The water that goes down the drain in a dishwasher typically follows the same path as the wastewater from other sources in your home. Let's walk through the general process of where the water goes:
Drain Hose: The dishwasher is equipped with a drain hose that is connected to the dishwasher's sump or pump. When the dishwasher completes its wash and rinse cycles, the used and dirty water is pumped out of the dishwasher through this hose.
Garbage Disposal or Air Gap (optional): In some homes, the dishwasher drain hose is connected to the garbage disposal unit located under the kitchen sink. The dishwasher drains directly into the disposal unit, which grinds up any food particles and sends the water and waste down the same drainpipe used by the sink.
In other cases, especially in some regions with building codes or regulations, a dishwasher air gap may be installed instead of connecting directly to the garbage disposal. The air gap is a small, visible device installed on the sink or countertop near the dishwasher. It prevents the dishwasher's wastewater from flowing back into the dishwasher and ensures an air break between the dishwasher and the household drainage system.
Household Drainage System: After going through either the garbage disposal or the air gap, the dishwasher wastewater continues through the household drainage system. It merges with other wastewater from sinks, showers, toilets, and other sources in your home.
Sewer System or Septic Tank: The combined wastewater from your home eventually enters the municipal sewer system or, in some cases, a septic tank. In the municipal sewer system, the wastewater is treated at a wastewater treatment plant before being released back into the environment. In a septic system, the wastewater is treated within the septic tank and then gradually leaches into the surrounding soil.
It's important to note that some regions may have specific plumbing codes or requirements for dishwasher drainage to ensure proper waste disposal and prevent contamination. Therefore, it's always advisable to follow local plumbing codes and manufacturer guidelines when installing or connecting a dishwasher.