon per day septic system. The county standards are that we could support 8 people with that septic system. This is a flow rate of just under 0.25 gallons per minute.
We only have two of us, and our actual water use, with no attempt at conservation is about 175 gallons per day, which would be 0.125 gallons per minute.
If you are not going to irrigate, I would put the minimum acceptable flow rate at 0.12 to 0.25 gpm for a residence. Now with that low of a well flow you will need a cistern to provide some temporary reserve capacity.
Our well is about 2.5 gpm, we irrigate about 1/4 acre, and we never have any issue with water quantity. We flush toilets, take a shower, and run the washing machine, and irrigate at the same time and have never even notice any flow restriction. The standard for the well test is to pump at full capacity for 1 hour and then measure sustained flow after that. We get around 7 or 8 gpm for the first part of that hour, and then the flow drop off to a sustained 2.5 gpm.
I do have a storage tank for irrigation, which is by far the biggest user, and restrict the input to 1 gpm and have zones to limit the total flow to irrigation from the tank to ~ 2.5 gpm. The cistern is about 500 gallons, and we only irrigate for about 1 hour several times per day, which allows the tank time to fill.
I had heard the 5 gpm rule of thumb before we started and paid dearly for it. The first well we drilled, in search of 5 gpm was ~ 700' deep and still only produced 2.5 gpm. The pump failed at an age of about 8 years because the bore collapsed due to poor strata at that depth. The majority of the flow came in at about 250 feet. We had to drill a second well which I stopped at ~ the 250 foot level, and we are much happier with this well.
FHA and most banks have gotten away from the old 5 gpm "standard", and will now loan on almost any reasonable well.
If your well produces good-tasting water it is vastly more than sufficient at 20 gpm. That is about 100 times more water than you really need.
Turbys_1700
Elite Member
My water is supplied by a surface spring that has been in use by my family for over 200 years. I have no idea how much flow it has. We've never run out even during our worst drought 12 years ago or so. We've not had a lot of houses built close to the farm over the years and I guess the water table has remained stable. I have a small pressure tank and a spring box with a foot valve running into the spring house. Guess the water is OK since crawdads stay in there. I tell everyone that the water was so bad that it killed my great grandfather at the age 94. Never had it tested but I can't stand the taste of treated water.
oosik
Epic Contributor
Hey, Turby - sounds a lot like my water supply. Its a spring, used by the original homesteader, starting in 1892. I upgraded it with cast,perforated cement rings to a depth of 16 feet. I surged it for 48 hours to reduce the silt & sand - dug with a tracked back hoe. Installed a 6" trash pump - pumped continuously for 48 hours - every hour I went down and "stirred the pot". After 48 hours of continuous pumping, the surface water level had not dropped an inch. I have a 3/4 horse submersible pump with a standard 60 gallon bladder tank, up here in the basement. The spring is around 150 feet from the house - down in the valley.
Never had it tested, however the little green frogs seem to like it just fine. It goes so very well with JD and a few cubes.
Never had it tested, however the little green frogs seem to like it just fine. It goes so very well with JD and a few cubes.
Turbys_1700
Elite Member
I figure as long as crayfish can live in my water it's OK to drink. Same with yours and the green frogs. I've got a few of them too. When you think about it the spring self cleans since it is constantly running. My grandparents used to keep milk in the spring house prior to electricity to keep it cool. About 10 years ago the county ran water past the house and wanted 2K to hook up. I passed. If my spring goes dry then I'll have to due to county ordinances unless I am 500 feet from the line. Think I am OK though.
crackerjack222
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Pretty much anything in the water can be filtered out.
