Orange coins

[drustino]

Pretty new here gang, but anyway, my daughter & I were out on Sunday & had our best day yet. We hunted a newly build school about 6 yrs. old. Prior to the new school, their was an amusement park on this site. We found 3 silver dimes, 7 pennies, 2 silver quarters
some clad, and some kinda belt buckle. Here' the delema, close by the the school their is a creek that has mine water in it, the shore lines are all orange, and needless to say all the coins we found except for one is half decent. The creek must have flooded the property in the past. Any suggestions to clean these coins up, I think the one dime is from 1960 but can't tell. Thanks all.