Muddy well water when we get a lot of rain?

Hello, I happened to run across this site, and it looks like a great place to find answers We've lived here in the same place for over 30 years now~in Missouri~and for the last 6 months or so, every time we get a LOT of rain, our well water gets very muddy?? This is very aggravating and inconvenient, as you can imagine, and I would really like to find out if anyone on here has any ideas of what might be causing this problem? One side note, but I don't know if it would have anything to do with the prob or not is~that there was a small pipe~about 3/4" diameter x 1' tall~ sticking out of the ground (That the dog destroyed) that somebody told me was for air or something, but anyway that is gone now Could dirt be seeping down that small hole possibly causing the mud? I can't even find the hole, so it will require a lot of rocky digging, but I'll give it a try if you think that could be contributing to the mud We don't use the water for drinking when it's muddy, naturally, but do you think other~colorless~things could be seeping into the water on a regular basis...something I should be concerned about?
Thank You so Very Much!! Lis

Yes that would be an air vent pipe so it needs to be replaced to prevent rain water carrying dirt into the well causing muddy water.