Submersible well pump runs continuously

This is my first post here, so I thought I'd make it a good one.

I have a shallow well, with a submersible pump (now 10yrs old) that until two months ago was giving me 50PSI house pressure. Now it is struggling to maintain 35PSI, and if I open the contacts on the pressure switch (i.e. de-energize the pump) it drops off to zero PSI. I believe that either the pressure tank (20gal 5yrs old) is fouled and not regulating the pressure or it is backflushing the water through the pump back to the well, it has a 35PSI air charge on the bladder. I also think that the pump is shot.

The Well is 75 ft from the house and is about 25FT deep and the water level has maintained relatively constant over the 7 years that we have been in the house. I have traced the line from the well to the house and there are no visible indications of any leaks on the outside, and none on the interior of the house, toilets do not run continuously, no drips at any faucets.

Back in November last year we started seeing unusually large ammounts of sand/sediment in the first stage filter which is located downstream of the pump, but the problem cleared up after a week. The only cause I could think of was that our neighbor (about 500 feet away) sank a new well on their property and tapped into our stream.

I have several questions:

1.) Could the sediment have worn the pump sufficiently to have rendered it unable to pump against the tank pressure?

2.) Could the sediment have fouled the water side of the tank to render it unusable, and all I am seeing is pump pressure?

3.) Could the pressure switch (replaced it the same time I replaced the tank 5yrs ago) be bad? (I don't see how this would fit in this scenario)

4.) How do I determine which is the cause without tearing the system down completely?

5.)If I installed a properly sized Jet Pump in the discharge of the submersible pump and then de-energized the submersible, given the distances and depth I listed above, would it pull enough suction head through the idle pump to get my house pressure back up to 45 - 50 PSI? This would be in the house 75 ft from the well and the existing pump, otherwise it would involve excavating and installing new water line and running power to the new pump at the well location.

6.) What else could be causing this, and how can I determine that cause?

7.) Am I biting off more than I can chew here, and should I hire someone to fix this? I am quite knowledgeable in plumbing and electrical matters from my 20 yrs as a Machinist Mate in the Navy.

 

From what you've described, I would think that the problem is with the pump itself. Pumping sand will wear a pump out in short order, although I assume that the pump has passed sand for a while, given that sediment filters are in use.
Another possibility is that there is a leak in the drop pipe between the pump and top of the well. Still, you would have to pull the pump to correct this.
The tank isn't the problem. Even if the bladder was bad, you would still see normal system pressure. The pump would cycle even if small amounts of water were used.
It wouldn't be a good idea to allow a jet pump to draw suction through the submersible. I would bet the pump would starve for water, even if you were able to prime it.
By the way, the tank doesn't regulate pressure. That is the function of the pressure switch.
Unfortunately, you'll probably have to pull it all to determine the extent of the problem.
Ron

 

The fact that the pressure drops off when the pump is turned off is a clue. You will have to pull the pump and I'll bet you find a hole in the adapter at the top of the pump. (especially if someone used a cheap galvanized adapter) Good luck
Waterdoc