The typical septic system drainfield for a three-bedroom home measures more than 800 square feet. For various reasons, whether it’s a small lot size or environmental concerns, adequate space isn’t always available to onsite system installers. That’s where the EnviroFin ­— introduced by Presby Environmental at the 2016 Water & Wastewater Equipment, Treatment & Transport Show — can enter the design process.

The EnviroFin is a passive onsite wastewater treatment and dispersal system designed to take up a footprint approximately eight times smaller than a typical conventional drainfield — just over 93 square feet for a three-bedroom home, using two units installed in sequence and treating 450 gpd. According to Lee Rashkin, Presby Environmental vice president, the product is an expansion on the company’s Advanced Enviro-Septic drainfield technology.

“We’ve had the AES on the market for 20 years, and it has been a terrific product for us,” he says. “The main need globally, though, has been creating large treatment capability in a smaller footprint.”

The EnviroFin exceeds NSF/ANSI Standard 40 treatment. Single units are shipped in a 2- by 2- by 4-foot box weighing 50 pounds for convenient shipping worldwide. The unit is designed for high treatment capacity in a small footprint by utilizing spider-like perforated pipe fins with a large surface area for bacterial growth.

After leaving the septic tank, warm effluent enters the centralized fin distribution unit, and is cooled to ground temperature, separating large solids from the cooled liquid effluent. Skimmers further capture grease and suspended solids from the existing effluent in the distribution unit. The effluent seeps through perforations in the distribution unit and into eight treatment fins containing a dense mass of coarse, randomly oriented fibers to separate more suspended solids from the effluent.

An air duct pipe at the top of each fin allows air to flow along its length and into the fibers and system sand to promote bacterial growth and treatment of the effluent. The pipe also serves as a conduit for removal of waste gases at a different point in the cycle. Effluent then passes into geotextile fabrics and grows a protected bacterial surface. Sand then wicks liquid from the geotextile fabrics, enabling air to transfer to the bacterial surfaces while attaining less than 10 mg/l BOD and TSS as well as a reduction of other wastewater constituents. The clean effluent is then ready for release.

“This unit can be used in many types of soil conditions, and its small size gives homeowners so much more flexibility over where they want the drainfield located,” says Rashkin. The EnviroFin will be used primarily  for the residential and commercial applications.
Presby Environmental is a longtime exhibitor at the WWETT Show, but thanks to the excitement created by the EnviroFin, Rashkin says the 2016 show was the company’s best.

“The reaction has exceeded our expectations. The installers I’ve talked with are genuinely excited to get them and start installing them for their clients,” Rashkin says.  800/473-5298; www.presbyeco.com.