Heavy sediment damaging well pump

[Ranco]

Hello All. Newbie! Found this forum while researching answers for my problem. Have read through the several posts and found a lot of good info. I originally posted this to another thread but it was suggested that I start a new one as the other was very long.

I have a relatively new well (less than 3 years)drilled to 580 feet. First pump hung at approximately 530 ft. Yield reported to be 1 gpm. Initial problem was extremely high iron content and discoloration. Testing showed 16.5 ppm ferrous (red) iron, turbidity 104 ppm. First pump failed after just less than 2 years although usage is minimal as the house is not yet occupied due to renovations. Second pump hung at 470 - 480 feet thinking sediment at bottom was entering pump. After serious research, a backwash filter system for iron and for sediment was installed to improve water quality. During the backwash the second pump failed presumably due to the higher flow drawing in more contamination.

Well driller believes the softer rock above the pump is falling into the well and being drawn into pump and clogging it. There was some accumulation on the top of the first pump noted when it was pulled, but this could have been scraped off when pulling the pump. The pump is 1 hp 5 gpm. I questioned whether that is strong enough for a 500 ft lift and the contractor said it was.

I have not yet pulled the second pump as I want to address this issue before installing a 3rd pump. I have looked into a Lakos centrifugal sand filter and the potential of using a flow inducer. Obviously the flow inducer would be cheaper but I am more interested in fixing the problem and not just using the cheapest method.

I would appreciate any suggestions that would help solve this issue. Please let me know if you need further info to evaluate. I will try to post a pic showing the discoloration.

 

[Valveman]

The best way to figure out the problem is to study what happened to the old pumps. If they are clogged with iron, that is your problem. If they are worn out from sediment, a long flow inducer or a Lakos sub-k would help. If the motor is just getting hot, it is top feeding and a regular flow inducer will help. Sediment usually causes a gradual decline in pump performance. Overheating the motor like when top feeding will take it out much quicker.

 

[Sponsor]

 

[Ranco]

The best way to figure out the problem is to study what happened to the old pumps. If they are clogged with iron, that is your problem. If they are worn out from sediment, a long flow inducer or a Lakos sub-k would help. If the motor is just getting hot, it is top feeding and a regular flow inducer will help. Sediment usually causes a gradual decline in pump performance. Overheating the motor like when top feeding will take it out much quicker.

Unfortunately, the installing contractor took the 1st pump away before I could examine it, and I have not pulled the 2nd until I develop some plan to address the situation. I visited a local supply house and eyeballed the Lakos device which appears to be a very expensive version of a flow inducer. $15 of PVC pipe with a few cross drilled holes and a flapper valve at the bottom. I am sure there is a lot of engineering and testing involved but without a secure feeling that would fix my problem I am hesitant to spend $500 for such. I am f the current opinion that a long flow inducer is the way to go and can probably fabricae one myself.

Thanks for the comment. Hopefully some more will be posted.

 

[Reach4]

The pump is 1 hp 5 gpm. I questioned whether that is strong enough for a 500 ft lift and the contractor said it was.

It probably is more than enough. The Grundfos 5s10-22 and others can pump can lift from 600 ft. It is the distance down to the surface of the water that matters, not the distance from the pump.

This assumes that pump just filling an atmospheric pressure tank, and there is a separate pressure pump to provide the pressure topside.

 

[Valveman]

At 5 GPM or less, even in 1" pipe, the velocity is only 1.8 fps. That is so slow that the heavy stuff may not be getting to the surface. At that low velocity the heavy stuff just settles back down to the bottom and may never be getting out of the pump. It just grinds the pump up in a much shorter time than if the sediment gets shot out with enough velocity to get to the top of 500' of pipe.