Valveman, I would appreciate your comments on my situation:
I have a well on my ranch, SE of San Antonio, 700' deep, 5hp pump set at 360" in 4" pvc casing. The static level measured 20 years ago when it was drilled was ~50'. The pump will make about 40 gpm all day long. the problem: it has always made sand, a lot of sand. I call it sand, but it is a grey powder when dry. It will go through a "Whole House" filter with paper cartridge. There is so much sand it would be useless to put a finer filter because it would fill up in minutes. I can turn the pump on discharging on the ground thru 2" pipe and for the first ~minute the water will be clear as the pump draws from the casing. After about 1 minute the water turns gray with sand, then slowly clears up after 30 minutes to an hour. At one time I put the pump on a timer to cycle the pump on for an hour every 4 hours. After a few days of this there was not so much sand, but after sitting for a few days we were back to the same problem. Originally, I wanted to use this well to irrigate a large garden but the water is too bad (high TDS and salt) for that. I now use the well only for a bunkhouse and use bottled water for drinking.
I am considering two possible solutions, either replace the pump with a smaller one, say 1 hp, or put in a ~1000 gallon settling tank and pump out of that from about half-way down with a jet pump. My thought is that the smaller pump will not draw (as much) sand from the bottom of the well. The settling tank would likely only be partially effective depending on how soon water was drawn from it after the well pump had topped it off.
If you have any suggestions, I am all ears (or eyes in this case).
Valveman, I would appreciate your comments on my situation:
I have a well on my ranch, SE of San Antonio, 700' deep, 5hp pump set at 360" in 4" pvc casing. The static level measured 20 years ago when it was drilled was ~50'. The pump will make about 40 gpm all day long. the problem: it has always made sand, a lot of sand. I call it sand, but it is a grey powder when dry. It will go through a "Whole House" filter with paper cartridge. There is so much sand it would be useless to put a finer filter because it would fill up in minutes. I can turn the pump on discharging on the ground thru 2" pipe and for the first ~minute the water will be clear as the pump draws from the casing. After about 1 minute the water turns gray with sand, then slowly clears up after 30 minutes to an hour. At one time I put the pump on a timer to cycle the pump on for an hour every 4 hours. After a few days of this there was not so much sand, but after sitting for a few days we were back to the same problem. Originally, I wanted to use this well to irrigate a large garden but the water is too bad (high TDS and salt) for that. I now use the well only for a bunkhouse and use bottled water for drinking.
I am considering two possible solutions, either replace the pump with a smaller one, say 1 hp, or put in a ~1000 gallon settling tank and pump out of that from about half-way down with a jet pump. My thought is that the smaller pump will not draw (as much) sand from the bottom of the well. The settling tank would likely only be partially effective depending on how soon water was drawn from it after the well pump had topped it off.
If you have any suggestions, I am all ears (or eyes in this case).
Egon
Epic Contributor
Clay particles.
oosik
Epic Contributor
CrackerJack,
It may be worthwhile to have a well driller look at your situation. If you aren't bottomed in a clay layer, he may be able to surge the well and pump out the majority of the silt & clay. They have the equipment to put a LOT more force into the well and draw the fines out from a long way around the intake.
It may be worthwhile to have a well driller look at your situation. If you aren't bottomed in a clay layer, he may be able to surge the well and pump out the majority of the silt & clay. They have the equipment to put a LOT more force into the well and draw the fines out from a long way around the intake.
Valveman
Platinum Member
It is always better to solve the original problem when you can by cleaning or developing the well. But surging or blowing a 700' well will not be cheap, and is not guaranteed to work. Reducing the flow rate could help lower the amount of clay you are getting. But you still need enough velocity in the drop pipe to get the fines to come out the top of the well. When you have too little flow in too large of a pipe the velocity will not bring up the sand. It will just settle to the bottom until there is enough to hold the check valve closed. So if you switch to a smaller pump, you should also switch to smaller pipe.
The reason the water first comes out clean is because it has had time to settle in the drop pipe. This is a good thing because at least the stuff will settle. Stuff that stays suspended in the water is hard to get rid of.
You could use a gate or ball valve to throttle the output of the pump to about 20 GPM, which is about as low as you want velocity in 2" pipe. Then I would use two smaller storage tanks instead of one. Bring the well water into the first tank about half way down. And bring it in with large pipe to slow the velocity. Then let the first tank overflow into the lower half of the second tank. You should draw pretty clean water from the upper half of the second tank. But you will need a booster pump to supply this water to the house.
