If the creek is contaminated what about the drinking wells?

I live near a creek that is contaminated with basically animal poop (coliform). No one swims in it. I just moved to place where our well is nearby. Also, the water contains a lot of sulfur. We either boil it or let it aerate to make it drinkable. My question is, do the bacteria make it down to the well water? If we let it aerate for a couple of day do the bacteria multiply making it worse? I would normally buy water or a filter, but as it is, I'm temporarily poor, poor, poor and hauling water is a hassle on the bus. Should I give up my organic veggies in lieu of a filter or does it matter? Thanks for your help. I'm thirsty and uneducated on the matter. Also, can't find any relevant info with state water quality standards...just notes on the public water system, not wells.