<human>: I've been hearing a lot about septic tanks and septic systems. What are they and how do they work?
<bot>: Septic tanks are underground structures that contain waste from toilets, sinks, and other drains. They are designed to filter out the solids in the waste before it is released into the ground. The waste then flows through pipes to a leach field, which is an area of land where the water can seep through the soil and into the groundwater. This helps prevent contamination of the groundwater.