Greywater is household wastewater from baths, sinks, showers, and laundry. It generally does not contain toilet water or water from the garbage disposal. Greywater often contains hair, soap, and other contaminants that can clog septic systems. Despite this, it is typically safe to direct greywater into a septic tank. However, the contaminants may impact the system over time.
Septic Systems and Maintenance
Shower water, water from sinks, and other drains empty into either a septic tank or wastewater treatment plant. Septic tanks clean water naturally before it seeps into the ground. Wastewater treatment plants clean water chemically before reuse. In general, septic tanks need pumping every three to five years, depending on usage and household size.
Regulations and Alternatives
Some states regulate greywater like septic water, requiring a septic-like disposal system. Others allow separate greywater systems in certain conditions. These systems have many stipulations for storage, disposal, piping, and backflow prevention. Their cost often deters homeowners. Letting greywater seep into the soil filters out bacteria, replenishing water tables.
Wastewater from washing machines and dishwashers is problematic due to high soap, grease, and paper content. If a septic tank completely clogs, water rapidly backs up into the house. Partial clogs slowly drain fixtures as water struggles to enter the tank. Greywater should soak into the ground, not pool or run offsite. Multi-stage filtration greywater systems filter out lint, hair, and impurities for toilet flushing or irrigation. However, legislation varies regarding greywater system regulations and use.