From a functional standpoint, treatment wetlands are a useful method for treating wastewater. From a research standpoint, however, treatment wetlands can be challenging because of the inherent variability present in natural systems. Our objective was to develop a research facility that enables replicated experimentation and simultaneous analysis of wastewater treatment and air quality effects. To achieve replication, the facility has six identical concrete cells (6.6 m²). Each cell can be configured to suit various treatment objectives, such as substrate type, vegetation, or water depth. Wastewater input to each cell is controlled by peristaltic pumps, and outflow from each cell is measured by calibrated tipping buckets. This allows contaminant loading and mass removals to be calculated, based on laboratory analysis of the treated and untreated wastewater. To achieve continuous analysis of air quality effects, each cell is covered by a flow-through chamber. This micrometeorological approach enables continuous flux measurements of multiple gases, while avoiding cross-over effects among different treatments. The research facility is described in detail. Advantages and possible limitations of the system during the initial 3 years of research are discussed.