Incredible noise from incoming water.

[valser]

Any thoughts on this problem would be appreciated. Incoming water line from well has incredible air? noise when the pressure switch turns the pump on. This subsides just fefore turning off. Due to the differing pressures can the water in the line run back to the well? In my case this appears to also be uphill, as the house is below the well on a hill. When the tank is full the house pressure and plumbing system operates normally, no huge amount of air, there is some however. Some of that probably comes from the iron filter which has its own air induction system. There is a check valve right where the line comes out of the ground, I do not know about one in the well, it is also a new pump and tank, about a year old. The old system sounded very simular however. The pump was changed due to pressure, it was plugged. Lastly the noise has gotten worse after the last power outage when the pressure was run down to nothing in the tank. Any thoughts? Thanks.