Another idea would be to test the well with the existing pump. You can safely pump a 5HP at flow as low as 3 GPM. What you want to know is the water level in the well while drawing say 5-10 GPM for a long period of time. If the water level only draws down to say 100', then you could use a much smaller pump, set at a much shallower setting. Drawing lower flow from higher up in the well may allow the fines to settle in the well, and never get to the pump. If water is only used for the house, a 3/4HP, 10 GPM sub could be set at 120' and would produce 10-12 GPM at 50+ PSI.
I have also done wells that no matter what you did they would make fines for a while after they were started. In one case we set up a little 1/2HP pump to run all the time. We just used a modulating pressure relief valve and dumped anything over about 75 PSI. In this case there was a stock tank where the water could go and be used. So when the house was not using water the pressure relief would dump 2-3 GPM to the stock tank. When the house used water the pressure would drop below 75, the pressure relief valve would close, and the house would have 8-10 GPM available at 50 PSI. When the house stopped using water the pressure would increase to 75 and the relief valve would again dump water to the stock tank. In this way the pump never shut off and therefore never made sand, unless starting back up after a power outage.
The reason the water first comes out clean is because it has had time to settle in the drop pipe. This is a good thing because at least the stuff will settle. Stuff that stays suspended in the water is hard to get rid of.
You could use a gate or ball valve to throttle the output of the pump to about 20 GPM, which is about as low as you want velocity in 2" pipe. Then I would use two smaller storage tanks instead of one. Bring the well water into the first tank about half way down. And bring it in with large pipe to slow the velocity. Then let the first tank overflow into the lower half of the second tank. You should draw pretty clean water from the upper half of the second tank. But you will need a booster pump to supply this water to the house.
Another idea would be to test the well with the existing pump. You can safely pump a 5HP at flow as low as 3 GPM. What you want to know is the water level in the well while drawing say 5-10 GPM for a long period of time. If the water level only draws down to say 100', then you could use a much smaller pump, set at a much shallower setting. Drawing lower flow from higher up in the well may allow the fines to settle in the well, and never get to the pump. If water is only used for the house, a 3/4HP, 10 GPM sub could be set at 120' and would produce 10-12 GPM at 50+ PSI.
I have also done wells that no matter what you did they would make fines for a while after they were started. In one case we set up a little 1/2HP pump to run all the time. We just used a modulating pressure relief valve and dumped anything over about 75 PSI. In this case there was a stock tank where the water could go and be used. So when the house was not using water the pressure relief would dump 2-3 GPM to the stock tank. When the house used water the pressure would drop below 75, the pressure relief valve would close, and the house would have 8-10 GPM available at 50 PSI. When the house stopped using water the pressure would increase to 75 and the relief valve would again dump water to the stock tank. In this way the pump never shut off and therefore never made sand, unless starting back up after a power outage.
flusher
Super Member
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- Getting old. Sold the ranch. Sold the tractors. Moved back to the city.
The well on my ranch in Tehama County is a very good well: 154 ft deep, 1.5 hp Franklin pump at 120 ft, water level in 6" dia casing 54 ft initially. The driller said it's capable of more than 100 gpm. 30 gpm is the normal flow.
However, in the 11 years since that well was drilled (May 2005), the water level is now at 105 ft, 15 feet over the pump. My neighbor's pump at 90 ft down began sucking air in early 2015. Fortunately there are 3 or 4 monitoring wells within a half-mile of my well, so we have annual measurements of the ground water level in my neighborhood. About 2/3 of the drop has occurred in the past 3 years, corresponding to the time when the orchard growers in my area were cut off from river water by the local irrigation district.
Moral of the story: whether a well is good or not may depend a lot on weather conditions (drought) and how much your neighbors are depressing the water table. So keep an eye on both of these factors.
