We have had our system pumped once in 27 years, and that was because the stupid 2 piece tank began leaking at joint. Had unit pumped, then ripped it out of ground and replaced with fiberglass unit. Other than that, ive never had any issues. I do electrical pump wiring on new septic systems (only new) for a contractor up here. He uses 1 hp, 240 volt sewage solids ejector pumps when transfer between holding tanks (non digesting) and the true septic tank that digest it and sends it to leach field. These are sized for length of run and lift required thru the supplier.
When we had our tank pumped, the truck that came only carried 100’ of hose, and it took up a heck of alot of space on truck. I can only imagine what 300 feet would take up. Luckily no bridges and flat land here.
Some of the newer septic systems are truly scary. I hooked up a system by the lake here that used 3 solid concrete tanks and one of these are filled with gravel. The system runs thru a computer dose timer. Multiple pumps and floats. Timed dose rates to cycle effluent. Myriad of wires and pipes. A true cluster f that only an engineer can design. Will it work, probably. Will it last. Doubtful. Need an MIT degree to program it. Costs exceed $40,000.