CEN 50
CEN 50 Tank Cutaway

Designed to treat up to 4,500 gallons per day of domestic strength wastewater, the one-tank CEN50 model is designed for commercial enhanced nitrogen removal in nutrient sensitive areas. Designed to NSF/ANSI 40/245 standards, this exceptionally small footprint system has demonstrated best-in-class nitrogen removal performance in multiple-state field testing protocols.

System design assistance is offered with all FujiClean commercial treatment systems. Our experts will help design a treatment train tailored to your site and wastewater needs. This service is offered free of charge to wastewater professionals for specifying FujiClean products. Please fill out the Commercial System Design Worksheet located on the FujiCleanUSA.com website or contact your local FujiClean distributor to get started.


The CEN50 is a dependable, robust, one-tank workhorse. Featuring a footprint of only 25'-4" x 8'-2", this system is rated to treat domestic strength wastewater flows of 4,500-gallons per day to NSF 40/245 standards making it a perfect choice for septic professionals designing systems in environmentally sensitive locations where maximum nitrogen reduction is required or desired.

Weighing only 2,400 pounds, this fiber-reinforced plastic (FRP) unit can be squeezed into tight and difficult sites using standard excavating equipment. Designed to accommodate variable flows and shock loadings as well as being highly energy efficient (14.8 kWh/day). The CEN50, like the other CEN models, is ideally suited for both replacement sites and new construction. Designed for efficient maintenance, the unit can be completely inspected and serviced in less than one hour.

Ideal for cluster system designs with one or more units set in parallel configurations.


  • Reliable, Robust Performance. Based on both 3rd party testing in the U.S. (NSF) and corroborated by thousands of field test data points worldwide (including the U.S.), the CEN50 produces a consistent effluent quality with a pollutant removal ratio of around 97% - 98% and nitrogen reducing ratio of 75% (NSF data).

  • Proven Design. With over 50 years' experience, over 2+ million residential and 50,000 commercial installed and operating systems, FujiClean Co., Ltd. (FujiClean USA's parent company) is the world's leading manufacturer of high efficiency onsite wastewater treatment systems. The company employs over 30 full-time staff engineers who oversee product testing and product improvement. The breakthrough CE and CEN model series are the company's most popular and successful product lines.

  • Low Profile. Aesthetically pleasing, the only visible indications of this one-tank system are the at-grade covers. The unobtrusive football-sized FujiMAC 200R blowers and very small alarm panel can be located up to 100-ft. away and easily shielded from street view.

  • Easy Maintenance. The CEN50 unit is designed for efficient and effective maintenance; the majority of which is accomplished with simple turning of control dials that purges heavy bio-film growth from the treatment media. No messy media removal or hose-down is necessary. A typical service visit of a commercial system that includes solids backwash cleaning takes less than one hour. The system is designed for efficient storage of sludge. A typical sludge pump out for commercial systems is recommended once every 1-2 years.

  • Low Operational Cost. Best-in-class MAC Series linear diaphragm air blowers are both energy efficient and durable with typically twice the warranty of competitive blowers. Compare the CEN50 system's 14.8 kWh/day power draw with the energy required of other systems. Low-cost air blower rebuild kits are available from all certified FujiClean service providers.

  • Quiet. Four FujiMAC 200RII blowers operate at a "dishwasher quiet" 58 decibels.

  • Easy Installation. Plug-and-play units are ready for installation upon delivery. No onsite system assembly required.

Model CEN21 Spec Information Table