The Castor Underground Storage (UGS) Project passed a number of milestones in the first half of 2008. Foremost was receiving the Castor Development Concession from the Spanish government (Ministry of Industry) in May 2008. This was the crucial approval that paved the way for project construction and completion. It allows the project to begin purchasing the long-lead-time equipment recommended in the FEED study that was completed in October 2007.

All major contracts still need to be awarded. ACS Servicios Comunicaciones y Energis (ACS), the largest construction company in Spain, will be the main engineering, procurement and construction (EPC) contractor. ACS is also responsible for raising equity financing, managing debt and providing any guarantees required for the project.

The partnership has chosen the two-platform design recommend by its FEED study. Construction of the wellhead platform, from which the planned 12 storage wells will be drilled, is expected to be completed by mid-2009, with the first storage well planned to be drilled in Q4 2009. Construction of the larger natural gas processing platform is scheduled to coincide with the completion of storage well drilling in 2010.

The partnership has received strong support for Castor UGS by all levels of government in Spain's Valencia region.