Comprehensive Efforts to Facilitate Safe Decentralized Residential Wastewater Treatment and Recycling in Hawaii

We have been involved in assessing the risk of existing on-site disposal systems (OSDSs) to drinking water and coastal waters in Hawaii, development of State selection/design guidelines for a diversity of OSDSs, developing a State inspection/maintenance/permitting program for all OSDSs, development of State gray water treatment and use guidelines, and pilot evaluation of aerobic treatment units (ATUs) for compliance with secondary effluent limitations and recycled water regulations. The conclusion from studies is that a whole series of regulations, design guidelines, risk evaluations, and technology evaluations are necessary so that wastewater can be treated and reused on-site in residential areas without endangering public health or the environment. These various components are necessary so that designs can be adequate, homeowners can make informed decisions regarding system selection and maintenance, and regulators can have the tools needed to effectively regulate such systems.