Approximately how many residents in Washington state utilize septic systems?

In Washington state, approximately 2.25 million residents utilize septic systems, as a significant portion of homes, particularly in rural areas, rely on this type of wastewater treatment. Septic systems are used to treat and dispose of household wastewater effectively, especially where municipal sewer systems are not available. This number reflects not only the residents using septic systems but also demonstrates how common these systems are in less densely populated areas where more traditional sewage treatment methods may not be feasible. It highlights the importance of proper septic maintenance and management in ensuring environmental safety and public health in these communities.