The EnviroFin passive onsite wastewater treatment and dispersal system from Presby Environmental is designed for residential and commercial applications. The compact system can be installed in tight spaces. It has no mechanical parts, does not need chemicals or have energy requirements. Effluent leaves the septic tank and enters the system, which consists of a center fin distribution unit and eight treatment fins filled with oriented green plastic fibers and a perforated pipe acting as an air duct. The effluent fills the FDU until it enters the treatment fin through perforations around the FDU. The unit, buried in system sand and C-33 concrete sand, is installed with differential vents for airflow. 800/473-5298; www.presbyeco.com.