For industries: Marine Offshore This section is only for development help

Evac EcoTreat Cost-effective biological treatment plant

The Evac EcoTreat biological wastewater treatment plant delivers the best of both worlds for owners of small vessels, with cost-effective treatment of black and gray water that meets and exceeds the latest environmental standards.

Evac EcoTreat is a biological system for the efficient treatment of black wastewater from toilets and urinals and gray wastewater from washbasins, sinks, galley, laundry and showers. Treating wastewater in this way completely eliminates the need for any chemicals or filters. The plant has been designed to make operation and maintenance as easy and cost effective as possible. Its compact footprint and low weight means it is suitable for smaller vessels where space restrictions may be tight.

Evac EcoTreat uses the submerged fixed-film bacteria principle with enchanced settling matrix for solids separation and UV light for final disinfection. Available in capacities from 2–11 m3/day, the plant is compatible with both gravity and vacuum-based wastewater collection systems.


  • Certified and Type approved by DNV according to IMO MEPC 227(64)
  • Approved by US Coastguard and Transport Canada
  • Compact design and low weight
  • Chemical-free
  • Low and easy maintenance requirements
  • Cost-effective
  • Black steel or stainless steel as standard
  • Environmentally friendly
  • More than 800 plants delivered since 2002

Operating principle

Evac EcoTreat uses the submerged fixed-film bacteria principle. Black and gray water waste streams are fed to the inlet mixing tank either by gravity or by a vacuum pump. From there, the wastewater is transferred to the bioreactor tank by a macerating pump, which mixes gray and black water and cuts up solids. The wastewater is then driven through the matrix in the bioreactor tank by compressed air that is supplied by diffusers in the bottom of the tank. The air supplies oxygen and also enhances the biological process.

The treated water flows from the bioreactor tank into the settling tank by gravity, where it passes through the settling matrix. Before being transferred to the clean water tank, the water is exposed to an advanced UV light filter to eradicate all heat-resistant coli bacteria. Any organic or mineral sludge that accumulates in the settling tank is transferred back to the bioreactor tank for further treatment or removal from the system.

ModelHydraulic load (m³/day)Organic load (kg BOG 5/day)Dimensions W x L x H
Evac EcoTreat 21.850,752210x1320x1570
Evac EcoTreat 43,701,502310x1620x1570
Evac EcoTreat 55,552,252910x1620x1570
Evac EcoTreat 77,403,003510x1650x1570
Evac EcoTreat 99,253,753310x1650x1860
Evac EcoTreat 1111,204,503760x1650x1860
The units are available in coated black steel, stainless steel and coated stainless steel. Units are also available with vacuum creation equipment (C). The units with vacuum creation equipment (C) are 500mm longer by length.