Larch-Northrop Substation Project

Larch-Northrop Substation Project

SMUD is proposing to replace existing substation equipment at the Larch-Northrop substation including a 20MVA transformer, switch-gear, 69 kV switch pole, and 69 kV tap pole. The existing capacitor banks will be removed. Approximately 3 to 5 feet of soil will be excavated to install the new transformer and associated substation equipment and will be back filled with compacted Class II Aggregate Base. The ground conditions in the substation area are made up of crushed gravel. To properly bring the substation up to present standards, the civil engineering work will also be updated. This work includes adding an oil containment pit, with oil minder sump control and a battery slab. Additionally, some of the underground conduit will need to be replaced which house the 12kV feeder getaways and capacitor bank cables and new conduit will be added for offsite power. The substation gate will also be replaced and improvements will be made to the driveway. Lastly, additional grounding will be added throughout the substation, including grounding around the new equipment, placed 18 inches from the foundations. The upgraded substation equipment will not create a need to increase the existing footprint. The site of the substation is listed as low density residential in the City of Sacramento's General Plan. Construction is anticipated to start in October 2020 or soon thereafter and last for approximately 9 months.

Sacramento