Do septic systems need power?

Only some do. A standard gravity system has no moving parts and needs no electricity. Power is needed whenever the design includes a pump (pressurized distribution, a pump to an uphill or distant drainfield, a sand filter or mound), an advanced treatment unit with an aerator, or a high-water alarm. If yours does, plan for a dedicated circuit, an alarm the household can see or hear, and a plan for outages; a pump tank holds some reserve, but a long outage means cutting water use until power returns.