CEN 21
CE30 Tank Cutaway

Designed to treat up to 1,900 gallons per day of domestic strength wastewater, the one-tank CEN21 model is designed for commercial enhanced nitrogen removal in nutrient sensitive areas. Certified 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.


The CEN21 is a dependable, robust, one-tank workhorse. No preceding septic tank is required or necessary for robust, dependable treatment (unless dictated by state or local regulations). Featuring a footprint of only 15'-4" x 6'-7", this system is rated to treat domestic strength wastewater flows of 1,900-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 1,543 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 (5.4 kWh/day), like the other CEN models, is ideally suited for both replacement sites and new construction. Low maintenance requirements allow the unit to be completely inspected and serviced in less than one hour.


  • 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 CEN21 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 installed and operating commercial 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 50 full-time staff engineers, with a focus on 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 two 20" diameter and one 24" at-grade covers. The unobtrusive football-sized FujiMAC 150R blowers and very small alarm panel can be located up to 100-ft. away and easily shielded from street view.

  • Easy Maintenance. The CEN21 unit is designed for efficient and effective semi-annual 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. 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 CEN21 system's 5.4 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. A pair of FujiMAC 150RII 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. Systems are compatible with both Tuf-Tite and Polylok risers.

Model CEN21 Spec Information Table