S.C. Code Ann. § 3-5-360

For the purpose of determining the lands and property necessary for the uses herein set out the Department of Health and Environmental Control or the United States Government, or the agents of either, may enter upon any lands along the general line of said right of way and make such surveys and do such other acts as in their judgment may be necessary for the purpose of definitely locating the specific lines of said right of way and the lands required for said purposes and there shall be no claim against the State or the United States for such acts as may be done in making such surveys.