Water not clearing up from “newish” well

[vwguygti]

Hi there - long time reader, first time poster here.

I have a 6 month old well that took a few weeks to clear up when new and since then occasionally would get murky. Here are some specs:

* 300’ deep well, pump set at 278’.
* 40’ of 6” steel case, remaining 4” pvc
* 40’ benonite seal
* 5 gpm, 15’ static water level
* first 30’ was sand, from 30’ to 105’ was decomposed granite, from there to 300’ was salt and pepper granite

I do have a 100 mesh spin down followed by a 5 micron whole house filter. I’ve been replacing the filter every month and regularly purging the spin down.

The water has become very silty and murky as of recent. For the last week, I’ve been running it a couple hours a day from the hydrant. Driller told me to keep doing what I’m doing to help clear it up. Results haven’t changed.

Any thoughts or recommendations would be greatly appreciated.

I’ve attached a picture - from left to right, water after 30 min, 1 hour, 1.5 hrs, 2 hrs… all at 3.5 gpm. These are pre filter from hydrant at well head.

 

[Valveman]

It takes a long time to develop a well at 3.5 GPM flow rate. It would take a couple hours to just empty the 400 gallons in the casing, which isn't doing anything the outside of the well where the water comes from. 3.5 GPM is probably not enough velocity to get any sediment to come straight up 275'. I would pump at least 10 GPM for 50 minutes or more if it will do that. Drawing the water level down decreases down hole pressure and allows more flow into the well. Then shutting the pump off when the well is dry allows the water level to rise and rinse the formation. You may have to do this for days and pump thousands of gallons down the ditch to get the well clean. Seems like a waste of water but probably less than a life time of cleaning and back flushing filters.

Also, if pumping at 3.5 GPM is causing your pump to cycle on and off, you are also surging the well up and down, making more sediment. A steady draw of any rate is needed to develop a well.

 

[Sponsor]

 

[vwguygti]

Thanks so much for the reply. I have a constant pressure system. Goulds centripro 3 phase/inverter motor with the solo2 controller.

So you would suggest running it wide open basically for 50 minutes or until it draws down to the pump? The pump will shut itself down as soon as it drops below 47psi and gives a low water/prime error at the controller.

 

[LLigetfa]

3.5 GPM is probably not enough velocity to get any sediment to come straight up 275'.

When I started developing my well, it would not produce enough GPM so I had to dump it into a large barrel where the sediment could settle and skim some of the water off the top to send back down the well. As it opened up, I could send less and less back down the well until the water could keep up to the pump draw rate.

 

[vwguygti]

I t

When I started developing my well, it would not produce enough GPM so I had to dump it into a large barrel where the sediment could settle and skim some of the water off the top to send back down the well. As it opened up, I could send less and less back down the well until the water could keep up to the pump draw rate.

Interesting. I have access to another very well established well. Would it be beneficial to run clean water down mine while running it wide open? The sediment in mine is very fine but I still worry about pump wear. Maybe the added clean water would dilute the sediment while still drawing water and down and keeping velocity up (?)

 

[Valveman]

Thanks so much for the reply. I have a constant pressure system. Goulds centripro 3 phase/inverter motor with the solo2 controller.

So you would suggest running it wide open basically for 50 minutes or until it draws down to the pump? The pump will shut itself down as soon as it drops below 47psi and gives a low water/prime error at the controller.

I am sorry for the problems you will have with the variable speed type pump. The first of which is not being able to run at less than 47 PSI. You will find out why many people switch to a simple Cycle Stop Valve after having the VFD type system. But that is just one of many things to learn about pump systems.

The best you can do is restrict the output to about 50 PSI and see how long it will run. The problem is the output will need to be further and further restricted as the water level drops to keep the pressure above 50 PSI. It would be best if you could disable that feature to get the well developed. You need to get the crud that will come out of the well pumped out. The sediment that won't come out of the well turns into a sand media filter that keeps any sediment from coming into the well. But it takes lots of pumping to do this.

