More than a million onsite wastewater treatment systems operate in Ohio. Consequently, about a quarter of a million acres of soil, or about a billion tons of soil is used in Ohio to renovate wastewater. Soils are the most important wastewater treatment resource in the state.
Many natural soils and soil materials are well suited to the task of renovating wastewater. Physical, chemical, and biological processes in soils work to remove nutrients, organic matter, disease-causing organisms, and odors from wastewater, to deliver clean water to the environment and for human use. Success in wastewater treatment in turn depends on appropriate properties of the soil and site, and a good match between the system design and the opportunities and limitations of the site. A detailed assessment of a proposed site and soil resources is essential for design of a functioning wastewater treatment system, and its continued operation in the long term.
This bulletin is a guide for Ohio onsite wastewater treatment system designers and regulators, as they consider developing appropriate sites, systems, and designs.