However, in the 11 years since that well was drilled (May 2005), the water level is now at 105 ft, 15 feet over the pump. My neighbor's pump at 90 ft down began sucking air in early 2015. Fortunately there are 3 or 4 monitoring wells within a half-mile of my well, so we have annual measurements of the ground water level in my neighborhood. About 2/3 of the drop has occurred in the past 3 years, corresponding to the time when the orchard growers in my area were cut off from river water by the local irrigation district.
Moral of the story: whether a well is good or not may depend a lot on weather conditions (drought) and how much your neighbors are depressing the water table. So keep an eye on both of these factors.
turnkey4099
Elite Member
I have seen that standard in reported in many different sites over the years. Don't ever recall seeing and "official" one.
As for flow rate? Gotta agree there. I had a new well drilled, they hit water when I was a work and gave me a 24 gpm rate. There was no sign at all of them ever having pumped any water out on the ground other than the usual during drilling. They would have had to pumped through a hose for a good 150 ft - no sign of anything in the ditch eitther.
OP
Pettrix
Platinum Member
Great point!
Any agricultural high-draw can drop the water table in a significant way. If more water is removed than recharged, especially in a smaller aquifer, it can create problem for homeowners.
My lot is fortunate in that it backs to 600+ acres of state land and there is no agricultural allowed.
It's always a good idea to monitor the well since it will alert you of potential future problems before they hit. They sell a cool device (kind of pricey at $1,100) but it uses sound waves to measure the water level within 5 seconds. It's fast and easy but a little pricey.
Water level meter | Groundwater monitoring | Eno Scientific | Well Sounder 2010 PRO
OP
Pettrix
Platinum Member
Most banks will not lend/loan for a property that sees LESS THAN 5GPM on the private well. Water is life and without it, property values plummet. So banks and the FHA set it at 5GPM for a private well.
Drawdown is very important but rarely tested. It will show the proper recharge rate of the well.
That's why during my drilling I had the well driller go deeper. That's the time to do it, during the initial drilling, not later on when the well pump is in. The cost to go back, pull the pump, restart the drilling will be 3x more money.
I hit water at 210 but had them go down to 500 feet them to give me the reserve for drawdown and the safety parameters for droughts and a dropping water table. There was no risk of cave-in so I had them drill deeper. Plus they installed PVC casings down the well hole to keep them from closing in.
A local resident hit water at the same depth (220) but only went down another 100' (320) but now is at risk is of running the pump dry. If the pump is run at 18GPM for 1 hour, the water table will be at the pump level (320) which will run the pump dry and run the risk of burning it out.
TWD
Gold Member
We have 14GPM at around 400', I forget the rest of the tests.
Family of 4, and we can go multiple days on 120G pressure tank (~50 usable at pressure set) when power is out using it to wash hands and flush toilets only.
If you don't do high demand usage at once then 5GPM is plenty. Don't shower 2x at once, don't water outside + shower at once, etc... all depends on your 'flow' too.
It's more noticeable for us to have a temp drop during high usage than it is not enough water. Multiple usage at once = lots of 'fresh cold water' coming up from the well, vs. the warmed pressure tank water/mix.
Our plan is to add a 2600G tank for garden/animals/etc and then add 3-4 more pressure tanks so we can go 3-5 days without power and shower a couple times, or even longer just on toilet. It really doesn't matter now as we can use a well for the pump I just haven't wired it in yet
hehe.
Family of 4, and we can go multiple days on 120G pressure tank (~50 usable at pressure set) when power is out using it to wash hands and flush toilets only.
If you don't do high demand usage at once then 5GPM is plenty. Don't shower 2x at once, don't water outside + shower at once, etc... all depends on your 'flow' too.
It's more noticeable for us to have a temp drop during high usage than it is not enough water. Multiple usage at once = lots of 'fresh cold water' coming up from the well, vs. the warmed pressure tank water/mix.
Our plan is to add a 2600G tank for garden/animals/etc and then add 3-4 more pressure tanks so we can go 3-5 days without power and shower a couple times, or even longer just on toilet. It really doesn't matter now as we can use a well for the pump I just haven't wired it in yet
hehe.
