Guide to Typical Substation Construction

Subject to permitting requirements, substation construction typically, but not always, occurs in the following sequence:

Site Development

Site development begins with the clearing of vegetation at the site. Temporary environmental controls, such as silt fence, are also installed at this time. The area is then leveled by cutting and filling as necessary to bring the site up to subgrade. Sand and aggregate fill materials may be brought in to make a level site for construction.

The substation site development also includes the installation of any required environmental controls such as plunge pools, retention ponds, or rip-rap slopes. The final grading and seeding of the areas outside of the substation fence will be installed during this phase.

Foundation Installation

Soon after site development is completed, the equipment foundations will be installed. The foundations are reinforced concrete and may be drilled pier or spread footing foundations depending on the size and weight of the equipment.

Equipment Installation

Following installation of the foundations, the substation equipment is delivered and installed at the station. The equipment installed at the stations includes, but is not limited to, substation security fence, steel structures, circuit breakers, transformers, capacitor banks, and control buildings.

After the equipment is installed, a finish layer of crushed stone (typically 6 inches deep) is installed over the entire station up to the base of the structure foundations. This gives the station its "finished” look.

Final Restoration

Upon completion of construction, the contractor will do the final restoration of the site. Final restoration consists of the removal of all temporary environmental controls, final seeding, and the installation of any vegetative buffers.