While I commend LLigetfa for ingenuity in reusing water to keep enough flow to clean the well, yours doesn't need that. You just need pump that will let you pump the water that is in the well. Restricting the flow rate to maintain a pumping level just above the pump setting and running the pump 24/7 is usually best Sometimes turning the pump off and letting the level rise before pumping it hard again will help. Sometimes you have to both of those things a lot before the well will clear. Developing a well can take much longer and be more technical than the drilling itself.

 

[vwguygti]

I am sorry for the problems you will have with the variable speed type pump. The first of which is not being able to run at less than 47 PSI. You will find out why many people switch to a simple Cycle Stop Valve after having the VFD type system. But that is just one of many things to learn about pump systems.

The best you can do is restrict the output to about 50 PSI and see how long it will run. The problem is the output will need to be further and further restricted as the water level drops to keep the pressure above 50 PSI. It would be best if you could disable that feature to get the well developed. You need to get the crud that will come out of the well pumped out. The sediment that won't come out of the well turns into a sand media filter that keeps any sediment from coming into the well. But it takes lots of pumping to do this.

While I commend LLigetfa for ingenuity in reusing water to keep enough flow to clean the well, yours doesn't need that. You just need pump that will let you pump the water that is in the well. Restricting the flow rate to maintain a pumping level just above the pump setting and running the pump 24/7 is usually best Sometimes turning the pump off and letting the level rise before pumping it hard again will help. Sometimes you have to both of those things a lot before the well will clear. Developing a well can take much longer and be more technical than the drilling itself.

That sounds good. I can adjust the pressure setting down to 20 psi. So do you recommend running it at 5gpm 24/7 with occasional 10gpm runs? At this point, I’m okay with wasting the water as I just want a properly developed well. Thanks again, valveman!

 

[vwguygti]

-Update-

I have been running the well at night for 12 hours at a time @3 gpm. When I run the hydrant at 5 gpm, it seems to run down to the bottom after some time. I know a few months ago this wouldn’t have happened, so I believe my production got worse.. possibly as a result of whatever the reason was that my water suddenly got cloudy.

In the mornings when I shut the hydrant off after 12 hours of continuous runtime, I flashlight down the hole and can see the water filling up. Within a couple of minutes, we’re back 20’ which is near static level (15’). Heres me question:

The 4” pvc liner starts at 20’, which means there’s a 20’ overlap between the 6” steel case and the 4” pvc. When the water level is rising towards static, it gets to the 20’ level and at that point starts flowing over into the 4” pvc. Once full it finishes the last 5’ to static. This morning it gurgled and poured water into the 4” pvc for 5 minutes before filling up and going the last 5’ to static. Is this normal? It tells me the bore is filling faster than the 4” pvc. Logic tells me they would equalize on the way up, correct?

The 4” pvc is sitting on granite @ 300’, with the last 20’ section having 1/8”x4” slots. Pump is right above that at 278’

 

[Bannerman]

By your description, it seems the water entering through the 1/8"slots at the bottom of the 4" casing is restricted, likely by the silt, sludge or debris that has accumulated at the bottom of the casing. Once the water level has risen close to 20' below grade, the water level outside the casing rising at a slightly faster rate than within the casing, is entering through the overlap gap between the 6" steel casing, and the 4" PVC casing.

A well is often developed by disconnecting the drop pipe at the top of the casing, thereby allowing the pump to run hard with the least amount of restriction to maximize the flow rate to pump out as much debris as possible into the surrounding field.

Sometimes turning the pump off and letting the level rise before pumping it hard again will help. Sometimes you have to both of those things a lot before the well will clear. Developing a well can take much longer and be more technical than the drilling itself.

Because your well currently has a slower recovery rate than the pump is capable of pumping, pumping at the maximum rate will need to be performed for short periods to prevent the well from being pumped dry, repeating with sufficient time between cycles to allow sufficient water recovery.

Repeatedly pumping the water level down to a low level, will often increase the flow rate through the bottom screen, thereby reducing the recovery time and increasing the flow rate the well will deliver on an ongoing basis.

