Inside a septic tank, grease and oil (known technically as scum) rise to the top, while solid waste (called sludge) settles on the bottom. Risers on top provide access for maintenance. By Jessica ...

Capacities vary, but the average home septic tank is 1,250 gallons, which is usually big enough for a house with four bedrooms, according to Angi. Access riser: Tightly capped plastic or ...

Don’t ever try to open the lid of your septic tank (or the cap to an access riser) yourself. Doing so could expose you to dangerous sewer gases like hydrogen sulfide and methane. Only a ...