This septic tank is not gravity fed. Instead, the waste water coming from the cabin flows into a cement chamber and is pumped uphill from there into the septic tank. Sump pumps (or lift stations) can also be used to pump water from the tank to the leech field. This picture shows the concrete chamber where the pumps are being installed. In the background the tank and inlet pipe are visible. This job was at a cabin in Shaver Lake.