Onsite Wastewater Treatment Systems commonly known as OWTS are used to treat wastewater from a home or business and return treated wastewater back into the receiving environment. 

The most common and traditional septic systems consist of a septic tank that gravity flows to a soil adsorption field for final treatment and dispersal.  The septic tank allows particulate matter to settle to the bottom of the tank so that large solids do not plug the drain field.  An effluent screen placed in the outlet of the septic tank is used to filter suspended solids out of the effluent.  Final treatment and dispersal of the wastewater takes place in the soil adsorption field.

An alternative type system performs the same basic actions as the conventional septic systems.  Differences arise when location, space, laws and regulations, soil type, and/or quantity of wastewater being treated become a limiting factor.  An alternative type system in this case refers to any OWTS that uses pumps or advanced treatment.  These systems use technologies that require greater frequency of operation and maintenance.

Permitting activities are divided into three main stages: site-suitability, design review, and construction inspection. Site-suitability is a preliminary stage which assesses the suitability of a parcel of property for on-site sewage disposal. Design review entails a review to determine a design's compliance with State standards, rules, and regulations including setbacks to drinking water wells, water supplies, and sensitive water bodies. Proper design and installation is essential to protect public health and avert the potential adverse impacts of OWTS on water resources. Construction inspections are conducted during installation in addition to the inspections conducted by the Designer. Annually, the RIDEM undertakes approximately 2,300 suitability assessments, 5,000 permit reviews, and 11,600 inspections. Additionally, the RIDEM has developed a process for approving innovative septic system technologies.