The purpose of onsite wastewater treatment is to provide economical removal of dissolved nutrients, pathogens and other contaminates from septic tank effluent to avoid the pollution of groundwater or creation of other health hazards. The effective use of conventional soil adsorption systems is limited by a number of factors including site characteristics, soil type and condition, and the proximity of the system to surface waters or a source of potable water. On adverse sites, where the use of conventional subsurface soil adsorption systems does not provide acceptable levels of treatment, Sphagnum peat may be used as an economical method of onsite wastewater treatment. The peat system, when properly designed and constructed, is relatively simple to install, requires minimal energy and maintenance, and provides a high quality effluent without additional disinfection. 19 refs.