When the Union Coun­ty Board of Com­mis­sion­ers deter­mines that the topog­ra­phy of land will not per­mit ade­quate screen­ing of exist­ing junk yards or scrap pro­cess­ing facil­i­ties or junk yards or scrap pro­cess­ing facil­i­ties law­ful­ly estab­lished but which become non­con­form­ing, the Union Coun­ty Board of Com­mis­sion­ers may acquire by gift, pur­chase or by the exer­cise of the right of emi­nent domain such junk yards or scrap pro­cess­ing facil­i­ties, or por­tions there­of, nec­es­sary to secure com­pli­ance with this Arti­cle.  When it is more eco­nom­i­cal to move such junk yards or scrap pro­cess­ing facil­i­ties, or por­tions there­of, the Union Coun­ty Board of Com­mis­sion­ers may acquire by gift, pur­chase or by the exer­cise of the right of emi­nent domain such lands or inter­est in lands as may be nec­es­sary to secure the relo­ca­tion of such junk yards or scrap pro­cess­ing facil­i­ties, or por­tions there­of, and pay the costs of such relo­ca­tion.  The Union Coun­ty Board of Com­mis­sion­ers may also acquire by gift, pur­chase or by the exer­cise of the right of emi­nent domain such land or inter­ests in land as is nec­es­sary to effec­tive­ly screen exist­ing junk yards or scrap pro­cess­ing facil­i­ties law­ful­ly estab­lished, but which become nonconforming.