When the Department determines that the topography of the land will not permit adequate screening of existing junkyards or scrap processing facilities or junkyards or scrap processing facilities lawfully established but which become nonconforming, the Department may acquire by gift, purchase or by the exercise of the right of eminent domain such junkyards or scrap processing facilities, or portions thereof, necessary to secure compliance with this Act. When it is more economical to move such junkyards or scrap processing facilities, or portions thereof, the Department 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 junkyards or scrap processing facilities, or portions thereof, and pay the costs of such relocation. The Department 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 junkyards or scrap processing facilities or junkyards or scrap processing facilities lawfully established, but which become nonconforming.