The aerated Engineered Wetland ecotechnology was developed in the 1990s during the BREW Project the initial objective of which was to develop advanced natural, passive treatment, CW-based processes, primarily for the treatment of domestic wastewaters. The superiority of the BREW Bioreactors (BBRs) ecotechnology in removing oxidizable contaminants from wastewaters of all sorts has been demonstrated in a variety of pilot-, demonstration- and full-scale projects, and may now be regarded as fully proven. The seminal application of very large-scale Eco-Engineered Bioreactors Systems ecotechnology is at Buffalo Niagara International Airport in upstate NY, USA where there are four very large rectilinear vertical sub-surface flow (VSSF) BBR cells located in an open area near the airport's main runway. BBRs and vertical sub-surface flow (SAGR) Bioreactors are types of in-ground, semi-passive, aerated Eco-Engineered Bioreactors that evolved from early Engineered Wetlands. In addition to the nitrification performance of SAGR Bioreactors, polishing treatment has also been observed with them.