Good vs Poor Wells - What makes a well a good well?

[flusher]

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.

 

[turnkey4099]

I have not heard of that near-standard.


Also, domestic well-drillers around here cite GPM flow rates for maybe 5 minutes, which is a near-
meaningless spec. They rarely measure the draw-down rate.

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.

 

[Pettrix]

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.

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

 

[Pettrix]

Also, domestic well-drillers around here cite GPM flow rates for maybe 5 minutes, which is a near-
meaningless spec. They rarely measure the draw-down rate.

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]

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.

 

[Pettrix]

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.

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]

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]

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.

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]

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.

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]

That was a problem with the house plumbing, not the well. I have a 20gpm well and big pressure tank. Still get way too hot shower if someone flushes the toilet. The toilet is plumbed in just upstream of the shower.

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.