Slimes in cities

The vast majority of cities will not allow anyone, unless under official sanction, to kill the slimes, harm them, or thin them out, that are living city sewers or storm ponds. They see it as disgusting, and detrimental to the cities well being. Though this is a careful lie built by the local governing bodies, because, slimes dissolve refuse. Clean that refuse into clean water. Unless a slime colony has merged into a greater slime, which is actually dangerous to the city, they will not allow anyone to ruin such an efficient, low cost, system.