New Well pumping silt

Hello everyone,

Hoping someone may have some ideas on this.

I had a new well drilled in Feb. 2009 because the old well was pumping large amounts of silt. Looked like wet muddy sand from the beach. The new well is 175 feet deep. The well seemed to be OK until about Aug 09 when we started to see small amounts of silt coming through. I had a local guy who services wells come in to inspect and he changed the whole house water filter (filter is approx 10" wide). After about 30 days that filter clogged again so he came back and removed the entire filter system and installed what he called a cyclone filter which has a smaller filter cartridge but it can be removed, washed and re-installed. The casing of the old filter system was very difficult to remove due to sand getting in which was the reason for the new system. Now the problem seems to be that the filter gets plugged after 1 or 2 days and all water in the house stops until the filter is removed and cleaned.

After speaking with the gentleman that installed the filter he told me that I should be going back to my well driller and pushing him to fix the well. His thoughts are that it possibly has something to do with the screen and it's an error on the drillers part because the well should be pumping sand free water. He also mentioned that it requires getting the rig back in there?? I called the driller he says he's not sure what the problem could be. He wants to see a water sample first. I called another well driller as well and his opinion was to pump the well continuous for 12 hours, let it stand for 1 hour then pump it again for another 12 hours and repeat. My filter guy doesn't think that will work from his experience with servicing wells.

Sorry for the long post. Looking for advice.

Thanks. Mark.

I tend to agree with your filter guy. This sounds like a well that was never properly developed by the driller in the first place.

Why blame the well driller? If the first well made silt, why speculate that a second one in the same area - acre or two - would be different? Do you even have a true sand screen on the submersible?

You can pull the pump and screen it correctly, and or add a cyclonic suction device under the pump that "spins out" some or all of the silt. You can do a BIG filter with an auto backwash also. Finally, evaluate your pumping rate. Are you pumping with large HP at a high GPM? Rather pump at low HP at a very slow GPM [or throttle it back] to slow the velocity of incoming water - that may prevent the strata from releasing its silt into your incoming water.

Silt or sand pumping is a well problem! Occasionally I have seen where overpumping a well or to large a pump can cause silt or sand to be pumped. This is something that the driller that drilled the well should be able to determine.

Ballvalve mentioned that, "You can pull the pump and screen it correctly, and or add a cyclonic suction device under the pump that "spins out" some or all of the silt".

I believe the mention of a well screen means the well is cased with a well a well screen in the casing where the water enters the well. Placing a screen on a pump or installing a cyclonic suction device under the pump will only delay the problem until the well eventually fills with silt or sand.

Any reputable well driller that drills wells doesn't want the reputation of a sand pumping well anywhere. Most well drillers like to brag that have never drilled a well that produces silt or sand.

I would continue to communicate with the driller that drilled the well and keep him advised of your continuing problem. I don't recommend that you be threatening, but be serious about your problem.

Be aware though, the driller will probably have to return with his drilling equipment or service rig to rectify the problem. Depending on whether he installed the pump or someone else, he may want the pump installer to remove and reinstall the pump. Sometimes this can be a touchy situation and the homeowner is in the middle! Hopefully the driller and pump installer cooperate in situations like this. It shouldn't be the homeowner's problem or costs!

In my drilling contracting days I liked to be the pump installer as well. That way the well, pump system and clear water was my responsiblity, however time has changed things. Many drillers today don't install pumping systems.

Thank you everyone for the replies thus far.

My well driller also installed the pump, so I'm good in that dept.

How much silt is an acceptable level for a new well to pump? Is it zero? Should a new well pump crystal clear water or is there any acceptable amount which would necessitate installing a whole house filter?

Trying to be prepared before I speak with my driller again and bring him a sample.

I'm hearing that the solution may involve bringing the rig back in? That may be a very big problem. The property of the house sits at a lower level in relation to the roadway. There is a large downhill from the road to the house and to where the well is. The driveway is also higher than the front lawn level. To get this well drilled the driller brought in 2 loads of stone and dumped it on the property to bring the level up to the driveway so that he could park the rig. Once the job was complete I hired a landscaper to remove all the stone, add topsoil and lay new sod and re-grad. It was a huge mess for a while. If the driller really did screw up and needs to bring the rig back in, he may try to fight it or avoid me.

You should always leave a well where the pump man or driller can get his rig in there. If you don’t need that service tomorrow, you will need it some day. And it always happens at the worst time. I have had people build a three car garage over a well after I left. Then they where mad because I couldn’t get in there to fix it when the pump had problems 10 years later. A well and/or pump is not a permanent fixture. It will need repairs just like your refrigerator or furnace someday.

Of course after hearing about the rock being removed, I would not blame the driller for wanting to try and pump out the silt with your pump. Even after proper development with the drill rig, sometimes you have to pump it for a while to get a well cleaned up. Maybe pumping for a while will clean things up. But if it doesn’t, then something is probably wrong with the well or screen, because the technology exist to make a sand free well in most cases. I have seen a few wells, that no matter what was done, will still make sand or silt.

Pump it hard and see if you can get it cleaned up. Then if it doesn’t clean up, don’t be mad at the driller for needing those rocks put back in place, so he can at least get his rig in there.

The location of the new well was chosen by the driller. The driller arranged everything to complete the job and billed me for the cost of the stone, the grading of the stone and the well drilling. I hired the landscaper to clean up once spring arrived 3 months later. If the driller needs to get his rig back in, I'll hold him financially responsible to fix the well and clean up the property.

Does your pump short cycle?
How long from the time the pump comes on, untill it cuts off? It should not be less than one or two minutes.
If it does come on and off in less than one minute, that could be your problem.

A bad check valve can make the well produce sand or silt.( when the well shuts off, the water in the pipe will fall back in the well, and back flush the well screen, causing silt/sand.)

A pump that short cycles can make a good well produce silt or sand. As a pump starts and stop a lot, its kinda like plunging the well.

If the well did ok for 6 months and then started to pump sand/silt, I don't think it can be blamed on the well it self or the driller.
From reading the posts above, I think there is a problem that can be fixed without the whole thing getting out of hand.


Just some thoughts I had.

Travis