Conventional wastewater treatment in the U.S. is an energy dependent and carbon dioxide emitting process. Typical mechanical systems consume copious amounts of energy, which is most commonly produced from fossil fuel combustion that results in the production of CO2. The associated organic load is also metabolized by microorganisms into CO2 and H2O. As the desire to reduce CO2 output becomes more prominent, it is logical to assess the costs of conventional treatment methods and to compare them to alternative, more sustainable technology. Vegetated Sand Bed (VSB) and Reed Bed (RB) systems are green technologies that provide environmentally superior treatment to conventional systems at a fraction of the cost both environmentally and economically. Using mass balance equations the net CO2 produced from wastewater treatment at 3 conventional facilities, (Amherst, MA, Ithaca, NY and Shelburne-Buckland, MA) and 3 VSBs, (Lloyd, NY, Shushufindi Slaughterhouse, Ecuador and Shushufindi Municipal Facility, Ecuador), will be estimated. Carbon dioxide sources considered are BOD5 microbial respiration, power demand, and sludge treatment. Using the BOD5 reduction and the average daily flow from each of the conventional facilities, hypothetical VSB and RB systems will be sized for the 3 conventional systems. The land area for each hypothetical VSB and RB and the CO2 reduction for equal treatment are estimated for each conventional facility. Estimates of annual CO2 production for Amherst, Ithaca, and Shelburne-Buckland, are 3,021 metric tons, 5,575 metric tons, and 158 metric tons of, respectively. The annual CO2 reduction potential for the conventional facilities Amherst, Ithaca, and Shelburne-Buckland, when compared to VSB and RB technology is estimated to be 74.0%, 83.2%, and 86.3% respectively. VSB and RB technology also provide promising results for sustainable wastewater treatment and reuse. Ammonium and nitrate reduction at the Joseph Troll Turf Plot VSBs were 72% and 88% respectively. The mean ammonium microbial growth rate constant was – 0.14 d-1 and the mean nitrate microbial growth rate constant was – 0.23 d-1. The implications are ammonium and nitrate reduction is possible with VSB and RB technology. Further investigation to understand the processes and fate of nitrogen including separate testing of ammonium and nitrate reduction are recommended.