Three root-causes were noted during the investigation: (1) the use of incompatible materials in the manufacturing of the PRD valve, (2) improper assembly resulting in over-torquing of the inner assembly, and (3) over-hardening of the inner assembly materials by the valve manufacturer. These problems could have been avoided by adequate quality assurance/quality control procedures during the design and safety reviews.

The canopy was added to the station as an afterthought, sometime following the HazOps review. The prestart-up safety review by all parties and the local authority having jurisdiction did not recognize the setback distance of the canopy. Had an engineering management of change, follow-up HazOp or other form of risk assessment been conducted, it is likely that the vent stacks adjacent to the canopy would have been raised in order to avoid any damage in the event of a fire.

Prior to reopening the station, physical changes were made using the correct PRD valves and higher vent stacks, and new and modified procedures were instituted to improve the timely communication of station status during emergency events. Additional training of personnel focused on improving the response time and effective communication between employees, first responders, and the hydrogen equipment supplier.