I was walking by my pump and I heard a noise coming from the well casing. At first I thought the pump was running, but then realized what I heard was water running. As nothing was running in the house, and nothing was leaking in the basement, I opened the well cap and looked inside with a flashlight. I could see water running back in from the pipe running to the house.

This well is 65 feet deep with the well hanging at about 50 feet. Does this sounds like a non functioning check valve? If so, where should the check valve be located? Directly on top of the pump, below the pitless adapter? between the house and the well?

Also, If I have to pull the pump to access a check valve in the well casing, how is this done? Inside my well casing is a 1/2" nylon rope, and a steel cable about 1/8" dia. What does what?