BEC chose Burns & McDonnell and its direct‑hire subsidiary, Ref‑Chem, to serve as the engineer‑procure‑construct (EPC) team on the substation project. The work involved upgrading transmission substation facilities from 69‑kV to 138‑kV at the Leakey, Utopia and Tarpley substations. Between the new transmission line and substation upgrades, the overall project is the largest in BEC’s history.
For the substation upgrades, the team provided engineering and construction oversight services, which were integrated with high‑voltage substation construction work. The construction team set up and installed the equipment, followed by the wiring, switchgear and control panel work.
The Leakey substation required replacement of two distribution power transformers with new dual-rated 138/69-kV transformers. The scope of work included a new gas circuit breaker, a new aluminum bus and new relay panels in the live control house. These upgrades had to be extensively planned and coordinated because the work was completed near in‑service panels.
Construction of electrical upgrades was also provided for the Utopia and Tarpley substations, which were upgraded from 69-kV to 138‑kV. For both of these substations, an existing distribution power transformer was relocated and circuit breakers were added.
All three substations were tied from one end to the other, leaving no redundant feed options for a secondary side. Creativity was necessary to perform the work in a way that would not take any members offline. This involved sequencing the construction with the installation of substation mobiles that were used to keep electricity online.