GCG was commissioned by Sofia for Phase 2 after earlier involvement in Phase 1. Our role was to provide technical support on site as trenchless technology experts, working as part of the Client’s Sofia Site team. We liaised with the HDD sub-contractor to monitor the drilling works. We analysed the site activities, drilling data and drilling performance. This allowed us to lookahead and to highlight in advance, risks, opportunities and options for the project and our client. A number of unusual technical challenges were encountered by the project which we support the project and our client with. The two remaining HDD drills were successfully completed by June 2023.