I say go ahead and use the creek water to wash dishes and shower with. No doubt there are posters on this thread who will tell you how their Granddaddy drank creek water and another who will have changed professions to be able to say he had no issues in 50 years - whatever.
Just have a plan on dealing with dysentery, and know where the closest hospital is located.
Maybe you already have experience using water from this creek - you didn't say, but things change. Nitrogen levels in the soil can increase during the winter since there are no crops to soak it up. When the snow melts then you have runoff.
I didn't answer the pump question as others already have - just don't use a green garden hose - right? . Have fun!