Woodchip Bioreactors

Woodchip bioreactors are subsurface trenches filled with a carbon source, mainly wood chips, through which water is allowed to flow just before leaving a field to enter a surface water body. The carbon source in the trench serves as a substrate for bacteria that break down the nitrate through denitrification. Woodchip bioreactor costs include the control structures, woodchips, design, construction, seeding, additional tile, management and maintenance.

Photo credit: "Christianson and Helmers, 2011"

The Many Advantages of Woodchip Bioreactors:

• They use proven technology
• They require no modification of current practices
• No land needs to be taken out of production
• There is no decrease in drainage effectiveness
• They require little or no maintenance
• They last for roughly 10 years

See a woodchip bioreactor under construction and learn more about their benefits in the video below, produced by The Illinois Water Resources Center:

Further Reading:

• The University of Illinois Extension has created a wonderful resource about bioreactors. 
• Read about the design and construction of a bioreactor, and view illustrations. 
• Check out this fact sheet about bioreactors from Iowa.
• A resource from Iowa shows videos and a list of published research about bioreactors. 
• See where people are using woodchip bioreactors all around the world.