Geotechnical Data Reports (GDRs) are used for underground pipeline projects in order to provide subsurface information to the design engineers and contractor where the proposed pipe will be installed by trenchless construction methods. These methods include tunneling, guided boring, directional drilling, pipe bursting and pipe and jacking. Holt Engineering has over 20 years providing this type of geotechnical investigation and is fully familiar with meeting the Requirements for Geotechnical Investigations for Pipeline Projects spelled out in the COA Utilities Criteria Manual.