Section 552.35 - Rights-of-entry for survey and exploration(a)Voluntary. Where it is necessary to enter upon non-Government-owned real estate during site selection, particularly for the purpose of conducting topographic surveys and test borings, the appropriate division or district engineer will negotiate rights-of-entry for survey and exploration. The instrument is in the nature of a license which does not convey an interest in land but precludes the entry from being a trespass. Since the entry is for a limited purpose and for a relatively short period of time, the landowner is not offered rental for the privileges requested. Where the landowner insists upon payment for the privileges requested, district engineers are authorized to negotiate short-term co-use leases, within the limits of existing regulations.(b)Involuntary. Where rights-of-entry for survey and exploration or short-term co-use leases cannot be negotiated, the right-of-entry may be obtained through the institution of proceedings for the condemnation of a short-term co-use leasehold interest. This action is taken only where it can be shown that the entry is imperative and that it is impossible to negotiate a voluntary right-of-entry or short-term co-use lease.