An in-field evaluation of the ability of 12 established denitrification woodchip bioreactors and constructed wetlands to remove plant pathogens and/or human enteric pathogen indicator organisms from horticultural and agricultural wastewaters and runoff was conducted. Removal effectiveness was correlated with parameters affecting performance (e.g. media, residence time, temperature, oxygen, pH, depth). The information supports the design of on-site systems that will consistently remove plant and enteric pathogens as well as nutrients from agricultural runoff and wastewaters in order to facilitate its reuse and/or protect surface and ground water resources from contamination

This study was an extension of the WRAMI project for second season to include early spring and late fall monitoring (cool temperatures) at the edge of field sites, modified hydraulic retention times and/or nutrient characteristics of waste streams to the bioreactors at the greenhouse sites, and the performance of a newly constructed wetland system treating recycled leachate water from a greenhouse, where the most significant water treatment requirements occur over the winter period. Removal effectiveness was correlated with parameters affecting performance (e.g. design, media, residence time/flow rate, temperature, oxygen, depth) in order to support the design of on- and off-site systems that will consistently remove plant and enteric pathogens as well as nutrients from agricultural runoff and wastewaters.