Don't laugh too hard before you think about all the issues.
FYI I work for an environmental agency in a state were decomissioned Navy solid rocket/missile fuel is disposed of by a simple method (and the only viable one) they take it outside into a large metal pan (literally its 10 yds by 10 yds and about a foot deep) and set it on fire. Where its destroyed by open burning. All kinds of nasty stuff coming out of that smoke and fumes.
I'm not sure if the Minuteman is a solid fuel or a liquid fuel. But in most rockets/missiles the fuel has a shelf life and it must either be replaced, or the entire weapon decomissioned and a new one built. Either way the old stuff has to be obviously disposed of in some manner or another because its highly flammable and explosive under the correct conditions.
And not I'm not a tree hugger... I'm an engineer.