The next step in our analysis was to elucidate drivers for cost and GHG emissions. First, the overall system was broken down into individual units, and the relative contributions to cost and emissions were estimated. The categories for cost included capital, operation and maintenance, and electricity. The categories for emissions included capital, energy, operation and maintenance, and direct emissions from waste. The results from this analysis are shown in Figure , where the percentage of total daily user cost and percent of annual GHG emissions per user are demonstrated for both scenarios. Additionally, the total magnitude of daily user cost and annual GHG emissions per user are shown in Figure .