 

[vwguygti]

Thanks Bannerman. Similar to what another member did above, what if I used another water source to supply my well from above and run it wide open from the hydrant to really try and move sediment? Does it make sense to let the well drawn down or keep the level up and run it harder for a longer period of time?

 

[Bannerman]

As stated, drawing down the water level will often increase the flow rate through the screen.

I suspect much of the debris is entering with the fast inflow through the overlap gap. If the screen flow restriction is reduced to allow water to more rapidly enter the casing through the screen, I expect the water outside of the casing will not rise as rapidly, thereby reducing the flow rate entering through the gap which should reduce the amount of debris entering through that gap.

 

[vwguygti]

why do you suspect the debris is entering through the overlap gap? Just trying to better understand it.

 

[Bannerman]

why do you suspect the debris is entering through the overlap gap?

You said: "When the water level is rising towards static, it gets to the 20’ level and at that point starts flowing over into the 4” pvc."

You also said the 40' 6" casing overlaps the 4" casing by 20'. Since the top of the 4" casing is 20' down, then it seems obvious the water flowing over into the 4" PVC casing is flowing from outside of the 4" casing, rising within the 20' overlap space between the two casings.

Since the water flowing over into the 4" casing only does so when the water level within the 4" casing has risen to below the 20' level, that suggests the water flowing over into the 4" casing, is rising faster than the water entering through the screen at the bottom of the 4" casing. Because there is no screen between the two casings, I suspect the loose silt etc on the outside of the casing, is being carried upward by the rapidly rising water into the 4" casing. Since the sediment will be heavier than water, it will settle and accumulate on top of the debris that has previously accumulated at the bottom of the well, and possibly accumulating around the pump.

Once the pump is activated, some of the debris is then likely becoming agitated and fluidized by the rapid flow of water entering the pump inlet, which is then carried by the velocity of water being pumped into your home's plumbing system.

 

[vwguygti]

You said: "When the water level is rising towards static, it gets to the 20’ level and at that point starts flowing over into the 4” pvc."

You also said the 40' 6" casing overlaps the 4" casing by 20'. Since the top of the 4" casing is 20' down, then it seems obvious the water flowing over into the 4" PVC casing is flowing from outside of the 4" casing, rising within the 20' overlap space between the two casings.

Since the water flowing over into the 4" casing only does so when the water level within the 4" casing has risen to below the 20' level, that suggests the water flowing over into the 4" casing, is rising faster than the water entering through the screen at the bottom of the 4" casing. Because there is no screen between the two casings, I suspect the loose silt etc on the outside of the casing, is being carried upward by the rapidly rising water into the 4" casing. Since the sediment will be heavier than water, it will settle and accumulate on top of the debris that has previously accumulated at the bottom of the well, and possibly accumulating around the pump.

Once the pump is activated, some of the debris is then likely becoming agitated and fluidized by the rapid flow of water entering the pump inlet, which is then carried by the velocity of water being pumped into your home's plumbing system.

That’s all true and I agree with your reasoning. I didn’t think about outside the 4” rapid rise in water carrying debris and dumping into what ultimately is what’s being pumped.

Someone in another thread mentioned a surge block. I think that could help clear up the slots and prevent what’s going on as you described.

 

[Reach4]

I suspect what you have is 4 inch pvc liner.

 

[vwguygti]

I suspect what you have is 4 inch pvc liner.

Correct - 6” steel from -2 to 38’. 4” PVC from 20’-300’

 

[Reach4]

Correct - 6” steel from -2 to 38’. 4” PVC from 20’-300’

How high does the pitless come up... to just under the pitless?

 

[vwguygti]

How high does the pitless come up... to just under the pitless?

Pitless is 6’ below well head… 4’ below final grade.

 

[Reach4]

Pitless is 6’ below well head… 4’ below final grade.

I meant to ask how high the PVC liner comes up.

 

[LLigetfa]

I meant to ask how high the PVC liner comes up.

You should not have to ask since it is stated in the thread that it starts 20 feet down.