OP
Pettrix
Platinum Member
Our plan is to add a 2600G tank for garden/animals/etc and then add 3-4 more pressure tanks so we can go 3-5 days without power and shower a couple times, or even longer just on toilet. It really doesn't matter now as we can use a well for the pump I just haven't wired it in yet
Those pressure tanks (120 gallon) run about $700+ per tank so getting 4 more tanks will run you close to $3,000
I think the better option would be to get a generator and then install a transfer switch. That way you can run your well pump on a $1,500 generator and not worry about running out of water. A NorthStar generator at 6,500 watts with a copper genset and Honda motor will run around $1,500.
crackerjack222
Silver Member
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Thanks to oosik and Valveman for the responses to my sand problem. When the well was drilled the driller jetted the well with a portable compressor mounted on a small trailer, probably about 150 cfm. After the pump was installed and the sand problem appeared, I had the driller come back, pull the pump and jet the well again. This time he used a large skid mounted compressor on a trailer. He put the back of the trailer over the casing and put a jack between the casing and trailer frame to keep the casing from blowing out of the well. With that compressor jetting the well, the water was shooting up in a 20-30' geyser. This went on for hours.
Valveman, your suggestion to use smaller pipe for the smaller pump is well taken. I probably would have used the 2" pipe again to save money. And the two-tank idea is also good. And I had planned to have the small sub pump set higher to get further away from the bottom of the well. I didn't mention it in my op but the 5 hp pump has been in the well for 20 years now and if it runs for more than about 3 minutes it will trip the breaker. As long as I am not using much water it works ok and does not make sand but I know it is on its last legs. When it dies I will go back with a 1 hp pump.
Valveman, your suggestion to use smaller pipe for the smaller pump is well taken. I probably would have used the 2" pipe again to save money.
And the two-tank idea is also good. And I had planned to have the small sub pump set higher to get further away from the bottom of the well. I didn't mention it in my op but the 5 hp pump has been in the well for 20 years now and if it runs for more than about 3 minutes it will trip the breaker. As long as I am not using much water it works ok and does not make sand but I know it is on its last legs. When it dies I will go back with a 1 hp pump.
Valveman
Platinum Member
Thanks to oosik and Valveman for the responses to my sand problem. When the well was drilled the driller jetted the well with a portable compressor mounted on a small trailer, probably about 150 cfm. After the pump was installed and the sand problem appeared, I had the driller come back, pull the pump and jet the well again. This time he used a large skid mounted compressor on a trailer. He put the back of the trailer over the casing and put a jack between the casing and trailer frame to keep the casing from blowing out of the well. With that compressor jetting the well, the water was shooting up in a 20-30' geyser. This went on for hours.
Valveman, your suggestion to use smaller pipe for the smaller pump is well taken. I probably would have used the 2" pipe again to save money.
Try restricting the flow to 20-30 GPM with a gate or ball valve. You probably have a 25 GPM, 5HP, and it is pumping 40 GPM because the static level is only 50'. That will make the motor pull maximum amps and will cause the pump to upthrust, which is not good. Restricting the flow should reduce the amp draw and keep it from tripping the overload. If it still trips the overload, the motor is probably damaged from the sand.
Valveman
Platinum Member
I agree a generator is a much better way to have water when the power goes off. You can never count on pressure tanks for storing any water. When you are using a 40/60 pressure switch, the tank(s) are full at 60 PSI and completely empty at 38 PSI. You have no way of making sure the pressure is at or close to 60 when the power goes off. As a matter of fact if Murphy has anything to do with it, the pressure will always be at 41 PSI when the power goes off. Even with a room full of big tanks, at 41 PSI you only have a couple of gallons left before the tank(s) are empty.
A generator will keep the water flowing for as long as you have fuel. The longer the power stays off, the more important a generator is.
mapper
Veteran Member
Your shower valve must be 20+ years old, the newer pressure balancing valves will compensate for that and you would never know when someone flushed. The most you might notice would be a slight deposit in pressure.
